UK MOD in a muddle over F-35C

Program progress, politics, orders, and speculation
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Unread post26 May 2012, 02:54

This excerpt is in the very long thread. It will be worthwhile to trawl through there (perhaps search for 'Ski' on the F-35 forum will be helpful). Anyway here is an excerpt from an article - I'll add some extra text by typing soonish.

Harrier Operations on a Ski Jump by Major Art Nalls, USMC 1990

http://www.history.navy.mil/nan/backiss ... 0/mj90.pdf

"In December 1988, a detachment from the Naval Air Test Center (NATC), Patuxent River, Md., conducted a flight test program matching up a Spanish aircraft carrier, Principe de Asturias, and the U.S. Marine Corps AV-8B Harrier II vertical/short takeoff and landing attack aircraft. The flight test results were nothing short of amazing. Takeoff performance of the AV-8 was dramatically improved, as well as safety and the potential for true Harrier/helicopter interoperability. All of this was realised from a single device with no moving parts - the ski jump....

...Ski jump operations are not entirely new. Since the mid 1970s, the British have routinely employed ski jumps on their Harrier carriers, but they fly the Sea Harrier, which is a variant limited to roughly 25,000 pounds gross weight. NATC also performed a brief flight test evaluation of the YAV-8B on a land-based ski jump in the late seventies, but a land-based ski jump is limited to the ambient winds (low wind over deck) and the YAV-8B was basically an AV-8A with an AV-8B wing and was still limited to 23,000 pounds gross weight. These operations were far too limited in maximum gross weight and wind over the deck, which are where the real advantages of the ski jump become apparent.

For years, it was thought that the performance improvements in the AV-8B were so substantial over the AV-8A that a ski jump was unnecessary. It's true that the AV-8B clearly out performs the -A, but the aerodynamic improvements that make the AV-8B superior also make it ideally suited for ski jump operations: excellent slow-speed handling qualities, rapid acceleration, and improved vertical/short takeoff and landing capability. 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.


The aircraft takeoff performance was so dramatically improved that the heaviest Harrier ever flown from any ship - 31,000 pounds gross weight - was launched from Asturias with only a 400-foot deck run. The 31,000 pounds equals the maximum gross weight capability of the AV-8B. To put this in perspective, a "typical" AV-8B with a close air support ordnance load of full fuel, full water, guns, and 12 MK-82 bombs would weigh only about 29,000 pounds. On a typical 59-degree Fahrenheit day, with 35-knot winds over the deck, this load could be launched from a 300-foot deck run with a 12-degree ski jump. The same ordnance load would require the entire 750-foot flight deck of an LHA...."

I guess the whole article should be typed out for better future reference, however all of it I think is on the very long thread. I'll check.
______________

And in case anyone thinks that Art Nalls is some kind of numbnuts here is his bio:

Sea Harrier Set To Fly On | 16 March 2007

http://myweb.tiscali.co.uk/hawkerassoci ... flyon.html

‘...[Newsletter] Editor's Note. In answer to some questions raised by the above, Art [Nalls] sent the following.....’

“I was a military test pilot at Pax River, having graduated from the USAF Test Pilot (TP) School with Class 85A. At that time the new AV-8B was being introduced and there was no shortage of work. In fact, I had been offered a TP job Edwards AFB while a student there but Marine Colonel Harry Blot, my former CO, told me in no uncertain terms that if I accepted a job testing for the Air Force I was to stay there and never come back to the Marines; I had been sent to Edwards to become a qualified TP so had better get back to work for the Marines!

I was the project officer for the ski-jump testing aboard ship. The first ship was the Italian Navy Garibaldi, with a 6 deg ramp, designed specifically for Harriers. The ship must have been designed by someone who had never actually been aboard a fighting ship - centre deck elevators, centre hangar bay with passages round the outside, fuel lines running round the ship perimeter, no deck-edge scuppers and no lights - but it does look good!

Anyway, we did the tests and provided the launch bulletin for them. The second ship was the Spanish Navy Principe de Asturias with a 12 deg ramp. This had a much better configuration being based on the unbuilt US designed Sea Control Ship sponsored by Admiral Zumwalt, USN.

The ski-jump so impressed me that I authored several technical papers and was a huge advocate for the USMC to push the USN to install it in our amphibious ships (LHDs). We could then use the single flight deck as essentially two runways; the helos launching from the stern, the Harriers from the bow. There is nothing that can be loaded on a Harrier that it can't take off with from 400 ft with 15 knots wind over deck - absolutely nothing - and the flight deck is 800 ft long on the LHDs.

Doubled take off performance, increased inherent safety from the launch trajectory and no moving parts. Seemed like a no-brainer to me but the USN didn't want to jeopardise their big deck carriers. I even attempted to orchestrate a cross-deck operation with the Russian ski jump ship Tiblisi.

Towards the end of my flight testing career I conceived and got official approval to take a test team to Russia to explore the YAK-141 supersonic VSTOL fighter and to fly and report on the YAK-38 Forger. I was the first western TP to do this.”
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Unread post26 May 2012, 04:22

Here is the complete article.

Harrier Operations on a Ski Jump by Major Art Nalls, USMC, Naval Aviation News, May-June 1990

http://www.history.navy.mil/nan/backiss ... 0/mj90.pdf

In December 1988. a detachment from the Naval Air Test Center (NATC), Patuxcent River, Md., conducted a flight test program matching up a Spanish aircraft carrier, Principe de Asturias, and the U.S. Marine Corps AV-8B Harrier II vertica/short takeoff and landing attack aircraft. The flight test results were nothing short of amazing. Takeoff performance of the AV-8 was dramatically improved, as well as safety and the potential for true Harrier/helicopter interoperability. All of this was realized from a single device with no moving parts - the ski jump.

For Shipboard takeoffs, the AV-8 does not use a catapult like other conventional aircraft. The AV-8 pilot simp­ly aligns the aircraft with the short takeoff line on the flight deck. On the launch officer's signal, he slams full power and accelerates. When he reaches the bow, the pilot rotates his four engine exhaust nozzles downward. The combination of engine lift from the nozzles and wing lift al­lows the aircraft to fly. The amount of deck run is determined for each takeoff and varies primarily as a func­tion of aircraft gross weight, wind over deck, and ambient temperature. The most limiting factor in Harrier takeoff gross weight capability is the deck run available. It is currently limited in U.S. amphibious ships to 750 feet on the Tarawa-class amphibious assault ship (LHA) and approximately 800 feet on the new Wasp-class multipurpose am­phibious assault ship (LHD).

What makes this Spanish carrier so different from any U.S. ship is the additlon of an upwardly curving surface on the ship's bow, called a "ski jump." Based on an original U.S. design for sea control that was never con­structed, Asturias was built in Spain and delivered to the Spanish Navy in May 1988. ln December of that year, the United States was given the unique opportunity to perform, for the first time, a complete shipboard flight test program using instrumented AV-8Bs on an operational ski jump up to the gross weight limits of the AV-8B.

Ski jump operations are not entirely new. Since the mid-1970s, the British have routinely employed ski jumps on their Harrier carriers. but they fly the Sea Harrier, which is a variant limited to roughly 25,000 pounds gross weight. NATC also performed a brief flight test evaluation of the YAV-8B on a land-based ski jump in the late seventies, but a land-based ski jump is limited to the ambient winds (low wind over deck) and the YAV-8B was basically an AV-8A with an AV-8B wing and was still limited to 23,000 pounds gross weight. These operations were far too limited in maximum gross weight and wind over the deck, which are where the real advantages of the ski jump become apparent.

For years, it was thought that the performance improvements in the AV-­8B were so substantial over the AV-8A that a ski jump was unnecessary. It's true that the AV-8B clearly out per­forms the -A, but the aerodynamic im­provements that make the AV-8B su­perior also make it ideally suited for ski jump operations: excellent slow-speed handling qualities, rapid acceleration, and improved vertical/short takeoff and landing capability. 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.

The aircraft takeoff performance was so dramatically improved that the heaviest Harrier ever flown from any ship - 31,000 pounds gross weight - ­was launched from Asturias with only a 400-foot deck run. The 31,000 pounds equals the maximum gross weight capability of the AV-8B. To put this In perspective. a "typical" AV-8B with a close air support ordnance load of full fuel, full water, guns, and 12 MK-82 bombs would weigh only about 29,000 pounds. On a typical 59-de­gree Fahrenheit day, with 35-knot winds over the deck, this load could be launched from a 300-foot deck run with a 12-degree ski jump. The same ordnance load would require the entire 750-foot flight deck of an LHA.

Any flight deck in front of a Harrier is unusable for any other flight ops until the AV-8 is airborne. On the other hand, any flight deck behind the Harrier can still be used for concurrent heIo/MV-22 Osprey operations. If the deck run can be shortened from 750 to 300 feet, a valuable 450 feet for concurrent flight ops is acquired - an important consideration in amphibious operations. For all practical purposes, the 820-foot flight deck of an LHD could be utilized like two completely separate ships - the front 400 feet for Harrier launches and recoveries, and the back for completety separate and concurrent helo/MV-22 ops.

Another important aspect of ski jump operations is the inherent safety over a flat deck launch, after which the aircraft is only 60 feet (height of the flight deck) above the water for the accelerating transition to airborne. With a ski jump, the Harrier ALWAYS has a positive rate of climb due to the incline of the ramp. The accelerating transition begins at approximately 150 to 200 feet, vice 60 feet [ASL]. This altitude cushion is a considerable increase in safety should the pilot encounter any emergency.

This NATC flight test program served to highlight the significant performance improvements in takeoff capability and safety that could be realized by the addition of a ski jump to our existing amphibious ships for the AV-8B. In fact, every navy in the world that operates Harrier carriers uses ski jumps, except one: the United States. Rarely before has such a dramatic increase in performance been achieved from a device with no moving parts."
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Unread post26 May 2012, 06:51

French Navy develop their own new deck coating - in their own time... I wonder if it is as good as THERMION?

New DCNS carrier deck coating process validated on CVN Charles de Gaulle

http://www.navyrecognition.com/index.ph ... iew&id=458

"Recent tests have demonstrated the effectiveness of new coatings applied to the flight deck of CVN Charles de Gaulle using a process tailored by DCNS. Phase I of this programme involved the application of new coatings to the landing zone, the portion of the flight deck subject to highest stresses.

The tests, involving landings by Rafale Marine combat aircraft, demonstrated the new coating’s qualities. The advanced materials and application process help reduce nose gear loads [?] suffered by in-coming aircraft while ensuring excellent grip between tyre and deck....

...DCNS contributed to the success of phase I and to meeting all milestones. The DCNS teams assigned to the programme are now preparing for phase II which will involve the application of new coatings to CVN Charles de Gaulle’s tow-ways and parking areas when the ship is laid up for its next scheduled refit in 2013."

Get Arrested at the JUMP! :D
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Unread post26 May 2012, 10:49

I don't know if the French coating can take the heat of an Osprey or B jet... or will the CdG melt and burst into flames?LOL
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Unread post27 May 2012, 00:28

spazsinbad wrote:Here is the complete article.

Harrier Operations on a Ski Jump by Major Art Nalls, USMC, Naval Aviation News, May-June 1990

http://www.history.navy.mil/nan/backiss ... 0/mj90.pdf

...This NATC flight test program served to highlight the significant performance improvements in takeoff capability and safety that could be realized by the addition of a ski jump to our existing amphibious ships for the AV-8B. In fact, every navy in the world that operates Harrier carriers uses ski jumps, except one: the United States. Rarely before has such a dramatic increase in performance been achieved from a device with no moving parts."


Frankly, I think the USN is terrified of ski-jumps because installing them would give weight to the perception of assault-ships as real carriers, especially with the F-35B coming into service soon. Informed individuals know that there's no way an LHA or LHD can compete with a CATOBAR carrier when it comes to operational tempo and capability; but the temptation would certainly be there for stupid politicians looking for any opportunity to cut military spending. So we keep the decks flat and avoid discussing ways to improve the TACAIR contribution that these versatile ships can can make to the fleet.
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Unread post27 May 2012, 02:19

This thread is after all about the UK and their flip-flopping on the Ski Jump/Conventional Carrier F-35B/F-35C so I don't see how the USN/USMC comes into it - except to illustrate the worthwhileness of the ski jump - as exemplified in recent posts. But I know the anti USN ski jumpers spare no effort as seen in the very long thread. But it doesn't bother me because we know the result but we speak about the CVF with ski jump and any others that have or will have a ski jump on their flat decks. In other words I do not care to hear about the USN/USMC and ski jumps thanks.
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Unread post27 May 2012, 13:57

Art once landed an AV-8A sans engine power on a 7000 rwy after it flamed out during routine training flight. Not an easy thing to walk away from -- and they gave him a medal for it. He bought a late model SHAR a few years back and now travels the air show circuit is the U.S.

His second observation about performance (nothing you can't shoot from 400' with 15 kts of WOD) is more realistic, since what the book says one can do and what one does in actual practice are not always the same. At high t/o gross weights, AV-8B also has some fore/aft CG restrictions that you have to work around with different fuel and external stores loadings. Ramp doesn't help you there at all.

Biggest inhibitor to use of ramps on US ships is fact that the primary mission of those ships is to deliver expeditionary forces -- not to launch strike aircraft. Ramp reduces landing spots and complicates aircraft handling up front.
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Unread post27 May 2012, 14:05

As mentioned earlier I don't care to hear about the USN / USMC problems with ski jump ramps. This thread is about CVFs and F-35Bs on ramps - both designed to be used together but we don't know many details yet - except details about the ramp itself, as designed for the CVF. In the meantime here is another story about Art:

Flameout - Why the fire in a perfectly healthy jet engine can die. By Peter Garrison
Air & Space magazine, September 2006

http://www.airspacemag.com/flight-today ... c=y&page=3

"...Art Nalls, now retired from the Marine Corps, recalls a wintertime test of a TA-4J—a training version of the single-engine A-4 Skyhawk—at Edwards Air Force Base in California. The giant lake bed, an alternate landing site for space shuttles, is normally bone dry, but recent rains had soaked the ground and left it largely flooded.

The test card called for restarts at selected points along the edge of the restart envelope; if the engine failed to relight, Nalls would move to the “heart of the envelope,” where the engine was considered sure to start. “One of the last points was a low-altitude, slow-airspeed point that left little margin for error,” he remembers. “Only a small portion of the lake bed was available for landing, and it was soft. Quite possibly the airplane could flip over. But it was legally usable and met the criteria of our test plan, so we elected to continue. We were almost done with the project, everything had worked normally so far, and get-home-itis had started to set in.”

Already at a low altitude when the test began, Nalls found it impossible to restart the engine. Only when he was below 1,000 feet, seconds away from a landing on the muddy lake bed, did the engine finally relight. It later turned out that the cause of the trouble had been a malfunctioning ram air turbine—the backup electrical source for the engine’s igniters.

Nalls was a test pilot, and test pilots feel strong pressure to bring back the ship in one piece. Under the same circumstances, a service pilot whose jet had flamed out would long since have ejected. The likelihood of making a successful dead stick landing in a jet fighter is considered so slight that the military services have wavered on whether “flameout approaches” should be taught at all.

Though the reliability of jet engines is far better than that of the reciprocating engines that they largely replaced half a century ago, the danger of flameouts hasn’t disappeared. Flameouts are a natural consequence of the way jet engines work. They live on an island of stable operation—a dynamic balance of powerful forces—ringed by a sea of instability."
_______________________

http://www.nallsaviation.com/BIOGRAPHY.htm

"...While on a training mission attached to VMA-231, Art’s “Harrier” suffered a catastrophic engine failure near Richmond, Virginia. With little time to react, he essentially landed the Harrier engine-out at a civilian airfield. This was an extremely precise and risky landing, not normally attempted. The emergency procedures recommend an ejection. Art is the only person to have made such a landing and he was consequently awarded an Air Medal, with gold numeral one for the act. With over 900 hours in the AV-8A and over 400 shipboard landings, Art was selected as the single Marine Corps Pilot to attend the USAF Test Pilot School at Edwards, AFB, CA for Test Pilot Course, 85A. One Marine, per year, is sent to Edwards, and for 1985, it was Art...."
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Unread post27 May 2012, 17:14

Biggest inhibitor to use of ramps on US ships is fact that the primary mission of those ships is to deliver expeditionary forces -- not to launch strike aircraft. Ramp reduces landing spots and complicates aircraft handling up front.


Just outside my house right now my son and his buddies are jumping their bikes off a ramp made of wooden boards. When the big kids take a turn they just increase the angle of the ramp for a bigger jump. When the little kids take a turn they pull out some 2X4s and then it works for them.

I understand that F-35s and AV-8s are not kids bikes but the principal is a simple one. If we really need a ramp sometimes you can have one and when you don't need that much angle could be reduced sufficiently for rotary wing loading, departure and landing.
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Unread post27 May 2012, 22:21

In this 'very long thread' AFAIK the 'movable angle ski jump ramp for USMC' was discussed I believe: http://www.f-16.net/f-16_forum_viewtopic-t-12631.html Perhaps a search of this F-35 forum will find page(s). AsIrecall the extra top weight of the mechanism to raise/lower the ski jump ramp would 'outweigh' the benefit of such a ramp. Top weight effects on flat tops need to be minimised. Increasing the ramp angle does introduce other difficulties for the aircraft entering the ramp so there is an ideal. The Brits and Italians and the Spanish have worked out their ideal angle for F-35B use. Here are some aspects about what that might mean with the 'very long thread' having a lot more info. I might put the 'CVF Ski Jump Ramp Optimisation' PDF on SkyDrive as it seems to be no longer available at the original website. Anyhoo...

Using Simulation to Optimize Ski Jump Ramp Profiles for STOVL Aircraft Dec 01, 1999
Greg Imhof and Bill Schork | Naval Air Warfare Center/Aircraft Division | Air Vehicle Department | Patuxent River, MD | Abstract for AIAA Modeling and Simulation Technologies Conference 14-17 August 2000 Denver, Colorado

http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA378145

Introduction
“Ramps have been used for many years aboard the Navy ships of many countries to reduce takeoff run distance and wind-over-deck (WOD) require-ments, as well as to increase the aircraft takeoff gross weight capability over that of a flat deck carrier. Under the Joint Strike Fighter program, an effort has been funded to evaluate various ramp profiles & ramp performance optimization methodologies. Results of these evaluations will be used with an advanced STOVL aircraft to provide the maximum benefit to takeoff performance, while not becoming a design driver for landing gear or adversely affecting ship designs.

The Boeing AV-8B Harrier is a true STOVL aircraft, in that it routinely performs short takeoffs and vertical landings. This allows operations from ships not equipped with catapults or arresting gear and that are considerably smaller than the US large deck carriers. This unique capability is obtained through a group of variable angle nozzles for vectored lift and a reaction control system for stability and control, which uses engine bleed air to provide thrust through several small nozzles located on the aircraft.

Many foreign navies operate Harriers from ships equipped with smooth profile ramps. The US Navy has conducted many ship and shore-based tests of smooth and segmented (flat plate) ramp profiles over the years to demonstrate the performance advantages of a ramp-assisted takeoff. Much of this work serves as the basis for our research initiative.

Preliminary Work
The first step was to collect data from prior flight tests to validate the AV-8B landing gear model. The test data were incomplete because the test aircraft did not have sufficient instrumentation to measure gear/store loads and accelerations. Therefore, criteria were developed which enabled us to compare predict-ed gear load trends and instead of actual gear and structural loads.

Preliminary Criteria for Ramp Optimization
I. The landing gear shall not compress to full closure at any point during the takeoff. Harrier flight tests have been conducted to within 1/2 inch of full closure with no adverse results.
2. Investigate a segmented ramp versus a smooth profile ramp, and how it could be used with the existing structural and operational requirements of the aircraft. If so, what is the maximum angle change between segments that can be tolerated by the aircraft and aircrew?
3. Resonance effects from segmented ramps on landing gear and wing mounted stores are unknown, and efforts should be taken to break up or reduce these loads.

Preliminary Results
Preliminary simulation runs have been completed. Test results indicate that the segmented ramp concept shows great promise and could allow ship designers options in building retractable or reconfigurable ramp designs for future STOVL capable ships. Segmented ramp takeoff performance is not diminished as compared with a smooth ramp. Initial results indicate that segmented ramp profiles can be modified to keep the gear loads well within their structural limits. Since the velocity of the aircraft remains fairly constant while it is on the ramp, an equally distributed (same length) segment pattern generates a recurring load on the landing gear at each joint. If the frequency of these inputs is close to the natural frequency of the gear, or transmitted through the aircraft structure to a wing store, a resonance condition could be excited. This will be investigated at in more detail in the coming months.

Preliminary Conclusions
The smooth and segmented ramp profiles have demonstrated significant performance gains over a field or flat deck ship takeoff. Work will continue over the next several months to expand & refine the optimization criteria and investigate various ramp profiles and quantify their benefit to aircraft performance.”
__________

And from Flight International 23 June 1979 is this news item:

http://www.flightglobal.com/pdfarchive/ ... 02348.html
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Unread post27 May 2012, 22:55

On page 38 [http://www.f-16.net/f-16_forum_viewtopic-t-15969-postdays-0-postorder-asc-start-555.html ] of this thread SWP asked: "Does that mean if the LHD hits a REALLY BIG swell just as an F-35B takes off, that it will detect the increased angle and not rotate?"

To answer in another way than earlier, it is also possible to do three types of STOs (with other possible variations of basic three perhaps itemised elsewhere - now excerpt below) whilst one of them is manual. And the Launch Officer on Brit ships (not mentioned below) says when to go, with perhaps the pilot being able to decide when to actually launch after that. So anyhoo...

Navy Sees Few Anomalies in F-35B Ship Trials Oct 31, 2011
By Amy Butler | Onboard the USS Wasp

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

"...There are three methods for takeoff: manual (pilot pulling back on the stick); using a button that actuates the nozzle at the rotation line; or auto STO, which places the aircraft at a known distance from the rotation line. In this auto setting the aircraft will actuate automatically when the pilot reaches that rotation line. Cordell says pilots were able expand the scope to experiment with the auto-STO mode...." [Remembering these are STOs with NO ski jump - so more variations to test at PaxRiver/ onboard CVF Ski Jump one day.]
__________________________________

Flying the Sea Harrier: a test pilot’s perspective By Peter Collins, Flight International 20/04/09

http://www.flightglobal.com/articles/20 ... ctive.html

“Royal Navy Cdr Nigel "Sharkey" Ward and the Royal Air Force's David Morgan gained their place in British military folklore by flying the navy's British Aerospace Sea Harrier FRS1 fighter with distinction during the 1982 Falklands War.

Flight International's UK test pilot Peter Collins offers a rare insight on flying the "SHAR", having sailed south aboard the rapidly completed aircraft carrier HMS Illustrious as the combat action drew to a close.

Freshly posted to Germany as an RAF Harrier GR3 ground-attack pilot, Collins was recalled to the UK after the war broke out and diverted to the Fleet Air Arm for a short tour flying the Sea Harrier. Type conversion was con-ducted with 899 NAS at RNAS Yeovilton in Somerset between June and July 1982.

"My first memory is of my first FRS1 familiarisation flight, including 'Ski Jump' launch," says Collins. "The FRS1 cockpit wasn't like the GR3's at all, with the engine and critical aircraft systems instrumentation on the left [rather than the right], to allow space for the Blue Fox radar display. There was no Sea Harrier T-Bird [two-seat trainer] and no simulator training; just a quick cockpit self-assessment in the last FRS1 left in the UK. And then go: taxi up to the very bottom of the ramp, gaze upwards at what looked like Mount Snowdon (the ramp was set at the maximum angle of around 18°), remember some words of wisdom from somewhere, pause, slam the throttle, depart the lip, take nozzles and fly away. Piece of cake!"

Collins then moved aboard HMS Illustrious – aka "Lusty" – with 809 NAS for the voyage to the South Atlantic. The vessel arrived in the Falkland Islands Protection Zone in late August, with its SHARs flying combat air patrol sorties to plug a gap until a new landing strip could be completed for the RAF.

Recalling one experience, Collins says: "It was a perfect day, but Lusty was heaving in a massive swell and the flight deck was pitching through 6°. I manoeuvred into my launch position while Flyco [Flying Co-ordination] had a think about it. Through my forward canopy the entire world alternated from completely bright blue to completely bright green (the sea was alive with plankton) as the ship pitched through more angles than I had ever seen before. Refusing the launch is mutiny: it has to be done by the pilot slamming the throttle as the deck starts to pitch down. Thankfully Flyco scrubbed the launch!" Illustrious returned home after two months of duty, with Collins having logged a total of 66 deck landings."

"I am immensely proud of my short time with the Fleet Air Arm," says Collins. "I wish them every continued success as a uniquely professional element of our fighting services.”
Last edited by spazsinbad on 27 May 2012, 23:32, edited 2 times in total.
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Unread post27 May 2012, 23:11

More about that increased angle and benefit of ski jumps but remember this is early days in 1976 whilst more is known today and the CVF ski jump ramp has been optimised for all required conditions for F-35B use. From Flight Global PDF archive comes the attached graphic 'Ski Jump Harrier' 20 Nov 1976:

http://www.flightglobal.com/pdfarchive/ ... 02666.html (PDF 1.5Mb)
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spazsinbad

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Unread post28 May 2012, 01:55

Remove any inferences of talk in this article about 'ski jumps' on any USN flat decks. It is submitted here to illustrate how the ski jump installations will likely be used on the 'already ski jumped other country flat decks' including CVF. This article written in 2002 is not here for the purpose of encouraging ski jumps on any USN flat decks. That is a dead horse well flogged here by now (similar to F-35Bs on Oz LHDs dead horse idea gone to the great knackery in the sky'). :D

The STOVL Joint Strike Fighter—From a Harrier Skeptic 2002 Captain A.R. Behnke USMC

http://dodreports.com/pdf/ada520417.pdf

“...Harrier Argument: Skeptics of the AV-8 “Harrier” argue that STOVL is forever a flawed concept, and proof of this is readily available when you focus your attention on the Harrier....

...Carrier STOVL Operations/Ramps: For the Marine Corps and Navy to reap the full benefits of the STOVL JSF, it must be deployed on carriers. In addition, the Navy should modify both the Tarawa and Wasp class (LHA/LHD) ships to include a ramp (ski jump). These two issues are not received well by most naval officials. Their arguments are: STOVL aircraft on the carrier will hinder the deck cycle, & modifying the LHAs and LHDs with a ramp is too costly (in ad-dition to losing one helicopter deck spot). However, it has been proven in many studies conducted by the American Institute of Aeronautics & Astronautics (AIAA) that both would greatly assist the Navy in sortie rate & deck cycle impacts.

Carrier: On a carrier the operations of STOVL recovery and respot are greatly simplified. In addition, vertical landing pads on the port side of the carrier take up less area than the landing area required for normal carrier aircraft. This facil-itates the simultaneous operations of launch, recovery, and respot. Therefore the flight deck is never fouled for any single operation, thus reducing the impact on sortie generation. For STOVL, the limiting factor of sortie generation then becomes aircraft servicing rate. Today’s CTOL carrier airwing has reached a near optimum level of mission perform-ance. That is, no increase in airwing size or availability will result in increased maximum sorties attainable....

VSTOL, on the other hand, has been shown to be limited by the servicing cycle only. Here significant increases in sortie generation capability and decreases in numbers of aircraft required to support that capability are attainable simply by increasing the number of servicing crews. It is evident from this excerpt and other studies by AAIA that the STOVL JSF on the carrier will not hinder operations. In fact, it will contribute to a better deck cycle and more sorties.

LHA/LHD & Ramps: The next step the Navy should take in support of the Marine Corps & the STOVL JSF is to modify its LHAs & LHDs with a bow ramp. By doing so, the Navy will increase the combat payload a STOVL JSF can bring to the battlefield, while improving deck cycle. With a ramp on the bow of the ship, the STOVL JSF can take off in only 400 feet, freeing the aft end of the ship for concurrent helicopter & MV-22 operations. The Harrier’s takeoff performance was dramatically enhanced; the heaviest Harrier—31,000 pounds—ever from the deck of any ship was launched from the [Spanish carrier, Principe de Asturias] with a deck run of only 400 feet. An aircraft whose weight precluded its launch from any LHA or LHD, even using the entire deck, used the ski jump to take off in approximately one-half that distance.

Conclusion: The STOVL JSF is the correct aircraft...”

Probably this article has been repeated elsewhere on this forum but submittted here again due relevance of CONOPS for CVF now.
RAN FAA A4G: http://tinyurl.com/ctfwb3t http://tinyurl.com/ccmlenr http://www.youtube.com/user/bengello/videos
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Unread post28 May 2012, 05:52

AGAIN this is in no way a plea for Ski Jumps on USN/USMC flat decks. Just passing along USMC Harrier pilot impressions of their first use of an onboard ski jump and the rest...

Marines experience Brit style on ‘Lusty’ By Vago Muradian Aug 8, 2007

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

“...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.”
RAN FAA A4G: http://tinyurl.com/ctfwb3t http://tinyurl.com/ccmlenr http://www.youtube.com/user/bengello/videos
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Unread post28 May 2012, 06:50

Harriers operate better with Ski-Jumps, but the gators are not aircraft carriers and not about the Harriers, they are about the helicopters/Tilt-Rotors and the Battalion-sized detachment of Marines they carry. As far as the Corps is concerned, how long it takes the Harrier detachment to take off is secondary to the ability of the V-22s and CH-53s to load Marines and equipment. With ships like the Invincible, PdeA, and Garibaldi, launching harriers is their primary mission. The Ski-Jump makes sense.
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