Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 20 Jul 2012, 12:52
by spazsinbad
NAS Patuxent River Ski Jump with BBC talking head:

Video snippet from here: http://www.bbc.co.uk/news/uk-18919388
__________________

How to land an F-35 fighter plane [SAME VIDEO AS ABOVE IT LOOKS LIKE!]

http://www.bbc.co.uk/news/uk-18919934#

"20 July 2012 The UK has been handed its first Joint Strike Fighter jet, also known as the F-35, for use by the RAF and Royal Navy.

Although not intended for use until 2018, British pilots have already been test-flying the new fighter - codenamed the Lightning II - at Patuxent River Naval base in Maryland.

The BBC's defence correspondent Jonathan Beale spoke to one of the pilots involved in the programme, Peter Wilson of BAE Systems."
_______________

Quote from elsewhere: “The mock ski-jump is 150-feet long, with a 15-foot high “lip” for aircraft launch. These shore-based ski-jump takeoffs will be conducted at varying airspeeds prior to the first UK ship detachment with the F-35B.”
_______________

“...Although the AM-2 matting is serving its purpose as vertical take-off and landing (VTOL) pads and a 1,900 x 96-foot runway for the EAF/STOVL testing, it also doubles as the run-up for a test “ski-jump” used in conjunction with JSF testing for the British Royal Navy. The AM-2 matting and the 12-degree ski-jump ramp were installed at the centerfield area last month [May 2009]....”

EAF enables JSF landing anywhere, everywhere | Jun 29, 2009

http://www.navair.navy.mil/index.cfm?fu ... ry&id=4144

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 30 Dec 2014, 04:45
by spazsinbad
Just a detail about the max. load expected on the Ski Jump gives an indication of the MAX. STO Mode for the F-35B which is also confirmed in the Marine Aviation Plan 2015.
17 -- Ski Jump Ramp
08 Jul 2005 Solicitation Number: N00421-05-R-0119 Agency: Department of the Navy; Office: Naval Air Systems Command; Location: Naval Air Warfare Center Aircraft Division Pax River

"The Naval Air Warfare Center, Aircraft Division (NAWCAD) intends to award a sole source contract to Williams Fairey Engineering Limited (WFEL), P. O. Box 41 Crossley Road Heaton Chapel, Stockport Cheshire SK4 5BD England. This sole source award will be made to design, fabricate, deliver, and provide analysis and set-up documentation for a Ski Jump Ramp in support of flight test operations of the F-35B Short Takeoff and Vertical Landing (STOVL) Joint Strike Fighter (JSF) aircraft, which weighs approximately 62,000 lbs...."

Source: https://www.fbo.gov/index?s=opportunity ... 4&_cview=0

Marine Aviation Plan 2015

"Max gross weight: F-35B = 61,500 lbs..."

Source: https://marinecorpsconceptsandprograms. ... 20Plan.pdf (16Mb)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 31 Mar 2015, 23:35
by spazsinbad
From AEROSPACETESTINGINTERNATIONAL.COM APRIL 2015 attached 2 page PDF about the Ski Jump at NAS Patuxent River. No details about 'current ongoing testing' just historical stuff - already mentioned in a few places on this forum - but amalgamated in the PDF.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 04 Apr 2015, 04:08
by spazsinbad
LETTERS: Ski-jump Harrier: something...
25 Dec 1976 LT CDR D.R. TAYLOR (Ski Jump Inventor) FLIGHT International

“Sir — "Ski-jump Harrier" (Flight, December 4) mentions a "something for nothing flavour." Misgivings on this score are understandable — I suffered them myself at one stage. As John Fozard has indicated. I began with the realisation that a semi-ballistic trajectory would reduce the launch speeds required. This was in 1969, and at that time I felt that various forms of catapult could provide the initial momentum.

Catapults had to be dropped for a variety of reasons, and it was while I was looking at inclined ramps that I began to worry about "something for nothing." A remark by my wife that one of my sketches looked like a ski-jump provided the analogy which reassured me that l had a simple alternative to the catapult.

But it is one thing to invent some thing and quite another to convince others of its value. I was working alone in my spare time, with no access to Harrier data, and so it was not until 1972-73 at Southampton University and with HSA assistance that I was able to make the concept respectable. It is therefore most gratifying – and rather surprising – that my first rudimentary calculations gave results close to the current predictions.

Why isn't it something for nothing? Because the take-off run to the transition point is longer for a Ski-jump launch than for a conventional short take-off launch. But with Ski-jump the runway is in the sky, of course.”

Source: FLIGHT International 25 Dec 1976

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 04:54
by spazsinbad
Lightning II ground
no date Sylvia Pierson is the F-35 Lightning II Patuxent River Integrated Test Force (ITF) public affairs officer

"...Runway trials
As team members returned to the ITF from their highly successful detachment aboard the Nimitz, they began to finalize preparations for wet runway and crosswind testing at Edwards Air Force Base and Naval Air Weapons Station China Lake in March 2015; and ski jump testing at Pax River in May 2015.... [I guess this is the B and not the C variant]

Source: http://www.aerospacetestinginternationa ... cleID=1189

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 06:39
by Corsair1963
spazsinbad wrote:Just a detail about the max. load expected on the Ski Jump gives an indication of the MAX. STO Mode for the F-35B which is also confirmed in the Marine Aviation Plan 2015.
17 -- Ski Jump Ramp
08 Jul 2005 Solicitation Number: N00421-05-R-0119 Agency: Department of the Navy; Office: Naval Air Systems Command; Location: Naval Air Warfare Center Aircraft Division Pax River

"The Naval Air Warfare Center, Aircraft Division (NAWCAD) intends to award a sole source contract to Williams Fairey Engineering Limited (WFEL), P. O. Box 41 Crossley Road Heaton Chapel, Stockport Cheshire SK4 5BD England. This sole source award will be made to design, fabricate, deliver, and provide analysis and set-up documentation for a Ski Jump Ramp in support of flight test operations of the F-35B Short Takeoff and Vertical Landing (STOVL) Joint Strike Fighter (JSF) aircraft, which weighs approximately 62,000 lbs...."

Source: https://www.fbo.gov/index?s=opportunity ... 4&_cview=0

Marine Aviation Plan 2015

"Max gross weight: F-35B = 61,500 lbs..."

Source: https://marinecorpsconceptsandprograms. ... 20Plan.pdf (16Mb)


So, does that mean a F-35B could take off from a Ski Jump at Max Gross Weight???

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 06:57
by spazsinbad
Why not? However it would be nice to know the other circumstances - as such we know that on CVF the F-35B will take 850 feet but I'm not certain about WOD/Temps - not in my memory anyway. The runup to the Pax River Ski Jump is AM-2 matting (on grass? or asphalt/concrete? SEE FIRST POST ABOVE) which replicates CVF deck length. Another thread shows this from a googie erf overhead shot perspective.

GO HERE for PaxRiver SkiJump overhead: viewtopic.php?f=22&t=14082&p=266110&hilit=Patuxent+jump#p266110

Immediately below is the CVF info on the same "F-35B/C and the Ski-Jump?" thread c.2014

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 13:30
by bring_it_on
Didn't the testing start in Feb?

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 13:55
by spazsinbad
Depends when you want to start quoting 'when the ski jump testing was supposed to start'. I'll guess we will hear/read about it all one day. IF tests only started recently then probably they are not finished.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 14:48
by bring_it_on
spazsinbad wrote:Depends when you want to start quoting 'when the ski jump testing was supposed to start'. I'll guess we will hear/read about it all one day. IF tests only started recently then probably they are not finished.


I was referring to this - http://www.reuters.com/article/2015/02/ ... AK20150224

Would love some pictures :mrgreen:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 18:04
by neptune
bring_it_on wrote:Didn't the testing start in Feb?


I'm thinkin' the Brits are supportin' the Marines to get to IOC in July and that might slide the Ski Jump a bit to the right on schedules. After the recent trip to the boat, a Marine General stated that no debilitating gripes were generated and now weapons certifications were the next goals. I remember posting a B dropping the dual mode Paveway IV precision-guided bombs, recently. :)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 22:12
by Dragon029
First photo?

Image

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 22:33
by spazsinbad
:applause: THANKS MUCH 'Dragon029' - at last - what a sight! :mrgreen:

And for 'bring_it_on' references to 'ski jump testing at Pax' were in the news from ..... (have to find it) but I'll guess got derailed by 'UK MoD in a Muddle Bidness' at the time.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 22 Jun 2015, 23:14
by neptune
Dragon029 wrote:First photo?

Image


...so no news was "Good News"... :)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 00:26
by Dragon029
[Redacted]

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 00:48
by spazsinbad
'Dragon029' :notworthy: :mrgreen: Next QUESTION.... HOW DO YOU GET this material - first off the mark - BZ - I LIKE it!? :devil: :applause:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 00:59
by Dragon029
[Redacted]

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 01:55
by bring_it_on
Nice find, I know Spaz and I had been frantically searching for pretty much whatever we could find for a few months now (he probably longer)..Interesting that they did this on the weekend, don't know about the Chesapeake Bay but we nearly had a Tornado touch down in Annapolis-Baltimore area on Saturday :)..

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:00
by Dragon029
Sorry guys, but I've had to remove the video for now at the request of the source; it should be available again soon however.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:33
by spazsinbad
It has been posted here (not by me):


Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:41
by neptune
Dragon029 wrote:Sorry guys, but I've had to remove the video for now at the request of the source; it should be available again soon however.


...shucks, I missed it...but looking back at that photo, I begin to be staggered at the flight control variables that are being computed beyond a (simple??) cat shot! ....errr, am I missing something? :doh: ....how do you keep the "Bee" on the ski-jump?...where do you calculate V2? ...at the bottom of the jump or at the top???...sorry, it's been a long day... :|...I am happy to see the photo.. Yay! :)

...and it's back again and the video explains most of it. The main strut seems to drop about 12" after lift-off (lite-load? (as one might expect?))...thanks again for the video from who ever. Cheers :cheers:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:45
by spazsinbad
:doh: :mrgreen: 'neptune' OK for your long day - I get that now - IN my timezone it has been a LONG MORNING and I ain't ate brekkie (breakfast) and it is almost lunch time so I'm a bit ornery.... :devil: :roll:

Another thread has a long description of HOW the F-35B does the ski jump STO and how the flight computer knows that the aircraft is on the ramp and to keep the wheels on the ramp before going ballistic off it - with the aid of significant wing lift now allowed (not on the ski jump though) and the engine lift. I may find it before I faint from low blood sugar. :drool:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:50
by neptune
spazsinbad wrote::doh: :mrgreen: 'neptune' OK for your long day - I get that now - IN my timezone it has been a LONG MORNING and I ain't ate brekkie (breakfast) and it is almost lunch time so I'm a bit ornery.... :devil: :roll:

Another thread has a long description of HOW the F-35B does the ski jump STO and how the flight computer knows that the aircraft is on the ramp and to keep the wheels on the ramp before going ballistic off it - with the aid of significant wing lift now allowed (not on the ski jump though) and the engine lift. I may find it before I faint from low blood sugar. :drool:


Thanks Spaz, I'll check it in the morn! :)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 02:53
by spazsinbad
For 'bring_it_on'... During a fainting spell I had this vision of the old news about old scheduled JumpDeSki but URL now discontinued so perhaps I'm making it all up? Dunno.
JSF ski jump tests due in 2011
08 Jul 2010 Someone

“'Ski jump' trials of the Lockheed Martin F-35B Lightning II Joint Strike Fighter are expected to take place in 18 months' time at US Naval Air Station (NAS) Patuxent River in Maryland. The tests will see if the F-35B can fly from the take-off ramps to be fitted to the UK Royal Navy's two new Queen Elizabeth-class future aircraft carriers (CVF), but BAE Systems F-35 test pilot Graham Tomlinson told Jane's that he expects such take-offs to be far more straightforward than those from flat deck aircraft carriers.”

Source: http://articles.janes.com/articles/Jane ... -2011.html

JSF programme to proceed with UK-specific land-based carrier trials
09 Jul 2012 Gareth Jennings

“The Program Office for the Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF) is to shortly commence UK-specific trials for carrier operations of the short take-off/vertical landing (STOVL) variant F-35B, it was announced at the Farnborough Airshow 2012. Speaking on 10 July, BAE Systems lead STOVL test pilot Peter 'Wizzer' Wilson said that 'ski-jump' launch trials will begin at Naval Air Station (NAS) Patuxent River, Maryland, in the near future, while work on the shipborne rolling vertical landing (SRVL) is also ongoing...."

Source: http://www.janes.com/events/exhibitions ... oceed.aspx

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 03:11
by spazsinbad
Just a reminder quote:
Ship Shape — F-35/QEC simulator
SEPTEMBER 2014 PAUL E EDEN | ATI Mag'n

"...300 Take-off run in feet from QEC for lightly loaded F-35B

800 Take-off run in feet from QEC for fully loaded F-35B..."

Source: AEROSPACE TESTING INTERNATIONAL September 2014

AND go here for a long detailed story about STOing:

viewtopic.php?f=57&t=24438&p=274982&hilit=Rusnok#p274982

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 12:48
by spazsinbad
SLOW MOTION 1st F-35B Ski Jump Launch 19 June 2015


Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 13:02
by sferrin
OMG PR STUNT!!!!! CGI!!!!! LM IS A BUNCH OF CROOKS!!!!!!! :mrgreen:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 13:31
by spazsinbad
:devil: AND the Fwits got it rong :mrgreen: The ski jump is longer than the previous one - wottableedin' liberty.... For the 'nep tunes' among us...
Carrier countdown [MORE of this HERE: viewtopic.php?f=22&t=20304&p=275767&hilit=Robinson#p275767 ]
30 June 2014 Tim Robinson

"...Not your father’s ski-jump
The QE-class’s ski-jump, too, has been carefully designed and engineered from the beginning — drawing on BAE’s Harrier
heritage. Says Atkinson: “We had to go back into the archives and talk to people who had actually been involved with trials with the Sea Harrier and Harrier to make sure we understood the history of ski-jump ramp development. The aircraft carrier ski-jump is a UK innovation and something the UK is very proud of”. The QEC’s ski-jump is longer (200ft) than the Invincible class (150ft) and designed so that the aircraft has all three (including the nose) wheels in contact right up until the point where the aircraft leaves the deck — giving positive nose wheel authority throughout. Additionally, the F-35Bs smart flight control system ‘knows’ when it is going up a ramp and will pre-position the control surfaces and effectors to launch at the optimum angle to avoid pitch-up or down...."

Source: http://aerosociety.com/News/Insight-Blo ... -countdown

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 15:33
by sferrin
http://www.defense-aerospace.com/articl ... -late.html

"OMG they're hidin' something!!!!!! Cancel the program; it's a disaster!!!!" Is it just me or has this guy just turned into a petty, whiny little man?

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 16:46
by Gums
Salute!

I did not see any "ballistic" arc, but more like the STO's from the Wasp.

Any Harrier troops out there to give us a clue?

I always thot the deal was provide an upward vector, unload and get to "wing borne" before coming back to the ground/sea. That sucker or two seemed to just gradually accelerate in that "in between" mode.

Gotta be a STO mode, as the Bee I saw here at Eglin awhile back flew a normal base turn and low approach with all the doors open. After stopping at mid field 100ft alt or so ( hover mode, apparently), it transitioned to forward flight and did a closed pattern for a fairly short landing with all the doors open.

Gums wonders....

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 17:55
by lamoey
That first run had a distinct tail drop when the main gear left the jumps edge, before the flight control system reacted by moving the nozzle more vertical for added lift. Hope the pilot did not soil himself 8)

http://www.defense-aerospace.com/article-view/release/164780/f_35b-makes-first-ski-jump-test-%E2%80%93-four-months-late.html

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 21:01
by spazsinbad
'Gums' this is my full explanation shorthand: "...keep the wheels on the ramp before going ballistic off it - with the aid of significant wing lift now allowed (not on the ski jump though) and the engine lift...". Yes the aircraft has an upward vector brought on by the ski jump but the F-35B has different engine and lift vectors compared to the Harrier family. There are a few Harrier ski jump explanations in this forum, written by experienced Harrier Pilots but of the many different threads now scattered here there and perhaps everywhere. :mrgreen: I can dig them out but if you require a Hairier Pilote to explain then I'll wait for same.

As you suggest 'Gums' the Bee is accelerating in this 'inbetween mode' and can keep that going up until the Mode 4 STOVL limit (with all the doors open) at 250 knots or less below 10,000 feet. The flight computer controls it all and does what the pilot requires within the limits set by the same flight computer. The are other combinations with different sets of doors open (but unusual). The usual STOVL Mode 4 has all the doors open and the aircraft then can fly backwards at thirty knots (a limit - right on the edge of control) hover and fly at any speed up to 250 knots below 10,000 feet.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 21:10
by spazsinbad
:mrgreen: 'sferrin' & 'lamoey' point to the (or one of them) "whiney little man" @defairspack. Said same missed the chance to complain about FOUR FRICKIN' YEARS LATE not just 'four months' - so I'll not miss that chance. :devil:

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 21:15
by spazsinbad
'lamoey' said above: "...distinct tail drop when the main gear left the jumps edge, before the flight control system reacted by moving the nozzle more vertical for added lift...". I guess it is all in the eye of the beholder. I see the 3BSN moving throughout the ski jump travel (watch the slow motion video over on beforehand page). So not only does the tail drop slightly but instead the nose rises slightly - a good thing and probably seen in the simulator. Remember this stuff has been tested ad nauseum on a 'moving' simulator at BAE Wharton, UK and not just at any sim at PaxRiver. These people know their stuff.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 23:05
by spazsinbad
Joint US and UK test team have begun testing the Short Takeoff capability for the Lightning II.
23 Jun 2015 UK MoD

"The F35B Lightning II has successfully completed another major milestone as the fifth generation stealth fighter was launched into the skies from a ski-jump, Friday 19 June.... [Oopps should be in 'milestone thread']

The land-based test — conducted by the F35 Lightning II Pax River Integrated Test Force — took place at Naval Air Station in Patuxent River, Maryland, US.

The joint U.S.-U.K. test team will continue phase I of ski jump testing this summer in anticipation of eventual U.K. aircraft carrier operations.

Peter Wilson is the BAE Systems test pilot and ski jump project lead for a highly diverse cadre of technicians, engineers, administrative support staff and test pilots based at the Pax River ITF and in the UK. ['Wizzer' Wilson quotes about F-35B ski jumping are scattered throughout this forum]

He said:
“Friday’s F35B ski jump was a great success for the joint ski jump team. I’m exceptionally proud of this team. Their years of planning, collaboration and training have culminated in a fantastic achievement that advances the future capabilities of the aircraft and its integration into UK operations.”


For more than 30 years, the U.K. has used the ski jump approach to carrier operations as an alternative to the catapults and arresting gear used aboard U.S. aircraft carriers.

The shorter UK carriers feature an upward-sloped ramp at the bow of the ship. Curved at its leading edge, a ski-jump ramp simultaneously launches aircraft upward and forward, [ballistic? with added OOMPH?] allowing aircraft to take off with more weight and less end-speed than required for an unassisted horizontal launch aboard U.S. aircraft carriers.

Peter added:
“As expected, aircraft BF-04 performed well and I can’t wait until we’re conducting F35 ski jumps from the deck of the Queen Elizabeth carrier. Until then, the de-risking that we’re able to achieve now during phase I of our ski jump testing will equip us with valuable data we’ll use to fuel our phase II efforts.”


The F35B’s design allows it to automatically position the control surfaces and nozzles for takeoff; a unique capability compared with previous STOVL aircraft. Such automation frees up pilot capacity and provides an added safety enhancement...."

Source: https://www.gov.uk/government/news/f-35 ... ns-testing

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 23:16
by spazsinbad
I think this video has been posted before but worth a second look - shame that the 'engineer' is really a PILOT. :doh:
How the F35B Lightning II works
Published on May 27, 2015 defenceheadquarters

"Royal Navy engineer [PILOT], Ian Tidball takes you on a tour of F35B Lightning II.

Discover how its capabilities will place the UK at the forefront of fighter technology, giving the RAF a true multi-role all weather, day and night capability. It will be able to operate from well-established land bases, deployed locations or the Royal Navy's Queen Elizabeth Class Aircraft Carriers."


Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 23:26
by spazsinbad
F-35B Leaps off Ski Jump for the First Time
23 Jun 2015 Brendan McGarry

"...“This test was a success for the joint ski jump team,” Peter Wilson, the BAE Systems test pilot and Briton who flew the June 19 mission, said in a press release. “The aircraft performed well and I can’t wait until we’re conducting F-35 ski jumps from the deck of the Queen Elizabeth carrier.”...

...note the F-35B has its nozzle directed downward to maximize rate of ascent. In the release, Gordon Stewart, flying qualities engineer representing the UK Ministry of Defence, touted the aircraft’s higher degree of automation during takeoffs and landings.

“For ski jump launches, the aircraft recognizes when it is on the ramp and responds by positioning the control surfaces and nozzles automatically for takeoff and climb,” he said. “We’ll be using these results — along with those from future testing — to help us prepare for the first shipboard ski jump launch from HMS Queen Elizabeth.”

Unfortunately, that may still be a long way off. The ramp test itself was delayed by several months [SHOCKA!] and F-35 trials aboard the Queen Elizabeth may not happen until around 2018 or later."

Source: http://defensetech.org/2015/06/23/f-35b ... irst-time/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Jun 2015, 23:32
by spazsinbad
F-35B STOVL (Short Take Off Vertical Landing) variant of the Joint Strike Fighter performs first launch from ski-jump in the hands of a British pilot.
23 Jun 2015 David Cenciotti

"On Jun. 19, BAE Systems Test Pilot Pete ‘Wizzer’ Wilson launched the Lockheed Martin F-35B from a land-based ski-jump for the very first time, at Naval Air Station Patuxent River, Maryland.

The trials aim at validating the troubled fifth generation multi-role aircraft’s ability to take off safely and effectively from a ski-jump ramp similar [SAME AS BOYO] to that which will be used on the UK’s new Queen Elizabeth aircraft carrier.

Ski-jump ramps on aircraft carrier help the launching plane take off with an upward flight path. Italy’s Cavour [is that Italian for CLOWN? see here for context: viewtopic.php?f=22&t=25623&p=293498&hilit=CLOWNS#p293498 ] aircraft carrier, destined to receive the Italian Navy F-35Bs that will replace the AV-8B+ Harrier II is also equipped with a ski-jump."

Source: http://theaviationist.com/2015/06/23/f- ... mp-launch/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 00:46
by charlielima223
Question.
Wont a ski-jump be more beneficial for a fully loaded (internal and external weapons) F-35B take off? If so, would these mean that USMC F-35Bs operating off from current USN LHDs can only go out with full fuel, internal weapons, and gun pod?

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 01:23
by SpudmanWP
That is not known yet as the testing from the Wasp had them taking off in multiple conditions, run-up distance, etc.

There are a couple of things that you could do from an LHD to takeoff with a better MTOW than the KPP:
1. Use more of the 840+ft deck (590ft is what has been demonstrated)
2. Use a little AB to get moving before the 3BN rotates towards the deck

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 01:25
by spazsinbad
'charlielima223' asked:
"Question. Wont a ski-jump be more beneficial for a fully loaded (internal and external weapons) F-35B take off? If so, would these mean that USMC F-35Bs operating off from current USN LHDs can only go out with full fuel, internal weapons, and gun pod?"

This is a 'how long is a piece of string' question. Specifically with very limited information the same question or similar has been asked on this forum in various ways. One way to answer is that the F-35B conforms to required KPPs - one of which is the USMC/RN/RAF/CVF requirement to carry out a STO blah blah blah on an LHA - now at 600 feet (formerly 550) whilst the CVF was 450 feet - with ski jump. And AFAIK there was some WOD and temperature/pressures set - ordinary.

With this limited amount of information one may extrapolate what 'taking off from 800 feet with ski jump' with a FULL internal/external weapon/fuel loadout (not specified in pounds nor conditions but probably standard) and then do some mathematics to account for the LHA deck length (which is what in each case?). Whatever the answer - the answer remains: IF the required KPPs for STO are able to be made then flying armed services using the F-35B are happy.

Because the RN/RAF F-35B use on CVF envisages a VERY HOT LOW PRESSURE DAY WITH NIL WIND in the east of Suez then they envisage an SRVL for bringback weight. Apparently the USMC are happy with that VLBB KPP also. Go figure - what is imagined about how good or bad one requirement is over the others is that IF the KPP is met then the F-35B is good to go.

I see 'SWP' has answered whilst I was typing.... To Answer 'SWP':

The F-35B takes about fifteen seconds to convert to STOVL mode four according to what I recall reading. The F-35B cannot use afterburner in STOVL mode so how can an A/B burst benefit a STO except to clear out anything behind it?
How it Works: F-35B Hover
Feature Article // July 01, 2014

"...For the pilot, converting from conventional flight to STOVL mode is no more complicated than pushing the STOVL conversion button. This is the same button that pilots flying an F-35A or F-35C aircraft would push to lower the tail hook.

After the button is pressed, the transformation to STOVL mode begins, which includes the opening of all STOVL doors and the propulsion system preparing to engage the clutch. Once all doors are open, the clutch engages when sets of carbon plates press together to spin the LiftFan® up from a complete stop to engine speed. Once the speeds between the LiftFan® and engine are matched, a mechanical lock is engaged to remove the torque load from the clutch and permit operation to full lift fan power. After the lock engages, the propulsion system completes conversion to STOVL mode and responds to aircraft commands. The entire sequence takes approximately fifteen seconds."

Source: https://www.f35.com/news/detail/how-doe ... -35b-hover

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 02:07
by SpudmanWP
I think you misunderstood (from me not being clear enough) what I was referring too when I talked about the rotation of the 3BN.

Assuming that the F-35B started will all the doors open (this takes the longest time to do of the 15 seconds), used his AB for just a couple of seconds, then rotates the 3BN for a normal STO takeoff.

Taking a look at this BF-1 STO, you get an idea of what I mean.


Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 02:47
by spazsinbad
I did not hear an A/B howl. AFAIK/have read the F-35B cannot use A/B when the aircraft is in STOVL mode. Do you see the A/B in action in that video? All we see is a short take off with the 3BSN not in view until some time down take off roll. So we can imagine - if we wish - that this was going to be a FAST STO take off. I believe these were done at the beginning - including fast rolling landings in STOVL mode before the first VL. This is all test stuff.

Time and again I see quotes that the aircraft cannot go into afterburner when in STOVL mode. I can post a list of such quotes fairly easily if required.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 04:02
by Dragon029
I don't think he meant that video was an example of it performing this, just saying that you could launch the F-35B similar to the video (starting off with the nozzle completely rearward, before rotating the nozzle down and taking off).

While the nozzle is straight, the lift-fan clutch is disengaged, and roll-post valves are shut, there should be nothing mechanically preventing it from engaging the afterburner - software-wise I wouldn't be surprised if there's code to prevent it from happening (to prevent the pilot from breaching the ~250kt barrier while the doors are still open / in the process of closing), but again, mechanically it should be fine.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 05:06
by spazsinbad
'Dragon029' 'SWP' has used 'use the AB' a few time now so there is that. Whatever you may think is possible with the STOVL doors open in Mode Four - it is clear that the A/B cannot be used. I doubt there are other configurations with another mode - not all doors closed - that allows the A/B to be used. IF this was a useful trait - AND allowed - then Shirley it would be tested? And yes a Brit Engineer thought to close the roll post doors early on in development to allow more thrust to other parts during the initial STO roll, before the roll effects required once on/off the ski jump.

For example novel doors open/closed wheels up conditions in flight have been tested in case of some kind of door failure or combat damage. We get away from the point perhaps - which is this. The F-35B at MTOW can take off from a ski jump on CVF under reasonable conditions - make of that what you will.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 05:20
by SpudmanWP
Dragon is spot on as to my point (again, sorry for not being clear enough).

Hardware-wise, there is no difference or hindrance to having the AB engaged for a few seconds prior to the 3BN rotating. You could even have (and would be better to already have) the lift-fan clutch engaged (to some degree) prior to the AB even igniting.

There is an obvious software safety disengage somewhere so they would have to develop and test a takeoff model to include this as an option like they do now for their various takeoff profiles (runways, LHD, ramp, vertical, etc).

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 05:42
by spazsinbad
'SWP' my sense is that IF this option were possible/feasible/practical then it would have been included in the amazing array of technology on display already. Why NOT ask about this possibility at LM or P&W website? They might give a comprehensive reply one way or another.

Rather than just stating this: "...Hardware-wise, there is no difference or hindrance to having the AB engaged for a few seconds prior to the 3BN rotating...." you might offer some proof?

Same for 'Dragon029' stating this: "...While the nozzle is straight, the lift-fan clutch is disengaged,...". Thanks one and all.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 06:13
by johnwill
I too have wondered about positioning the engine nozzle straight back for the takeoff run, then rotating it down for liftoff. In my thought, there is no A/B usage, just max dry power and the fan remains engaged. I understand the that with the nozzle straight back, there is a different back pressure in the engine which could affect the torque supplied to the fan. I'm pretty sure the experts that developed the system know what they are about, so the way it works now is optimum.

The slight pitchup seen just after departing the ramp could well be a programmed AoA increase to develop wing/body lift as airspeed is increasing. AoA on the ramp is zero, thus no wing/body lift, although the tails are deflected downward and may be contributing lift.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 06:21
by spazsinbad
Thanks 'JW'. One thought occurred to me - without much after thought is this: how much time from brakes off does this wunderkinder A/B pilot have during the STO to have the 3BSN swivel down enough (not all the way obviously as seen in the video whilst still on deck and on the ski jump). The flat deck STO pilots have commented on the enormous power response experienced during the STO on deck (Harrier pilots say similar things). One day we may know the weight and distance of a particular STO on deck to then time the STO (on a flat deck the F-35B is flying off before the end of the deck) without any edit cuts. Really a NATOPS would be so handy. :mrgreen:

And 'JW" from almost the end of page 2 of this thread is this quote:
"...designed so that the aircraft has all three (including the nose) wheels in contact right up until the point where the aircraft leaves the deck [ski jump] — giving positive nose wheel authority throughout. Additionally, the F-35Bs smart flight control system ‘knows’ when it is going up a ramp and will pre-position the control surfaces and effectors to launch at the optimum angle to avoid pitch-up or down...."

So unlike a flat deck STO the Ski Jumper has to have all wheels on the ramp (probably not at 1G perhaps but enough downward force to enable "positive nose wheel authority throughout". The old flight computer is doing a lot of stuff I reckon - let us not overwork it with A/B now. :mrgreen:

Here is a more detailed quote about STOVL conversion from conventional flight.
Blue Sky OPS
26 April 2012 Mark Ayton AIR International F-35 Special Edition 2012

"...When preparing to transition from conventional to STOVL mode the first thing the pilot must do is configure the aircraft to be able to fly at slow speed. This process is called conversion and from the pilot’s perspective it starts when the aircraft is moving at 250kts (460km/h) or less at which point he or she simply presses a button.

“Seconds later, assuming all has gone well, you are in the mode that allows the aircraft to go to the hover,” said Peter Wilson.

Nine external doors open in sequence taking about 8 seconds, after which the propulsion system (not to be confused with the engine) starts to spool up. The clutch engages to spool up the lift fan located behind the cockpit (which takes about 5-6 seconds) and the control laws change to make use of the propulsive effectors that have just been brought to life. The aircraft is now in STOVL mode and ready for a vertical landing….”

Source: http://militaryrussia.ru/forum/download ... p?id=28256?

And for difference between FLAT & Ski Jump STOs...
Lockheed Martin rebuts F-35 critics on cost, progress
15 Jul 2010 Chris Pocock

"...For short takeoffs you just power up; the system takes care of everything else. On the ski-jump, for instance, the system detects the change in deck angle & doesn’t apply any rotation as it would on a flat deck.”...”

Source: http://www.ainonline.com/taxonomy/term/ ... node/25359

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 06:37
by SpudmanWP
I believe the primary reason why it's not there is that it fell on the cutting room floor just like all the other items that were not needed and they could not pay for (in time or money) during SDD.

The most notable of these "not part of SDD but are feasible" features are greater than mach 1.6 top speed and 6 AAMs internal.

Since the US designed the requirement for the F-35B around the existing Harrier operations, it knew what deck size, payload, & range it could use and set the requirement to them.

Things can be added that the plane was always capable of, but not programmed for. Case in point: SRVL was not added to the program until the UK came on board and required it.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 06:43
by spazsinbad
'SWP' sure - however this is guess work on your part. I could dream up a lot of stuff and claim it all fell on the cutting room floor. And this A/B STO has not been mentioned... HOWEVER I will admit I was always puzzled by the JBD in the middle of the CVF deck early on (and then the ridiculous A/B conventional takeoffs of the CVF Ski Jump animations are just too much). So... perhaps there was an element of this 'early on' but again this is just guess work on my part.

And from the 'BLUE SKY OPS' article above is another 'Pete Wilson' quote:
"...F-35B Take-off Options
The F-35B STOVL variant has a range of take-off options using different modes to suit the basing. Take-offs from a ship, with either a flat deck or one with a ski jump, are also possible with a mode for each scenario. These are short take-off scenarios that can be achieved at speeds as low as 50kts with a deck or ground run of no more than a 200ft (60m). In the same mode, a take-off as fast as 150 knots is possible if the weight of the aircraft requires that speed. If the aircraft is
light it can take off at a slow speed and faster when heavy.

Take-off at speeds as low as 5, 10, 15, 20kts (9, 18, 27 and 36km/h) are also possible, each of which is effectively a vertical take-off while moving forward. There are different ways of rotating the aircraft in STOVL mode, including the usual ‘pull on the stick’. Other ways are by pressing a button or programming a ground distance required after which, the aircraft control law initiates the rotation and selects the ideal angle for climb-out...."

And the old cowpie throttle for one or tuther.
FLIGHT TEST: F-35 Simulator - Virtual fighter
31 Jul 2007 Mike Gerzanics

“...Seated in the simulator, my left hand fell to the large throttle, called the "cow pie" due to its size and shape, which moves along a long linear track. The active throttle is back-driven by the auto-throttle system and has variable electronic detents for afterburner and STOVL operations. There is no "cut-off" position, a single guarded engine master switch performing that function....”

Source: http://www.flightglobal.com/news/articl ... er-215810/

Pete Wilson again... I would want the LiftFan spinning at brake release - for a STO - no?
Precise and powerful
2012 RR PR

"...when the STOVL doors on the fuselage open, then the Rolls-Royce clutch engages, connecting the LiftFan™ just behind the cockpit via a shaft to the 40,000lb thrust Pratt & Whitney F135 engine. The 3-Bearing Swivel Module at the rear of the aircraft twists downward, and Roll Posts on the wingtips provide stabilising air thrust. The LiftFan spools up in about five seconds, which Wilson says sounds like ‘a big humming mosquito kind of noise. ‘Fifteen seconds after pressing the button, I’m in STOVL mode...."

Source: http://www.rolls-royce.com/defence/cust ... werful.jsp

The FLAT DECK STO difference.
Navy Sees Few Anomalies in F-35B Ship Trials
31 Oct 2011 Amy Butler | Onboard the USS Wasp

"...Though vertical landings are quite similar to those of the Harrier, the STO operations do vary for the F-35 owing to the
different lift qualities of the F-35s’ stealthy, supersonic-capable design. For testing on the Wasp, the nozzles and control surfaces actuate with 225 ft. of runway remaining on deck, creating an angle of attack and allowing for the
wings to produce enough lift for take-off from the deck, Cordell says.
The Harrier’s rotation line is at the bow, owing to its wing design creating the required lift without the corresponding angle-of-attack change...."

Source: http://www.aviationweek.com/aw/generic/ ... avy&next=0

And going back to those olden tymes when perhaps more things were possible?
THE JSF STOVL PERFORMANCE PROCESS FROM SMALL-SCALE DATABASE TO FLIGHT TEST DEMONSTRATION
Kevin M. McCarthy, JSF Program Office/Naval Air Systems Command Nov 2002

“...Fixing any two of: a) takeoff gross weight, b) deck run or c) wind over deck, STOPC can optimize for the 3rd parameter.

The STO deck run starts at brake release, which typically occurs at the maximum thrust that the brakes can hold. This is an input. The engine spool-up characteristics from this throttle setting to maximum power are considered during the acceleration portion of the deck run. Weight on main and nose gear is calculated, and must be monitored to maintain adequate deck handling characteristics. The code can represent both flat deck, typical of current generation US Navy ships, as well as any geometry of ski jump. Ski jumps are currently used by the navies of two of the JSF international participants, the UK and Italy....

.....STO demonstrations were a critical aspect of the flight test program as well. The X-35B performed two different technique STOs; 1) fixed nozzle and 2) auto-STOs. The fixed nozzle STOs are self-explanatory, and were used for the initial flight test STO maneuvers. For these maneuvers, the demonstrated performance was very consistent with predicted levels. The flight test auto-STOs featured a deck run nozzle angle (34/28 fan/main) and flyaway nozzle angle between 40/40 and 60/60, depending on aircraft weight. The auto-rotation was pilot actuated at the desired rotation speed....

...STOs are transient maneuvers, and highly technique driven, even for the auto-STOs. The “blind” pre-flight predicted performance estimates differed from the flight test maneuvers....

Source: http://pdf.aiaa.org/downloads/2002/CDRe ... 274d1857TR

And an interesting forum factoid... FROM 'QuickSilver' (HiHO!)
“The nozzle is angled down to ensure directional control (via NWS) is maintained during the takeoff roll until
rotation. You should also note that the nozzle rotates upward momentarily at the point where the takeoff rotation occurs. Such movement instantaneously alters the vertical component of lift between the lift fan and the main engine exhaust thereby contributing to the pitch rotation.”

Source: viewtopic.php?f=57&t=25401&start=15

Jumping Jack Flash
July 2014 unknown author AIR International F-35 Special Ed.

"...There are three ways to conduct a short take off (STO) in the F-35B: stick STO, button STO – and auto STO. “That’s a completely automated way to STO the aircraft off the flight deck. You punch in a distance and the aircraft will auto rotate to its optimal fly-out condition. It’s all based on distance: we know where the aircraft is spotted [before it starts its take-off run] and where it should start its actual rotation,” explained Rusnok. “Unlike a Harrier, which launches off the end of the ship flat, the F-35 rotates at about 225 feet from the bow, sits on two wheels until it gets to the end of the ship and actually takes off, a much different process to a Harrier. From a pilot perspective, you lose some sight of the front of the ship; in a Harrier you can see all the deck. But that’s all part of optimising a 35,000lb aeroplane to get off the ship compared to the Harrier, which is only 16,000 to 25,000lb.”

With stick STO the pilot controls the take-off by pulling back on the stick, holding it there and then rotating to the optimal pitch angle to fly off. In button STO, the pilot uses a trim switch which rotates the aircraft when pushed in, activating it when the aircraft passes the yellow STO rotation line positioned 225 feet from the bow of the ship.

“That was a temporary marking applied on the flight deck for this trial and is now being permanently installed on the ship with lighting,” explained Rusnok. “It’s based on optimising the performance of the aircraft and its flying qualities, so we can get the aeroplane off with the maximum amount of nozzle clearance and performance. The STO line is our visual cue to either pull the stick aft or hit the button; or if you’re on automated STO you should start seeing the aeroplane’s flight controls moving by the line, otherwise the pilot can intervene and pull back on the stick. We’ve never had to intervene.”

The pilot also has command of the throttle. Two power setting options are available for take-off: Mil STO and Max STO, as Maj Rusnok explained: “When you taxi to the tram line you stay in mode one, the conventional flight mode. You convert the aircraft into mode four, the STOVL flight mode, and it takes about 15 seconds or so for the doors to open up and the lift fan to engage.

“Then you push the throttle about halfway up the throttle slide into a detent position at about 34% engine thrust request. It sits there and you check the engine gauges: if the readings are okay you slam the throttle to either Mil or Max position and then release the brakes simultaneously. Pushing through to max is like an afterburner detent. But it’s not an afterburner – you can’t go to afterburner in mode four.

“It’s a very fast acceleration. The closest we would spot from the bow is 400 feet, so about 175 feet before we would actually start rotating the aeroplane [at the STO rotation line]; so very, very quick.”

One of the big test points for DT I was to ensure adequate nozzle clearance in all the different test conditions. The engine nozzle swings down and back up during the take-off in accordance with inputs from the aircraft control laws.

“It’s all automated,” said Rusnok. “The pilot is not in the loop whatsoever – either they’re pushing the button and letting the aeroplane do its own thing or pulling back on the stick to help it. Monitoring systems cue when something is wrong, so you have to rely on them to keep you safe because the flight controls are being moved unbelievably quickly.” Maj Rusnok said the take-off was very much like that ashore, with very little sink off the end of the deck. “The aeroplane is ridiculously powerful in STOVL mode. Just raw, unadulterated power.”..."

Source: AIR International F-35 Special Edition July 2014

AND maybe the last Ski Jump?
Stepping-Stones
08 SEP 2014 Tony Osborne AVIATION WEEK & SPACE TECHNOLOGY

“…Particular emphasis has also been placed on how the F-35 will launch from the Queen Elizabeth’s ski jump, which gives the aircraft valuable vertical impetus, allowing for greater takeoff weights as well as a positive rate of climb. The F-35B’s flight control logic has been written for the Queen Elizabeth’s new 12-deg. jump, which at 200 ft. long, is some 50 ft. longer than that used on the Invincible-class carriers.

With the aircraft lined up for takeoff, the pilot presses the short-takeoff-and-vertical- landing (STOVL) switch, activating the lift fan and rear nozzle. The lift fan is fully operational within 15 sec. The F-35B uses the same process and partially opens its weapons bay doors, which help provide more lift. [Perhaps it was meant that this is for the VL?] As the aircraft hits the ski jump, its flight control logic recognizes it is on the ski jump and uses the rear nozzle to keep all three wheels on the ground. The aircraft should be airborne at around 90 kt.

“It’s a luxurious way to get airborne,’’ says Wilson. “The pilot simply uses the pedals to keep the aircraft straight, and the aircraft recognizes the presence of the ski jump.” Test pilots have tried out the ski jump only in the simulator, but that work has been very valuable in addressing early concerns about the ground clearance between the ski jump and rear nozzle….”

Source: AVIATION WEEK & SPACE TECHNOLOGY 08 SEP 2014

MODES sort of explained...
F-35 Flight Testing At Pax
15 October 2012 Eric Hehs

"...Some of the flight test aircraft have special software that allows the pilot to override the standard control laws that actuate the various doors and nozzle angles. The flight control laws for the STOVL variant have six modes that are associated with specific actuations. Mode 1 defines conventional flight. Mode 4 defines STOVL. The other four modes define transitional states between the two primary modes. “If a pilot loses a hydraulic system in Mode 2, we know that the doors associated with STOVL flight will be positioned a certain way,” Faidley explained. “We are seeing how well the airplane flies in those conditions.”...”

Source: http://www.codeonemagazine.com/f35_arti ... tem_id=110

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 11:20
by quicksilver
As noted by Maj Rusnok in one of the clips above, AB is inhibited when the jet is in Mode 4 -- no exceptions, including the SWP video from Pax STO in 2010 (JW is generally correct about why).

The jet knows how much it weighs, where that weight is distributed (CG), and the propulsion system balances the horizontal and vertical components of lift (thrust split and thrust angles) between the lift fan, the main engine and the roll posts in response to pilot commands via the inceptors (stick and throttle).

The lift fan produces a significant vertical lift component even with the vane box nozzles at the aft-most defection. As a result, for STOs, the lighter the jet is the more downward deflection it needs from the main engine to keep the nose wheel firmly on the deck to provide directional control (via NWS) during the takeoff roll. Conversely, if the jet is heavier, main engine exhaust deflection is somewhat less.

If one looks very closely at about the 7-8 second mark of the SWP video, one can see a couple points on the 'feathers' of the main engine nozzle and also see the slight upward movement of the nozzle at the STO rotation point at about the 9 second mark.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 20:31
by noth
IT'S HAPPENED!!!!!!!!!!

http://www.flightglobal.com/news/articles/f-35b-demonstrates-short-take-off-capability-413986/

The UK and USA have carried out the first short take-off test of the Lockheed Martin F-35B Lightning II during a ground-based test at Patuxent River Naval Air Station in Maryland, USA on 19 June.

This marks the start of the first phase of testing to certify the UK’s short take-off and vertical landing F-35B as capable of take off and landing from an aircraft carrier. The work is being controlled by the F-35 Pax River Integrated Test Force (ITF), assigned to the Air Test and Evaluation Sqn 23.

Test aircraft BF-04 took off on a ski-jump, demonstrating the F-35B’s ability to integrate into the UK’s future operations. The UK has selected the ski-jump approach as opposed to the catapult and arresting gear approach favoured by the USA in its carrier operations.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 22:18
by Dragon029
noth wrote:IT'S HAPPENED!!!!!!!!!!
[/quote]

Yep, go to the 2nd page of this thread to see video.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Jun 2015, 23:50
by spazsinbad
These guys should not write about naval aviation or the partners in the JSF/F-35 program. Significant - Eye Candy - I lost my sense of humour with them a long time ago when they could not tell the front / back of a CVN with an X-47B on/off it.

http://breakingdefense.com/2015/06/eye- ... -takeoffs/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 01:02
by spazsinbad
Janes gets into the spirit of the event (unlike defaerospakfilla for example - a quote from dem follows - then JANES).
"(EDITOR’S NOTE: The above story, written by the chief JPO spokesman, was posted on a Pentagon news distribution website (DVIDS) late Tuesday night, but as of this morning neither the Navair [Why is this important - how relevant to USN NavAv are ski jumps? IS every test mentioned by NavAir?] nor JPO [here: http://www.jsf.mil/news/docs/20150619_SkiJump.pdf ] websites mention the test." http://www.defense-aerospace.com/articl ... -test.html [Weerd Huh] but this is a weirder: https://www.f35.com/news/detail/f35b-je ... ns-testing THIS PAGE does not appear in the 'news section' but it points to UK MoD baby - rock on whoever is responsible LM]

F-35B begins 'ski-jump' trials for carrier operations
23 Jun 2015 Gareth Jennings, London - IHS Jane's Defence Weekly

"The Joint Program Office for the Lockheed Martin F-35 Lightning II Joint Strike Fighter (JSF) has begun ground-based trials of the 'ski-jump' technique for launching the aircraft from the decks of aircraft carriers, the UK Ministry of Defence (MoD) announced on 23 June.

In the test, which relates to JSF's short take-off and vertical landing (STOVL) F-35B variant, the chief STOVL test pilot from BAE Systems, Peter 'Wizzer' Wilson, took off from Naval Air Station (NAS) Patuxent River in Maryland using a ramp that had been fitted to the Royal Navy's now-decommissioned HMS Illustrious. [WHAT BOLLOCKS!]

Wilson said the test on 19 June re-proved the concept developed by the UK to launch its Sea Harrier jets from the decks of its through-deck cruiser carriers in the late 1970s. Whereas Harrier pilots had to manually rotate the aircraft's exhaust nozzles slightly forward immediately after take-off to provide additional lift, the control surfaces and jet nozzle are adjusted automatically for pilots of the F-35B.

The 'ski-jump' concept enables the aircraft to take off with more fuel and/or weapons while using less deck space to build up speed, and provides an extra safety margin.

"The real benefit is one of timing," Wilson previously told IHS Jane's . "Once airborne, you are flying upwards rather than horizontal, and this gives you extra time to think if something should go wrong." Also, as was found during the Falklands conflict in 1982, the concept allows aircraft to be launched in far rougher sea states than possible with a conventional carrier equipped with catapults.

For the F-35B, the 'ski-jump' will be used to launch jets from the decks of the Queen Elizabeth and Prince of Wales carriers being built for the UK Royal Navy, and may be adopted by other customers such as Italy. Phase I testing will continue for two weeks, ahead of the Phase II trials to take place through the third quarter of the year. The MoD did not disclose what Phase II will entail, but it will likely feature shipborne trials aboard the Queen Elizabeth (QE) aircraft carrier (the first of the two QE-class ships) [AGAIN BOLLOCKS - ship trials 2018]...." [THEN follows a bunch of info about other CVF stuff]

Source: http://www.janes.com/article/52509/f-35 ... operations

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 01:23
by spazsinbad
:mrgreen: I LUV this shite - it is all so 'freekingly complicated - and EXPENSIVE' what oh laddie - take a shower (sewer preferably). :devil:

http://www.wired.com/2015/06/wildly-exp ... mp-launch/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 01:57
by spazsinbad
Now here is something more sober and useful to contemplate....
British pilot is first to test F-35B ski-jump launch
24 Jun 2015 BAE Systems Manufacturing Group

"Washington – The launch took place at Naval Air Station Patuxent River, Maryland, on June 19, 2015, from a land based ski jump and marks the start of an initial testing phase expected to last two weeks. The trials demonstrate the aircraft’s ability to take off safely and effectively from a ski-jump ramp similar to that which will be used on the UK’s new aircraft carrier. Ski-jump ramps provide the aircraft with an upward flight path meaning the aircraft can take off from the available distance with a greater payload, which means more weapons.

BAE Systems test pilot Pete Wilson said: “It’s always exciting when you get to do something in aviation for the first time. We spend literally years planning these ‘firsts’, with hundreds of hours in the simulator as the event gets close, but even with all the preparation the test team remains focused on the potential that something unexpected might happen. As is usually the case, the jet performed as expected and it was a real pleasure.”

BAE Systems plays a key role in the design, development and manufacture of both the aircraft and the aircraft carrier, and also leads the work to ensure that both are integrated seamlessly for the UK customer. These recent trials continue to inform the F-35 program and the BAE Systems engineers involved in it on both sides of the Atlantic. That includes BAE Systems flight test engineers based in the U.S. and engineers in Lancashire helping to develop and test the latest technologies for the aircraft.

In Warton, Lancashire, UK, the data from the flight trials will be used to further improve the models used in a unique simulation facility. Using the latest cutting edge technologies, engineers have developed a simulator that allowed pilots and engineers to fly the F-35 from the deck of the Queen Elizabeth carrier before either are available. This facility remains at the heart of developing a carrier strike capability for the UK...."

Source: http://www.onlineamd.com/british-pilot- ... 62415.aspx

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 03:05
by spazsinbad
Navy’s new F-35 jump jet flies from trademark ski ramp for first time
23 June 2015 RN Navy News

"...Veteran test pilot Peter ‘Wizzer’ Wilson took off in an F-35B using the jump – identical to those fitted on the Royal Navy’s new carriers.

...Ski jumps were fitted to the RN’s generation of Harrier carriers to give the jets more lift with less speed than a conventional flat flight deck.

The concept has been retained with the Queen Elizabeth class – although the replica ramp has been built in Maryland, not Yeovilton.

On the new carriers the structure rises about six metres (20ft) above the normal deck.

Two weeks of initial trials are being carried out with the data gathered fed back by the test team to engineers and designers, including those at Warton in Lancashire where F35 simulators help pilots ‘fly’ from the deck of HMS Queen Elizabeth – before they do it for real from 2018 onwards."

Source: https://navynews.co.uk/archive/news/item/12935

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 03:51
by spazsinbad
IF youse want a LaFf then go to the TidierRogerAway website to NOT only view the Obligatory Animated GIF [ https://i.kinja-img.com/gawker-media/im ... 907823.gif (2.8Mb) ] but see how the rong details are just that (probably at least one copied from a Shalal Reuters 'less thrust wrongun' earlier). Some jawdropping claims - as per usual.
F-35B Makes Its First Leap Off The Ski Jump
23 Jun 2015 Tyler Rogoway

"...This test was delayed last winter by about five months without a stated reason. [AND for four years without a reason stated.] Then, with little notice, this video was released by NAVAIR, Lockheed and BAe Systems showing the test in progress. Maybe that’s a function of just how unforgiving this type of test can be. If something goes wrong with the jet at such a low energy state and slowly climbing out at low-altitude and high angle of attack, mitigating any major issues probably has more to do with pulling the ejection handle than troubleshooting in the cockpit...." [No Kidding - and it will be automatic - numnuts]

Source: http://foxtrotalpha.jalopnik.com/f-35b- ... 1713406488

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 04:01
by geogen
Would like to see a test-launch of an (USMC) A-29 off a Jump... call it a day.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 25 Jun 2015, 06:07
by spazsinbad
This old URL has a lot more of the text from a complicated 'Optimise Ski Jump for F-35B' PDF that is no longer at URL mentioned: viewtopic.php?f=22&t=12631&p=178786&hilit=Revill#p178786

This year old 18Mb PDF has a lot of current/historic Ski Jump info and it will be updated once the various related F-35B on the ski jump news items/articles are online. This OneDrive PDF has the PDF cited below: https://onedrive.live.com/?id=CBCD63D63 ... E6&group=0
CVF ski-jump ramp profile optimisation for F-35B
Feb 2009 A. Fry, R. Cook and N. Revill, THE AERONAUTICAL JOURNAL FEBRUARY 2009 VOLUME 113 NO 1140

"...2.2 Principles of the ski jump
The ski jump ramp works by imparting an upward vertical velocity and ballistic profile to the aircraft, providing additional time to accelerate to flying speed whilst ensuring it is on a safe trajectory. This additional time is manifested either in a reduced take-off length for a given weight, or increased weight (i.e. launch performance) for a fixed take-off distance as in a ship based STO.


The additional performance does not come for free, with a significant increase in landing gear loads above those of a standard take off (which are very low compared to a landing). The increase represents the energy transferred to the aircraft as it translates up the ramp; and if the angle and curvature of the ramp are increased to obtain greater performance benefit, so are the loads. This is tolerable up to a point because the gear strength is defined by landing events and thus has the ability to accept the increased take-off loads, but loads act as an upper boundary on permissible ramp size, as illustrated in Fig. 5.

The ideal landing gear vertical load time history for a ski jump ramp STO is sketched in Fig. 6, with a rapid increase to a steady maximum where the area underneath the curve represents the energy imparted by the ramp. However, the actual loads are different, and reflect the complex dynamic response of the gear components as they enter and travel up the curvature of the profile.

References 1, 2 and 3 describe in further detail the principles behind the ski jump and its advantages as part of a STO manoeuvre compared to a flat deck launch and the design of the profile is described later.

It should be noted that non-STOVL aircraft can benefit from a ski jump manoeuvre, as illustrated by the Russian use of ramps with conventional type aircraft from their carriers. STOVL aircraft are unique however because of the flexible and complex manner in which the thrust and control effectors generate combinations of thrust and forward speed in conjunction with the speed dependent wing lift...."

...4.2 Safe launch metric
At the core of a ski jump performance analysis is the assessment of whether a launch case is achievable or not. The minimum safe launch is defined where the ramp exit speed does not result in any rate of descent during the trajectory until the aircraft has transitioned to fully wing-borne flight. This results in the launch profile shown in Fig. 8, with an inflection point at which the criteria for a successful launch are assessed.

There are two safe launch criteria derived from legacy STOVL experience that are used on the JSF program, of which the more stressing is adopted: (a) subtracting a margin from the WOD and requiring zero sink rate (known as Operational WOD); and (b) using the full value of WOD but requiring a defined positive rate of climb. Both also require a threshold forward acceleration...."

Source: http://www.raes.org.uk/pdfs/3324_COLOUR.pdf

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 26 Jun 2015, 20:27
by spazsinbad
An historical aside perhaps but maybe relevant to question 'why test' on land before 'test at sea' (another forum another time)
Costing Complex Products, Operations & Support
19 Oct 2011 Dr. Michael Pryce

“...Operations on the Harrier have led to constant discoveries of undercarriage O&S issues that needed to be addressed. Although the main undercarriage was very robust, being designed to operate off base and to take many unusual loads, such as landing while flying backwards, these discoveries were near impossible to predict and meant that the real-world experience of the undercarriage in use differed from the original design spectrum that they were built to meet.

For example, as Burton (1996) reports, seemingly minor differences in the build quality of the ski-jump ramps of the UK’s Invincible Class light aircraft carriers seriously affected the life of the undercarriage units, depending on which ship was being operated from. These ship build quality differences were not part of the original design assumptions, or subsequent modeling undertaken for a new ski-jump design fitted to UK aircraft carriers and its effect on the aircraft’s operating limits, and led to unexpected, and unexplained, cracking in the undercarriage units.

Upon investigation, down to individual aircraft and mission levels, it was discovered that the undercarriage damage suffered was not particular to the role or mission profile of the aircraft, or to the type of Harrier, but to the particular ship of a class that they were operating from. The damage was expensive to repair, but absolutely necessary in order to avoid a catastrophic failure mode that could not be predicted. Such a failure would lead to loss of an aircraft and likely serious damage to the ship. However, it was avoidable. The issues of the variability of carrier deck design on the class of ships concerned were known to the aircraft design team at least a decade before, with pitting and so forth causing problems on both deck and in the hangar (Brooklands Museum, 1985). However, in the calculation of undercarriage loads carried out during the design of the Sea Harrier, a smooth deck was assumed, based on design rules created by the UK Ministry of Defence (National Archives, 1978)....

...The fact that one of these ships caused damage to aircraft undercarriage units was not catastrophic in this case but, in large part, this was due to the undercarriage being of robust design, thanks to very different original requirements. If the undercarriage had been designed by the assumed loads for the ski-jump, modeled as part of the design and clearance program, it could well have failed in service use, leading to expensive re-design, remanufacture, and modification work for the entire fleet, or to the aircraft carriers. If the simple, baseline assumptions of the nature of ski-jump ramp design had been widened to look at possible worst case scenarios, the issue may have been accounted for earlier, and its costs would not have come as a surprise....”

Source: http://www.dtic.mil/dtic/tr/fulltext/u2/a555661.pdf (200Kb)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 26 Jun 2015, 21:00
by spazsinbad
What redesign of Harrier / SHAR gear may have entailed: http://www.flightglobal.com/pdfarchive/ ... 02666.html

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 26 Jun 2015, 23:53
by simon257
The Test Ramp was built in the UK, and shipped across the Pond a few years ago:

http://www.wfel.com/news/wfel-set-to-so ... ican-deal/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 27 Jun 2015, 01:16
by spazsinbad
Thanks 'simon257' :mrgreen: "somebody is wrong about this on the internet" about this has bugged since for a long time and info about the CVF EXACT REPLICA built in May 2009 on the PaxRiver Centrefield (after whatever was there before demolished I guess) is on this forum but SADLY information became scattered when this forum was divided into various sections (rather than being one AND people like me starting new threads - why? - :mrgreen: who knows. :mrgreen: Anyway searching on ['WEFL' but did not find anything?] should get some stuff with other search words as well as 'EAF' and anyway I'll find the clues eh.

Meanwhile attached is a PDF at maximum file size that has most of the info about Ski Jumpiness that has been collected & MOST of this stuff appears in this F-35 forum somewhere - finding it again & again has become a chore now.

Another version of this UPdated Ski Jump PDF will be online in a few weeks with more up to date info about recent tests.

[UPDATED now 151 page PDF below but it does lack new details likely to be published in a week or so about ski jumpin'.]

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Jul 2015, 01:38
by spazsinbad
OF course I'm interested in ski jumps - maybe less now that 'apparently' the Bs on LHDs are not in the near future for Oz - but never give up the ship gents. Meanwhile I had gone to pPrune to see what they had to say about the SKI JUMP but they were slow to start and then I only got back there today to replicate some good posts from the knowledgeable as seen below: [The posts that interest me the most start on Page 317 and finish on Page 318 - there may be more later - dunno]

http://www.pprune.org/military-aviation ... t-317.html
'John Farley' 23 Jun 2015: http://www.pprune.org/military-aviation ... ost9021527
"Re ski-jumps, it does not take much thought to realise that the ramp delivers any aircraft into free air in a nose up attitude and climbing. This saves the pilot having to arrange all of this when departing from the flat. Indeed back in 1977 when the boffins thought I was exaggerating how easy a jump was compared to a flat takeoff, I gave them the next record with a straight line on the tailplane and aileron traces for 35 secs after crossing the end. At the debrief they showed me the traces and apologised for the instrumentation drop out on the tailplane and aileron channels. I said “It was not a drop out I was not touching the stick - can you have a lower workload than doing nothing?” ....
&
Incidentally, if you look at any video of a B flat deck takeoff and watch the tailplane activity crossing the end and compare that with the tailplane activity off the ski-jump you will notice that even modern flight control systems find life easier from a ramp."
&
'ENGINES' 23 Jun 2015: http://www.pprune.org/military-aviation ... ost9021824
"Perhaps I can help out a bit here. What I can't do is improve on JF's succinct and 'spot on' comments about ski jump takeoffs. They are, by some distance, the lowest workload way of getting a combat jet into the air. The flat STO presented many more challenges to the F-35B team, and the lack of aft control surface movement shows how straightforward the evolution is.

However, it's a lot more than 'straightforward'. It's a little surprising, given that this is a pilots' forum, how few people mention the significant advantages it delivers. Firstly, operational: the ski jump will allow the F-35B to launch on task with at least another ton and a half of fuel and/or weapons. That's a ton (or two) of pure military goodness. Secondly, safety. As JF points out, the aircraft leaves the jump nose up and climbing without the pilot having to do anything. If anything does go wrong, the pilot has many more precious seconds to dump stores/jump out. At night, or in bad weather, or from a pitching deck, that's also a lot of goodness.

I do understand why some posters think this looks like a 'pucker' heavy evolution, but it's really, honestly, not. Every Harrier pilot I worked with said that it was a complete non-event. What's really amazing is that these gains come without penalty to the aircraft, which is fairly rare. The Harrier needed no mods to do ski jumps, save extra servicing checks on the nose leg. The F-35B has needed none. The flat deck STO drove the design, the ski jump came basically free.

Oh, and don't forget that it's another brilliantly simple and effective naval aviation idea from the UK's Fleet Air Arm. Respect.

JTO: Yes, the aft nozzle is definitely moving. I am not familiar these days with the F-35B control laws. but I would guess that what is happening here is that the aft nozzle is being left as far 'up' as possible to get to ramp exit speed in the shortest time (and distance), then programmed 'down' after ramp exit to support the 'fly away' profile. The Harrier did this manually, with the pilot selecting nozzles down to an adjustable 'STO stop' as it neared the ramp exit. F-35B does this for him/her.

For those that might not be familiar with the way a ski jump STO works, the key thing to 'get' is that the aircraft leaves the ramp BELOW flying speed. So the rate of climb starts to decay after ramp exit, depending on how much wing lift and jet lift is being provided. However, the aircraft is still climbing. As it accelerates, wing lift increases and jet lift can be reduced by altering the angle of the propulsion system's nozzles. At some point after ramp exit, the aircraft reaches an 'inflexion point', and the rate of climb starts to increase again. That distance between the end of the ramp and the 'inflexion point' is essentially a 'free runway in the sky' - around 1 to 1.5 km, depending on launch weight, temperature and other factors. That 'free runway' delivers the payload improvement.

The UK legacy performance limit for Harrier ski jump STOs was a minimum ROC of 400 feet per minute at the 'inflexion point'. Other nations have different limits.

A powered lift aircraft can 'schedule' (adjust) wing and jet lift so as to maximise the payload that can be delivered from the ramp. It can also be controlled well below wing borne flying speeds. Unfortunately, conventional aircraft can't do either of these. They have to launch at a speed at which they can fly controllably on wing lift alone. Their only option (with all thrust already applied) to arrest ROC decay is to apply more pitch, which increases drag, which slows the aircraft, which.....you probably get the picture. That's why the STOBAR option, being used by the Chinese and others, is, in my view, always going to be severely limited in effective payload...."

PITCH RATE QUESTION IS ANSWERED on next page 318: http://www.pprune.org/military-aviation ... t-318.html

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Jul 2015, 07:12
by spazsinbad
NITKA had me baffled for a long time - where was it on a map? :doh: NITKA is an acronym but long story short RuskieNewbies get to JumpSKI for the first time eh - in that Ukraine - is that Russia now?
Northern Fleet Su-33’s Redeployed to Crimea for Training
13 Jul 2015 SPUTNIK

“Three Su-25UTG aircraft and three Su-33 carrier-based fighters were redeployed from the Severomorsk-3 airfield of the Northern Fleet to the Saki airfield. The training sessions will take several weeks and include 10 flying shifts.

Crews of the shipborne fighter regiment of the Russian Northern Fleet aviation began on Monday practical training at the NITKA range in Crimea, the press-office of the fleet reported.

"Three Su-25UTG military training aircraft and three Su-33 carrier-based fighters were redeployed from the Severomorsk-3 airfield of the Northern Fleet to the Saki airfield. The aircraft will be involved in training flights. In addition, 70 servicemen of the flying and technical personnel of the shipborne fighter regiment of the Northern Fleet arrived in Crimea. Among them are five young pilots who have no experience in carrier take-off and landing," the report read.

The training sessions will take several weeks and include 10 flying shifts.

After the practice is completed the pilots will return to their deployment site. They will begin preparation for flights to the Admiral Kuznetsov aircraft carrier.

The NITKA range is a special aviation training facility which imitates the deck of an aircraft carrier. It is used for practicing carrier take-off and landing.”

Source: http://sputniknews.com/military/2015071 ... 56601.html

Nazyemniy Ispitateiniy Treynirovochniy Kompleks Aviatsii
"Novofedorivka
...It is located about 3 kilometres (1.9 mi) south of the regional centre of Saky, and about 70 kilometres (43 mi) north of Sevastopol. Formerly a base of Soviet Naval Aviation as "Saky-4", it came under the Ukrainian Navy control with the breakup of the Soviet Union. It was captured by Russian forces without resistance on March 22, 2014...."
https://en.wikipedia.org/wiki/Novofedorivka

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Jul 2015, 07:17
by spazsinbad

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Jul 2015, 07:29
by Corsair1963

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Jul 2015, 07:36
by Corsair1963

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 16 Jul 2015, 00:28
by XanderCrews
geogen wrote:Would like to see a test-launch of an (USMC) A-29 off a Jump... call it a day.


No thanks, we're fine

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 23 Sep 2015, 03:00
by spazsinbad
Some SkiJUMPy pics here (a bit late) : https://www.flickr.com/photos/lockheedmartin/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 27 Sep 2015, 17:39
by spazsinbad
Salty Dogs & Funky Jets
October 2015 Mark Ayton

"...Ski Jump Trials
Her Majesty’s Ship Queen Elizabeth (R08) is fitted with a ski jump like no other: a new design tailored to be used by very expensive new aircraft. Launching a 60,000lb F-35B off a ski jump requires some serious maths, engineering and testing.

The F-35B ski jump test campaign should have started in March of this year, but was delayed due to brutal sub-zero temperatures and snow that blighted Patuxent River at the time. Aircraft BF-01 was originally assigned to conduct the ski jump events but was unable to remain at Pax while the weather improved. It was already scheduled to deploy to Edwards Air Force Base, California to conduct wet runway and crosswind testing.

The test programme comprises two phases, the first of which eventually began on June 19 when BAE Systems test pilot Peter Wilson conducted the first take-off using the ski jump at Pax with F-35B BF-04. Sqn Ldr Edgell told AIR International: “Phase 1 is a risk-reduction phase designed to highlight any significant hardware or software updates that may be required prior to commencing the bulk of testing. It comprises 29 ski-jump launches.

“Phase 1 will ensure our models and predictions are correct. If anything needs addressing we can do so in a timely fashion and then go into the 140-sortie Phase 2.”

The ski jump used on HMS Queen Elizabeth has a curved leading edge designed to simultaneously launch an F-35B upward and forward with a greater take-off weight and less end-speed than required for an unassisted horizontal launch aboard an LHD-class amphibious assault ship, such as USS Wasp (LHD 1).

The reader may be surprised to learn that the ski ramp built at Pax River is based on the type used on the Invincible-class aircraft carriers which is a little bit shorter (50ft) and slightly shallower (0.5º) than the ramp on Queen Elizabeth-class carriers. Sqn Ldr Edgell explained: “The Pax River ramp design process dates back to 2005 but, at the time, the Queen Elizabeth ramp profile was not known. Analysis conducted in 2005 showed we simply needed to use a ramp with a profile that allows us to stay just under the predicted F-35B ultimate loads and the Invincible-class ramp achieved this.”

Pax River’s ramp allows the test team to make adjustments for different profiles and encompass everything below the ultimate loads of the aircraft. “Though the verification of our models during phases 1 and 2 we can tweak the control laws to work off other types of ramp, none of which are the same,” said Sqn Ldr Edgell. When the aircraft comes off the end it is ballistic and accelerates to the fly away air speed, typically 10-20kts higher than launch speed, and therefore reduces ground roll.

“There’s a fine line between ensuring we have suitable gear loads and fly away speed,” explained Sqn Ldr Edgell.

“We want lots of margin on both of those. To achieve margin for gear loads we need to be slow, i.e. start right at the bottom of the ramp. To achieve margin on minimum fly away speed we need to start towards the back of the run-up. We blend the two aspects together and meet in the middle to gain the safest launch spot. For the very first sortie, our spotting distance will be conservative and will launch the jet off the end of the ramp straight into a previously flown flight condition.”

Such regimes have been flown several times during short take-offs at the field and STOVL departures.

Sqn Ldr Edgell explained an interesting fact about the take-off : “You can be lined up three, four, five hundred feet back from the start of the ramp and as you slam the throttle forwards, the jet doesn’t know it’s about to go up the ski jump. It waits for certain triggers to alert it to the fact it’s going off the ski jump, at which point its flight control system moves the horizontal tails and the nozzles into the optimum position. It needs to hit 45 knots going up the ramp.

“The throttle needs to be above 65% ETR, with 6 degrees of attitude and a pitch rate of 6 degrees per second. At that point it moves all of the effectors into the right place. Bear in mind the ski jump at Pax is only 150 feet long, so the aircraft hits all of those parameters with less than 100 feet remaining. By the time it goes off the edge of the ramp all the surfaces and the nozzles are at the optimum position, the aircraft rotates up to the optimum pitch attitude to fly away. It’s pretty clever stuff.”

Sqn Ldr Edgell described the launch process: “You slam the throttle and guard the stick. There is no input on the stick required. As the aircraft moves down the tramline of the deck you track the centre line with your feet, just like any other carrier deck take-off, but there’s no pitch input required. The jet flies away. It’s effortless.” In the event of any kind of malfunction, the pilot takes control and manually flies off the edge of the ramp, which is why he must guard the stick during the roll.

There is no significant part for the pilot to play in the take-off – the result of a design philosophy to minimise the pilot’s workload. A good example is tracking the centreline on a rolling pitching deck at night. That’s a challenge in a Harrier but in the F-35B it’s his only task so he should do a much better job. The administrative burden on the pilot has been significantly reduced: in this situation to an effortless level.

Phase 2 will introduce crosswinds, external stores, asymmetry, minimum performance (minimum deck) launches from the bottom of the ramp, and simulated performance degradation all to increase the aircraft’s flight envelope in Block 3F configuration. That’s imperative work for the UK which will undertake first-in-class flight trials on HMS Queen Elizabeth in the final quarter of 2018...."

Source: Air International Magazine OCTOBER 2015 Vol.89 No.4

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 06 Nov 2015, 04:34
by spazsinbad
A Message from Lorraine Martin
22 Oct 2015 LM

"...Ski Jump testing at Pax River is ongoing, and the team is really doing some amazing work. They completed nine successful takeoffs from the ski jump platform. Throughout the testing they found some challenges to overcome and work, but the team has done a great job of working through those challenges. They have to complete eight more tests to finish up phase one testing. It’s exciting to see images of the F-35B taking off from the ski jump, and I know the U.K. and Italy are also excited about this testing and the capabilities it brings to their countries...."

Source: https://www.f35.com/assets/uploads/docu ... _22_15.pdf (0.3Mb)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 11 Feb 2016, 10:00
by spazsinbad

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 11 Feb 2016, 13:12
by sferrin


(Just in case it hadn't already been posted.)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 21 May 2016, 11:38
by spazsinbad
Visiting the Pax River F-35 Integrated Task Force: Todd Miller Provides an Update
20 May 2016 Todd Miller MORE HERE: viewtopic.php?f=22&t=45494&p=338896&hilit=Miller#p338896

"...Stewart noted the advanced intelligence featured by the F-35B when performing the ski jump take off, unique to the U.K. and Italy. “The aircraft knows its weight and center of gravity, it understands all that already, sets the control surfaces — the pilot essentially points it and launches.

When the pilot starts his or her run, they haven’t even told the aircraft to that point that they are doing a ski jump launch. When the F-35B senses the ramp, it understands it is on a ski jump and needs to apply the appropriate control surfaces — and executes.

A lot of process is automated, the aircraft has a lot of understanding of its current situation and the aircraft uses that to make the task very easy.” It brings to mind “Skynet” of the Terminator movie series and the moment Skynet becomes “self-aware.” Fortunately, in this case the F-35 is self-aware while remaining safely under control of human mind and hands!..."

Source: http://www.sldinfo.com/visiting-the-pax ... an-update/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 30 Jun 2016, 13:53
by spazsinbad
'bring_it_on' posted a great F-35B Ski Jump article here yesterday:
F-35 Control Law ‘Tweaked’ To Correct Ski-Jump Takeoff Anomaly
viewtopic.php?f=22&t=23690&p=345309&hilit=Tweaked#p345309

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 06 Jul 2016, 15:47
by spazsinbad
How it Works: An F-35B Ski Jump Takeoff
02 Jul 2016 LM PR

"For more than 30 years, the UK has used the ski jump for carrier operations as an alternative to the catapults and arresting gear used aboard U.S. aircraft carriers. The shorter UK carriers feature an upward-sloped ramp at the bow of the ship. Curved at its leading edge, a ski-jump ramp simultaneously launches aircraft upward and forward, enabling takeoffs with more weight and less end-speed than required for an unassisted horizontal launch aboard U.S. aircraft carriers.

With the partnership between the Lockheed Martin and the UK's BAE Systems, the design of the F-35B has incorporated the ski jump takeoff capability from the very beginning....

...Squadron Leader Andy “GARY” Edgell, RAF, is the first UK military pilot to complete a takeoff from the ski jump with an F-35B.

“The performance of the jet has been great. As the pilot, I have to do very little to accomplish a perfect ski jump takeoff,” commented Edgell. “I push the STOVL [short take off vertical landing] button to convert to Mode 4, push throttle to mil and use the pedals for minor directional inputs to remain on centerline.”

The F-35B automatically positions the control surfaces and nozzles for takeoff, a unique capability compared with previous STOVL aircraft. Such automation frees up pilot capacity and provides an added safety enhancement. The aircraft treats the take off just like a regular short take off until it recognizes the six-degree per-second pitch rate and six-degree pitch angle about half way up the ramp. The horizontal tails and nozzle then automatically maneuver downward, and the vane box does not budge. The vane box sits directly under the lift fan and directs the airflow to allow for the proper lift off the surface.

“As the jet travels up the ski jump it automatically makes the necessary adjustments to the nozzle and control surface deflections. With the F-35 automatically adjusting for the optimum takeoff, the pilot is free to adopt more of a supervisory role, monitoring for any off-nominal behavior and ready to immediately take full control, if necessary,” said Edgell. “Virtue of the superb F-35 STOVL handling qualities, the low pilot workload during launch and recovery from an aircraft carrier enables the pilot to focus more on the operational task at hand and less on the administrative aspects of the flight.”..."

PHOTO:"The F-35 flies over HMS Queen Elizabeth on July 1, 2016, during an in-country deployment for the RIAT and Farnborough Air Shows." https://a855196877272cb14560-2a4fa819a6 ... __main.jpg


Source: https://www.f35.com/in-depth/detail/how ... mp-takeoff

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 06 Jul 2016, 16:48
by spazsinbad
Same PR story is at Navy Recognition however they have this CVF Ski Jump photo showing the start at 150 feet mark:

http://www.navyrecognition.com/index.ph ... ew&id=4165

http://www.navyrecognition.com/images/s ... mp_QEC.jpg

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 13 Jul 2016, 12:55
by Dragon029
http://www.janes.com/article/62226/farn ... ump-trials

Farnborough 2016: F-35B completes initial phase of land-based ski-jump trials
Peter Felstead, Farnborough - IHS Jane's Defence Weekly
13 July 2016

The initial phase of land-based ski-jump testing for the F-35B short take-off/vertical landing (STOVL) variant of the Lockheed Martin Joint Strikes Fighter has been successfully completed at Naval Air Station (NAS) Patuxent River in Maryland in the United States, laying a key foundation for first-of-class flight trials with the UK's future Queen Elizabeth-class (QEC) aircraft carriers.

Briefing journalists at the Farnborough International Airshow on 12 July, David Atkinson, BAE Systems' F-35/QEC integration manager, said the flight trials were "critical to validate a lot of the work that has been done through modelling and provide the certification-quality evidence that's needed to allow service pilots to operate from the ship".

(108 of 1008 words)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 09:25
by spazsinbad
I think becuz of the posting restrictions this article (only brief excerpt above) has a lot of detail but I couldna post it. :x
Farnborough 2016: F-35B completes initial phase of land-based ski-jump trials
13 Jul 2016 Peter Felstead

"The initial phase of land-based ski-jump testing for the F-35B short take-off/vertical landing (STOVL) variant of the Lockheed Martin Joint Strikes Fighter has been successfully completed at Naval Air Station (NAS) Patuxent River in Maryland in the United States, laying a key foundation for first-of-class flight trials with the UK's future Queen Elizabeth-class (QEC) aircraft carriers.

Briefing journalists at the Farnborough International Airshow on 12 July, David Atkinson, BAE Systems' F-35/QEC integration manager, said the flight trials were "critical to validate a lot of the work that has been done through modelling and provide the certification-quality evidence that's needed to allow service pilots to operate from the ship". BAE Systems is under contract via the F-35 Joint Program Office to perform the ski-jump trials work.

Following on from the first F-35B take-off from a ski-jump ramp at NAS Patuxent River, performed by aircraft BF-04 on 19 June 2015, another 30 take-offs were made over the course of the next 12 months by aircraft BF-04 and BF-01.

Describing the parameters of the ski jump tests in the same briefing, Pete 'Wizzer' Wilson, the STOVL lead test pilot for the F-35 programme at NAS Patuxent River, said, "We've done weights up to full fuel and full internal stores; forward/mid/aft centre-of-gravity positions; a range of ramp exit speeds up to 95 KCAS [knots - calibrated air speed]; line-up distances from 315 to 620 ft; and we've done mil and max power [non-afterburning and afterburning] launches: a total of 31 in all. So we have successfully executed the initial phase of the F-35 ski jump testing; this is a very significant milestone from our perspective."

Wilson explained how "an awful lot is happening in a very short amount of time, about a second's worth", when an F-35B takes off from a ski jump: a process that is effectively automated and "cognitively simple for the pilot" in comparison with taking off in a Harrier jump jet.""

Source: http://www.janes.com/article/62226/farn ... ump-trials

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 10:03
by popcorn
spazsinbad wrote:I think becuz of the posting restrictions this article (only brief excerpt above) has a lot of detail but I couldna post it. :x
Farnborough 2016: F-35B completes initial phase of land-based ski-jump trials
13 Jul 2016 Peter Felstead

"The initial phase of land-based ski-jump testing for the F-35B short take-off/vertical landing (STOVL) variant of the Lockheed Martin Joint Strikes Fighter has been successfully completed at Naval Air Station (NAS) Patuxent River in Maryland in the United States, laying a key foundation for first-of-class flight trials with the UK's future Queen Elizabeth-class (QEC) aircraft carriers.

Briefing journalists at the Farnborough International Airshow on 12 July, David Atkinson, BAE Systems' F-35/QEC integration manager, said the flight trials were "critical to validate a lot of the work that has been done through modelling and provide the certification-quality evidence that's needed to allow service pilots to operate from the ship". BAE Systems is under contract via the F-35 Joint Program Office to perform the ski-jump trials work.

Following on from the first F-35B take-off from a ski-jump ramp at NAS Patuxent River, performed by aircraft BF-04 on 19 June 2015, another 30 take-offs were made over the course of the next 12 months by aircraft BF-04 and BF-01.

Describing the parameters of the ski jump tests in the same briefing, Pete 'Wizzer' Wilson, the STOVL lead test pilot for the F-35 programme at NAS Patuxent River, said, "We've done weights up to full fuel and full internal stores; forward/mid/aft centre-of-gravity positions; a range of ramp exit speeds up to 95 KCAS [knots - calibrated air speed]; line-up distances from 315 to 620 ft; and we've done [b]mil and max power [non-afterburning and afterburning] launches[/b]: a total of 31 in all. So we have successfully executed the initial phase of the F-35 ski jump testing; this is a very significant milestone from our perspective."

Wilson explained how "an awful lot is happening in a very short amount of time, about a second's worth", when an F-35B takes off from a ski jump: a process that is effectively automated and "cognitively simple for the pilot" in comparison with taking off in a Harrier jump jet.""

Source: http://www.janes.com/article/62226/farn ... ump-trials

Do I understand this to mean that the afterburner can be engaged simultaneously with the lift fan?

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 10:05
by popcorn
Deleted.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 10:30
by spazsinbad
No. The A/B cannot be engaged in STOVL Mode 4 (vertical landing / STO mode). However an almost equivalent engine power is obtained when in Mode 4 via the fwd/rear exhausts. YES I found the text curious and then remembered querying this some time back - to do with the linear throttle which has two soft detents for full power and A/B power (which still operates in Mode 4 but obviously the A/B is not engaged). I'll have to dig this reference out again - standby to standby....

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 10:46
by popcorn
Thanks for the confirmation, that's what I understood all along. So they were testing off the ramp w/o benefit of the lift fan..

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 11:01
by Dragon029
Maybe, but I'd closer believe that it was just a misreport; there's been a few typos and incorrect statements from Janes, AvWeek, etc these past couple of weeks.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 11:04
by spazsinbad
'popcorn' said: "...So they were testing off the ramp w/o benefit of the lift fan." NYET no one is EVA going OFF that ski jump in a conventional take off mode. The F-35B goes OFF in STOVL mode. Found reference....

Another good ski jumpy post: viewtopic.php?f=22&t=20138&p=303826&hilit=Salty+Dogs+Funky+Jets#p303826
Jumping Jack Flash
July 2014 unknown author AIR International F-35 Special Edition

"...The pilot also has command of the throttle. Two power setting options are available for take-off: Mil STO and Max STO [have not read about this before], as Maj Rusnok explained: “When you taxi to the tram line you stay in mode one, the conventional flight mode. You convert the aircraft into mode four, the STOVL flight mode, and it takes about 15 seconds or so for the doors to open up and the lift fan to engage.

“Then you push the throttle about halfway up the throttle slide into a detent position at about 34% engine thrust request. It sits there and you check the engine gauges: if the readings are okay you slam the throttle to either Mil or Max position and then release the brakes simultaneously. Pushing through to max is like an afterburner detent. But it’s not an afterburner – you can’t go to afterburner in mode four...."

magazine source but much more text here below slinky: AIR International F-35 Special Edition July 2014

Source: viewtopic.php?f=57&t=24438&p=274982&hilit=Rusnok+three+ways#p274982

AND... as always - there is more but always difficult to comprehend (for me anyways)
ACTIVE STICK & THROTTLE FOR F-35
16 October 2008 Joseph Krumenacker; NAVAIR Flight Controls / JSF Vehicle Systems

"JSF Active Inceptor System (AIS)
...Throttle:
– Variable aft & forward end-stops (e.g. STOVL mode is different from CTOL mode)
– AB gate (when STOVL system is not deployed)
– Launch gate (CV only)...

GO HERE &/or download a PDF made from the .PPT referenced below: viewtopic.php?f=22&t=24054&p=275894&hilit=Krumenacker#p275894 SEARCH forum on Krumenacker for more.

PDF: download/file.php?id=19248 (1Mb)

Source: http://www.csdy.umn.edu/acgsc/mtg102/SubcommitteD/F35 AIS Krumenacker SAE 081016.ppt

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Jul 2016, 12:25
by popcorn
Dragon029 wrote:Maybe, but I'd closer believe that it was just a misreport; there's been a few typos and incorrect statements from Janes, AvWeek, etc these past couple of weeks.

Looks like you're right. Spaz has clarified.

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 09 Aug 2017, 19:43
by spazsinbad
It is obvious to me that there are 'ski jump testing excerpt' articles scattered elsewhere but this is all SKI JUMPY! :roll:
F-35B Loads Up for Ski Jump Testing
27 Jul 2017 Jeff Babione

"... At Pax River, the team is doing just that as they began another round of ski jump testing for the F-35B. For this second phase of F-35B ski jump testing, the intention is to expand acceptable wind envelopes and maximum gross weight capability, including carriage of external stores. This will provide the fleet with the capability to carry heavy store configurations in a wider range of weather conditions while operating on board the Queen Elizabeth Class Carriers, which will begin initial trials with the F-35B next year. So far, the jet has handled the heavier loads well and the plan is to progress through the rest of the testing including symmetric and asymmetric loadouts while carrying external GBU-12s, Paveway IV bombs, AIM-9X and AIM-132 missiles."

Source: https://a855196877272cb14560-2a4fa819a6 ... _27_17.pdf (0.2Mb)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Aug 2017, 20:16
by spazsinbad
Video cited by 'doge' thnx in the 'MoD Muddle' thread so here is the article that goes with it but not much new said really:

VIDEO: viewtopic.php?f=58&t=15969&p=373739&hilit=phase#p373739

https://ukdefencejournal.org.uk/f-35b-p ... -continue/ 14 Aug 2017

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Aug 2017, 15:31
by spazsinbad
Another reiteration of the ski jump story with the added bonus as noted.
UK launches externally loaded F-35B from 'ski jump' for first time
13 Aug 2017 Gareth Jennings

"...This test at Naval Air Station (NAS) Patuxent River in Maryland is part of a wider campaign to validate for the F-35B the ‘ski-jump’ launch technique that was first developed by the United Kingdom to launch its Sea Harrier jets from the decks of through-deck cruise carriers in the late 1970s. This method enables the aircraft to take off with more fuel and/or weapons, and provides an extra safety margin compared with the US Marine Corps’ (USMC) system of launching from a flat deck. This is especially true during rough seas, when the ship will be pitching up and down...."

Source: http://www.janes.com/article/73080/uk-l ... first-time

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Aug 2017, 20:18
by steve2267
spazsinbad wrote:Another reiteration of the ski jump story with the added bonus as noted.
UK launches externally loaded F-35B from 'ski jump' for first time
13 Aug 2017 Gareth Jennings

"...This test at Naval Air Station (NAS) Patuxent River in Maryland is part of a wider campaign to validate for the F-35B the ‘ski-jump’ launch technique that was first developed by the United Kingdom to launch its Sea Harrier jets from the decks of through-deck cruise carriers in the late 1970s. This method enables the aircraft to take off with more fuel and/or weapons, and provides an extra safety margin compared with the US Marine Corps’ (USMC) system of launching from a flat deck. This is especially true during rough seas, when the ship will be pitching up and down...."

Source: http://www.janes.com/article/73080/uk-l ... first-time


I'm sure this has been discussed somewhere's heresabouts... but I'm gonna ask here anyway...

Once USMC pilots have cross-deployed on HMS Queen Elizabeth II, if they come home raving about the ramp... is there any possibility that ramp's could be retrofitted to the America-class LHAs? Or has that ship sailed? (I understand that the addition of a ramp takes away space for helo ops. For all I know, it messes with forward deck parking on the starboard side as well.)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Aug 2017, 21:51
by spazsinbad
USMC Hairier Pilots have returned from CVS deployment (there is a story in one of the threads) 'raving' about the ski jump. A respected Hairier Test Pilot has raved in print about same and has tested the ski jumps on Italian Carriers and written papers about the usefulness of ski jumps - to no avail. He even pointed out that the initial ski jump slope would not prevent a helo from using the spot on that slight initial slope. This thing 'USMC Ski Jumps' has been discussed a lot over the years here with the unofficial response (whether true or not) that helo spots are key requirements for the flat decks. No one has ever cited an official USMC response to non use of ski jumps - perhaps the USN doesn't like them either. Obviously there are no USMC ski jumps on the foreseeable horizon. Given the non-requirement one could only speculate HOW a ski jump would be fitted. Build it and they will use it - don't build it and they won't. Art Nalls (still flying civilian See Hairiers today in USofA) was the USMC test pilot so searching F-35 forum on Nalls etc will be useful.

Quote below and many other quotes and bits of info about ski jumps are in PDFs scattered in this forum so they may be found by searching or following the link at the btm of this post and then look in the folders at the two web sites on offer.

An 11Mb 152 PDF will be attached from folder: https://onedrive.live.com/?id=CBCD63D63 ... D6340707E6

USEful Art Nalls recent biography details here: viewtopic.php?f=22&t=14082&p=176316&hilit=Nalls#p176316
Run & Jump!
Winter 2014 The Kneeboard; Patuxent River Naval Air Museum Association

"...The Marine Corps tested an instrumented AV-8B Harrier II on the Spanish aircraft carrier Príncipe de Asturias (R-11) in December 1988 [just recently taken to the Turkish Knackery - see recent photo below of the start of the sad journey from Ferrol]. Then-Major Art Nalls, USMC, reported a Harrier at its maximum weight could takeoff in 400 feet instead of 750 feet on a flat deck...."

Source: http://tinyurl.com/nw47v36 (PDF 1Mb)

STOVL Air Power | The Ramps, Roads, and Speedbumps to Exploiting Maneuver Air Warfare
01 Apr 1996 Major Charles R. Myers USMC

Amphibious Ships Page 7
The most significant contribution that the Navy could make to STOVL air and helicopter-borne power projection is adding a ramp (ski jump) to all Tarawa- and Wasp-class amphibious assault ships. The technology is proven and for return on investment relatively inexpensive. A ramp not only improves dramatically a STOVL aircraft's takeoff performance, it facilitates concurrent fixed- and rotary-wing operations afloat. Of all countries that operate STOVL aircraft (the United States has more STOVL aircraft and ships to employ them than anyone) the United States is the only country without a ramp-equipped STOVL assault ship. Now is the time for ramps....”

& on page 9: “...The skeptics insist that ramps will displace landing spots. Tests prove otherwise. On a 12 degree ski jump approximately 150 feet long, the slope gradually increases from zero up to 12 degrees at the bow. The first half of the ski jump has a slope no greater than that of an LHA during wet-well operations with the well-deck flooded – both Harriers and helicopters can land on it...." [Major Art Nalls, USMC, "Why Don't We Have Any Ski Jumps," U.S. Naval Institute Proceedings, November 1990, 81.]


The ramp not only bolsters a STOVL aircraft’s combat payload to its maximum and enhances fixed- and rotary-wing interoperability, it provides a margin of safety to the pilot in emergency situations. The upward vector off the bow offers the pilot extra precious seconds to handle takeoff emergencies and an expanded ejection envelope if required. The price of one saved STOVL aircraft, and potentially the pilot’s life, would probably fund several ramps on amphibious ships. The Navy and Marine Corps need ski jumps on the big-deck amphibious ships....”

Source: http://www.dtic.mil/dtic/tr/fulltext/u2/a527872.pdf (50 Kb)

Harrier Operations on a Ski Jump
May – June 1990 Major Art Nalls USMC; NAN Naval Aviation News

"...The important difference between a ski jump and a flat deck is that the heavier the aircraft, and the higher the wind over the deck, the greater the advantage of using a ski jump...."

Source: http://www.history.navy.mil/content/dam ... f/mj90.pdf (4.2Mb)

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 15 Aug 2017, 23:34
by spazsinbad
Marines experience Brit style on ‘Lusty’
08 Aug 2007 Vago Muradian

“...Another philosophical difference is that the British are open to ideas that to Americans seem goofy, but work, such as the 12-degree ramp at the bow of the ship that dramatically improves Harrier operations. Senior U.S. naval officers over the decades have vetoed the idea, saying they don’t like how it looks and that it takes up three helicopter landing spots. British and Marine officers say only one deck spot is lost to the “ski jump.”

To a man, Marine pilots want the ramps installed on their ships to improve operational flexibility & safety. “We’re all in love with the ski ramp because when you come off that ramp, you’re flying,” Bradicich said. “From our ships, if you’re fully loaded, you need 750 feet, and even then you’ve got some sink once you clear the deck. Here, you can do the same thing in 450 feet and you’re climbing.”

But the ramp is intimidating at first sight, pilots said. “I expected it to be violent, but when you take off, it’s almost a non-event,” said Maj. Grant “Postal” Pennington, a pilot with VMA-513 at Marine Corps Air Station Yuma, Ariz. “Up you go, and you’re climbing. It’s a great experience.”

Equally important is the ship that’s bolted to the ramp, pilots said. “Some of our younger guys who haven’t flown from our ships yet are in for a big surprise when they do,” Bradicich said. “This is probably the best ship you could possibly fly a Harrier from. It’s not very big, but it’s really stable, no roll, just a little pitch, not like the flat-bottom gators that roll so much. You’ve got the island moving 30 feet in each direction when you’re trying to land. That tends to get your attention.”

The combination of ski ramp, stability and dedicated crew contributed to a breakneck operational pace. The Marines proudly logged a ship record 79 takeoffs and landings in one day. “These guys are great. We’ve qualed 28 guys in three days, most with eight landings and takeoffs, so even though we said that we were going to crawl, walk, run, our pace has been tremendous, even with different procedures,” Pennington said. “We like to approach the ship at 45 degrees and hit one of the spots, but they approach from dead astern, come to a hover abeam, slide over, then drop down to the deck. It’s different, but you get the hang of it.”

Source: http://www.marinecorpstimes.com/news/20 ... in_070805/

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 24 Aug 2017, 14:58
by spazsinbad

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 26 Aug 2017, 09:38
by spazsinbad
:doh: I do not have a subscription to AvWEAK to get more than this about Ski Jump Testing - so I'm sad. :( So is AvWEAK. :roll:
UK Preps F-35 Flight Trials On New British Carrier
23 Aug 2017 Tony Osborne

"With the arrival of Britain’s new aircraft carrier, HMS Queen Elizabeth, into her home port of Portsmouth, England, on Aug. 16, the first pillar of the UK’s plan to reinstate its carrier strike capability has fallen into place. Now, attention is turning to the F-35 Joint Strike Fighter and the testing that will marry aircraft and ship. The F-35 is no stranger to naval operations; F-35Bs have cut their teeth on U.S. amphibious assault ships, while the F-35C has operated ..."

Source: http://aviationweek.com/defense/uk-prep ... sh-carrier

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 14 Sep 2017, 02:23
by spazsinbad
The F-35 Lightning Integrated Test Force
12 Sep 2017 BLOG?

"Royal Navy Commander Nathan Gray is a member of the Integrated Test Force alongside other F‑35B Lightning developmental test pilots from the RAF, USN, USMC and industry located in Naval Air Station Patuxent River, Maryland, USA.

With over 10 years of Harrier experience, Cdr Gray has conducted numerous operations from both land and sea, but only recently experienced how the F-35B performs a Ski-Jump take-off:

“With both the Sea Harrier FA2 and to a lesser extent the Harrier GR7/9/AV8B, the pilot was very much in-the-loop and had to execute near-perfect timing and control to safely execute a Ski-Jump launch. With the F-35B, the whole experience is much more controlled and predictable with the majority of the launch autonomous, allowing the pilot to focus on the mission ahead rather than being distracted by the launch.”

Each F-35 Developmental Test aircraft is able to capture a significant amount of detailed engineering information about each flight test, being equipped with flight science technologies including specially-designed landing gear to capture all necessary test data. Testing occurs daily with particular focus on aircraft configuration, weight and wind flight envelope (which is the combination of speed, altitude and angle of attack when a flying object is aerodynamically stable)....

...Group Capt Willy Hackett, Joint Strike Fighter Programme Office added:

“As the only Level 1 partner in the F-35 programme alongside the United States, we have been able to place specialists deep within US industry and flight test community. This has enabled the UK, alongside our US colleagues, to take a leading role in the planning and execution of flight trials. This will enable us to unlock the seagoing ability of this air system onboard HMS QUEEN ELIZABETH and ensure we deliver optimum capability for the UK and our allies”...."

Source: https://ukcarrierpower.tumblr.com/post/ ... test-force

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 17 Oct 2017, 21:14
by spazsinbad
F-35 jet cleared for Carrier take-off, Defence Minister tells Select Committee
17 Oct 2017 Ministry of Defence, Defence Equipment and Support, and Harriett Baldwin MP

"The UK’s cutting-edge F-35 fighter jet is now cleared for take-off from HMS Queen Elizabeth following successful trials using the ski-ramp design featured on the UK flagship, Defence Minister Harriett Baldwin announced at the House of Commons Defence Select Committee this afternoon.

Defence Minister Harriett Baldwin said:
“Successful ski-ramp trials mean the F-35 is cleared to fly from the carrier as the momentum continues for this game-changing jet. This milestone comes as our pilots and planes prepare to return from the States, ready for next year’s unforgettable flight trials from the deck of the nation’s new flagship.”

The UK currently has 12 F-35 jets out in the United States where they are being tested ahead of flight trials from the Royal Navy’s 65,000 tonne carrier, HMS Queen Elizabeth, next year. Two more aircraft are set to be delivered by the end of the year.

During today’s Select Committee session, the Defence Minister announced that the F-35 Integrated Test Force, which includes five British pilots, has now successfully completed ski ramp trials. That milestone clears the aircraft for take-off from the deck of the Carrier....

...And elsewhere, just last week, the first F-35 flight with the latest software was conducted on one of the UK’s F-35Bs at Edwards Air Force Base in California. This software upgrade, technically known as Block 3F, represents the full warfighting capability the UK F-35s will have at Initial Operating Capability in December 2018...."

Source: https://www.gov.uk/government/news/f-35 ... -committee

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 18 Oct 2017, 06:48
by noth
I know this is a long shot, but how hard would it be to fit US LHD/LHAs with a ramp that can be raised and flattened depending on flight ops of the hour? Sounds radical but with hydraulics or whatever you just raise several parts of the deck to certain angles. Reliability might be a problem but that can be worked on. It would help tons for the USMC F-35Bs. And the choppers could still have their landing slots. Doesn't have to be a 100ft long ramp like the UK like to use, could be something shorter, depending on. 21st Century tech should be able to do this!

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 18 Oct 2017, 07:10
by spazsinbad
noth wrote:I know this is a long shot, but how hard would it be to fit US LHD/LHAs with a ramp that can be raised and flattened depending on flight ops of the hour? Sounds radical but with hydraulics or whatever you just raise several parts of the deck to certain angles. Reliability might be a problem but that can be worked on. It would help tons for the USMC F-35Bs. And the choppers could still have their landing slots. Doesn't have to be a 100ft long ramp like the UK like to use, could be something shorter, depending on. 21st Century tech should be able to do this!

This idea has been discussed on this forum some years back; however if the USN/USMC are not interested in having a ski jump by now they never will. And to get perspective you are incorrect about ski jump length.
"...The QEC’s ski-jump is longer (200ft) than the Invincible class (150ft)..." http://aerosociety.com/News/Insight-Blo ... -countdown


Recent 'ski jump' post with an 11Mb PDF: viewtopic.php?f=22&t=20138&p=373888&hilit=jump+info+various#p373888

Next post following from a decade ago shows USMC Hairier Pilot interest - no movement yet - different philosophy I guess.

SKI JUMP INFO VARIOUS Sep 2015 pp152 forumED.pdf (11Mb)
download/file.php?id=25188
_________________________________________________________

Addition: viewtopic.php?f=22&t=12631&p=230276&hilit=ramp+jump#p230276
&
Olden Goldie: viewtopic.php?f=22&t=12631&p=155538&hilit=ramp+jump#p155538

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 13 Feb 2018, 14:09
by spazsinbad

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 29 Apr 2018, 00:21
by spazsinbad

Re: Patuxent River Ski Jump Video (No F-35Bs on it)

Unread postPosted: 12 Aug 2019, 17:03
by spazsinbad
More JUMPY stuff from the excellent SaveTheRN website: https://www.savetheroyalnavy.org/royal- ... a-history/ It is a longish article best read at source.
Royal Navy aircraft carrier ski jumps – a history
12 Aug 2019 SaveTheRoyalNavy

"British inventors have been responsible for many of the innovations that have made carrier aviation possible. The ‘ski jump’ was first developed in the 1970s to enable the Sea Harrier jet to launch more safely and efficiently and is a feature of the new QEC aircraft carriers, helping launch the latest generation of jets. Here we look at the history, design and purpose of the ramp....

...On 5th August the 1977 first ski-ramp trial was conducted at RAE Bedford using a test aircraft (The first Sea Harrier did not fly until 20th August 1978). Within a year, the ramp had been tried at angles between 6.5 – 20º and the tests showed that the aircraft was indeed able to get airborne with much heavier loads. The ramp also added a considerable margin of safety, even if the ship pitched down at the moment of launch, the aircraft would still have enough height above the sea. If the engine failed during launch, the pilot had about three times the amount of time to eject than if launched off a flat deck.

In simple terms, the aircraft does not fly off the ski jump, instead, forward momentum is partially converted into vertical thrust by the ramp. Together with upward thrust generated by the vectored jet nozzles, the aircraft follows a semi-ballistic trajectory for a few hundred yards until it has enough forward speed for the wings to provide all the lift. As the aircraft moves along the ramp, there is additional force applied to the landing gear but both the Sea Harrier and F-35B were designed with heavy vertical landings in mind which often put far greater stress on the undercarriage....

Lessons learned
The ski jump is a relatively cheap and simple addition to the carriers, being a straightforward steel construction with no moving parts. However it was discovered, once in service that apparently small differences in the build quality of the ramps of the three ships affected the life of the Sea Harrier undercarriage. The original design work assumed an absolutely smooth ramp but small ruts or imperfections in the surface were enough to cause cracking on some aircraft landing gear. This issue was expensively resolved and the lesson led to higher design tolerances being specified for the QEC ramps. Additionally, the F-35 has a wide tricycle gear which is more affected by small bumps, demanding more careful ramp design than for the Harrier’s tandem main gear. The centre section of the QEC deck is slightly cambered to help water runoff, further complicating the interface with the ramp....

...Detailed work on the ramp design was started but in 2007, once Lockheed Martin had done enough simulator work and had developed mature flight control models. The QEC ramp was designed by BAE Systems with input from LM, rather than the shipbuilders. It is not immediately obvious but the ramp has two very subtle curves. The entry section is a long ‘cubic’ curve that leads to a second let-down or ‘ellipse’ section where the aircraft is launched....

The next generation
Work on ski jump trials with the F-35B began in 2014 in the United States at NAS Patuxent River, initially using offline and manual simulation. Most of the work involved exploring what would happen if problems occur during take-off, such as a sudden drop in wind velocity, loss of engine power, blown tyres or nose wheel failure. A UK company, Williams Fairey Engineering Limited (WFEL) was awarded a £2M contract to construct a test ramp in the Centre Field at Pax River. The design was based on the CVS ramp profile and completed in 2009, although the first F-35B ski-jump STO was not made until June 2015.

By June 2016, 31 test launches had been made testing a variety of approach speeds and internal loads with speeds off the end of the ramp ranging from 65-95 knots. Some issues were discovered during testing but nothing serious and the results informed the minor design changes to flight control software. A second phase of trials numbering around 150 launches was begun in 2017 to understand the characteristics of the aircraft during overspeed or underspeed take-offs and carrying external weapons, including asymmetric loads. When the first jet was successfully launched from HMS Queen Elizabeth’s ski jump on 25th September 2018, years of simulations and preparation ensured it was considered a very low-risk aspect of the programme….

...The US Navy has never adopted ski ramps for its Harrier and F35-B-equipped assault ships, although the benefits of the ramp are fully appreciated and well understood by the Marine Corps aviation community. Unlike other nations, who’s STOVL aircraft are the primary armament of the ship, the Gator Navy’s main purpose is to deliver Marines ashore and the helicopters have priority. With limited flight deck space, a ramp would take up at least two helicopter spots. The USMC concept of operations also sees the fixed-wing aircraft being sent ashore at the earliest opportunity to work in close support of the troops while flying from small airstrips. There is an unspoken political concern within the USN that the addition of a ramp might see the assault ships become perceived as small aircraft carriers, undermining the case for the giant conventional carriers (CVN) that are the centrepiece of the surface fleet. For the Royal Navy, this relatively simple invention will continue to play a key part in enabling fixed-wing operations from its two aircraft carriers for many years to come."

Source: https://www.savetheroyalnavy.org/royal- ... a-history/