Poor Maintenance Could Have Led To Fatal B-17 Crash

In October the Nine-O-Nine, a fully restored Boeing B-17G bomber owned and operated by the Collings Foundation, crashed with thirteen people on board. After landing hard and skidding into the de-icing tanks at the Bradley International Airport, all but the tail and port wing of the 74 year old WWII aircraft was destroyed. Seven lives were lost in the accident, including that of Pilot Ernest “Mac” McCauley, who was regarded as one of the most experienced B-17 pilots in the world.

While the National Transportation Safety Board (NTSB) investigation is still ongoing and hasn’t made a final determination as to what ultimately brought down the Nine-O-Nine, enough serious maintenance issues were uncovered while examining the wreckage that the Federal Aviation Administration (FAA) has decided to rescind the Collings Foundation’s license to conduct any more paid flights on their remaining WWII aircraft. While many have spoken out in support of these “living history” flights, the FAA says they must be conducted in such a way that they don’t hinder the safety of other air traffic.

With the vast majority of the B-17’s airframe gone, the NTSB investigation has focused on the four 1,200 horsepower Wright R-1820 “Cyclone” engines recovered from the crash site. Investigators found that hastily attempted repairs to engine number 4, which is believed to have failed in-flight, were actually hindering normal operation:

Regarding engine 4, to prevent the magneto “P” leads from separating from the
magnetos, someone had attempted to rig the magneto leads in place with safety wire.

Inspection and testing of engine 4 left magneto revealed the movement of the safety-wired lead caused grounding to the case, which rendered the magneto lead inoperative.

Further, all of the spark plugs in the number 3 and 4 engines were found to be fouled and had electrode gaps that were out of tolerance. From an examination of the aircraft’s maintenance records, it was also learned that an arcing and burned wire had been replaced without any investigative steps taken to find what caused the failure to begin with.

With basic maintenance tasks either not being performed or at least done incorrectly, the FAA has called into question the culture of safety at the Collings Foundation. The paper is careful not to directly accuse the Foundation or any of its staff with outright negligence, but the implication seems clear.

The loss of Nine-O-Nine hit especially close to home for Hackaday. Just a month prior to the crash we had the opportunity to tour the aircraft, and came away with a newfound respect for not only those who designed and built the iconic bomber but the brave young men who flew it. Losing such a rare and historically significant aircraft and its crew was already a tragedy, but to find that negligence may be to blame is truly inexcusable.

49 thoughts on “Poor Maintenance Could Have Led To Fatal B-17 Crash

      1. Depends on the news outlet – lead with the sensational part that might get fools riled up and paying attention to that outlet over the others. Some unfortunately are even worse leading with hugely misleading slanted headlines or just terribly poorly defined statistics…

        In this case damn that company really should be for the noose… Risking a rare important historical flying machine and folks lives with seeming very very shoddy maintenance. I can understand honest mistakes, even a questionably legal bodge to get the aircraft home for a proper repair, but not that level of failure. It doesn’t even make sense from the company beancounter point of view, skimp that badly on the maintenance if you are going to sell up and then rent back or other such stupidities to make the numbers good for this quater- just as long as it doesn’t become your problem. Ruining your own assets through lack of care makes them worthless, and with assets like these you can just get a new one.

        1. So we’ll lead with “Could your kids be killed on their next history field trip? That and more after the break, but first we meet Jojo the budgie who saved his young owner from eating a halloween candy with a butchers cleaver hidden in it…”

  1. I’m a CERTIFICATED airframe and powerplant mechanic…licensed by the Federal Aviation Administration. I’ve actually worked on NINE-O-NINE when the aircraft was a TOM RILEY’S once facility near Orlando FL. (Kissimmee, FL) My vast experienced with this once fine aircraft and other “war-birds” exposed sloppy and non-airworthy tasks PERFORMED BY UN-CERTIFIED PEOPLE!


    The work I’ve seen certainly wasn’t done by mechanics using any stretch of the imagination. Maybe the Collins Foundation and other flyers of these VERY old aircraft hire golden retrievers to “maintain” their fleet because sure-in-hell “they” have zero clue on what constitutes an AIRWORTHY AIRCRAFT! The loss of SEVEN LIVES and this aircraft is unfortunate proof of what happens when PEOPLE with “dimly lit attics” are handed tools and instructed to…GO FIND SOMETHING and FIX IT!

    Need another example of unlicensed pin-heads doing doing aircraft maintenance???


    Total loss of another great aircraft BUT, all survived!

    What was my career BTW over those years? 30 years as a commercial aircraft tech rep/mechanic and now retired after over a decade with the NTSB.

    1. Wow. Were the Collins Foundation or the FAA warned about the deficiencies such as those you found?

      There’s a flying Lancaster and other warbirds at the Canadian Warplane Heritage. I hope they’re taking better care of the birds. I know a few people who worked on them or fly them.

    2. With all due respect, I find it’s the people who brag about their credentials who tend to bodge the job and pass the blame onto other people. A piece of paper don’t make you an expert, no matter how “certificated” you are.

      1. I’ve never worked on safety critical systems, but a lot of the crappy work I see is done by people who brag about their skill, but also say things like “This is simple, we don’t need all that” when you try to add any kind of professionalism, reliability improvements, etc.

        They’re confident, but they don’t talk about any kind of credentials or anything, and they know they’re not up to industry standards, they just think it isn’t needed.

        They seem to think of themselves as “practical” without getting “bogged down in the details”.

        I suppose I could see those same people getting certs, but not actually following any of the standards you’re supposed to…

        1. Yeah, it goes two ways. Some people get certified by sheer effort or a fluke of luck, and then fail to maintain the standard – other people never get certified on anything and get along on sheer charisma. Both kind of people are dangerous because one has a reality distortion field that masks their incompetence, and the other has a certificate that says they’re competent when they’re not.

        2. i also worked in aviation… first as ramp agent, where i let some flights delay for various reasons, station management pressuring me i showed him the passenger list and said – so many ppl onboard, will you take it on your hat? then do startup routine yourself. thanks god my boss backed my decisions.

          furthermore i was later IATA certified (yes, yes…) dangerous goods expert, and this is where it becomes really funny, risking even lives of people not even aboard the plane, not to mention what might have happened in-flight.

          this is why everything is double, if not triple-checked. but as its a business where time is even more money, people tend to get sloppy because “hey it worked last time”. i even had to handle the “TC-ONR” on its last flight out of the EU – they got banned from european airspace for operating that near-dead horse which needed a COMPLETE overhaul. the engines took a whole 20 minutes on the airstarter to come alive. captains decision. this is where the savings done before end up expensive (no more charterflights within EU, repair….)

          i headed back to electronics and didnt really look back.

      2. I’d take 30 years of certified experience at face value.

        I worked in avionics. I was once pressured to certify a conditionally serviceable device as serviceable.

        I resigned.

        When you sign a cert as open serviceable you are singing a value to the lives of those onbourd and potentially the general public.

        1. I know what you mean, but I know people who have 30+ years of certified experience and are totally crap at what they do – they just got along by being intimidating and bullshitting everyone who dared to question their authority. It was all a show.

        2. >I resigned.

          Notice that by doing so, you opened a spot to another person who would certify. You absolved yourself, but you didn’t solve the problem. This is a systems issue where pressure from a higher authority will always be met because the subordinates have no option to refuse.

          This is known as the rule of: “Systems attract systems-people”. It means, the people who actually take responsibility and think with their own brains are ejected out of such systems, and the people who go by nominal credentials, ranks, titles and certificates, are promoted to the positions of power instead.

          1. There are two separate systems here.

            On the maintainance side it’s totally accountable. Every time you sign you are singing that you trust the information on the signed certs that you are given and certify a condition for the next stage.

            This goes right from the bottom through to the pilot who must sign to accept that he know and understands the state of the craft and conditions imposed on it’s operation. He can’t leave the ground without doing so.

            The other system, corporate management, has next to no accountability by comparison.

            So it’s the independence of these systems that is important.

            Sometimes corporate management will attempt to use human relationships that have built over time to influence maintainance decisions.

            By leaving, I destroyed the human relationship and the history that was being used as a tool of manipulation.

            The next person is then in a better position as they are less likely to experience any attempt of manipulation.

            I worked for one of the safest airlines in the world.

            The option of reporting may be less beneficial than you think.

            If you report then they can cover up as they don’t have accountability and succeeding in a cover up will only encourage them to continue the attempted manipulation.

            Your main objective is to maintain accountability and independence of your own system rather than trying to fix problems in the other system.

          2. >By leaving, I destroyed the human relationship and the history that was being used as a tool of manipulation.

            Not quite how it works. At any given time, there are a number of yes-men and a number of no-men in the organization. When the no-men resign, they are replaced by new people who may be one or the other. They are actively groomed and pressured by the corporate management to be yes-men or resign. Failing to comply or resign, they are demoted or fired in the next “performance review”. In other words, the system ejects people critical of the system and attempts to replace them with yes-men.

          1. People often confuse sociopathy with narcissist and histrionic personalities. The difference between is that narcissists crave power and admiration, while histrionic people want attention and glory. Both lie about their own achievements and put others down to satisfy their needs.

            Sociopaths on the other hand lack empathy and find manipulating others amusing.They don’t usually come out of the woodwork to beat their own drum unless there’s a greater payoff to it than just “look at me!”.

  2. It’s possible that a failed magneto would lead an engine to foul all its plugs. (Although I’m pretty sure the Cyclone had redundant magnetos: that’s ubiquitous in aircraft ignition systems.) But my memory is that it took very little mishandling for some of those big radials to very rapidly foul every plug. Ernest Gann wrote about flying a B24 that had the wrong temperature range plugs in three of the four engines, and said by the time he was a few hundred feet off the runway surface those three engines all stopped with fouled plugs and he had to do an emergency landing straight ahead in a field: maybe five minutes of operation.
    Part of the pre-flight check on smaller aircraft is running off just one, just the other, and both magnetos to make sure they’re both functional. I presume they do this on old multi-engine aircraft as well. It’d be interesting to find out how the high tension lead was supposed to be retained in place: what broke that had to be replaced with safety wire?

    1. Yes, a poorly performing magneto will foul plugs through incomplete combustion at higher rpm and loads.

      However this magneto was completely inoperable.

      Just as significant is the out of spec electrode gap of the spark plugs.

      The manufactures specification does not include the electrode gap.

      The electrode has to adjusted in accordance the the engine manufacturer specification prior to installation.

      Also as plugs wear out the electrode gap increases as a result of metal migration from the plug tip. They need to periodically replaced.

      So the important question is , is the electrode gap too large from failing to replace them on schedule or where they not correctly adjusted prior to installation.

      In any case this won’t be the cause of the incident but does indicate maintainence issues.

      1. The ntsb will have to dig through the maintenance records and find out when the plugs were last changed. That depends on honest record keeping. A few guys I’ve worked with over 10 years now tend to push paperwork that they don’t feel like doing. One time inspections, etc. The issue isn’t typically bad mechanics. The real problem is people won’t report each other, because when you work with these dudes for years, you form a brotherhood. It’s like how the police protect their own when something happens like a shooting. These people are like brothers, they won’t say a damn thing. We have inspectors to keep us all in check, people who don’t know us and think we are all trying to hide stuff. But that’s typically annually.

        1. The NTSB will send the plugs to a metallurgy lab.

          The replacement schedule for plugs is based on flight hours.

          The plug wear is a result of the sparking and that occurs once every two revolutions of the engine.

          They will be able to reasonably accurately calculate the number if flight hours since they were replaced.

          If the records differ then they have a signature and name of a person to go after.

  3. We were wondering why a single engine loss on takeoff should have phased a very experienced B-17 pilot, but if 4 was out and 3 wasn’t firing right, with the other 2 maybe not able to make full power either due to maintenance shortcuts, then I guess he had to try and drag it into the air by willpower.

    1. The thing was he had no problem getting it into the air. He flew away and circled around and came back. The problem was he came in way too low for the landing and struck the lighting towers in the grass before the start of the runway.

  4. Well what do you know. They found poor maintenance and improper repairs on several engines, including the one that failed in flight. These were replies to my comment on the previous HAD article, in which I suggested aircraft of this size and complexity could be beyond the resources of a small group of volunteers to maintain and operate safely:

    Flyer says:
    There’s also absolutely no reason to believe the crash happened due to the age of the plane, or even a hardware failure.

    Scott Smith says:
    Nonsense! The people who maintain these “large complex” aircraft do fantastic work! This comes from actual personal experience not uninformed opinion. They are dedicated VOLUNTEERS. They do it because they love it and want to, not because it’s a job. Please visit one of these flying museums and be impressed. And stop the speculation already let the investigators do there job.

    Root Cause says:
    With respect, you are clearly out of your depth and don’t understand the situation.

    Not Flyer. says:
    What is beyond absurd is when someone posts obviously ignorant crap, can’t accept the wisdom posted by someone who clearly has a clue, and comes back with bad arguments, rhetoric and sarcasm. It’s as if you’re asking for another beat-down.

    1. You’re still begging the question.

      First it has to be determined that a mechanical failure was the ultimate cause, then that the mechanical failure was caused by poor maintenance instead of being an unrelated problem, then it has to be established whether the maintenance crew was fundamentally incompetent or just negligent /this/ time.

      There’s a whole chain of investigations and questions to be answered before we get to your claim, and you’re simply assuming it all supports your point.

      1. Point being, the argument that these old planes cannot be maintained to be safe anymore depends on your assumptions about who’s maintaining them. You’re making the categorical assumption that such efforts are fundamentally implausible, which cannot be determined by this accident alone. You need to audit other such groups to find out whether this is a systemic issue or an exception.

        So not only is your claim jumping to conclusions, it cannot actually be decided by this case.

        1. And yet the FAA, based on the evidence of faulty maintenance already found, rescinded their license to conduct commercial flights pending the outcome of the investigation. That’s the prudent course of action, and stands in opposition to your suggestion that no action or judgement should ever be made until 100% of the evidence proves a specific, universal cause.

          And I made no categorical assumptions. It is a fact that mechanical things brake. It is a fact that these are large and highly complex aircraft. It is a fact that small groups of volunteers have limited resources, certainly far more limited than governments, for whom these aircraft were built and who themselves have long since taken them out of service.

          All I said was that it could be argued that these planes might beyond the resources of small groups to maintain safely. The responded I received were either strawmen, patently absurd, or devoid of anything beyond insults.

          Happy to revisit this issue pending the conclusion of this investigation.

          1. > no action or judgement should ever be made until 100% of the evidence proves a specific, universal cause.

            That argument was not made.

            >pending the outcome of the investigation

            Indeed. Pending.

            >I made no categorical assumptions

            Yes you did. That was your very argument: that small teams like these are categorically not able to maintain and fly old planes safely. Of course they have limited resources, but that does not make it impossible – you are simply asserting that it does.

            > it could be argued

            Well, are you or are you not? Don’t act all high and mighty if you aren’t willing to stand behind your own words.

          2. Note that you’re trying to argue two different arguments as if they were the same:

            1) these planes are beyond the capabilities of small groups to maintain safely
            2) this small group was incompetent in maintaining their plane

            Whatever actions and judgements apply to case 2 have little bearing on case 1 which was your original point. Your argument cannot be concluded by observing the judgement of this case – only by judgement of several similar cases to establish the pattern – yet this does not mean we cannot give judgement or action in terms of case 2, which is what the FAA is doing.

            What you’re doing is simply a common error in thinking: “This X is Y suggests all X are Y”. Inventing post-hoc rationalizations about why one data point proves a trend doesn’t prove that the trend exists, because you’re fitting your theory to the data.

    2. Luke is just one of those people despite having zero experience in commercial or military aircraft repair thinks he is a expert because he can argue.

      I will say this those flying antiques like the B-17 need full time mechanics who are given the resources and time to make sure those planes are airworthy. You don’t use volunteers. Look if the company is so destitute in terms of money that they have to rely on volunteers to keep their planes flying then it means they have no business flying those relics.

      It is no wonder the FAA rescinded their license given what the NTSB discovered.

      1. I don’t think I’m an expert because I can argue. I’m simply pointing out that you’re not one either, and your arguments are ill supported.

        It’s the old wisdom of, “It don’t take a chef to tell a s**t sandwich.”

        1. And even if you were an expert, it still doesn’t change the fact that a single data point doesn’t make a trend.

          An expert who fails to follow the basic philosophy of science is known as a crank – they may know a lot of a specialist subject, but their lack of self-doubt makes them liable to make gross errors in thinking and practice. There’s a lot of these “I have 30 years of experience, you can’t learn this stuff from books!” types out there who make bridges and planes fall because they think they have some divine knowledge of the subject that other people just can’t fathom.

      2. Volunteers may well be the most experienced. Hired help is more likely to be less skilled in the context of flying large complex ex military aircraft. Look at most resto groups, be it locomotive, stationary engine fanciers etc. I’d take retirees over apprentices who have only touched bug smashers.

  5. Fouled spark plugs….

    I learned how important it was to get proper spark gap before I was even a teenager. This is why you make your kids repair their own damn equipment….

    How the literal fuck do you let an engine go without checking the damn spark plugs… ICE maintenance 101…

  6. It’s always difficult to dive in and comment on a tragic case like this, but I feel my experience has some relevance because the FAA’s findings accord with some of that. I flew as a passenger in both the Collings Foundation B-17 and B-24 on consecutive years. I took a pilot’s licence some time ago and I maintain all my own vehicles. I greatly enjoyed the two flights I took but I had some concerns. At the time it was clear to me just how much physical exertion controlling the B-17 caused the now-deceased lead pilot Ernest McCauley. He was in his early sixties at the time but it was obviously considerable effort and he was only flying round on a simple joy-ride. At the time of the fatal crash he was 75 and he was attempting to control a large, heavy and malfunctioning machine at low altitude. His co-pilot was 71. Regardless of any other culpability on his part or that of the Collings Foundation it strikes me that a pilot of such advanced age is not really who you want at the controls in a crisis situation. The pilots who flew these bombers in WW2 were 50 years younger, far fitter and often experienced at landing B-17s with one or more engines down.

    As for the passengers, although we were strapped down for take-off we were told we could release the straps almost the moment we rotated and left the ground. On my flights the passengers were all moving about the aircraft immediately. I do not know whether on the fatal flight they had been told to strap themselves back in. I do not recall that anything beyond the most cursory pre-flight checks were made, including a magneto test.

    Much has been made of Ernest McCauley’s 7,000 hours experience but none of that surely involved trying to execute emergency landings with only two engines working properly. In short, I’m not sure how useful his experience would have been in this exceptionally hazardous situation. With only the two port engines working properly the aircraft would inevitably have yawed to starboard as it came in, requiring the pilots to try and counteract that extreme force (the B-17 is pulled that way as a matter of course because of prop rotation – just watch the take-off sequence in the Memphis Belle movie) while landing. The fact that there had already been engine trouble that day ought to have meant he should have used his experience to decide not to take off, and certainly not to take off with passengers before he had ascertained everything was working properly.

    As for maintenance, the FAA’s findings are very worrying. I’m afraid familiarity breeds contempt and complacency. The use of wire to secure the magneto lead suggests a lack of elementary knowledge about ignition electrical circuits, as does the lack of routine maintenance of plugs, or sheer carelessness. Although an aircraft piston engine will function with one of the two magnetos working, it is very obvious during pre-take-off tests that power is markedly down. Not only is it a cause of great concern that the wire had been used to secure the magneto lead but also that no-one else had noticed. Perhaps no-one else had the opportunity to examine the engines and the botch repair that had been employed. One wonders how long it had been in place. It may well have been a botch repair used by whoever was responsible in the past on other occasions without ill effects, resulting in the assumption it was ‘okay’ to use it again – but that is pure speculation. The wire repair can only have been done by someone who did not know it was hazardous or was sufficiently over-confident not to care. With aviation there is simply no room for that type of error because the consequences are so drastic. There is footage on Youtube of Ernest McCauley servicing an engine recently. I’m afraid the impression that left on me was of an elderly man who had difficulty just moving while trying to stand on steps to to access the engine.

    Like all accidents there were a number of factors involved and like most accidents they were mostly avoidable. This was an ill-maintained machine presided over by a lead pilot and team who made errors in maintenance that appear to have contributed to failure in flight. Once confronted with an emergency, whatever the cause, the aircraft had to be landed in moments by two septuagenarians who had never executed such a manoeuvre before, on an airfield they only used occasionally and which will have demanded high speed decision making and fast reactions to succeed. I don’t think anyone can suggest that men aged 75 and 71 respectively would be considered ideal in such circumstances. That doesn’t mean other, younger pilots would not also have ended up with the same outcome, but I think it’s reasonable to suggest they might have had a better chance of not doing so. And then there is just plain bad luck: that de-icing tank just happened to be in the way which meant that after everything else had gone wrong, the aircraft happened to run into them and burst into flames. And sadly aluminum burns very well. The result was a convergence of factors. The response now ought to be to make sure that the avoidable errors are ruthlessly pinpointed and measures taken to reduce the chance of recurrence. First must be rigorous enforcement of maintenance procedures. Self-regulation and self-supervision are not good enough. Secondly, an upper age limit ought to be considered where pilots are carrying passengers. These are of elevated importance when deaing with vintage aircraft. In WW2 in a war theater these aircraft were maintained by young and agile crews who not only knew the machines inside out but also had access to brand-new replacement equipment, including complete engines and magnetos.

    I will never forget the day I saw the Collings team with the ‘909 in Chicago fixing a puncture in the tail wheel tire with a repair kit. I asked them about it and they said even inner tube spares were hard to get. I was pleased I had had my flight and I wouldn’t be landing in an aircraft with a patched tire. I don’t doubt this general issue of spares availability forms part of the backdrop to this tragedy.

    1. I flew in that beautiful bird in Chicago in July 2017 and July 2018. It was the most fun I had in a long long time.

      I was going to fly in July 2019, but only went to see it at executive airport in Wheeling IL. I had another engagement later in the day and had to leave early. Also, Captain McCauley standing on a ladder spraying carb cleaner in engine number 3 with the cowling removed along with the valve cover is a memory and picture I have!

      I remember my wife saying I could fly it again in 2020 (she did not like my flying in it anyway, but she let me do it twice. I know she was worried since I watched her bless herself as we taxied away.). I remember touching the tail of the aircraft and looking at how the paint was fading on the surface. It looked tired and said to my wife I will never see this plane again.

  7. Jim, I share your memories of a fabulous experience and one I too will never forget. It was a huge privilege. It has been privilege not only to have known 8th Air Force aircrew but also to have participated in excavations of B-17s in the UK. Like you I am filled with sadness about this tragedy. Your observation is very poignant. Lead pilot McCauley and the B-17 were about the same age. I’m afraid that keeping a machine like this airworthy needs a lot more than a setup that relied on fixing magnetos with wire, squirting carb cleaner, and leaving an elderly man in principal charge. I think your judgement is correct. Something was bound to go wrong. Over here we have the Battle of Britain Memorial Flight. It’s an ultra slick operation with top caliber serving RAF pilots and a team of dozens of dedicated engineers, not a pensioner with a can of carb cleaner and a roll of wire.

  8. Guys, I was blessed to have flown in 909 a few months before the terrible crash and the loss of life.Being part of the B17 history Facebook page I view the terrible loss of aircraft and more importantly the loss of those brave crews. Being a novice to all the comments of those much more knowledgeable than I as to speculation as to why it happened, i keep thinking and seeing many examples of returning B17 to England in such a bad way. Guess I don’t understand how these so badly damaged returning B17’s over Germany and 909 crashing the way it did with issues on one engine. Gentleman, I’m just trying to have a better understanding of why 909 met it’s end. To those that lost their lives on 909 and the 35,0000 WWll crews that lost their lives RIP.

  9. Having been in and around aviation for 40 years , single engine private as well as warbirds . I personally viewed some alarming care free attitude in sept 2019 Princeton Nj , the b-24, b17 -909, p-51 and p-40 where present . I stood around for hours waiting for a ride on the b-25 but we were guy short , in the hours I said to my friend , the collins crew have a non nonchalant approach with these precious warbirds and clearly said its a matter of time .It deeply saddens me for the loss of life , however I spent 45 min alone in the 909 and cry when i see crash pics . Now with the discovery of botched repairs / maintenance collins foundation should never be allowed to fly again for profit .

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