F-35C DT-II TESTING CVN

Production milestones, roll-outs, test flights, service introduction and other milestones.
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by spazsinbad » 12 Oct 2015, 19:12

Sammy does SloMo - Groan - Geddit?: http://news.usni.org/2015/10/12/video-s ... eisenhower 09 Oct 2015



This next one is real time motion ???????????????


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by sferrin » 12 Oct 2015, 19:48

spazsinbad wrote:The previous odd landing / arrest does not look so bad when zoomed at three quarter speed but YOUSE BE THE JUDGE!

Also a wide variation of file size/video quality F-35C downloads for free here: https://www.dvidshub.net/tags/video/f35c



Anybody know the cause? I've seen vids of Hornets doing the same thing. :?:
"There I was. . ."


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by spazsinbad » 12 Oct 2015, 20:55

Potential causes have been canvassed earlier in this thread on page four for example. viewtopic.php?f=57&t=28046&p=304700&hilit=ensure#p304700 The deck is moving whilst rolling can have an effect although perhaps only a smidge of roll in that landing. The new ARC system may cause some hiccups in various landing situations although there is the touch and go earlier with that hiccup. I repeat: arrested landings are violent. Usually they are seen from vantage points that do not highlight what we see in that video clip. IF there are similar Hornet videos online then please point to them. Otherwise I'm not going to search for them myself.

As I recall the 'entire' original video shows a waveoff then the touch and go then the arrest. This is a test event. The pilot PERHAPS is approaching at NOT optimal wind/sea/deck conditions as a test so he gets his 'eye in' for the not optimal approach and waves off (is waved off by LSO) then the touch and go - as a test - which goes well enough for the arrest to follow. However I can only guess - and it is a test event all round - with the pilots becoming deck qualified first thing.

These test pilots are finding the limits for operating the aircraft for the RECOVERY BULLETIN which will guide all concerned: aircrew - LSOs and uncle tomcobbley and all about how the aircraft can be recovered to an arrested landing in non optimal conditions (which have been ascertained during DT-1 aboard NIMITZ). Now the pilots go for the limits - perhaps we see a 'limit' approach/landing/arrest.

Meanwhile here is a problematic A4G DECK ROLLING LANDING ARREST viddy:



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by johnwill » 12 Oct 2015, 21:50

Couple of things come to mind, off-center engagement, cable dynamics, gear strut servicing, and pilot induced. The first three are not the likely cause, but there is evidence the roll may be pilot induced. Take a close look at the right, excuse me starboard, flap and aileron at the time of the roll. Seems to me they are driving the roll rather than opposing it. A close look at the test data could verify that, and i'm sure someone has already done that. Note also the horizontal tails go TE up at the same time. Here's what may be happening. At cable engagement, the pilot pulls back on the stick and inadvertently puts left roll command in at the same time. He has relatively little experience with a side stick, so he may be experiencing the same learning curve as early F-16 pilots with a side stick. Here is a link to a discussion of the F-16 case.

viewtopic.php?f=23&t=27219&start=15


Another remote possibility just occurred to me. The flight control system sensors, especially roll axis (roll angle, roll rate, etc.) may be adversely affected by the impact shock of the landing and put out false roll indications. The system may think the airplane has a right roll and input left roll command to the flap and aileron. Here again, someone has already checked that out.


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by spazsinbad » 12 Oct 2015, 22:05

Thanks 'JW' I forgot about the side stick. However these test pilots have been test arresting ashore and just plain landing navy style ashore - remember there is 'shake rattle and roll' among all the other carrier testing done ashore - so these guys would know about the side stick I'll imagine. It has been stated clearly they will find the limits for landings on the carrier. This test event could have found a limit. And yet in the grand scheme of things I do not see it as a big deal. Coming to a dead stop or even just touching down hard on a moving deck does all kinds of weird 'n wonderful things with all the variables involved with those six degrees of freedom - "it is only rock and roll but I like it". :mrgreen:

Graphic from: http://www.dtic.mil/cgi-bin/GetTRDoc?Lo ... =ADA469901 (PDF 2.5Mb)
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by spazsinbad » 12 Oct 2015, 23:01

'JW' to follow on from your post about the F-16 sidestick - perhaps these test pilots are doing 'nugget' unhinged approaches with inappropriate sidestick input on touchdown/arrest. Perhaps they factor in this bit that otherwise more experienced pilots will not fumble. Conjecture about it can never end I guess without a specific detailed explanation.


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by johnwill » 12 Oct 2015, 23:36

Spaz, of course you are right about the pilots having FCLP experience, but just human nature, he may have had the gain turned up just a bit with these early real carrier landings. Also possible the roll was intentional, certainly nothing hazardous about it. i really hope they let us know what it was, but doubt they will. Respects to all who land airplanes on boats.


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by spazsinbad » 13 Oct 2015, 00:11

'JW' I would be hazardous with that side stick. I'm going to look for info about it in my PDFs however I think perhaps the Avionics sub forum in the HMDS thread near the beginning has info about the side stick - whether it is relevant I do not recall. Here is a quote from this post: viewtopic.php?f=62&t=16223&p=263842&hilit=stick#p263842
"...On the right hand side of the cockpit is the side stick controller, which has a fair bit of movement and in the case of the F-35B STOVL variant so that the pilot can hover the aeroplane.

The throttle is on the left hand side and has a long linear throw rather than a rotary arc. This allows pilots of all physical sizes (from really small 104lb all the way up to 245lb) to fit and reach the controls, and sit comfortably in the aeroplane...."

This next quote will be somewhere in this forum however I'll only quote the stick bits.
Blue Sky OPS
26 April 2012 Mark Ayton spoke with Peter Wilson, a former Royal Navy Sea Harrier pilot and now STOVL lead test pilot at NAS Patuxent River - AIR International F-35 Lightning II

"...One very notable system on the F-35 is the side stick located on the right side of the cockpit. The mechanics of the side stick are well balanced with just the right amount of movement (about 1½ inches or 38mm) according to Peter Wilson who said: “You first notice this when using the stick to rotate and bring the nose up to establish an attitude at which the aeroplane’s going to climb away. The aeroplane feels absolutely rock solid, the handling feels precise.”

A very distinct feature of the F-35 is noise both inside the cockpit and out. “From the cockpit it’s not especially loud but it doesn’t sound like any other aeroplane that I’ve flown,” said the lead STOVL pilot.

The ride quality of the F-35 is also different, especially the precision with which the pilot can manoeuvre the aircraft using the side stick to put it exactly where he or she wants. “It’s most noticeable when you’re trying to do a tightly controlled formation task, like air refuelling. I’ve plugged into a tanker many times with a remarkably high success rate, higher than I would have had on the Harrier, and with a different technique. The pilot formates the air refuelling probe directly onto the basket of the tanker, sits behind it, and just plugs it when it’s steady and level.

Coming in to land is also precise. “Even in a cross wind it’s easy, the aeroplane points its nose into wind very nicely and reduces side slip,” said Peter Wilson.

Symbology in the helmet-mounted display allows the pilot to see the aircraft track, confirming that he or she is aligned with the runway even if the nose is not because of crosswind. The side stick is extremely precise for both flaring (the technique used to gradually reduce the descent rate) the aircraft and adjusting any drift, but even if he or she does not make any correction the aircraft will land and straighten itself up “beautifully” according to Peter Wilson. “It’s the easiest aeroplane I’ve ever landed and really does look after you. When I tell you how easy it is to land, in the back of my mind, I am thinking ‘isn’t that going to be great for the young pilot who has worked hard throughout the mission and needs to get home when he is tired’,” he added....

...The throttle commands thrust and not the rpm of the engine, so at idle the engine is providing 10% of the thrust available and when pushed forward to the mil stop it provides 100% of the available thrust or full mil power. The throttle gives a linear variation of the percentage of thrust available with its position, which makes it subtly different to use. One hundred percent thrust means just that, with no variation (which can be the case with a legacy aircraft), so the pilot knows when the engine is providing all of the power that it can...."

Source: militaryrussia.ru/forum/download/file.php?id=28256 (PDF 12.5Mb)


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by spazsinbad » 13 Oct 2015, 00:43

ACTIVE STICK & THROTTLE FOR F-35
16 Oct 2008 Joseph Krumenacker; NAVAIR Flight Controls/JSF Vehicle Systems

Source: http://www.csdy.umn.edu/acgsc/mtg102/SubcommitteD/F35 AIS Krumenacker SAE 081016.ppt (13.8Mb)

"Delivery of first fleet F-35C starts countdown to debut
(NAVY TIMES 08 JUL 13) Mark D. Faram

"...Flies Beautifully’
Tabert, a test pilot, is one of the Navy’s most experienced pilots in the JSF, with more than 130 hours of stick time to date. He was the first military pilot to fly all three F-35 variants— Air Force, Marine Corps and Navy — and was involved in the initial tests of the Navy and Marine versions at Patuxent River, Md., before reporting to VFA-101 in February. As the Navy’s most experienced F-35 pilot, it’s his job to get the squadron’s other pilots — nearly all with 3,000-plus hours flying F/A-18s off carrier decks — up to speed as instructor pilots.

“It’s not a difficult airplane to fly,” Tabert said. “The systems and the sensors are very new and state of the art.” One main difference between the Lightning II & previous Navy fighters is the placement of the control stick, used to steer the aircraft. “This is the first ‘side stick’ control [carrier-based] aircraft the Navy has,” he said. “That’s a little bit different than the center-stick Hornet we came from. They did a great job aligning it & the aircraft flies beautifully.”..."

Source: http://hrana.org/news/2013/07/navy-jsf-arriving/
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by johnwill » 13 Oct 2015, 00:48

That (38 mm) is considerably more motion than the YF-16 stick (zero) or F-16 stick (+/- 0.25 in.).


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by spazsinbad » 13 Oct 2015, 00:57

'JW' the bit in 'a' quote about side stick movement needed for the hover in the F-35B was left out/not quoted above.

Lots of mumbo jumbo about the stick/throttle and computers and wires and such like in this excellent artickle. And included is an explanation about the 'criteria' for a safe carrier landing at beginning. Rereading it again this article is highly recommended to read at source to get all the good bits. Only some parts excerpted here.... (for comp geeks).
Tailored to Trap
01 Dec 2012 Frank Colucci

"...Safe carrier approaches require the airplane be stabilized in the correct glideslope and attitude to touch down with the proper geometry [aligned for and aft with the angle deck centreline and on centreline of the angle deck] and rate of descent. Carrier pilots maintain that glideslope with visual reference to an optical landing aid on the ship, or “meatball.” They make continuous power changes while holding the aircraft at a near-constant angle of attack (alpha). According to Canin, “If we’re going to hold alpha constant, then the only way to change lift is by accelerating or decelerating the airplane. We do this with power, but because of engine lag and aircraft inertia, there’s a lot of anticipation required, and a lot of corrections and counter-corrections. Doing that well requires skill, seat-of-the-pants [flying], and a lot of practice.”

He offered, “A much better approach would be to control the coefficient of lift itself, by changing the camber of the wing.”... [the IDLC/Delta Flight Path (magic carpet) wizardry]

......IDLC is commanded by an Approach Mode Control button on the F-35 active inceptor stick. “You really could have done this with any other airplane,” acknowledged Canin, “but the implementation would have been more complicated.” He added, “It’s easier and cleaner to do this with a flight control system that’s naturally a pitch-rate-command system.”

Flying With Feeling
The triplex-redundant flight control system of the F-35 has flight control laws embedded in three identical, independent Vehicle Management Computers (VMC) made by BAE Systems in Endicott, N.Y. Corin Beck, BAE product director for fixed-wing control systems, said typical quad-redundant legacy flight control systems route all interfaces back to a central Flight Control Computer. The F-35 VMCs are separated for survivability and work as network controllers. They interface with aircraft sensors, active inceptor controls, actuators, and utilities and subsystems, and they provide a bridge to the F-35 mission system network. The distributed network replaces big, dedicated wire bundles with high-speed serial buses to save weight.

The VMC was also designed for affordability and meant to control life-cycle sustainment costs with managed obsolescence. The baseline configuration supports two Freescale PowerPC 7410 processing elements and can expand to support up to four such processors and three SAE AS5643 1394b high-speed serial buses. Based on BAE experience with F-22A, F-16, F-15 and F/A-18 flight control systems, Beck stated the expandable VMC design is more than sufficient to manage any likely growth or added functionality over the life of the F-35 program.

BAE Systems Electronic Systems in Rochester, U.K., also makes the F-35 active inceptor system including the active throttle quadrant assembly, active side-stick control assembly, and an interface control unit. The motorized inceptors transmit pilot inputs to the F-35 fly-by-wire flight control system and give the pilot tactile cues with resistance ramps, gates and stops to provide aircraft “feel” and warnings. Unlike traditional springs, stick shakers and other mechanical force-feedback mechanisms, the motorized sidestick varies feedback forces with aircraft condition.

The throttle is likewise back-driven to give the pilot situational awareness about the energy state of the airplane and the corrections being made. If or when the pilot breaks out of Approach Mode, the throttle position is synchronized to the engine thrust request (ETR). “If the throttle is physically jammed, the approach mode will still work. One of the redundancy features of the airplane is that the physical throttle linkage is no longer required,” Canin said.

Engine thrust request is the driver for IDLC surface deflection. The Moog electro-hydrostatic actuators that move the F-35 control surfaces promise survivability and maintainability advantages over more conventional hydraulic actuators. They also provide slightly greater bandwidth than hydraulic actuators for IDLC. However, Canin observes, “We could have done this with hydraulic actuators. The magic is in the control laws.”..."

Source: http://www.aviationtoday.com/av/militar ... 77964.html


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by spazsinbad » 13 Oct 2015, 01:23

IN FOCUS: Why the UK’s carriers will not be ‘airfields at sea’
11 April 2012 Peter Collins

"...LANDING SPACE
But for all its total size, the carrier’s angled deck, with four arrestor wires, only measures 786ft (240m) in length and 114ft in width between the painted side “foul lines”. From the stern “round down” to the first arrestor wire is 170ft. The arrestor wires are spaced about 40ft apart, with the number three wire being the target that any pilot will aim to catch. A typical approach speed for a mid-weight F/A-18E/F is 140kt (259km/h) indicated air speed, flown at an 8.1˚ angle of attack (AoA)...."

Source: http://www.flightglobal.com/news/articl ... ea-370186/


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by spazsinbad » 13 Oct 2015, 01:41

And the wizewoids of Art Tommassetti:
The Making of a Joint Strike Fighter Pilot Welcome to the fifth generation.
November 2013 Art Tomassetti Air & Space magazine

"...Why would anyone start training with an airplane that was only partially capable? Because we are building uderstanding, familiarity, and compatibility. Center stick pilots need to become side stick pilots.Push button and analog pilots need to become touch screen and digital pilots. Head-up-display pilots need to become helmet-mounted-display pilots. Fourth generation pilots need to become fifth generation pilots. We’re still learning what the F-35 can do, and we need people who know the airplane and can continue to drive it to its ultimate performance...."

Source: http://www.airspacemag.com/military-avi ... 70321.html


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by XanderCrews » 13 Oct 2015, 03:04

spazsinbad wrote:And the wizewoids of Art Tommassetti:
The Making of a Joint Strike Fighter Pilot Welcome to the fifth generation.
November 2013 Art Tomassetti Air & Space magazine

"...Why would anyone start training with an airplane that was only partially capable? Because we are building uderstanding, familiarity, and compatibility. Center stick pilots need to become side stick pilots.Push button and analog pilots need to become touch screen and digital pilots. Head-up-display pilots need to become helmet-mounted-display pilots. Fourth generation pilots need to become fifth generation pilots. We’re still learning what the F-35 can do, and we need people who know the airplane and can continue to drive it to its ultimate performance...."

Source: http://www.airspacemag.com/military-avi ... 70321.html


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by spazsinbad » 13 Oct 2015, 04:46

And apologies to TURBO for msmelling his surnam. :mrgreen: No wonder the Greekish Surnamed Chappie [ download/file.php?id=21863&t=1 ] was looking concerned waiting to be catadepulted (see earlier photo) - youse'll find the quote below.
Navy Winds Up F-35Cs Development Tests On USS Eisenhower
12 Oct 2015 Colin Clark

"...The pilots were using the third generation helmets, a little over a month since the first one was delivered by Rockwell Collins. The verdict from three different pilots: it improved their ability to fly and land on the carrier at night, perhaps the most difficult feat for any pilot. They also got the chance to push the plane and the carrier to their limits. The carrier was operating in crosswinds of up to 40 knots, [this seems to be a mangled quote by either hearer or sayer - the limit for any crosswind is 20knots with an intention for 25knot limit eventually after testing and this is ashore on runways. What is meant to be said most likely is that the ship was generating WOD of forty knots with a crosswind component that was within limits (that we do not know yet)] and the planes were taking off with nearly full fuel loads of 50,000 pounds [we have to bear with retorter that he means the combined fuel/sim. weapon load was that] at the lowest speeds possible to establish the baseline for F-35C operations from here on out.

As the planes cleared the bow after being catapulted forward, they were falling up to 17 feet, testing :devil: the pilots’ abilities to control the plane, as well as pushing the planes avionics and control surfaces. Joe DellaVedova, the F-35 program spokesman, called the effort “once in a lifetime” testing. :devil:

One of the more intriguing comments on the interaction between ship and planes came from the Mighty Ike’s captain, Stephen Koehler, a former F-14 pilot who now commands one very big ship. He noted that the ship drivers use each of the four huge propellers to best position the ship as she’s underway to give pilots the best combination of wind and takeoff [CATAPULT] speeds.... [Good Oh]

...One thing that separated this from the first flights aboard the USS Nimitz was that the three-wire, the one pilots like to hit the most and for which they garner the most praise, was out of commission through the voyage. So we couldn’t report on how the F-35 pilots were besting their F-18 Super Hornet colleagues on catching the three-wire every time as happened aboard the Nimitz. However, several pilots I spoke with said they had been targeting the same area and hit the target each time...."

Source: http://breakingdefense.com/2015/10/navy ... isenhower/
Last edited by spazsinbad on 13 Oct 2015, 16:15, edited 1 time in total.


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