Forum: F-35 Lightning II

F-35 Back in the Air
Posted by Graham Warwick2@avaitionweek at 10/5/2010 7:31 PM CDT

The suspension of flights of the Joint Strike Fighter was lifted today (Oct. 5), with F-35A CTOL test aircraft AF-1 taking off from Edwards AFB, Calif. this afternoon.

Lifting of last week's suspension comes after loading of a software modification to overcome a fuel boost-pump sequencing issue uncovered in the laboratory.

Lockheed Martin says the two F-35As at Edwards were cleared to return to flight today, with the four STOVL F-35Bs at NAS Patuxent River, Md. expected to resume up-and-away flying later this week*.

The F-35Bs will continue to be restricted to conventional-mode flying until a solution is implemented for the auxiliary inlet-door hinge problem that led to suspension of STOVL-mode flight tests.

*NOTE: I originally, mistakenly, wrote STOVL-mode flying would resume later "this year" - not incorrect, but overly pessimistic!

http://www.aviationweek.com/aw/blogs/de ... d=blogDest

Smile

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Mostly good news, with no mishaps out of any discoveries made.

Now fix them darn hinges and get the program back on track, eh? Thumb

Another article on this same subject:
http://www.flightglobal.com/articles/20 ... rsist.html

This one includes some statistics on flights completed to date. As of October 5, the nine flight test aircraft had reportedly completed 270 flights, surpassing their overall target for this point in the year by some 25 flights. Of these flight tests, 115 had been completed by the F-35A aircraft, compared to a total of 54 planned up to that date. The F-35B aircraft, meanwhile, had completed 141 flights, 40 fewer than scheduled.

Not surprisingly, perhaps, the most complex of the three variants continues to lag relative to the other two. That's part of development. Unfortunately, it gives the critics of the program (most of whom have never been around an aircraft development effort) something to crow about.

I'm glad problems like these were found on the ground instead of in the air. This program has been pretty safe in terms of men and machines when compared to other US fighter programs. Critics seem to forget that.

From: http://www.flightglobal.com/articles/20 ... rsist.html

"At least two more flight-test aircraft - BF-5 and AF-4 - are due to complete first flight before the end of the year." They'll help.

discofishing wrote:

I'm glad problems like these were found on the ground instead of in the air. This program has been pretty safe in terms of men and machines when compared to other US fighter programs. Critics seem to forget that.

F-35s resume flight operations, but problems persist

By Stephen Trimble@flightglobal

.....The F-35B STOVL fleet has been cleared to resume conventional flights, and Lockheed officials expect the type to resume tests shortly.
Lockheed has also discovered the root cause of a problem with a hinge on an auxiliary air inlet door immediately aft of the F-35B's lift fan. The company describes the cause as a "durability issue involving a bearing-retention feature in the door's forward hinge".
A solution is being installed "immediately", Lockheed says, but STOVL flights are ruled out until the modification clears airworthiness certification.
Although the grounding was brief, the combination of the two issues increases pressure on the flight-test schedule Sad

.....
The programme now has less than 90 days to complete 124 flight tests to remain on track by the end of the year. Lockheed also has other commitments to meet. At least two more flight-test aircraft - BF-5 and AF-4 - are due to complete first flight before the end of the year.

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

Has anyone posted a date for retro-fitted BF-2 to start instrumented STOVL flights. Question

Quoting tmofarrvl, "Unfortunately, it gives the critics of the program (most of whom have never been around an aircraft development effort) something to crow about." You're absolutely correct. If everything was perfect the first time, there would be no need to test. To quote Albert Einstein, “If we knew what it was we were doing, it would not be called research, would it?” This is why we test to discover problems before fielding the unit. We live in the "microwave age" where we want instant gratification. Life isn't that way nor is fielding a new, highly complex aircraft. In due time, people will be singing the praises of the F-35 and all would be forgotten.

Anyone know the status of the fix for the hinge problem?