F-35 Lightning II (2) testing and production thread

From my understanding P&W have fixed the design problem. However the engine in question was built before the fix as it was part of the initial batch of test engines delivered for the program.

The redesigned engines won't be available until later this year. P&W and Lockheed decided not to hold up flight tests waiting for the redesigned engines. They decided to test the half dozen engines already built with the original design at and above operating conditions which will be experienced during flight testing. The engines that pass are delivered as flight ready so testing of the airframes can proceed with them at least until the new engine batche arrives, the ones that don't pass are discarded, for the time being. Personally I don't really foresee any lengthy delay in the test flight schedule.

reply to post by WestPoint23


Other then the fact that they are now down one more engine and at the moment we are unaware as to where the other 4 engines are at as 2 now have failed in testing. Your right its a issue that we knew of its just going to put more stress on the testing of AA-1 and BF-1 with less powerplants and no new ones till next year if I understand correctly.

aye these 2 engines were all build before the redesign - but what is interesting is that according to another forum - this is a different part of the engine to fail than back in august.

It's a unique vibration that causes high cycle fatigue. It appears to be in the third turbine stage in the STOVL engine. It's delaying the first flight of the aircraft until they figure out what's going on. Ground testing is delayed at least a month possibly more while they proof test another engine.

reply to post by Zaphod58


So then it that case they are only testing one engine at a time then? Also any idea how long the testing takes to clear a engine for use? Any sources on how long the delay will be Zaph? What your saying sounds reasonable but if you have a linky that would be great

I've found a couple of sources as to what they were testing for, both stating that they're facing a PROBABLE delay of 1 month at minimum in ground testing, which will delay the first flight, but nothing confirmed yet.

From what I've found so far it appears to be unsteady flow in the wake up the stator upstream of the LP turbine third stage. It looks like they chose to simply proof test the engines that were in stock instead of delaying the program even more and waiting for the new engines to be ready. From what I've heard to date they have solved this problem with the new engines, and it appears to be primarily with the STOVL engine.

Sorry, I can't give out my sources.

Originally posted by Zaphod58
Sorry, I can't give out my sources.

Fine sheesh I guess I understand.

Well more information has come out from a report on Flight Global and it says that P&W have tested a number of other of the 6 engines and 2 of the conventional use engines that are used on the F-35A/C. The two that passed where engines 1-3 and they have been cleared for use in flight testing.

"FTE 6 was next in line. A single LP turbine blade responded to the vibration and broke," says Bill Gostic, F135 programme vice-president. "That was the intent [of the proof test]. We fully expected to find blades that cracked, but believed we could identify them before they broke. That was the surprise."

To replace the damaged STOVL engine, P&W planned to begin proof testing FTE 2 on 8 February, but the incident will delay the start of propulsion system testing on BF-1 at Lockheed. "The extent of any delay is still to be decided," says Gostic.

At the current rate P&W have rolled out a engine a month for the flight test program. So Zaph is right in that the delay wont be to significant and 30 days isn't too substantial in the long run at the time being.

P&W thinks the problem is restricted to STOVL F135s, because the LP turbine works harder when powering the shaft-driven lift fan. Although the F135 is derived from the F119 engine powering the Lockheed F-22, the third LP turbine stage was added to power the lift fan.

P&W is redesigning the third-stage LP turbine vane, but plans to proof test all ground- and flight-test F135s. Gostic expects the improved design to be implemented beginning with the second low-rate initial production batch of STOVL engines.

www.flightglobal.com...

In return for not giving up sources, here's a peace offering for you.

www.youtube.com...

reply to post by Zaphod58

The engineer in the bottom corner is awesome. You can totally tell he/she is like "awe yeeeah". Makes up for it extremely well Zaph I hadn't seen that yet.

[edit on 8-2-2008 by Canada_EH]

I thought you'd like that one. What I found interesting was the counter-rotating sections of the engine as it rotated 90 degrees.

Yeah, you could tell they were pretty happy with this test, that's a good sign for the engine rotation system at least.

I wonder if the RR F-136 is having any similar problems?

To the best of my knowledge I haven't seen any news on the F-136 running into problem other then funding. Makes you wonder considering the amount of issues that the program has had with the F-135 that they would still want to cut it. Boils down to politics and money as usual.

Well before we continue on the debate of the powerplants I figured it was about time for time out and some images since I such a visual person and most os us here can appreciate a neat looking aircraft.

The F-35B is turning into a neat plane thats for sure as these images attest too and for all the issues and costs you have to step back and just take it in (admit to doing the same with the Su-30M project). I hope things get settled a bit more and the cost is turning into a major issue for countries like Canada and Aus (no documents just gut feeling).

Anyways here is the beaut.





Got to say that new fan cover/cowling is still pretty neat looking. Neat to see the ladder placement and minus covering and its shape. I must say as well that even with Waynos valid concern on the shape of the vert stabilizers they do in a simplistic way work with the overall feel of the plane.

Some interesting insight into the Washington snake pit. My question is who is biting who and why can't they just focus on a well balanced force and what that would be and not who makes the most at least some of the time. I know I know when will that happen. Seems to me like anything that touches this part of government is more or less given the kiss of death. Anyways here it is.

England "lost a succession struggle" at Lockheed, Thompson wrote, and "now wants to kill his creation". England's "creation" apparently means the F-22, which he is indeed trying to kill to secure the future of the F-35 Joint Strike Fighter.

I know what you're asking: Both aircraft of course are built by Lockheed, so why would England's industry past alone presuppose him to favor one or the other? Could Thompson's mercurial hint about a past "succession struggle" at Lockheed have played a part in England's current Raptor antipathy?

One of the jobs up for grabs in the spring of May 8, 1995 was president of the restructured Lockheed Martin's Fort Worth-based aeronautics division. The position was left vacant after the previous occupant, Kenneth Cannestra, decided to "retire" early in the wake of a bribery scandal in Egypt. The article says:

There was a struggle for Cannestra's powerful Lockheed Martin position, and the winner was James A. 'Mickey' Blackwell Jr., formerly head of Lockheed's Georgia-based military aircraft division. Blackwell's elevation prompted England, one of the other competitors for the job, to leave, company officials said.

www.flightglobal.com...

I give a quick reminder that this information though political in nature is directly tied to the F-35 program and its development and production. So any comments on said information should pertain to mentioned projects.


[edit on 11-2-2008 by Canada_EH]

www.star-telegram.com...


given all thats going on with the developement of this aircraft


firing 650 of the engineers isn`t really the smartest thing to do

Well more news as the F-35B BF-1 has cleared vibration testing and has been moved from the fuel bay. Sounds like one more step forward. They estimate that the first transition flight will take place in Dec or Jan 09. Also a bit of insight into the current state of the AA-1.

Lockheed’s first conventional take-off and landing F-35A has meanwhile now completed 32 test flights, with recent work having focused on expanding AA-1’s flight envelope following its return to flight late last year. “The aircraft continues to retire risk, and is setting unprecedented marks for reliability,” says Standridge. Lockheed expects to commence inflight refuelling trials with the aircraft in the near future, he adds.

The first F-35s could be available for foreign military sales customers in 2014 and they all have been briefed on its classified material and all 6 partners are said to have no issues with the program.

www.flightglobal.com...

F35B to only fly CTOL till years end at least

www.flightglobal.com...

Flight testing of Lockheed Martin's short take-off and vertical landing F-35B will be confined to conventional up-and-away flying until Pratt & Whitney can fully clear its F135 engine for STOVL operation. Aircraft BF-1 is planned to fly in June, but will not begin STOVL flight testing until the end of the year.

Following a turbine blade failure in the F135 planned for BF-1, P&W is proof-testing a replacement flight-test engine, but it will not be cleared to full STOVL thrust, where the vibration occurs that causes the blade to crack. "We believe the problem is a vibration in powered lift mode at very high power," says Bill Gostic, vice-president F135 programme

with a heavy weapons load bring back for a vtol landing , which has been done many times - high engine power is very much used , so this could be very problematic to say the least.


when is GE going to fly the F136?

I heared 1361kg weight has been reduced from F-35B version compare to original plan.

I heared 1361kg weight has been reduced from F-35B version compare to original plan. Are there any more informations substantiated?

[edit on 29-2-2008 by emile]

F-35B first airframe BF-1 has completed fuel leak and system checks.

The important fuel checks of the design and build of the aircraft was led by BAE Systems and involved constant testing, 24 hours a day for 13 days, which checked the calibration of the aircraft’s fuel gauging systems. Testing took place at Lockheed Martin’s Fort Worth plant in Texas where the first STOVL aircraft, BF-1, is currently undergoing a series of tests in preparation of first flight later this year.

Following the fuel testing the aircraft is undergoing structural coupling and ground vibration testing, as well as completing hydraulic testing of the doors and landing gear.

www.baesystems.com...

Nice that they finished early and if they can keep up the small gains in getting back time we may see less of a delay to the test flight schedule. Hope fully we could see some similar video on the testing of the gear etc at some point like we did for the engine transition check to the vertical position.