Elevator failure at 4500 feet in a Cessna 150

I was flying with my student in his Cessna 150 on a routine cross-country flight. It was a beautiful day: blue skies, calm winds and great visibility. On the return leg of the flight at 4500 feet, the aircraft started bouncing around, pitching up and down. I asked the student what he was doing. He responded, “I can’t control the plane!” I immediately took over and, looking around, I noticed that the left elevator was flapping up and down uncontrollably. At this point the aircraft was about seven miles east of Brookhaven Airport (KHWV), our home field.

Cessna elevator
Simple, but not foolproof.

The Cessna control system for the elevator is very simple. A bolt connects the elevator to the horizontal stabilizer. The bolt passes through a bushing and is tightened into a self-locking nut plate and torqued into place. There is no way it could come loose! In this case, the elevator came loose and was flapping like a bird’s wing. The aircraft would pitch up and down with any movement of the control wheel.

My immediate concern was that the elevator would bend and pitch the aircraft into the ground. I elected to not move the controls. No flaps were used because lower flaps in a Cessna 150 causes the nose to pitch up.

Luckily the aircraft was almost aligned with runway 24 at Brookhaven airport. Making a small power reduction lowered the nose slightly and the aircraft began a slight descent. At 4500 feet I estimated the aircraft could get close to the runway. Varying the power ever so slightly, I could start and stop my descent. Sunrise Highway was close to the airport and I thought I could land on it, but there were too many cars on the road and any mistake could possibly hit a car.

I elected to continue to the runway and, at worst, I thought that I might land in the trees or the runway clearway on the approach. As the aircraft got closer to the runway, we hit some slight turbulence at about 500 feet, causing the aircraft to start pitching up and down and I thought we were going into the ground right then and there.

Luckily the turbulence subsided and the aircraft became stable again. On short final I elected not to move the yoke to flare the aircraft because I did not know what it might do. The elevator could bend and pitch the aircraft uncontrollably into the runway. The aircraft touched down on the nosewheel and I let it slam down on the runway. “My God!” I thought. “We are down!”

I have talked about this incident at pilot and instructor meetings. Questions were asked about using trim to control the elevator, but, in this case, the elevator itself was disconnected and moving the trim wheel would cause the elevator to move from “trail” position behind the horizontal stabilizer and rock the aircraft up and down. Banking the aircraft or using flaps would require movement of the elevator, causing the aircraft to become uncontrollable. I found that as long as I did not move the control wheel, the aircraft would stay stable and fly straight ahead.

I thought how close my student and I came to becoming a fatal accident statistic. Had the elevator disconnected in a climb, I would have lost control of the aircraft as it pitched into the ground. Turbulence was an issue on short final during the landing because the elevator would move. Had the day been windy or turbulent, I would not have been able to control the aircraft. Very gentle movement of the power is what brought the aircraft down safely.

Cessna 150
Even a Cessna 150 is difficult to fly with no elevator control.

I gently applied pressure on the rudder, slightly yawing the aircraft to the “right” on my long descent, successfully aligning the aircraft with the landing runway. Luck was with us and the wind was very light, blowing a steady, gentle 10 knots from the left of the aircraft, helping to align us with the runway.

Lessons? Always try and stay calm during an emergency. Don’t do anything until you assess the situation and then react slowly. (The only time I would deviate from the above recommendation is if the aircraft is on fire!)

It is agreed that the worst control to lose is the elevator. Lateral control can and has been deadly in flight. Fortunately, aircraft have few control failures in flight. I remember reading the accident reports where pilots have lost all control of their aircraft. The engine or engines were used to bring the aircraft within a position to land. Training is important and instructors teach their students to use trim and power to control the aircraft.

A rudder failure or aileron failure can be controlled with proper training. We all know someone who left a gust lock in place and had to land an aircraft. The failure of the elevator is the most dangerous and survival statistically is poor. I realized that the outcome of this flight could have been deadly and another fatal in the NTSB accident statistics. It was as close as one can get to not crashing an aircraft.

I have asked the NTSB to recommend that an Airworthiness Directive be issued against all Cessna 150 aircraft with this current control system design. I estimate that there are 3,000 possible aircraft affected from 1959-1970. It would require a hardware change to that used on the Cessna 152. Not a lot of money to fix and safer. I have yet to have any decision made.

So far the NTSB still has the case open with preliminary information available on their website. Cessna Aircraft has not responded and the FAA has closed their investigation.

The insurance carrier spoke with me after the investigation. The agent was an instructor also and experienced. He thought that it was amazing that I was able to bring the aircraft down in one piece. He was glad to pay the claim!

You can watch a video of the incident, shot from outside, below:

32 Comments

    • I’m bad at reading ok. I reread your article and the report. Your account has only 2 attach bolts on the control surface and both are secured with nutplates. That never should have been ok, they should be castle nuts with cotter keys, and a secondary to prevent the bolt from backing completely out of the hinge. But the other failure is possibly with the mechanics, the nutplates should be checked for tightness at every install and replaced if the self locking feature always it to be threaded in by hand.

    • Nathan

      First off the reason I wrote this article more then two years after the incident is because there are approximately 3000 older Cessna 150’s with this attaching hardware. My recommendation to the NTSB and the FAA was to issue an AD to change this system to a casilated nut with a Carter pin. Later 150 and 152 aircraft already have this hardware. So far FAA only issued a Special airworthy information bulletin SAIB. This is unacceptable to me.

      If you look at the diagram of the system, the bolt goes through a bushing and is tightened into a self locking nut plate. The bolt came loose and so far there is no explanation as to why. In my opinion some how the bolt fused to the bushing and moved in and out of the nut plate until it’s self locking ability wore out and the bolt fell out. The right side was also loose and eventually this bolt would have fell out also

      Thanks

      • Richard,
        Obviously, you want an AD to be issued, but how often has this actually occurred? If it’s exceedingly, or even vanishingly, rare (especially given the 150’s role as a trainer) then that is the kind of thing that should NOT be an AD, and the SAIB could be good enough. And maybe a pre-flight pre-flight by the instructor (we have a list of “s### that will kill you”, and control hinges and cable attachments are at the top.)

  • Seems to me when you do a walk around and the controls and you take a look at the fixating devices. That’s how I was trained. That’s what I always did. I had to airplanes, a Cessna 180 and a MEYERS 200 D I was always looking wiggling thinking of the worst thing that could happen. My two cents

    • As an A&P of 23+ years I have learned pretty early in my career to “be very touchy feely” when conducting post and pre-flight inspections. I tap and hit about a hundred different places and run the control surfaces manually on the exterior, much in the same basic ways as I would during a 100hr or an annual inspection. Even other mechanics think I am “performing an Annual” while doing a pre-flight. My point of view is, it takes relatively little time but I want to know that my main control surfaces are sound and it has never steered me wrong except for leaving a few extra finger prints on a “pretty plane” but better safe then finger print free…

  • Gee guys, maybe the airplane did pass a PreFlight checklist. If you think about how often that elevator gets moved in Flight either by the control wheel or by the wind, I can see how it could pass a test on the ground and then come loose in the air a couple of hours later.

  • Serious problem here. If the elevator hinge bolt came loose in flight it was probably loose on the ground. As an A&P mechanic I can’t tell you how often I saw pilots preflight inspections consisting of checking the fuel and oil, wiggling the controls but not actually looking at what’s going on. Lucky outcome.

    • Yes the loose bolt should have been caught at the walk around. It should have been caught at the annual, but it wasn’t. It was an accident waiting to happen.

      So how can it be prevented and not happen again? It is easy for me now to do what needs to be done.

      Self locking nuts are used extensively in our aircraft. They are designed to hold bolts from loosing up from vibration. Most are easy to check. The rule is when installing bolts the end of the bolt should protrude at least two threads out the other side of the nut, Simple. In this case the nut plate is hard to see. It is often covered with dried lubricant and dirt. The Pilot Operating Handbook shows the correct walk around for the pilot to inspect different areas of the aircraft. Instructors show their students how to visually inspect each area of an aircraft. I usually spent hours initially showing students the correct way to pre-flight. The POH does not. A mechanic looks at an aircraft differently then a pilot. Yes I have seen many instructors do a quick check on the aircraft and jump in the cockpit!

      So the question still is unanswered. Why did the bolt fall out? The bolt on the right side was also loose!

      Simply the lock nut wore out and it was not easily seen in these aircraft model years. The correct procedure in checking the elevator attaching bolts in this area is to push your finger behind the nut plate and move the elevator and feel if the bolt is moving. One has to be carefully or your finger could be squeezed by the elevator. There is usually dirt and dried old lubricant in this area. A visual inspection would not indicate anything wrong. The other procedure would be is to remove the plastic end caps on both elevators and then move the elevator. and see if the bolt is loose or the bolt head is moving.

      If I know anything about lessons learned from accidents this one in on the top of my list. Newer model Cessna 150 and 152 aircraft have a different attaching system. Simply a castellated nut and a cotter pin staring you in the face and easy to see. No chance the bolt could come loose here!

      So I want the FAA to issue and AD and change the old system. That is my reason in making this accident public. Two years plus have gone by with no change.

      Is there another one out there ready to happen? I hope everyone that owns or flies an older Cessna 150 checks this out

      THanks all

      Rich Wyeroski

  • I watched a video of the landing that a pilot flying in the pattern shot upon hearing of this emergency from the start. I believe that if it were not Rich flying this 150, there would have been 2 dead flyers and a pile of scrap aluminum instead. His knowledge and a lifetime of experience saved the day here.

  • How is it, that everyone on here thinks that it was missed in pre-flight or has something to say. Stuff happens that doesn’t get caught in pre-flight, Everyone is an expert, an authority and special when typing a comment, on the ground. It’s amazing. Nice job Rich. I fly out of KISP and and we’ve run in the same circles. Nice write up and thanks for putting it out there, considering the dopey comments that you know will follow.

    • Sal

      Thanks for the reply. Yes it was not seen of the walk around. It was not seen on the annual which was done 4 months previously. The proper inspection is never usually done. Like wiggle the controls looks for the fuel costs being on. Check oil cap and make sure nothing is leaking any where.

      My main reason for posting the article was to inform those 3000 possible 150 owners out there how to check for this problem. If one can removing the end calls on the elevator will definitely show up the problem….I had some people tell me I should have used trim……That would be a NO…NO….because it would have aerodynamically moved the elevator and the aircraft could be harder to control. The aircraft liked one thing and one thing only……”A power reduction, “…which Lowered the nose ever so slightly….nothing else would have worked! ……No banks…..do it differently and This story may have never been told!

      The NTSB still has the case open for some reason?

      Thanks again!

  • What was the damage claim the insurance paid? How hard did the nose wheel smack the runway? Did your student fly again?

    My question isn’t to criticize. You (and your student) walked away from the landing.

    • David:

      No problem,I mentioned to AIRFACTS that I would answer all question as to the incident in the name of safety and to help prevent this from happening again. The damage claim totaled $11,000 dollars. One elevator had to be replaced (USED) and all hardware also replaced on the rudder. The old system was changed to using a casillated Nut with a cotter pin (aircraft grade stainless steel) The bell crank was changed and the attach points on both ends of the horizontal stabilizers were also changed. All flight controls were removed and the attaching points were checked for stress and cracking.

      The aircraft hit hard because I pulled the power at the last second and did not flare the aircraft at all. The gear was checked at it’s attaching points also.

      The student and I went on to get his private and the aircraft is flying today

      • Great job, but it’s a “castellated” nut, like the castellations on a castle that archers shoot from.

    • Carl

      Most aircraft use casillated nuts with cotter pins except this Cessna Model. There are about I estimate 3000 aircraft using a bushing with a lock nut. (take a look at the diagram above) I recommended strongly to the FAA and the NTSB to issue an AD to change the system to the newer models of Cessna which had the change done around 1970-71.

  • Nice job. And excellent article. The attached video offers great ‘value added’. Rich, is there an NTSB report for this, and if so where?

    There’s another, similar event in a C152 3 years ago caused by a fouled yoke & wire bundle. The video was recorded in the cockpit, and tracks the event from beginning to landing. I didn’t see in the article where you declared the Big “E”, but your video narrator used the “E” word so I assume you did declare. The other CFI (it was also an instructional flight) called Pan Pan, but declined to declare ‘Emergency’. You cleared the air as you made your approach and landing. He didn’t, and might have suffered the consequences had his luck ran out. Kudos again.

    Did you have ARFF on field? Was your choice of landing site the closest long runway with emergency services available? What is the airport code? I’d like to look at the approaches and layout so I can better understand what you were up against.

    Thanks again, and many KUDOS!

    • John

      There is an NTSB web site direct link at the bottom of the article underlined. I declared an emergency with the Unicom at the Brookhaven Airport KHWV. If I had to do it again I would have did it with ATC. They would have called emergency services as the Unicom operator told me (later) that the fire department told him to call back if I crashed. I must admit I was slightly aggravated at the fire department! There is no fire department or fire truck located at the field!

      • Rich:

        Thanks for the additional information. I was unable to get the underlined link to open. Would you post the full URL of the preliminary report (not masked with the linked text)? ———–

        FWIW, I own and fly a C172 of about the same vintage as your C150. About six annuals ago several of the bearings for the rudder and elevator were replaced, as were the rudder pedals on the left side because of excessive wear on the bearings (the holes were worn from round into very definite ellipses). About 10 annuals ago I pulled the wires from my wings to the position lights when I installed wing tip strobes. I found deep friction wear in the insulation at every spar in both wings… and now have new wires to strobes & running lights. Other little things have shown up at other annuals. I guess 60 year old aircraft wear at key points just like my own joints. 🙂 ———-

        Important Learning Point: Don’t skimp on any preflight, and pay very close attention to any potential wear points at each maintenance event. Be prepared to spend a little money over the cost of an annual (or 100 hour) inspection to avoid spending a lot of money later.

        • John

          Here is the link for the NTSB preliminary report. The case has not been closed as to the actual cause of the failure. It’s been 2 and a half years since the incident. I called the NTSB and they said they would eventually get to it.

          Since I was PIC I want to know the results of the investigation because I consider the incident very serious.

          Thanks

          NTSB Link: https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20160816X44909&AKey=1&RType=Prelim&IType=LA

          • Rick: I Agree re: this structural failure was a BIG DEAL. It made me think of the wing failure in the PA28-200R in Florida, and the number of imminent failures discovered when the wing attach emergency AD was issued. Also reports of failed attach rivets (from electrolysis of dissimilar metals) for the aileron weights on some elderly, humid location Cessnas. —————————————-

            What is the history of your C150G? Was it hangared, tied down on the line or under an open canoy? Was it, based near the Atlantic or in the SE for much of its 50 year history…, etc? Did it have a history of periodic corrosion proofing (Corrosion X, ACF-50, or other)? I seldom see accident reports that dig into ‘the rest of the story’, yet that’s the most interesting stuff. Ditto for a lot of ADs. Do you have access to my account email? It would be interesting to discuss this in depth.

  • If you read the 2014 Mar/Apr FAA Safety-Bulletin page 13, a excellent article on flying without touching the control wheel, ie elevator.
    Note also that in hands-off flight control, the rudder for direction and power change for pitch could/should be normal flight control. I often start taxi, takeoff, climb, descend and approach without using the control wheel.
    a complimentary e-book about flight control is available from bob@safe-flight.net.

    • Robert

      I held the controls from moving. Any movement in the control wheel would cause the aircraft to oscillate up and down. At one point the aircraft hit some turbulence at 500 feet and almost pitched the aircraft down and into the ground. The last minute was critical and the temptation to move the control wheel would have caused a problem.

  • Was taught in A&P school years ago that all bolts subject to rotation should be mechanically locked ie. cotter pin, safety wire, lock tab, etc. Maybe that bolt is tightened onto a bushing and the rotation is on that but it still seems like a poor design.
    They changed it for a reason.

  • Duane

    The system worked well for years (50) If you look at the attaching hardware in the diagram you would see that there is no area of rotation. The bolt moves around in side a bushing is torqued into a self locking nut plate. The bushing corroded to the bolt because of poor maintenance and the movement of the elevator moved the bolt in the self locking nut and literally wore it out. The right side was also loose and it would have detached also. Yes a poor system with poor maintenance.

    Unfortunately I believe there are other aircraft out there with this situation and will fail too! I hope I am wrong here! But that why I want an AD or at least inform the aircraft owners out there to call their mechanics and have everything checked.

  • Changing from the nutplate to a castellated nut could be challenging, but a bolt with a drilled head, safety wired to something nearby would be a no-brainer mod.

    • Greg

      The accident aircraft was converted to a castellated nut. Considering the consequences of the old design, it is a fix worth doing by Cessna 150 owners with these aircraft. I estimated that there are 3000 aircraft with the nut plate design flying.

  • BTW drilling a bolt to put safety wire through it is not recommended because it could weaken the bolt head……..

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