via WSJ
The Pentagon temporarily grounded the entire F-35 Joint Strike Fighter fleet at the start of the weekend after one of the advanced jets suffered an engine oil leak and declared an in-flight emergency.And then this...
While the suspension of flight and ground testing on Friday was described by F-35 program officials as a precautionary move, it is the second time in 16 months that engine problems have grounded the entire fleet. It comes just two weeks before the plane is due to make its first international appearance.
Engine maker Pratt Whitney, a unit of United Technologies Corp. UTX -0.05% , said most of the 104-jet fleet had been cleared to resume flying by late Saturday following the safety inspections mandated by the F-35 managers on Friday. The F-35 program office said these revealed potential problems on two more jets.There are more than a few burning questions that need to be answered.
What was the tick tock of events leading to the pilot declaring a in-flight emergency? Are these recurring engine problems due to weight saving measures? Why is Pratt Whitney and the Program office not on the same page? The office is saying there are potential problems with two more jets while PW is touting the clearance of the "majority". Are we seeing some type of systemic design or maintenance problem?
Engine oil leakage can lead to some serious engine failure. Check the QF 32 out, the A 380 that experience a turbine explosion in the air, which is caused by "engine oil leak".
ReplyDeleteand it is too early to say it's a design fault, as it can be poor workmanship/ residue stress/material etc
hay Sol,
ReplyDeletewow, they found a problem during "flight and ground testing". isn't that, the whole point of testing, such a complex system of systems??
this kind a failing has gotta be way better than some of the early failings on other fighters, namely the f-14, the first, test aircraft, crashing, on it's maiden flight!!!!.
teething troubles are to be expected, noted, analysed & resolved, by the designers of the aircraft.
Thats sometimes the problem with the internet, passing judgement on an ugly duckling, dissecting every wrinkle, before it matures into a swan.
Solomon believes this aircraft to be utterly irredeemable, we agree on this point, unfortunately he chooses to express this belief by pounding his fists and fear mongering about every inconsequential little problem that arises during its transformation from ugly duckling too one seriously lame ass swan.
Deletedarren1678. its been in testing for 10 years. 10 years. the tech...especially the engine tech should be stable and performing well now. it isn't. there obviously is some type of systemic problem somewhere.
DeleteSamuel Suggs. i don't need you to speak for me with regards to my beliefs. additionally you've never seen me pound my fists. fear mongering? no, i don't do that. raise reasonable doubts? you bet ya.
Its interesting the F14 Tomcat was brought up. I did a little research and the F14 was developed after the USN received permission to withdraw from the TFX program after design compromises to Navy missions. The TFX program was a joint fighter concept between US Airforce and Navy. After five years development between 1969 and 74 the F14 entered service and performed missions in Vietnam.
DeleteSo yeah, an oil leak on its own maybe common when developing war planes however in context it continues to highlight the problems with the JSF program. Given the problems of past joint projects they should have had a lower risk tolerance to cancel the project before excessive cost escalation and design compromises. Rand has a report that describes how the program has surpassed the cost to develop three separate variants in contrast to the JSF goal of reducing costs. Oil leaks after 10 years of testing and five more years before entering combat does not describe a successful program when the F14 was fully combat ready in five years.
http://militaryhistory.about.com/od/militaryaircraft/p/f14.htm
http://www.rand.org/pubs/periodicals/rand-review/issues/2014/spring/aircraft.html
It's all about performance, man. The flight test progress is side dishes~
ReplyDeleteEven the program ran smoothly, it will deliver nothing good to the AF in terms of range/payload/maneuver (except stealth, which will be not that stealth in 2020 due to advancing radar technology)
The timing is interesting. The in-flight emergency on the aircraft occurred on Tuesday and the flight suspension was called on Friday. My take is that, because there was a high-level F-35 steering committee going on the middle of last week, the flight suspension call was delayed thus endangering other aircraft and crew.
ReplyDeleteThe overall scenario also should be noted. Because the F-35 development program has stretched into an eighteen-year (at minimum) program, 2001-2019, and because the program features concurrency, which is the low rate manufacture of faulty prototypes during development way beyond what they need for testing, like what the Marines have at Yuma, there are a lot of untested faulty prototypes flying around which the fan-boys like to brag about until, not being fully tested, they fail. That's dangerous.
Two reasons: one, it took a few day to evaluate the failure. Was it simply a mx issue, or was it more of a systemic issue; two, it's better to release bad news on a Friday.
DeleteIt seems that the issue was determined not to be a mx failure, so the grounding and inspection mitigation order was issued. It looks to be a QA or QC problem, since two other aircraft *may* have the same conditions that lead to the failure. So, it's probably not a design issue, and the fleet has been returned to operation status.
Sorry, I don't get it. A failure is a failure. Wrong or inattentive mechanics' work can also be systemic, can't it? Not knowing should lead to not acting. Do you have an SOP on waiting and hoping it doesn't occur on a second aircraft in the meantime?
DeleteNope, I like my theory. There was a high-level F-35 "steering committee" meeting going on, including foreign partners, to discuss F-35 cost and poor sales, and a grounding announcement during the meeting could have been "fatal."
And I will remind that they found two more planes with similar problems, on Saturday. So better late than never, but earlier is better than later when it comes to heavier-than-air objects.
DeletePS: Add a not in my above comment. --Not knowing should NOT lead to not acting. Nothing like a triple negative for clarity.
It looks like incident aircraft, as well as all the aircraft identified with the potential issue are F-35Bs based at Yuma, which suggests a procedural issue of some. Other F-35s based elsewhere have been inspected and cleared - including other -Bs at Pax.
DeleteAn oil leak - especially feeding a bearing - on a single engine aircraft can have catastrophic consequences when there is no place to land - like a transatlantic crossing. You can bet that the F-35Bs transiting to the Air Tattoo event will be up high and taking the northerly routing over Labrador, Greenland, Iceland, Ireland....
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ReplyDeleteMakes the mission planning for the hop across the pond to the UK suddenly... a bit more sporty.
ReplyDeleteWow down time was 90 min per Aircraft. 3 more had issues with the oil line, all F-35Bs at Yuma. None of the UK or Marine Aircraft in Florida or Maryland had this issue. None of the USAF or USN birds either. This part is common to all variants. These 4 aircraft were in multiple production blocks. The only thing is common is they are all at MCAS Yuma.
ReplyDeleteSo systemic, in that sense. Some mx focus at Yuma right now. The first squadron scheduled to go "IOC," next year. These guys are charged with maintaining faulty, not fully tested prototypes to operational standards. Pity.
DeleteYou need to take a long look a MX in the Corp.
DeleteI had to replace a radio on a KC-130T at Nellis in 1994. It was the newest air-frame I ever worked on. It was not even 4 years old. Looked like someone had used a machete on the wiring harness in the hell hole. I put the new Radio in but would not sign off on the forms. The pilot had a fit, so the ops crew called out the Lt Col who was on duty. He was one of the QA goons. He climbed into the hole came out 5 minutes later. Told the MC Major he has 30 min to be in the air before he grounded the plane. They were airborne in 25 minutes, not had give they they were fueled and loaded wanting me to sign the forms.
I also watch them disassemble the first fuel cell on brand new F/A-18C, it had a bad fuel pump. As the aircraft had 80 hours it was MacAirs issue (Boeing had not bought them yet). Unfortunately the Marines had ripped the fuel cell open on to discover that the new block, had a new design and they did not have the tools. If they had checked the TO's they would have know that. The MacAir rep thanked them, the MX guys had just saved them $4500.00 and voided the warranty on the air frame.
The crew chief has told us TO's were for pussies. So that trans alert team watch them go to town. I always wondered what happened to him.
Speaking of oil lines and loose fittings, the F-35B features a "fueldraulics" system which brings fuel to the aft end to operate the hot nozzle ninety degree swivel.
ReplyDeleteThat is not a new concept many military birds have used that to control the exhaust nozzle since the the 60s. The hot fuel is partially cooled and then sent to the combustion chamber. The SR-71 used it for the spike and the turkey feathers on the back. This is not a new technology. The F/A-18 (ALL) uses this system, even in the land down under.
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