Home » Aviation » Sources: Engine ‘Definitely’ to Blame for June F-35 Fire

Sources: Engine ‘Definitely’ to Blame for June F-35 Fire

A F135 engine undergoing testing. DoD Photo

A F135 engine undergoing testing. DoD Photo

A June 23 fire that severely damaged a Lockheed Martin F-35 Joint Strike Fighter at Eglin Air Force Base, Fla., is “definitely” related to the aircraft’s Pratt & Whitney F135 after-burning turbofan, multiple sources told USNI News.

The Pentagon grounded the entire F-35 fleet on July 3 after it became apparent the June fire on an Air Force variant of the fighter was much more serious than originally thought. The fire, which started at the rear of the aircraft while the jet was taking-off, was initially believed to be a one off incident possibly related to the jet’s integrated power pack.

The power pack combines a 200hp gas turbine with battery and acts as a starter for the F135 engine.

While the F-35 Joint Program Office has declined to comment on the investigation, the focus is on the aircraft’s engine. Sources unanimously pointed to the engine as being at the center of the investigation.

“P&W has the engine now [and is] doing a tear-down,” one military source told USNI News.
“No smoking gun, yet.”

Meanwhile, the Pentagon has ordered additional inspections of F135 engines installed across the roughly 104 aircraft strong F-35 fleet. That includes all three variants flying with the U.S. Air Force, Navy and Marine Corps. Pratt & Whitney officials said the company is cooperating with the investigation.

“We are working closely with the Air Force Safety Investigation Board to determine root cause and inspect all engines in the fleet. Safety is our top priority,” company spokesman Matthew Bates told USNI News on Monday. “Since the incident is the subject of an investigation it is inappropriate to comment further.”

The Air Force has classified the damage to the stricken F-35A as a Class A incident—where the cost estimates for repairs or write-offs exceeds $2 million.

USNI News understands that the F-35A in question suffered extensive damage and may be considered a write-off.

The June fire is the most severe incident to occur in the more than decade old F-35 program that — despite widely reported cost overruns and changes to the program — maintains a very good record for safety.

  • ELP

    Blame? Poor project management.

  • Christopher Walker

    So, no RIAT or Farnborough appearances this year.
    More seriously, didn’t everyone apart from the bean counters know it was a mistake to bin the F136?

    • 2IDSGT

      Canceling F136 hasn’t changed anything at this point in time and has absolutely no bearing on F135 reliability.

      That said, the loss of F136 might yet bite us down the road in regards to costs. Time will tell…

  • It’s time to cut our losses on this failed project

    • Ctrot

      That is a ridiculous statement. Are you old enough to remember the teething problems of the F-14, F-15, F-16, F-18?

      I am. And all those aircraft were called “too expensive” in comparison to F-4’s, F-8’s etc. they were replacing.

      All US legacy fighters, save new build F-18E/F/G’s, are very long in the tooth. they must be replaced. It doesn’t make any sense to replace them with 30 year old designs when Russia and China are building their own 5th gen fighters.

      The F-35 is SORELY needed. We have to get it right.

      • Goose

        A repacement is sorely needed. If the F-35 is the best and most efficient solution remains to be seen. But I doubt it.

        • We have Viable alternatives such as the F-15 Silent Eagle, Advance Super Hornet, Block 60 F-16 and we can always bring back the Harrier design and update that for the 21st century.

          • Ctrot

            None of which match the 5th gen aircraft Russia and China are developing. Do you want US pilots flying inferior aircraft?

          • Do you want to pay the F-35’s Price tag

          • Ctrot

            Yes, it’s a better use of my tax dollars that 90% of what the feds spend it on already.

          • El_KaBong

            Said from the comfort and security of your basement…

            You obviously won’t be on the front line.

          • What a sad loser

          • E1 Kabong

            Yes, you are.

          • El_KaBong


            Those outdated designs from the 70’s?


            BTW, it’s great to see you lambaste the F-35 while utterly missing the fact the Sub-par Hornet had SERIOUS development issues.
            Here’s a hint: wing pylons.

          • You seriously have issues dude. Do your research

        • proudrat

          The decision to stop the F-22 poduction at 178 was stupid.

    • Warren Peters

      Do you know how long it took the RAF to perfect the Harrier?

    • ninjacat

      What do you know about this plane that you are calling it a failed project? so lets see cut the plane, lay of thousands of people, use to money to fund welfare while national security goes further down the tube havent you learned anything from the ongoing border crisis ? or are you to dense to even comprehend how all of this work?

      • superhornetfanboy

        You are an angry person, how about this..find a successful long stay jet fighter in the us military built by lockheed and then make an argument for this aircraft instead of insulting people with statist fear mongering.

    • El_KaBong

      It’s time you stopped displaying your utter ignorance.

      When was the last major fighter program, involving THREE variants, and CONCURRENT testing and production that run that didn’t have problems?

      • You must be an LCS & F-35 Fanboy

        • E1 Kabong


          Answer the question, instead of trying (and failing) to squirm out of being called on your BS.

  • CharleyA

    Bring on the F136, or an improved, more efficient version thereof…

  • goalkeeper

    This is the type of issue that I can’t help but see as perfect rationale for the 2nd engine manufacturer. With concurrent development and production, who knows how long it will be before all the flaws and issues are identified and resolved and how many aircraft will be produced by then. With 2 engines, at least the chance of 100% of the fleet being grounded would be less likely. Considering how unpredictable the world is, any scenario where 100% of our presumed work horse is grounded is a scary thought…

  • Marklemagne

    Oh-ver ray-ted.
    Give me an F-18 any day. Seriously, please give me an F-18.

    • FWGuy

      I want a F-16, lower fuel bill 😉

      • Marklemagne

        I was hoping they would throw in a few thousand hours of fuel too. If I have to buy it myself, then I will definitely reconsider.

      • Marklemagne

        Actually, if I had my choice of any U.S. jet — just for show, not for go — I would have to flip a coin between an F-86 and an F-4, and I would be happy regardless of how the coin ended up.

        I guess I’m showing my age.

  • Diogenes

    Persistent whispers of brittle turbine blades that shatter and get sucked into engine still swirling around… USMC testing in AZ had such a problem it is said…

  • CWO Oldschool

    “Back in my day we had the Curtis P36 and the Boeing P26 and none of this turbine nonsense occurred. I agree with everyone who says it’s time to slip back into the early 20th century technology and let the rest of the world worry about the future. We never had no stinking turbine blades breaking or after burner fires back then.” Major Grandpappy Amos “Tailgnawer” McGurk, USAAC (ret.)
    With the absolute success we have had dominating the threats to our security in 2014 why do we need future tech when we could be flying old garbage that makes dinosaurs feel nostalgic about their youth? It’s obvious by watching Iraq, Iran, Israel and Afghanistan, and let’s not forget the Ukraine, that the U.S. military has completed the Bush-Rumsfeld doctrine of stabilizing the planet via the use of military force so why do we require anything designed after the fall of the Soviet Union when we won the Cold War.
    It’s kind of pathetic that so many find the answer to current problems to be abandoning the future and blasting back to the past because it gives them that warm and fuzzy all over feeling as they sink below the waves of time.

  • meanmarine

    Real pilots don’t need HUDs to fly, that’s what a former RAF Spitfire pilot told me some years ago.

  • paladin58

    A > $50M single engine aircraft with no backup. Every time the engine has a hiccup, scratch one plane. Not too smart a design.

    • Ctrot

      Other combat aircraft with a single engine:

      F4F Wildcat
      F6F Hellcat
      P51 Mustang
      P47 Thunderbolt
      F4U Corsair
      F8F Bearcat
      AD1 Skyraider
      F9 Cougar
      F9F Panther
      F86 Sabre
      FJ-1 Fury
      F11F Tiger
      F100 Super Sabre
      F102 Delta Dagger
      F105 Handkerchief
      F106 Delta Dart
      F4D Skyray
      F3H Demon
      F8 Crusader
      A4 Skyhawk
      A7 Corsair II
      F16 Falcon

      Next simplistic argument?

      • NavySubNuke

        If you want to actually address his comment – which you didn’t – you will need to look up the procurement cost of each of those and then adjust their cost to FY14 dollars – how many of them were actually more than $50M each (in FY14 dollars)? I would be shocked to find out if any of them were.
        Or better stated – how many F-16s did we build and deploy? How many F-35s are we going to?

        • Ctrot

          Every new generation of combat aircraft is more expensive (inflation adjusted) than the last, often much more so. The current gen 4 aircraft were much more expensive than the F-4’s / F-8’s they replaced, because they are much more sophisticated. No different with the F-22 / F-35.

          As for production numbers, the F-16 has been in production for 40 years and there has yet to be as many Falcons built as were F-4’s in a production run that lasted only 20 years. The total number of F-15’s and F-16’s built over 40 years barely exceeds the total number of Phantoms built in 20.

          • NavySubNuke

            Again you still haven’t answered the question the author posed which you dismissed as a “simplistic argument” –> of course it is simplistic if you ignore half of it.
            We keep spending more money on these planes and buying fewer of them because they are more sophisticated (or course no one bothers to ask if they are more sophisticated then we need them to be – how is the F-35 helmet working these days anyway?) but that means we need each one to perform that much better and be that much more survivable or we will simply be buried by numbers.
            It only matters how awesome your F-35 is if you are able to kill your opponents Air Force with them (or at least achieve local air superiority) and take out his IADs (again at least locally) and then actually get around to doing whatever it is you wanted to do with your airpower. Example: If you have 100 F-35s and he has 1,000 cheaper and less sophisticated fighters than you better be able to achieve a better than 10-1 kill ratio including losses to IADs – and then use whatever planes you have left to actually achieve your objectives.

          • euphy

            According to the military people running this program, the F-35 will be able to see and “kill” opponents from distances 10x greater than where the F-35 would be able to be detected by said opponent. There are no “simplistic” arguments that apply to this topic – only the simplistic thinking that people insist on using. This apparent engine failure is a huge concern, but not a reason to dismiss the program as a failure. Whatever claims are being made by proponents or opponents won’t be tested until this plane is in service.

          • NavySubNuke

            I agree – until it is in service we won’t know for sure but I the more I read about the program (besides just the most recent trouble) the more worried I become. The plane was supposed to be 70-80% common – allowing for a mostly common spare parts stream among other advantages – it is actually more like 30% common. A lot of compromises were made to make something everyone could live with – this may or may not mean that the plane not only isn’t optimized for each service but that it isn’t good at anything (again time will tell).
            I’m sure the people running the program will tell you whatever you need to hear in order to keep funding it. I hope they are actually right – but we will see. Developments in non-traditional radar bands (i.e. lower frequencies) appear to be cancelling out many of the low observable advantages.

          • Ctrot

            paladin58, the original author of this line of comments, did not pose a question he made a statement. I replied to that statement. You then claimed I didn’t “address his comment” and made comparisons of cost and production numbers, which I responded to. Just because you can’t, apparently, comprehend the responses I have posted doesn’t change the fact that I made them.

          • NavySubNuke

            what he said was ” > $50M single engine aircraft with no backup.” you then listed a bunch of aircraft that were a lot cheaper but had a single engine so your post was half right. In addition to being cheaper those aircraft were built at a time where we spent a lot more of our GDP on defense so we could afford a lot more – no such luxuries any longer.
            These platforms cost so much that we will require each to do a lot more – and so far it doesn’t appear that the F-35 is capable of delivering that. I hope I am wrong but we will see.

      • Amicus Curiae

        None of those jets had back-up engines in parallel development either, although some of them used engines that were intended to be multi service (like the J-75 in the -105 & -106). The F-16 got another alternative when it was realized the F-100 reliability was going to be bad for a while. The Skyhawk and the A-6 had the same engine for a while. The F-8 Crusader and the F-100 Super Sabre also had the J-57, I believe. The A-7 had non-afterburning TF-30s for the Navy (Common to the F-14), but the Air Force re-engine it with the TF-41, which was basically a RR Spey anyway.
        I’ve seen the F-105 referred to as Thunderchief, Thud, Lead Sled, but never Handkerchief.

      • proudrat

        Don’t forget the AV8 Harrier.

    • FWGuy

      stupid statement, the F-16 has a slightly lower Class-A mishap rate than the two engine F-18. You are not fight jet or aerospace engineering savvy to make your statement on proper design.

    • El_KaBong

      Name the other current production fighters with optional engines.


      *insert chirping crickets sound here*

  • ninjacat

    I really love how people who havent served in the military, worked on fighter aircraft, have the educational background or work on these new planes just jump to conculsions based on some reports in the news STFU already until you actually touch the aircraft!

    • NavySubNuke

      actually what is scarier is talking to an actual test pilot – the one (I admit one is a poor sample size but it is all I’ve got) I talked to is begging to go back to hornets after flying this. He said something along the lines of low capability boondoggle.

    • Chesapeakeguy

      Should comments about anything only be allowed if the commentator has ‘hands-on’ experience with the subject matter? Can someone who didn’t wear a uniform, but actually BUILT ships, take part in these discussions, or is that not to be allowed either? Much about the military involves politics, should only those who have held or at least ran for an office be the only ones who partake in chats about that? Is being a concerned taxpayer with an interest in the military, who wants this country to succeed, especially when it involves our people and their hardware going into harm’s way, just not enough?

      Every opinion and offering on these boards are valid. From everybody!

    • superhornetfanboy

      Do you care to explain your experience with the aircraft?

  • NavySubNuke

    Suddenly cancelling the second engine doesn’t seem like such a good idea. Of course a better idea would have been to cancel the entire program a decade ago and just buy more Super hornets and Eagles.

    • Ctrot

      I have a LtCol friend in the military who works with F-22 pilots every day. Now the F-35 isn’t the F-22 but the low observable technology is similar, and in some respects the F-35 is superior in avionics, and the F-22 beats all comers, at as many as 10 to one odds, almost daily over the Gulf of Mexico. Building more legacy aircraft is a terrible idea.

      • NavySubNuke

        Now, the F22 is a very different animal. There is a reason the cockpit of that aircraft is a SCIF when fully online (the glass polarizes so no one an see inside). When the Japanese and Australians wanted to keep the line open by buying some themselves we told them to pound sand.
        I think the decision to kill the F22 and keep the F35 is one we will ultimately regret. Had we kept building a few hundred more F22s that would have more then compensated for cancelling the F35 in favor of legacy aircraft.

        • Ctrot

          They are not so different. The F-22 has better all around low observable technology but the F-35 has DAS and some other avionics tricks that the F-22 does not. I agree that the F-22 should have continued in production, not at the expense of the F-35 but in addition to. The F-22 also has some systemic issues of its own reflective of its use of cutting edge technology that the F-35 program has learned from and improved upon. Ten – twelve years ago they were people making the same accusations about the F-22 that you make now about the F-35.

  • Chesapeakeguy

    For those who advocate for that ‘alternative engine’, what’s next? ‘Alternative wings’? Alternative landing gear? Alternative cockpit arrangement? Where do you stop? What makes anyone believe that that alternative engine would solve all the problems? I thinks it’s within the realm of possibility that it could generate some problems of its own! I think the culprit here is that these planes are being rushed into production before all the bugs are rooted out.

    • midnighteye

      I believe it is the engine that is the problem. Changing the wings would be unlikely to be of any great benefit. After all these years it is difficult to agree that anything has been unduly rushed.

  • tylersocal

    Welcome to aircraft development. If this was easy, every country would have their own version of an F35.

    • acmavm

      And maybe theirs wouldn’t burst into flame.

  • imongo

    Every country will have a version of it…and I suggest we use the Brits Rolls Royce engine.

  • acmavm

    Gee, ins’t an engine a pretty important part of this aircraft? And we’re paying for HOW MANY?