Posted on 09/14/2009 10:58:20 AM PDT by Yo-Yo
A Pratt & Whitney F135 engine for the F-35 Joint Strike Fighter has been damaged during qualification ground-testing. The news comes as the Pentagon scrutinizes the F135’s costs and Congress prepares to decide the future of the General Electric/Rolls-Royce F136 alternate engine.
The conventional takeoff and landing F135 was 2,455 cycles into a 2,600-cycle durability test leading to initial service release when “sparks were noticed coming out of the jet pipe,” says a P&W program expert. The engine was still running and capable of producing thrust when it was shut down.
Inspection revealed tip damage to a “handful” of blades on the first and section fan stages, which are integrally bladed rotors (IBR). Downstream damage was confined to the compressor. There was no visible damage to the combustor and turbine.
Pratt is working to identify the root cause, which could be foreign object damage - something coming from outside the engine - or “domestic object damage” - something failing inside the engine, perhaps due to a manufacturing defect or durability issue.
The F135 was 5 hours into an 11-hour supersonic high-cycle fatigue test and was “being pushed very hard” through a sequence of throttle transients designed to excite blade vibration. For this test, the inlet-plenum hardware on the test stand had recently been changed to run at supersonic conditions.
Pratt says inspection of the inlet hardware is underway, but no missing pieces such as bolts or seals have yet been found. The engine is being torn down. “There is something at the bottom of the engine [between the fan and compressor] that we want to retrieve,” says the program expert.
On the impact to the F-35 program, the expert says the Joint Program Office is estimating it will take Pratt five days to identify the root cause and the corrective action. If it is a durability issue, the expert says there is plenty of time to design and retrofit a fix as the test engine had accumulated the equivalent of 8 years in service when the damage occured.
Pratt also says there should be no impact on F-35 flight testing, as the engine that failed has the “second-generation” IBR fan, which is lighter. The flight-test engines have the first-generation fan, which has already undergone durability testing, the company says. There is no halt to flight testing or engine ground testing, Pratt says.
Two other second-generation engines are on ground test and are being examined. The damaged engine should be repairable to retstart and complete qualification testing, the expert says. The fan will have to be replaced, but damage to the compressor blades is blendable and the rest of the turbomachinery looks undamaged.
Waste of money. We have a muslim running the country and the country os broke. We do not need advanced jet fighters. Take F-4’s out of mothballs.
At least they are not stinking General Electric engine.
What about those stinking Pratt & Whitney TF30s?
Also, the stinking General Electric F110 seems to be a big hit in the F-15 and F-16 new sales department. Saudi Arabia is swapping out their F100s for F110s because of premature failure of the F100s in their hot and sandy climate.
If all it was was the blade tips on the first and second set then it was either FOD or impurities in the original stock of one of the blades.
Usually when they do these tests the engine components are triple checked to avoid this kind of failure. My guess would be FOD.
The Russians and Chinese thank you for your short-sightedness and defeatism.
Pratt & Whitney are lesser stooges than stinking general Electric aka MSNBC, NBC, Universal. GE hates America. I will never buy anything from GE.
I know doctors who tried to buy GE MRIs and they said GE are gangsters. Totally corrupt company.
The Russians and Chinese are less of a threat than Hussein, ACORN and their goons.
Don’t know squat about jet engines. But...surely they would do a FOD sweep before a test? Seems if this was done on a test stand at a range the environment would be controlled for FOD.
Maybe in the short term. You also assume that addressing these threats is an either/or.
Post of the day.
Pratt Alum on this end. I won't call them gansters, but they don't play fair. Welch's finance arm made Pratt non-competitive until the mask came off that beast and the stock fell through the floor after he left.
Great Engineers at Pratt, so focused on excellence it is scary.
But watch, pay back is a Bitch.
Mark my words Pratt is going to eat their lunch with the Geared Turbofan..... See below...
Ummmmmmm....errrr.....where is my 1/2 inch open end??????
At this stage of testing if they didn’t see a tip rub I’d be hard pressed to say it was internal as well. FOD is a strong possibility.
having served as a plane captain in the navy, this is without a doubt FOD.....wonder what it sucked in?????
Birds on the ground?
The guy on the windmill dropped it to ya, didn’t you see it?
It might have been FOD, or it could have been another blade failure.
Good news. I hate stinking General Electric aka MSNBC aka NBC akak CNBC aka Universal Studios. I will not buy any GE products. Lowes uses GE credit cards. AVOID.
I had a friend who worked for United Technologies on a defanse line. The factory workers are all stinking union goons. The friend tried to be very discreet but they found out he was not a Dem. He was driven out a month later.
GE can go to h*ll. GE are freaking gangsters. I once called them about a building they had for sale. I called CT HQ and they were nasty idiots. I could care less about that but they are Obama’s propagandists because Obama bailed out GE Finance loan portfolio filled with crap.
Their MRI medical division is filled with arrogant gangsters.
That was a 7/16 .........I think......LOL
Likely a missing wrench from the GE commercial.
That which was spent on your education certainly was.
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