Jeremy Fonseca I have walked right where he is back in the late 80s. There were three of us changing the elevator trim cable on a PA28-181. When we were done all three of us verified, or so we thought, that the cable was installed correctly by operationally checking the system. An Instructor came over to pick the aircraft up. We briefed him on the maintenance we had accomplished and away he went. He took off and came right back and informed us that the trim was backward. Luckily he was experienced and picked up on it immediately. I will never forgot how horrifying that day was for all of us. After that, we changed several more cables and trim drums and verified correct operation a gazillion times prior to releasing the aircraft. It makes me shake to this day.
Jeremy Fonseca You need to listen again. He never admitted that he screwed up. He kept using passive voice. "The control cables had done a 180 when they were put on the actuator." "I realized where the mistake was." "That step was missed." and "I never thought that I would have missed it." Yes, it would take courage to say "I screwed up" or "I attached the cables backwards" but he never did. Not courageous...gutless.
Jay, you are right. This guy could have killed two people. Wouldn't a proper ops check have found this problem? Any flight control that is touched requires an ops check. I'm not so forgiving on "accidents" or "mistakes". I've worked with mechanics that don't take this seriously enough and take short cuts. The mechanic in the video emphasizes following the AMM. It's common practice to not follow the manual when being pressured to get a job done. That is NOT a mistake. That is a choice and a violation. I wonder if part of his penalty was community service in making this video?
@@giggleherz people have been drinking, smoking, in a funk, mind elsewhere for whatever reason. your mechanic has to be top-notch person 365 days of the year ; ) and that's a fact.
Two things surprise me about this video. The fact that the pilots figured this out while fighting the airplane is amazing. The fact that the mechanic admits and talks about his mistake is awesome. Definitely respect all three of them- Great information.
Hats off to theA&P who was willing to go on camera with his mea culpa. He has the character to match the skill we all hope for when we get into an airplane. Somebody buy that man a drink!
I would add my voice to those expressing appreciation of the mechanic's video mea culpa. There's a palpable sense of his regret. That said, the trim should have been checked by the pilot before the engine was started. The sixth item on my pre-flight checklist is trim check. That means fully deflecting the trim tab in both directions and observing that it's moving in the correct direction and moving fully to each stop. It should be checked for every flight but especially on a post maintenance flight where the mechanic specifically advised the pilot that the trim was re-rigged!! it may have been the mechanic's mistake but it's the pilot's responsibility for the flight controls to be correct.
This actually happened to me. I had the good fortune to recognize the problem shortly after takeoff because I was The pilot that was responsible for returning the aircraft to service after maintenance. The mechanic stated that he had worked on the trim tab. After departure when I trimmed for nose up, it acted like nose down pressure. I had the good fortune of realizing that the rigging was inverted and immediately tested that hypothesis by reversing the trim wheel input. The process worked so therefore I neutralized the pressure on the control wheel and then returned the aircraft for an uneventful landing and I immediate return to the shop that did the work. It was discovered that the bell crank had been turned 180° the cable therefore activated the trim tab in the opposite direction. It was just another normal test flight for me but I did not realize that over half a dozen people lost their lives with a similar mechanical error. Excellent video on unexpected in-flight emergencies. The Cessna 172 did not have electric trim, thank goodness.
I realise that my comments here are two and a half years after this video was published, but I have to put my two cents in. I have been a Licensed Aircraft Engineer for some 15 years now and I have done this same and similar jobs many times. Luckily I have not had any issues so far. Those that have made negative comments below about the mechanic don't obviously realise that some parts of airplanes are almost impossible to see into to detect errors such as what happened here and how easy it is to cross-rig trim cables. Years ago "The Right Stuff" was never to admit your errors. Today, we have learned that was absolutely the wrong thing to do, and you have to put your hand up when you have made an error. Nobody has enough time to make all the mistakes, so we have to learn from those of other people. Stephan, you have my total respect for fronting up on this video and telling your story. I, like you have heard the stories and read the reports. Next time I play with a flight control, I will think of your story.
These videos are so important. From now on I will check the directional movement of the trim wheel and the actual trim after any maintenance. Then I will check the movement of the trim wheel when using the electric trim switch. Thank you for sharing your experiences. Double kudos to the mechanic who shared his error publicly to make aviation that much safer. Takes a big man to do that. We ALL make mistakes, but the more we check and double check the work of others, the safer we can all be. This video reinforces that in spades.
As many comments stated, this A&P is very admirable! He was in disbelief at first but didn't deny it. He completely owned it and is probably even better at his job! I'd want him taking care of my plane! It's great that both pilots were level headed, worked together and landed without incidence!
THANK YOU NTSB and the mechanic & pilots involved. This is your BEST VIDEO yet! After all, we need to learn from each others mistakes, since we will never fly long enough to make them all ourselves!
Did he not check his own work??? Checking the angles of trim at certain settings is part of the procedure. I'm a retired A&P, and when he said he was playing with trim, getting worse, my immediate thought was that he looped the cables opposite
I've been there and "participated in that." Let me set the scene: 1969, Wiesbaden, Germany, Wiesbaden Air Base. T-39 Aircraft. Working as a "Instrument Repairman" with an "Electrician" on, I think, an elevator trim actuator replacement. Following the replacement of the actuator, the Electrician asked me to "ops check the system." I did, and told him it worked backwards! He said: "No way." The trim tab came "Up" which meant the nose of the plane came UP, and the trim tab came DOWN, which meant that the nose of the T-39 came down. WRONG! When the tab goes up, it deflects the elevator DOWN, thus, the nose of the plane goes down, and vice-versa. After a few "run throughs" the Electrician agreed. I then "signed off" the trim system. This is how trim system problems are allowed to come into being. USAF Ret. N-6395T
I have a commercial cert with inst rating SEL (320 TT), and am a career structures maintenance man on commercial and military big iron. The only time I've done rigging was in A&P school, but it seems that a rigging procedure should have been followed with a visual check of proper elevator trim tab travel after maintenance by the mechanic/IA, and before the work was signed off for return to service. Additionally, as a pilot, one should also do a visual check of elevator trim tab proper travel, knowing that particular work was done, though I understand a pilot not doing this. Honestly, I probably wouldn't have if called for the post-maintenance flight, especially with the mechanic standing there explaining what he'd done. Proper trim tab travel is not a normal part of a pre flight check by the pilot. Proper main flight control surface travel IS normal pre flight (thumb up, surface up). The mechanic here said "the control cables had done a 180 when they were put on the actuator." Damn! How was that not seen with the naked eye? One unfortunate part of aviation maintenance is that humans make mistakes. I've made mistakes as a pilot and mechanic. Some could have been life-threatening, but since I work under a repair station my work is checked and signed off by an IA or designated inspector. I have a nephew who picked up a Mooney after major maintenance associated with an annual inspection, including main flight control rigging. When he rotated he quickly discovered right was left and left was right with the ailerons. He crashed the plane on the grass strip, completely destroyed it, and miraculously walked away with no injuries. Flying is one of the safest things a human can choose to do, but it is very unforgiving of mistakes by people in charge of maintaining thousands of pounds of aluminum and steel rocketing through the atmosphere. During my commercial training my instructor had me fly a 172 with full down and full up elevator trim. It wasn't fun, but was doable. I'm glad these two men were able to do it, too. I guess if it wasn't for the risk, flying wouldn't be so damn much FUN!
So why didn't anyone mnually check the flight surface movements after the re-rigging? Activate the trim and watch the surfaces move. Simple checkout that should be mandatory after re-rigging the trim system. And another silly question, why the hell aren't the cables made in such a way as to not be able to connect the cables to the wrong location? Whoa....imagaine that?!
In my transport category work years ago, it was a maintenance check list item to check proper direction of flight controls, even if we hadn't disturbed them. My guess is that someone in the past had overlooked an improperly connected flight control, and the powers that were wanted to make certain that it could never happen again.
As an ex aircraft mechanic from the military, is there no QA to ensure work was properly performed? Besides QA, what's wrong with a visual inspection while someone actuates the trim tabs to ensure flight surfaces are moving in the direction selected? It's way too late once the aircraft has taken off to realize it's rigged wrong.
I know nothing or aviation but I too was wondering how the mechanic could carry out work on the trim and not actually physically check that it was working properly. It would seem common sense to push the trim button and actually see that it's working properly.
@Debbie : Yes... it is more important to check that the operation is correct after work is done than to follow instructions religiously. I'm sure some might be scandalized by this statement, but there are good reasons to think this and operate this way. For example, something may get twisted or reversed or pinched or tweaked or otherwise changed somewhere that literally *CANNOT* be seen. Therefore, the *ONLY* way to assure correct function of the airplane after work is done is to verify the final results of the system are doing what they are supposed to do. In this case, this is easy... just look at the direction the trim portion of the elevator is moving when you "trim nose up" and "trim nose down" with the cockpit control. If the trim surface moves the correct direction in both cases (and to the full positive and negative extent), then this is better verification the system is working properly than anything else. To be sure, perform the correct actions in the correct order per instructions, but the final check is at least as important, if not more important. Also note that many airplanes have been modified many times, and thus the nominal instructions for that make and model may not be correct for any given airplane. In such cases, the *ONLY* way to realize the airplane won't work properly is... to visually verify that the system *DOES* function properly after the work is done. PS: Every pilot is supposed to check the control surfaces (ailerons, elevator, rudder) move (and move in the correct direction) before every takeoff. When I watch youtube videos, most pilots go through the checklist so fast that clearly they are mostly just pretending to check some of the items, this being high on the list for being careless. However, I've never seen a checklist that includes checking whether the trim controls are operational and moving in the correct direction. This makes me want to add this to my list. In theory these item should never be connected backwards except after repairs, service, maintenance is done. But... the number one law of the universe is Murphy's Law, so... don't be too sure! :-o :-)
@@maxbootstrap7397- I can't speak about the civil aviation process, but in Naval Aviation, you follow the book or people die!!! Like was always said, procedures in the books (Maintenance Instruction Manuals (MIM's)) are written in blood! You're right Max, there are equipment variances even in the same type/model aircraft, and the maintenance instructions are written to address all configurations. Post maintenance checks (MIM's QA Inspections) would be written to ensure the control surfaces move in the correct direction for each control input. By The Book Maintenance!!! P-3C IFT U.S. Navy (Ret.)
@@markb.1259 : We don't really disagree, but let me ask you the following question. What if you repaired an airplane and you were super-duper-hyper-vigilant to follow every word, phrase, sentence, instruction. Further, let's assume your "bible" doesn't include instructions to perform a visual check of behavior at the end. But just for fun (or because you are a prudent guy), you go ahead and push the yoke back and forth (to make the elevator surface move up and down), and then you rotate the trim wheels and notice the trim surface moves in the opposite direction as the main elevator surface? Would you just say to yourself... hey, I believe the instructions (my "bible")? Or would you more believe your own eyes and brain (and understanding of how airplanes work)? Go ahead and answer this question. Then answer the following question. You are a pilot who is flying an airplane that you know (or don't know) was just serviced or repaired. But when you move the trim wheel in your airplane... it repeatedly has the opposite effect that you want in both directions. Would you continue to trim in the direction that causes you to crash... because that's what your POH (pilot operating handbook == the pilot "bible") tells you to do? Or would you "believe your lying eyes" (so to speak) and reverse the direction you turn the trim wheel until you are safely on the ground and able to more thoroughly figure out why your pilot expectations (your eyes and senses and behavior of the airplane) do not match your "bible" (your training, instruction, expectations and POH bible)? Get the point?
This is a perfect example of when your doing something like adjusting trim and the aircraft isn't doing what you want stop and return to the airport don't mess with it try to trouble shoot it in the air unless it you have to in order to land it. Also do your own pre-flight check make sure everything goes the right direction.
We wouldn't be human if we didn't make mistakes... But we can learn from them, unlike machines. In UK aircraft maintenance, duplicate inspections are called up in respect of any flight or engine control that's been disturbed. The first inspector will be licenced specifically on the aircraft type or hold a group rating. The second inspector must be licenced but need not necessarily be rated on the aircraft. Correct ranges of movement (including 'sense') and locking devices will be inspected and both signatories will have a thorough understanding of controls and their effects. It's a good system and I'm surprised that the FAA haven't introduced it. Murphy's Law is always happy to apply itself to lone or fatigued workers.
Two things - respect for maintenance engineer ! Really talking in a good way about his mistake - isn't really possible to manufacture those parts with a bit of "child safe" design ? Why both fixing extremities have same diameter for example ? I think those errors can be avoided by design
I agree with checking the direction and operation of flight controls and trim tabs after they've been worked on. I've read too many stories about this kind of problem. Add one more fan of Fletcher's attitude here. He owned it.
A great lesson here..... after messing with control system, cables, tell the pilot !! Also, the pilot and mechanic should set max up and max down trim and verify each of those.
It is on every pre flight inspection for every airplane. If not add it to the end of the preflights Controls free and clear, moving in the right direction. Pull up, elevator up, push down, elevator down, right bank, right surface up left down, left bank, left surface up right down. Rudder free left peddle left, right peddle right. A also cycle flaps looking for symmetrical deployment and retraction. Cycle trim tabs up and down right and left. Looking for up for up, down for down, left left, right rudder right. Do it as the end of your walk around inspection. ESPECIALLY AFTER ANY MAINTENANCE WORK. I do it every time.
Why weren't the control surfaces and trim actuation checked on the ground upon completion of rerigging? It seems to me that would be standard practice in part of the rerigging process... Not doing so seems completely irresponsible and unprofessional of the AP Tech that worked on the aircraft...
Preflight for worked on planes out to include visually verifying trims function properly. Trim tab sticking up forced elevator down which is opposite. I'm sure those guys will check planes a little better from now on.
So nobody - engineers, pilots - checked the trim movement before departure? The engineer made the initial mistake but ultimately it's the PIC's responsibility to make sure the a/c is safe for flight. Neither pilot seemed to recognise this in the video.
That is exactly what I was gone say. How the hell can you not check the flight control surfaces, especially after maintenance. This was mostly the mechanic's fault because when you do your pre flight you do check the main control surface's and hinges, but almost no pilot ever check the trim control surfaces to see if they're reversed, the most they might look at is the hinges of the trim tab. It was the responsibility of the mechanic to check all the flight controls before handing the plane over to the pilot, especially since he worked on that part of the plane.
+Will Givenoname Agreed it was the responsibility of the mechanic to check after he'd done his work, but once the PIC took the aircraft, and *didn't* check it himself (and I think it is reasonable to expect that a pilot checks his trim movement, it's not hard), he accepted responsibility for that mistake. He's in command, it's his ship, and he didn't check it properly. And at the end of the day, it's his life on the line.
I want to thank you all for sharing this important Learning lesson video. We need to be aware of proper control movements during preflight inspections...
As a non expert I assume that this would have been picked up in both post maintenance check, post maintenance pre flight check, and a normal pre flight check. Check trim direction.
Roy Chadwick, the man who designed the Avro Lancaster was killed in 1947 as a passenger in an Avro Tudor which had been serviced and had its aileron controls reversed. Any flier, even a model aircraft flier, will tell you that there is no way out of that. When we were flying fullsize gliders in the 1960s, before the first flight of the day we would check not only controls free and full in movement but all moving in the correct sense, eg, Left Aileron up, Right Aileron down etc, elevator trim tab moving through up, down and centred. Always seemed to make a lot of sense to we youngsters.
This is an age-old problem. In fact, the designer of the Avro Lancaster bomber of WW2 was killed in an accident where the ailerons were mis-rigged! Respect to the pilots for getting out of that just needing fresh underwear and props to the mechanic for going on camera to talk about his mistake! That takes guts.
"The control cables had done a 180 when they were put on the actuator." So even after the fact, this mechanic is subconciously blaming the cables instead of himself. "I put the control cables on that actuator backwards" is the honest answer.
Just echoing what others have said down below... 12:22 Why don't they just say: After re-rigging flight controls, double check that trim tabs and other surfaces move in the correct direction before getting in the damn plane to fly it? In the maintenance manuals: After re-rigging flight controls, double check that trim tabs and other surfaces move in the correct direction before giving it back to the pilot? Where is the common sense? GA been flying almost a hundred years now... and yet to even FIND the error, you need a high power flash light and a mirror to discover the cause? Sheesh! This is insanity on steroids! Oh well, preaching to the choir in this comment section.
A line boy once put the wrong type of fuel into Bob Hoover's Aero Commander. Bob crashed after takeoff, was not hurt. What do you think the line boy felt ???? Bob, a fine man........... told the boy that Bob knew he would never make that mistake again, therefore that one boy would always be the refueling person whenever Bob's plane needed fuel. ( later on, the gas nozzles, etc were changed to different shapes for avgas vs jet fuel. )
What happened to phisically looking at the trim travel after rigging to varify correct travel? I've rigged 3 in past 12 months and it's just too easy to have someone roll the trim tab wow you're visually monitoring the direction of travel before the aircraft ever leaves the shop. There is no excuse for bad rigging
As a non pilot from another engineering discipline, I am surprised the rigging connectors are not keyed to prevent the possibility of this maintenance error ever occurring. It's the equivalent of having a road vehicle turn to the left when the steering wheel is turned right, imagine trying to drive under those conditions, let alone fly an aircraft!
G'day, Yay Team ! It's a bit scary that the LAME who did the job could brief a Commercial Pilot with Twin-Engined Single-Pilot and Instrument Ratings on how the Elevator Controls had Bin-Rerigged, but neither of them, nor the other (less experienced) Copilot actually NOTICED what they were looking at during the Post-Maintenance and Inspection and Pre-Flight Checks.... Apparently, none of them had ever consciously thought-through the way in which Trailing-Edge "Servo-Tab" Trim, work...; THE TAB MUST ALWAYS MOVE COUNTER TO THE DIRECTION ONE WANTS TO DEFLECT THE CONTROL-SURFACE.., if you dial in "Up Trim" then the Tab's Trailing-Edge must move Down, and vice versa... It should be an integral part of the Visual Inspection..., all 3 times. As for the Pilotage and Airmanship...; I thought one held the desired Nose-Attitude with the Elevators, and then moved the Trim-Control to remove the Stick Pressure without even looking at the "Trim-Indicator"..., because... The idea is to "Titrate the Dose" by feel, not to blindly believe the Instruments just because they're certified to tell the truth....; this young Pup's Instrument Rating nearly killed the both of them, before he began to think to even try to Fly The AEROPLANE, rather than to trying to Crash it by believing in whatever the (lying mongrel) Trim-Indicator had to say...! Maybe it would help if every Pilot were required to complete 15 or 20 Hours in Sailanes, before beginning to get fixated on operating the Powerplant...; Stick & Rudder Skills, and seat-of-the-pants Pilotage and Airmanship seem to have somehow Bin-Discarded, in the haste to teach Autopilot-Management and Navigation by GPS...(?). ;-p Ciao !
watching a mis rigging video from the faa is quit similar in some ways to being forced to watch the movie of how hair is starting to grow out of my armpits in middle school by the health dept, thank you big brother !
I didn't hear anyone mention "Independent Inspections" during the video. Are they not specified by the FAA? In Australia where I am a LAME (Equiv of your A&P IA), if we carry out maintenance on ANY part of the flight control system, it requires an Independent Inspection by a second LAME who has had nothing to do with the work that was carried out. The inspection MUST ensure that the work was carried out properly and that the whole system that was worked on has been reassembled, has been correctly locked, correct tension and full free CORRECT movement.
The brain is self--protective. The denial or even stronger dissociation can take over instantly. It isn't intentional. It's not a choice. Relax and pull thoughts back for a long look, a fresh perspective. Take a deep breath. The brain also works on reflex not only intentional thoughts.
Good CRM and thought processes, but this illustrates why "Full and Free movement of controls and trims in the correct direction" should be in the checklists somewhere before take-off for any flight. (Pre-taxi wastes the least amount of time if something's wrong.) Its absolutely vital after any maintenance more invasive than inflating the tyres. Murphy's lurking any time something's changed or disconnected; the literature's full of such errors. They were lucky it was only the trim, (which can be overcome with brute force on most light aircraft) rather than the actual controls. There usually isn't time to diagnose that.
Can't help but notice the rigger's electrical outlets are installed upside-down... (That's a joke, don't light me up. I'm glad it all worked out in the end and no one got hurt)
Gotta agree with WarblesOnALot. It's hard to believe that, after a trim tab re-rig, all involved never stepped back and verified the Tab position at it's extreme nose-up/nose-down position from an aerodynamic point of view before this aircraft took flight. Show's a total lack of understanding of HOW the controls work. I'm surprised the NTSB did not even cover the basic aerodynamic principles involved in this vedio....what a missed opportunity. I'll bet even now you could take the same crew and rig the trim properly and mis-rig the elevator and they'd taxi out for a flight.
I have noticed that even fighter pilot's on multimillion-dollar jets will check the movement of all control surfaces before takeoff. I suspect this kid will never skip that part again.
I don't understand this. Why wouldn't you ground test the trim tabs before you flew the plane. Along with the flaps, rudder and all systems that could have been affected by maintenance work.
How is it possible that a mechanic can release an airplane without checking flight control surfaces and did anybody else notice that the power outlets in the office where upside down
it's not enough to admit your mistake. he should have admitted he did not function check the controls prior to signing off on the work and therefore he was negligent and could have killed those two boys. I first got my pilot's license in 1965 (SEL). I have over a 1000 hrs of flight time. I quit flying in 1988 for health reasons but the point I want to make is that in all that time checking directional control of the trim tab was never part of the airplane pre-flight walk around checklist. Apparently this is not an uncommon problem. These guys were very lucky.
The elevator tab moves in the same direction as the trim wheel,that's how I always remembered it. Also in flight trouble shooting should be avoided,that's what killed Alaska 261.
Well, that's just stupid. That's like wiring the hot to the neutral on electrical outlets. Talk to yourself when you're wiring or rigging cables. A $30 label maker or 3M electrical tape would serve as well. Finally, check your work by having a partner operate the controls while one observes from the outside. Why are we even having to talk about this?
this is garbage....any sane pilot doing a preflight will check the neutrality of the trim on the elevator during a walk-around.....I've caught this many times after maintenance. The checklist calls for it. It's the PIC's job on a preflight to determine proper trim tab position. An aircraft should be controllable no matter where the trim is set. CFI CFII MEI ATP Gold seal.....11,000+ hrs
Not to cast disparaging remarks, but a 400 hr pilot is really not in a position to do a "Maintenance Flight Check." Not really. Hey, as a 1,000hr PP I'd say I'm in the "rookie category," but I have worked on a LOT of airplanes, as a G.I. and also as a Civilian. I've seen the mistakes that can be, and ARE made, even with two people looking at a completed job. Even with all of the credentials, you have to understand the "mechanics" as to how "things work." Yes, follow the maintenance manuals, but understand what you are reading.
It's probably a good thing they had TWO decent ppl holders on that flight, plus they were young - this is a lesson both will carry the rest of their lives.
The AMT who was willing to go ON CAMERA and admit his mistakes has shown an unprecedented amount of courage to help us all. THANK YOU!!!!!!
A&P: Airframes and Powerplants, yeah he is good guy to go on camera.
It must have taken a lot of courage for the maintenance engineer to admit his mistake for this video. Thanks for sharing!
Jeremy Fonseca I have walked right where he is back in the late 80s. There were three of us changing the elevator trim cable on a PA28-181. When we were done all three of us verified, or so we thought, that the cable was installed correctly by operationally checking the system.
An Instructor came over to pick the aircraft up. We briefed him on the maintenance we had accomplished and away he went. He took off and came right back and informed us that the trim was backward. Luckily he was experienced and picked up on it immediately. I will never forgot how horrifying that day was for all of us. After that, we changed several more cables and trim drums and verified correct operation a gazillion times prior to releasing the aircraft. It makes me shake to this day.
Jeremy Fonseca You need to listen again. He never admitted that he screwed up. He kept using passive voice.
"The control cables had done a 180 when they were put on the actuator."
"I realized where the mistake was."
"That step was missed."
and
"I never thought that I would have missed it."
Yes, it would take courage to say "I screwed up" or "I attached the cables backwards" but he never did. Not courageous...gutless.
Jay, you are right. This guy could have killed two people. Wouldn't a proper ops check have found this problem? Any flight control that is touched requires an ops check. I'm not so forgiving on "accidents" or "mistakes". I've worked with mechanics that don't take this seriously enough and take short cuts. The mechanic in the video emphasizes following the AMM. It's common practice to not follow the manual when being pressured to get a job done. That is NOT a mistake. That is a choice and a violation. I wonder if part of his penalty was community service in making this video?
Yeah, hundreds or maybe even thousands of jobs done, anyone can make a mistake. Key is to learn from it and not repeat..
@@giggleherz people have been drinking, smoking, in a funk, mind elsewhere for whatever reason. your mechanic has to be top-notch person 365 days of the year ; ) and that's a fact.
Two things surprise me about this video. The fact that the pilots figured this out while fighting the airplane is amazing. The fact that the mechanic admits and talks about his mistake is awesome. Definitely respect all three of them- Great information.
Hats off to theA&P who was willing to go on camera with his mea culpa. He has the character to match the skill we all hope for when we get into an airplane.
Somebody buy that man a drink!
I would add my voice to those expressing appreciation of the mechanic's video mea culpa. There's a palpable sense of his regret. That said, the trim should have been checked by the pilot before the engine was started. The sixth item on my pre-flight checklist is trim check. That means fully deflecting the trim tab in both directions and observing that it's moving in the correct direction and moving fully to each stop. It should be checked for every flight but especially on a post maintenance flight where the mechanic specifically advised the pilot that the trim was re-rigged!! it may have been the mechanic's mistake but it's the pilot's responsibility for the flight controls to be correct.
I feel great respect for Stephan Fletcher for sharing his lesson. This story may someday save lives. Thank you, Stephan.
im impressed that all parties involved were willing to talk, thumbs up guys this is a step forward for all of us!
This actually happened to me. I had the good fortune to recognize the problem shortly after takeoff because I was The pilot that was responsible for returning the aircraft to service after maintenance. The mechanic stated that he had worked on the trim tab. After departure when I trimmed for nose up, it acted like nose down pressure. I had the good fortune of realizing that the rigging was inverted and immediately tested that hypothesis by reversing the trim wheel input. The process worked so therefore I neutralized the pressure on the control wheel and then returned the aircraft for an uneventful landing and I immediate return to the shop that did the work. It was discovered that the bell crank had been turned 180° the cable therefore activated the trim tab in the opposite direction. It was just another normal test flight for me but I did not realize that over half a dozen people lost their lives with a similar mechanical error. Excellent video on unexpected in-flight emergencies. The Cessna 172 did not have electric trim, thank goodness.
I realise that my comments here are two and a half years after this video was published, but I have to put my two cents in.
I have been a Licensed Aircraft Engineer for some 15 years now and I have done this same and similar jobs many times. Luckily I have not had any issues so far. Those that have made negative comments below about the mechanic don't obviously realise that some parts of airplanes are almost impossible to see into to detect errors such as what happened here and how easy it is to cross-rig trim cables.
Years ago "The Right Stuff" was never to admit your errors. Today, we have learned that was absolutely the wrong thing to do, and you have to put your hand up when you have made an error. Nobody has enough time to make all the mistakes, so we have to learn from those of other people.
Stephan, you have my total respect for fronting up on this video and telling your story. I, like you have heard the stories and read the reports. Next time I play with a flight control, I will think of your story.
These videos are so important. From now on I will check the directional movement of the trim wheel and the actual trim after any maintenance. Then I will check the movement of the trim wheel when using the electric trim switch. Thank you for sharing your experiences. Double kudos to the mechanic who shared his error publicly to make aviation that much safer. Takes a big man to do that. We ALL make mistakes, but the more we check and double check the work of others, the safer we can all be. This video reinforces that in spades.
As many comments stated, this A&P is very admirable! He was in disbelief at first but didn't deny it. He completely owned it and is probably even better at his job! I'd want him taking care of my plane! It's great that both pilots were level headed, worked together and landed without incidence!
THANK YOU NTSB and the mechanic & pilots involved. This is your BEST VIDEO yet!
After all, we need to learn from each others mistakes, since we will never fly long enough to make them all ourselves!
Did he not check his own work??? Checking the angles of trim at certain settings is part of the procedure. I'm a retired A&P, and when he said he was playing with trim, getting worse, my immediate thought was that he looped the cables opposite
I've been there and "participated in that." Let me set the scene: 1969, Wiesbaden, Germany, Wiesbaden Air Base. T-39 Aircraft. Working as a "Instrument Repairman" with an "Electrician" on, I think, an elevator trim actuator replacement. Following the replacement of the actuator, the Electrician asked me to "ops check the system." I did, and told him it worked backwards! He said: "No way." The trim tab came "Up" which meant the nose of the plane came UP, and the trim tab came DOWN, which meant that the nose of the T-39 came down. WRONG!
When the tab goes up, it deflects the elevator DOWN, thus, the nose of the plane goes down, and vice-versa. After a few "run throughs" the Electrician agreed. I then "signed off" the trim system. This is how trim system problems are allowed to come into being.
USAF Ret. N-6395T
I have a commercial cert with inst rating SEL (320 TT), and am a career structures maintenance man on commercial and military big iron. The only time I've done rigging was in A&P school, but it seems that a rigging procedure should have been followed with a visual check of proper elevator trim tab travel after maintenance by the mechanic/IA, and before the work was signed off for return to service. Additionally, as a pilot, one should also do a visual check of elevator trim tab proper travel, knowing that particular work was done, though I understand a pilot not doing this. Honestly, I probably wouldn't have if called for the post-maintenance flight, especially with the mechanic standing there explaining what he'd done. Proper trim tab travel is not a normal part of a pre flight check by the pilot. Proper main flight control surface travel IS normal pre flight (thumb up, surface up). The mechanic here said "the control cables had done a 180 when they were put on the actuator." Damn! How was that not seen with the naked eye? One unfortunate part of aviation maintenance is that humans make mistakes. I've made mistakes as a pilot and mechanic. Some could have been life-threatening, but since I work under a repair station my work is checked and signed off by an IA or designated inspector. I have a nephew who picked up a Mooney after major maintenance associated with an annual inspection, including main flight control rigging. When he rotated he quickly discovered right was left and left was right with the ailerons. He crashed the plane on the grass strip, completely destroyed it, and miraculously walked away with no injuries. Flying is one of the safest things a human can choose to do, but it is very unforgiving of mistakes by people in charge of maintaining thousands of pounds of aluminum and steel rocketing through the atmosphere. During my commercial training my instructor had me fly a 172 with full down and full up elevator trim. It wasn't fun, but was doable. I'm glad these two men were able to do it, too. I guess if it wasn't for the risk, flying wouldn't be so damn much FUN!
So why didn't anyone mnually check the flight surface movements after the re-rigging? Activate the trim and watch the surfaces move. Simple checkout that should be mandatory after re-rigging the trim system. And another silly question, why the hell aren't the cables made in such a way as to not be able to connect the cables to the wrong location? Whoa....imagaine that?!
In my transport category work years ago, it was a maintenance check list item to check proper direction of flight controls, even if we hadn't disturbed them. My guess is that someone in the past had overlooked an improperly connected flight control, and the powers that were wanted to make certain that it could never happen again.
As an ex aircraft mechanic from the military, is there no QA to ensure work was properly performed? Besides QA, what's wrong with a visual inspection while someone actuates the trim tabs to ensure flight surfaces are moving in the direction selected? It's way too late once the aircraft has taken off to realize it's rigged wrong.
I know nothing or aviation but I too was wondering how the mechanic could carry out work on the trim and not actually physically check that it was working properly. It would seem common sense to push the trim button and actually see that it's working properly.
@Debbie : Yes... it is more important to check that the operation is correct after work is done than to follow instructions religiously. I'm sure some might be scandalized by this statement, but there are good reasons to think this and operate this way. For example, something may get twisted or reversed or pinched or tweaked or otherwise changed somewhere that literally *CANNOT* be seen. Therefore, the *ONLY* way to assure correct function of the airplane after work is done is to verify the final results of the system are doing what they are supposed to do. In this case, this is easy... just look at the direction the trim portion of the elevator is moving when you "trim nose up" and "trim nose down" with the cockpit control. If the trim surface moves the correct direction in both cases (and to the full positive and negative extent), then this is better verification the system is working properly than anything else. To be sure, perform the correct actions in the correct order per instructions, but the final check is at least as important, if not more important. Also note that many airplanes have been modified many times, and thus the nominal instructions for that make and model may not be correct for any given airplane. In such cases, the *ONLY* way to realize the airplane won't work properly is... to visually verify that the system *DOES* function properly after the work is done.
PS: Every pilot is supposed to check the control surfaces (ailerons, elevator, rudder) move (and move in the correct direction) before every takeoff. When I watch youtube videos, most pilots go through the checklist so fast that clearly they are mostly just pretending to check some of the items, this being high on the list for being careless. However, I've never seen a checklist that includes checking whether the trim controls are operational and moving in the correct direction. This makes me want to add this to my list. In theory these item should never be connected backwards except after repairs, service, maintenance is done. But... the number one law of the universe is Murphy's Law, so... don't be too sure! :-o :-)
@@maxbootstrap7397- I can't speak about the civil aviation process, but in Naval Aviation, you follow the book or people die!!! Like was always said, procedures in the books (Maintenance Instruction Manuals (MIM's)) are written in blood! You're right Max, there are equipment variances even in the same type/model aircraft, and the maintenance instructions are written to address all configurations. Post maintenance checks (MIM's QA Inspections) would be written to ensure the control surfaces move in the correct direction for each control input. By The Book Maintenance!!! P-3C IFT U.S. Navy (Ret.)
@@markb.1259 : We don't really disagree, but let me ask you the following question.
What if you repaired an airplane and you were super-duper-hyper-vigilant to follow every word, phrase, sentence, instruction. Further, let's assume your "bible" doesn't include instructions to perform a visual check of behavior at the end. But just for fun (or because you are a prudent guy), you go ahead and push the yoke back and forth (to make the elevator surface move up and down), and then you rotate the trim wheels and notice the trim surface moves in the opposite direction as the main elevator surface?
Would you just say to yourself... hey, I believe the instructions (my "bible")? Or would you more believe your own eyes and brain (and understanding of how airplanes work)? Go ahead and answer this question.
Then answer the following question. You are a pilot who is flying an airplane that you know (or don't know) was just serviced or repaired. But when you move the trim wheel in your airplane... it repeatedly has the opposite effect that you want in both directions. Would you continue to trim in the direction that causes you to crash... because that's what your POH (pilot operating handbook == the pilot "bible") tells you to do? Or would you "believe your lying eyes" (so to speak) and reverse the direction you turn the trim wheel until you are safely on the ground and able to more thoroughly figure out why your pilot expectations (your eyes and senses and behavior of the airplane) do not match your "bible" (your training, instruction, expectations and POH bible)?
Get the point?
Thanks to all of the people who participated in this video. I learned a very important lesson.
This is a perfect example of when your doing something like adjusting trim and the aircraft isn't doing what you want stop and return to the airport don't mess with it try to trouble shoot it in the air unless it you have to in order to land it. Also do your own pre-flight check make sure everything goes the right direction.
why wouldnt anyone run the trim on the ground and watch the tabs? like we do on the ailerons ....on the ground.
Why did pilot not visually inspect and verify trim control before takeoff, especially post maintenance?
I'd like to congratulate whoever masked out the registration of aircraft N2790L for doing such a complete and thorough job on this video. Um... not.
We wouldn't be human if we didn't make mistakes... But we can learn from them, unlike machines.
In UK aircraft maintenance, duplicate inspections are called up in respect of any flight or engine control that's been disturbed. The first inspector will be licenced specifically on the aircraft type or hold a group rating. The second inspector must be licenced but need not necessarily be rated on the aircraft. Correct ranges of movement (including 'sense') and locking devices will be inspected and both signatories will have a thorough understanding of controls and their effects. It's a good system and I'm surprised that the FAA haven't introduced it.
Murphy's Law is always happy to apply itself to lone or fatigued workers.
Two things
- respect for maintenance engineer ! Really talking in a good way about his mistake
- isn't really possible to manufacture those parts with a bit of "child safe" design ? Why both fixing
extremities have same diameter for example ? I think those errors can be avoided by design
What a candid interview, congratulations on a great educational video.
I agree with checking the direction and operation of flight controls and trim tabs after they've been worked on. I've read too many stories about this kind of problem. Add one more fan of Fletcher's attitude here. He owned it.
This seems like it could be avoided by running the trim through it's paces while on the ground and checking for proper deflection.
Kudos for the AP talking about the mistake.
Glad it worked out👍
A great lesson here..... after messing with control system, cables, tell the pilot !! Also, the pilot and mechanic should set max up and max down trim and verify each of those.
They got lucky! And I'm glad they made it. Thanks for sharing.
That mechanic is so happy that plane made a successful landing that he was happy to make the video.
It is on every pre flight inspection for every airplane. If not add it to the end of the preflights Controls free and clear, moving in the right direction. Pull up, elevator up, push down, elevator down, right bank, right surface up left down, left bank, left surface up right down. Rudder free left peddle left, right peddle right. A also cycle flaps looking for symmetrical deployment and retraction. Cycle trim tabs up and down right and left. Looking for up for up, down for down, left left, right rudder right. Do it as the end of your walk around inspection. ESPECIALLY AFTER ANY MAINTENANCE WORK. I do it every time.
Why weren't the control surfaces and trim actuation checked on the ground upon completion of rerigging? It seems to me that would be standard practice in part of the rerigging process... Not doing so seems completely irresponsible and unprofessional of the AP Tech that worked on the aircraft...
Preflight for worked on planes out to include visually verifying trims function properly. Trim tab sticking up forced elevator down which is opposite. I'm sure those guys will check planes a little better from now on.
So nobody - engineers, pilots - checked the trim movement before departure? The engineer made the initial mistake but ultimately it's the PIC's responsibility to make sure the a/c is safe for flight. Neither pilot seemed to recognise this in the video.
That is exactly what I was gone say. How the hell can you not check the flight control surfaces, especially after maintenance. This was mostly the mechanic's fault because when you do your pre flight you do check the main control surface's and hinges, but almost no pilot ever check the trim control surfaces to see if they're reversed, the most they might look at is the hinges of the trim tab. It was the responsibility of the mechanic to check all the flight controls before handing the plane over to the pilot, especially since he worked on that part of the plane.
+Will Givenoname Agreed it was the responsibility of the mechanic to check after he'd done his work, but once the PIC took the aircraft, and *didn't* check it himself (and I think it is reasonable to expect that a pilot checks his trim movement, it's not hard), he accepted responsibility for that mistake. He's in command, it's his ship, and he didn't check it properly. And at the end of the day, it's his life on the line.
...and not just post maintenance...we are talking re-rigging of flight controls!!
Thank you so much for sharing this story!
You know which mechanic I'd trust to rig my elevator trim? The guy who admitted his mistake. I'd bet he never does it twice.
Great job, thanks for sharing!
That tow bar left attached bothered me so much i had to watch the video twice.
Why the design allow a mis-rigging? Electric connector could be keyed and cable attachment could be designed to be NOT interchangeable.
I want to thank you all for sharing this important Learning lesson video. We need to be aware of proper control movements during preflight inspections...
As a non expert I assume that this would have been picked up in both post maintenance check, post maintenance pre flight check, and a normal pre flight check. Check trim direction.
The importance of a thorough Operational checkout can't be understated. ESPECIALLY for Primary Flight Controls.
Seems like the sort of thing that would come from the factory which can only be assembled one way, the ends not being interchangable.
Roy Chadwick, the man who designed the Avro Lancaster was killed in 1947 as a passenger in an Avro Tudor which had been serviced and had its aileron controls reversed. Any flier, even a model aircraft flier, will tell you that there is no way out of that.
When we were flying fullsize gliders in the 1960s, before the first flight of the day we would check not only controls free and full in movement but all moving in the correct sense, eg, Left Aileron up, Right Aileron down etc, elevator trim tab moving through up, down and centred. Always seemed to make a lot of sense to we youngsters.
This is an age-old problem. In fact, the designer of the Avro Lancaster bomber of WW2 was killed in an accident where the ailerons were mis-rigged! Respect to the pilots for getting out of that just needing fresh underwear and props to the mechanic for going on camera to talk about his mistake! That takes guts.
What about My kids? They died
"The control cables had done a 180 when they were put on the actuator." So even after the fact, this mechanic is subconciously blaming the cables instead of himself. "I put the control cables on that actuator backwards" is the honest answer.
Damn newfangled MCAS system!
Just echoing what others have said down below...
12:22 Why don't they just say: After re-rigging flight controls, double check that trim tabs and other surfaces move in the correct direction before getting in the damn plane to fly it?
In the maintenance manuals: After re-rigging flight controls, double check that trim tabs and other surfaces move in the correct direction before giving it back to the pilot?
Where is the common sense? GA been flying almost a hundred years now... and yet to even FIND the error, you need a high power flash light and a mirror to discover the cause?
Sheesh! This is insanity on steroids!
Oh well, preaching to the choir in this comment section.
A line boy once put the wrong type of fuel into Bob Hoover's Aero Commander. Bob crashed after takeoff, was not hurt. What do you think the line boy felt ???? Bob, a fine man........... told the boy that Bob knew he would never make that mistake again, therefore that one boy would always be the refueling person whenever Bob's plane needed fuel. ( later on, the gas nozzles, etc were changed to different shapes for avgas vs jet fuel. )
What happened to phisically looking at the trim travel after rigging to varify correct travel? I've rigged 3 in past 12 months and it's just too easy to have someone roll the trim tab wow you're visually monitoring the direction of travel before the aircraft ever leaves the shop. There is no excuse for bad rigging
Exactly. You are the guy I want working on my plane, not this fool that didn't verify his work.
@@Flying_Snakes Thank you Sir. I thank you for your service first and foremost!!!!!
@@randywilliams324 Thanks for your support, sir, and thanks for keeping us flying safely!
As a non pilot from another engineering discipline, I am surprised the rigging connectors are not keyed to prevent the possibility of this maintenance error ever occurring. It's the equivalent of having a road vehicle turn to the left when the steering wheel is turned right, imagine trying to drive under those conditions, let alone fly an aircraft!
G'day,
Yay Team !
It's a bit scary that the LAME who did the job could brief a Commercial Pilot with Twin-Engined Single-Pilot and Instrument Ratings on how the Elevator Controls had Bin-Rerigged, but neither of them, nor the other (less experienced) Copilot actually NOTICED what they were looking at during the Post-Maintenance and Inspection and Pre-Flight Checks....
Apparently, none of them had ever consciously thought-through the way in which Trailing-Edge "Servo-Tab" Trim, work...; THE TAB MUST ALWAYS MOVE COUNTER TO THE DIRECTION ONE WANTS TO DEFLECT THE CONTROL-SURFACE.., if you dial in "Up Trim" then the Tab's Trailing-Edge must move Down, and vice versa...
It should be an integral part of the Visual Inspection..., all 3 times.
As for the Pilotage and Airmanship...; I thought one held the desired Nose-Attitude with the Elevators, and then moved the Trim-Control to remove the Stick Pressure without even looking at the "Trim-Indicator"..., because...
The idea is to "Titrate the Dose" by feel, not to blindly believe the Instruments just because they're certified to tell the truth....; this young Pup's Instrument Rating nearly killed the both of them, before he began to think to even try to Fly The AEROPLANE, rather than to trying to Crash it by believing in whatever the (lying mongrel) Trim-Indicator had to say...!
Maybe it would help if every Pilot were required to complete 15 or 20 Hours in Sailanes, before beginning to get fixated on operating the Powerplant...; Stick & Rudder Skills, and seat-of-the-pants Pilotage and Airmanship seem to have somehow Bin-Discarded, in the haste to teach Autopilot-Management and Navigation by GPS...(?).
;-p
Ciao !
watching a mis rigging video from the faa is quit similar in some ways to being forced to watch the movie of how hair is starting to grow out of my armpits in middle school by the health dept, thank you big brother !
In GA there is no QA, but the mechanic should verify control movement prior to releasing the aircraft to service. Complacency is to blame
Pilot did a GREAT job.
I didn't hear anyone mention "Independent Inspections" during the video. Are they not specified by the FAA? In Australia where I am a LAME (Equiv of your A&P IA), if we carry out maintenance on ANY part of the flight control system, it requires an Independent Inspection by a second LAME who has had nothing to do with the work that was carried out. The inspection MUST ensure that the work was carried out properly and that the whole system that was worked on has been reassembled, has been correctly locked, correct tension and full free CORRECT movement.
Fletch the mechanic should have known it was the Fetzer valve!
The mechanic at left himself a little bit of wiggle room when he mentioned that somebody else had a very powerful flashlight but all in all it's cool
The brain is self--protective. The denial or even stronger dissociation can take over instantly. It isn't intentional. It's not a choice. Relax and pull thoughts back for a long look, a fresh perspective. Take a deep breath. The brain also works on reflex not only intentional thoughts.
Good CRM and thought processes, but this illustrates why "Full and Free movement of controls and trims in the correct direction" should be in the checklists somewhere before take-off for any flight. (Pre-taxi wastes the least amount of time if something's wrong.) Its absolutely vital after any maintenance more invasive than inflating the tyres. Murphy's lurking any time something's changed or disconnected; the literature's full of such errors. They were lucky it was only the trim, (which can be overcome with brute force on most light aircraft) rather than the actual controls. There usually isn't time to diagnose that.
"Controls Free, Clear and Correct!".
Activate trims! Someone verifies! WTF???
A C-T182T became an old C-172?
Can't help but notice the rigger's electrical outlets are installed upside-down... (That's a joke, don't light me up. I'm glad it all worked out in the end and no one got hurt)
My name is Stephan James Fletcher junior....[shame politicians don't own it like he did]
Why would they (pilots) not check the trim tab during preflight? After maintenance was done?
Don't they visually check trim operation while on the ground after repairs?
Gotta agree with WarblesOnALot. It's hard to believe that, after a trim tab re-rig, all involved never stepped back and verified the Tab position at it's extreme nose-up/nose-down position from an aerodynamic point of view before this aircraft took flight. Show's a total lack of understanding of HOW the controls work. I'm surprised the NTSB did not even cover the basic aerodynamic principles involved in this vedio....what a missed opportunity. I'll bet even now you could take the same crew and rig the trim properly and mis-rig the elevator and they'd taxi out for a flight.
why doesn't that Cessna in the back ground have an N number on the side ?
The outlet plug on the background are upside down
jack torrence why did they change it?
I think that’s a myth.
I have noticed that even fighter pilot's on multimillion-dollar jets will check the movement of all control surfaces before takeoff. I suspect this kid will never skip that part again.
If the cable end fittings were color-coded would that prevent reversing problems?
It was the trim rigging gnomes.
I don't understand this. Why wouldn't you ground test the trim tabs before you flew the plane. Along with the flaps, rudder and all systems that could have been affected by maintenance work.
Probably a Spartan A&P.
HIs first clue that he misrigged it was the pilot walking into the shop and taking a swing at him.
How is it possible that a mechanic can release an airplane without checking flight control surfaces and did anybody else notice that the power outlets in the office where upside down
Shouldn't this be caught on a flight control check before takeoff?
That's what killed old DeHavilland after WWII in a new 4 engine job...ailerons reversed as I read.
Dont they test All that BEFORE
Flight ¿¿¿¿
it's not enough to admit your mistake. he should have admitted he did not function check the controls prior to signing off on the work and therefore he was negligent and could have killed those two boys. I first got my pilot's license in 1965 (SEL). I have over a 1000 hrs of flight time. I quit flying in 1988 for health reasons but the point I want to make is that in all that time checking directional control of the trim tab was never part of the airplane pre-flight walk around checklist. Apparently this is not an uncommon problem. These guys were very lucky.
The elevator tab moves in the same direction as the trim wheel,that's how I always remembered it. Also in flight trouble shooting should be avoided,that's what killed Alaska 261.
Gas planes are so retro! Electric is the future.
Well, that's just stupid. That's like wiring the hot to the neutral on electrical outlets. Talk to yourself when you're wiring or rigging cables. A $30 label maker or 3M electrical tape would serve as well. Finally, check your work by having a partner operate the controls while one observes from the outside. Why are we even having to talk about this?
this is garbage....any sane pilot doing a preflight will check the neutrality of the trim on the elevator during a walk-around.....I've caught this many times after maintenance. The checklist calls for it. It's the PIC's job on a preflight to determine proper trim tab position. An aircraft should be controllable no matter where the trim is set.
CFI CFII MEI ATP Gold seal.....11,000+ hrs
Not to cast disparaging remarks, but a 400 hr pilot is really not in a position to do a "Maintenance Flight Check." Not really. Hey, as a 1,000hr PP I'd say I'm in the "rookie category," but I have worked on a LOT of airplanes, as a G.I. and also as a Civilian. I've seen the mistakes that can be, and ARE made, even with two people looking at a completed job.
Even with all of the credentials, you have to understand the "mechanics" as to how "things work." Yes, follow the maintenance manuals, but understand what you are reading.
It's probably a good thing they had TWO decent ppl holders on that flight, plus they were young - this is a lesson both will carry the rest of their lives.
@@perltech They are Commercial pilots, not Private Pilots.