How ONE NUT Saved 25 People | Danish Air Transport Flight 54
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- Опубликовано: 14 дек 2021
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ATR 42 Image: Ronnie Robertson - ATR 42 OY-CIR IMG_0524
Images: AIBN
This is the story of Danish air transport flight 54. On the 31st of january 2005 a crew started their day. On that day their day was packed they had to fly multiple hops. By about 11 am had already flown between floro and bergen. Now they were getting ready to fly another trip to floro from bergen. On the ground the pilots tested out the rudder and the ailerons just to make sure that everything was working, the first officer put the elevator through its full range of motion. It was a bit stiffer than usual. He associated that to the wind that day and didn't think too much of it. When youre on the ground the wind can push up against the elevator giving it a bit of stiffness its nothing to be concerned about and so they taxied to the runway.
The ATR 42 lined up with runway 35 and flight 54 started the takeoff roll at 11:28 am. The plane accelerated and within minutes the pilots were ready to takeoff. But as the captain pulled back on the stick he noted that he needed more force than usual to takeoff. His mind raced and he thought that he had set the trim incorrectly for takeoff. But as the plane climbed away from floro they both knew that that wasn't the case. Something was wrong with their plane.
In the cockpit the pilots were struggling to keep their plane under control. Both pilots wrestled with the controls just to keep the plane stable. The elevator was now moving in an uneven fashion, completely different from what they had observed on the ground. The captain didnt even bother turning the autopilot on as he knew that it would disengage.
At 11:29 am flight 54 was 3 nm north of the airport and they were at 2000 feet. They needed to land as soon as possible and so the pilots put out a mayday.The approach controller at flesland put the plane on a westerly course guiding it back to runway 35 and asked them to climb to 3000 feet. They needed to climb as there was some terrain in the area that they had to clear before they turned south. As they turned the captain could see the runway. The controller cleared the plane for a left downwind approach to runway 35. The pilots told the controller about their control issues and asked the airport to have emergency vehicles on stand by.
Within minutes the airport had fire trucks near the runway. By now the controllability issues had eased up a bit but the pilots lined the atr with the runway. I wonder what the pilots must have been thinking at that point. They were so close to their destination. 7 minutes after takeoff flight 54 landed back at floro. When the plane was back on the ground the captain asked the cabin crew member how the cabin was throughout the incident. Apparently in the cabin things were fine. No one in the cabin knew how serious the incident was.
After they had landed the pilots decided to inspect the plane. This is what they saw, the source of their troubles. The right hand elevator had mostly separated from the stabilizer. Three bolts and hinges were supposed to hold the elevator to the stabilizer and of that only one hinge was intact. I guess you could say that their success hinged on that one intact bolt. See what i did there? You know what, never mind. 
Наука
At about the 4 minute mark I said that each pilot controls one elevator. Now what I meant to say was that each pilot could control their respective elevator if needed due to a shear linkage in the system. Apologies for the confusion!
Your language is still a little confusing. Each pilot can control the SAME elevator. Although the elevator appears to be split, each side of the elevator does not move independently. Unless you're talking about a fighter jet or a very advanced fly by wire system.
Good that you address the elevator control error.
BUT...are you still maintaining that the pilot can control the drivers side elevator, and the copilot can control the passenger side elevator? I have never heard of that on a passenger airliner of any type.
Had me going there, for a minute...
On this aircraft in case of a jammed elevator the flight crew can manually uncouple the elevators by moving their control columns in opposite directions. A "PITCH DISCONNECT" warning light and Master Warning lights will then illuminate.
Hardware don’t have serial numbers it’ll have a part number but no serial number.
I've found in my own life that "just one nut" can cause all kinds of problems.
I knew something like this was coming. Expected it on top tbh
haha bloody good structuring
ZING!!
Not for me, I nut and bolt!
Yeh, we've got one here in the UK - his name is Boris Johnson !!
I had a situation back in about 1969. I had a student in a single engine plane seem to be a little slow in using the ailerons when told to turn one way or another. I told the student I needed to feel the control yoke. I discover that there was a lot of slop in the aileron movements. We landed at the closest airport. I began to remove inspection covers under the wing and found the aileron control turnbuckle had no safety wiring in it: it was slowly unscrewing itself since the last 100 hour inspection done within the last 10 hours. The 100 hour inspection just happened to have been done at the FBO where we had landed. The operator of that FBO wasn't happy. I heard later that the mechanic was fired.
Wow, that could easily have become a fatal accident if you, or another instructor, hadn't flown the plane. Quite reasonable that a student with no experience to compare it to would never notice.
Are the turnbuckle parts captive or would it eventually have unscrewed completely apart? I've seen both kinds but I don't know much about the hardware in aircraft.
Common sense dictates critical components be checked more often, in this case 6 years nobody has done anything about it, in case of flight 123 in Japan nobody checked bulkhead in 747 for 7 years after Boeing people “fixed” it, Alaska Air ending in Pacific because someone didn’t lubricate drive screw…on and on and on! I’m staying home.
When the pilots walked around the plane after landing and seeing the elevator just barely hanging on there must have send some serious chills down their back.
What would have happened if the elevator had detached, - would it have been completely unrecoverable?
@@philhughes3882 Maybe not impossible, but very difficult. They’d still have the left elevator, so they’d still have a bit of pitch control. That would give them quite a bit of roll, but they might be able to use the ailerons to counteract that. But they’d need to realize what happened very quickly that low to the ground, and it would be a real test of their piloting skill. I certainly wouldn’t want to be aboard a plane missing an elevator.
Confer Zero - Thank you, - much appreciated. I'm obviously not a pilot, just fascinated by it all. Thanks again.
@@conferzero2915 Here is an idea for pilots to see problems in the air: How about having a small electric current (say 10 volts) can be sent through the bolts and elevator mountings of a plane. If a bolt is missing, the current would measure zero. Then, the computer screen in the cockpit can show a diagram of where the missing bolt is, and sound a warning. If corrosion is an issue instead, the conductivity would drop, therefore, a corrosion warning could be sounded as soon as the plane's electrics are turned on. :)
Absolutely. There’s a term “catastrophic control loss”. It’s a reason for the same kind of takeoff abortion or emergency return as say an unextinguishable engine fire, because a plane without control is probably the most dangerous vehicle in that situation.
@4:16 The elevators aren’t controlled separately by each pilot. The elevators are connected to the control yokes in the cockpit as part of the overall control surfaces. Each pilot has their own yoke, but a single pilot controls the entire system at any given time. Otherwise if one pilot was incapacitated, the plane would crash since the other pilot was only controlling one elevator.
Yes but the linkage is designed to shear if one locks up and if needed each pilot can control the elevators individually
@@MiniAirCrashInvestigation But what you said was the pilot controls the left elevator and the copilot controls the right one which isn’t correct. Pilots control both elevators together, not one each.
@@Scott-RoyalExplainer I forgot to mention that each pilot control both at the and time my bad
I noticed that as well.
This has caused accident before, I can't remember much detail but the gist was that each pilot was putting in opposite action on the yoke (or maybe it was a joystick and computer controlled) and as a result each elevator was opposite the other. They lost pitch control and crashed the aircraft
If that final bolt had failed, they would’ve probably spiraled into the ocean or to the ground. They were right to declare an emergency and haul it on back to the house. Appreciate the pun, keep up the work and you’ll soon be a world-class dad joke expert. Love your stuff, happy holiday season.
It could have flown with one completely detached?
@@skuula It could have flown if the elevator completely detached, but it probably wouldn't have. It would still have been connected by the control cable or linkage and would have thrashed around until that failed. This would have likely damaged the rudder and/or tail plane. They definitely made the right call.
@@skuula one of two elevators detached = need to more deflection (most probably more than 2x - it depends on current case) to do same downward lift (horizontal stabilizer create negative lift in most cases). Commercial planes mostly have bigger stabs area (divided by wings area and tail length - which creates angular momentum) than GA planes, so they sometimes (extremely rare, but it happens) fly safe with little damaged stabilizer.
@@norbert.kiszka On top of which, the pitch control (elevator) would be somewhat unbalanced (full elevator on one side but not the other). So not only would you need more deflection on the elevator, you'd need to add some roll (ailerons) or yaw (rudder) to keep the plane moving in the right direction whenever you used the elevator. You'd be reasonably OK for straight/level flight, given that the stabilizer was still there, just the pitching would be problematic.
To sum up the three responses: Yes, it could have flown with the elevator detached. It could have been one nasty flight, the pilots' skill would have been tested, the plane would have probably taken some more damage, and landing safely wouldn't be very easy--but there's a pretty decent chance that it would have flown and landed safely.
100% agree with the pilots hauling their tail(s) back to the hangar, though. Just because a plane CAN fly damaged doesn't mean it SHOULD--if you've got a damaged bird, terra firma is your friend, and the more firma the less terra, so get down as fast as you can safely do it.
@@erichusmann5145 yes, but elevators in most cases are much closer to fuselage than ailerons, so ailerons deflection wont be that big.
Situations like this emphasise the importance of over-engineering every component to take far more stress than the design calls for.
Planes are built as lightly and cheaply as they can be and still operate. Look at a military transport aircraft, which DOES have built in redundancies, which adds weight, which uses more fuel. Commercial planes are made from the thinnest aluminum and composites possible, and still fly. It's actually kind of scary.
that was not the issue ... the bolt was not properly tightened so over engineered or not improper installation was the issue
@@steves659 I was talking about the bolt that was tightened, and managed to hold everything together long enough to land.
I was not talking about the other bolts that weren't tightened.
This near-disaster shows us _exactly_ why you build aircraft with redundancies.
@Carl Klinkenborg honestly not, aircraft are not like cars, shit HAS to be redundant, so they make it redundant.
@Benjamin Finlay & CessnaFlyerVT, Those 'redundancies' in this case would have been the cotter keys that keep the nuts on the bolts...
@Carl Klinkenborg , on planes, most threaded fasteners do have some sort of safety devices to keep them from vibrating loose... Sometimes they are nylon inserts inside of the nuts, or the threads might be slightly pinched in on the nuts. Sometimes the safety devices could be cotter keys, or a large bolt, with a smaller bolt that goes right through the length of it (Airbus type), sometimes only the head of the fastener is exposed but they still need to be saftied, so the heads are drilled, and safety wire is used on them... There are still other ways to safety threaded fasteners. It is obvious that NONE of these 3 elevator hinge bolts, had been safetied prior to the plane being dispatched after the work was done to it... This is a sign of very poor maintenance...
@@wolfgagger planes only have one elevator, one rudder, one left wing, one right wing, etc...
@@jimhansen5395 How about F-14's, F-15's, F-18's, F-22's, F-117's ? All with 2-vert stabs,, 2-seperate horizontal STABILATORS that move independently... Many different concepts, on many different aircraft...
As always the content you make is amazing. Can we just say that this particular case the crew were extremely lucky. The CRM was on point.
Yes Sir! Case in G.R., MI on I-96 where Capt saw Hwy Trk swerving violent when realized his liner stationary. Full flaps-gas, gear up, slight nose down & entered flat dive in severe downdraft into woods. Hvy smoke, but from engines as liner gradually rose. Plane shot, 1st Ofcr crying, all cabin cr serious inj, no radios, flew around landing, GRPD cuffed him pulling oak limbs out of belly, but claimed he still felt lucky!! Gigged by airline & NTSB but still felt lucky. On lucky meet 4 yrs later in Tampa, I gave Capt proof Hwy Trk existed for NTSB, & he got over $300,000 back for wages, & re-train, tests, & certs he had to pay for reinstatement. NTSB Investigator said Capt felt luckier yet!! Directly after that, NWS in G.R. got one of 1st Doppler Weather Radars thanks to NTSB....wasn't that lucky??
The center bolt falling out should have been caught on an inspection the regs require that all critical attachments be inspected the elevator hinges are critical attachments
This was in 2005 so maybe rules were different then? Plus I think the bolt fell out as the plane did it's takeoff.
I’ve been an A&P for 49 years and the rule was in place before me!
Another awesome video. Love the stories of pilots overcoming broken planes!
Another great video. What I really like about your videos is the calm, clear delivery of the commentary. Far too many RUclips channels have videos with loud, almost shouting commentary, delivered at a fast pace that can make them difficult to understand.
I think they're lucky, and I wonder hiw only one bolt was properly tightened and the rest were never inspected. An interesting case, love your videos!
mechanic was interrupted, perhaps for a shift change
Maybe another person checked only one bolt, and if one is good, then most probably "I dont need to check the other ones". People are lazy - thats why.
Hans, what are you doing this weekend?
The Tightened nut was obviously done by a good mechanic, however, in civilians airlines, the Coffee break often ensues and human nature being what it is, arises the question, ' Now where was I, oh yeah I tightened the three nuts erh??? of well she'll be right mate' .
@@terryofford4977 so then, coffee was the reason of this incident.
Nut implied a funny or crazy person when I read it in the title. Had it been BOLT it would have registered in my mind as Bolt. Bolt having one definition instead of Nut which has more than one meaning.
I thought of a hazelnut at first but realized that was unlikely. 😆
@@23nine Otherwise, this would've been a story of how Nutella saved an airplane. :)
If we're going to measure twice and cut once in carpentry on the ground, you'd think they could have someone double checking all maintenance work for something that is going to go flying through the air with people in it.
Complacency.
It is a control surface, FFS. How could anyone say it is "not critical" is beyond me. To determine what is critical ask what would be the severity impact if it went wrong (which is distinct from the probability it could go wrong).
Eh, it would cost just a couple more bucks.
A couple bucks too much sadly for many operators.
But hey, luck is all you need. I mean, why do something you are not yet forced to do.
@@Penoatle IDK, reputation? Fly QUANTAS.
@@jamescaley9942 Exactly! Between the removal and reinstall and rig check, all should have required a supervisor or inspector check.
Absolutely love your analysis of flight incidents. I don't usually comment or like or subscribe, but you are amazing
😂😂😂I used to be like this. Commented once in a similar manner to this and now I do these things regularly. Issa trap!
Having installed many elevators on Airbus and Boeing airplanes, the bearing that the bolt goes through does NOT hold in the bolt. The bolt is secured by a nut with a cotter pin. The bolt shown appears that the bearing also failed caused the wear on the bolt. The purpose of the bearing in the hinge is to provide a hardened surface to prevent wear and reduce the friction. When I worked for airlines we would inspect the elevator hinges annually and clean and lube as well. After we were done an inspector would look it over and sign it off.
Annually????!!!!! When I fly I inspect it before every flight!
@@ashtonbailey3970 I guess every time still is true, but mentioned periodic inspection is a matter of how closely you inspect.
At least I expect an anual inspection to be more in depth, spending more time on each part.
This one used a self locking nut, as the bolt was not supposed to be be subject to rotational forces.
It looks liked the bearing failed and the bolt got galling damage. This didn't happen overnight.
@@Gonte88 I agree. Quality plays a big part
My favourite crash channel. Thank you for this one. Let us look from a different angle; Times without number a maintenance team have spotted faults like this, all that would have been said would go something like this, "That's interesting, look what is happening here." Then the maint. crew would fix and check the other one. No one would know that that team had saved dozens of lives. Why do I know? Because I worked with maint. crews in factories for forty years. Peace be unto you.
Yikes, this is amazing and terrifying. Kind of reminded me of Emery Wordwide 17 with one nut causing chaos
EDIT: Oh the hinge pun...I'm no not sure if I want to bolt from the video or not...that pun caught me seeriously off guard. I'm not used to you putting puns in...but I like it
I guess you could say that pun was absolutely nuts
I'm enjoying this *_thread._*
FedEx 705 is another case where one nut caused chaos aboard an airliner.
At 4:17 you state " the captain controls the left elevator and the co-pilot controls the right one'. That's not the case. Elevator control is shared and all flight surface controls are duplicated at both flight seats in a two person crewed aircraft.
The aircraft in the incident is built with a shear pin type mechanism that connects the left and right control columns. It is designed to shear so that the two columns can move independently in case one elevator gets jammed. So yes, technically what he said was correct, but until the shear pin breaks they are still synchronized. So the F/O's column moves the right elevator and the Captains the left, but the shear pin moves both columns together.
As always, a good, clear description of events. I really do like this channel, as these video's are so well made.
I think you do a tremendous job explaining these accidents and I hope you continue. I'd love to see your take on historical accidents, say, pre-1960, if you can lay your hands on the information. Excellent work.
This comes to show that even the slightest overlook can mean life or death. This simple mistake nearly cost the lives of everyone aboard but one nut managed to hold on and save everyone. If that nut failed... Everyone Is History
P. Candice Goddard - And greasing this vital yet missing bolt? Now THAT'S confirmation bias.
THERE'S BEEN ONE THAN MORE CRASH DUE TO MANAGEMENT.
Make sure to screw Properly and to use enough Grease.
There's a poem, of sorts, about that... For want of a nail, a shoe was lost. For want of a shoe a horse was lost. For want of a horse a soldier was lost. For want of a soldier, an army was lost. For want of an army, a battle was lost. For want of the battle, a kingdom was lost. And all for want of a horse-shoe nail.
Meaning, even the smallest detail can have huge consequences in the end - even potentially unforeseen consequences.
@@CandiceGoddard , there is a difference between you (understably) perceiving safety to be on a knife edge and it actually being so. The certification process requires demonstration that an everage pilot can cope with such issues as this - and more. Maintainers are humans, so they have human performance limitations - hence the system has to be designed to fault tolerant, because no matter how hard we try to do a good job, we will make mistakes. The real thing to worry about is when people deliberately go outside of the approved procedures, mainly because they are very experienced and think they know better. But this one seems like an ordinary collection of blunders. Maybe the maintainer doing the job got a phone call that his daughter had been run over and left the job before it was completed, and the defences against that job not being done were inadequate. Sometimes the approved maintenance procedures just don't work. I have sometimes had to have the manuals altered because the specified procedure, if followed, will certify a system as working when it doesn't actually work, because of the inspection procedure being inadequately designed. It may be that in this case, the DVI instructions where such that they would not detect this. In which case, the DVI would not be changed, for instance, requiring the removal of more parts of the aircraft structure to gain access to the area.
I am a Retired Aircraft Maintenance Engineer from Singapore. For Flight Controls its Mandatory to Carry Out Duplicate Checks before they are Signed Out. The Technicians who carried out the Fitting of the Bolts did Not do a Proper Job. Also during Hangar Maintenance Checks were inspections made???
Any flight control surface that has been removed and reinstalled is a required inspection item in the United States which puts 2 sets of eyes on all the steps involved so in theory this couldn't have happened in the US.
Same goes for flight controls in Denmark, so even though DAT are Danish, the maintenance work must have been done outside Denmark. As a matter of fact, flight control work takes both 2 sets of eyes but also minimum 2 sets of sign offs. It would actually require more, since part of the final sign of, would be a test flight. In this case, it though should be clear, that the test flight would not have shown any indications of a faulty installation. I am not familiar with the ATR, but I am personally kind of puzzled that the apparent lack of bolts, in at least one of the positions, had not been detected. I would guess that the bolts lube points must have been filled over 12 times since the apparent faulty installation. He says that it seemed to have been connected to work done in connection with it having been taken of and repainted, so - and this is pure speculation - maybe it was done in connection with a sale and a intermediate broker with maintenance capabilities. So part of purchase price are a "maintenance resetting" "D" check or above, and prep for operation for new owner (?), Would have been interesting with some more in-depth knowledge and analysis in the above clip. Out of the "whom, where, when, why", we only got the "when and why".
Never say "never"! Especially in aviation.
You said it yourself: in theory. People break rules if they get a perceived benefit and think if they can get away with it. I mean, there are laws against murder, and murder still happens. And of course, it could simply have been a mistake. A miscommunication, everyone thought the other one had checked the bolts when nobody did.
What matter is that nobody got hurt and lessons were learnt.
In theory, DC-10s weren't supposed to have engine and pylon removed together with a forklift. Mistakes and errors in judgement happen everywhere.
You would so totally fit in with me and several of my coworkers in the break room at work. We are always talking about aviation and making hilarious puns at each chance we get.
Keep up the great videos.
Great job. Keep the good work up. As always, I enjoyed your video. Very informative and easy to follow.
Amazing episode as always, it goes without saying those souls were very fortunate that flight!!!🙏👍✈️
You have a great voice and intonation. I am so happy to see your channel grow. All the best, thank you
Your videos are getting a lot better and I appreciate the detailed explanation (as well as the puns) keep up the good work, I always look forward to seeing your new videos.
Thanks David!!
Never heard of divided elevator control before. Suggest you fact-check this. Both sides of an elevator should respond to a single control input. To split this between pilots would introduce hazards. But both pilots would have access to duplicate flight controls.
The two controls are linked together, in this case at the tail (see diagram at 4:16). So either control stick operates both elevators. Unless one side jams in which case a sufficiently hard pull will 'split' the elevators.
The B767 has a similar linkage, except under the cockpit floor. Probably most pre-fly-by-wire airliners do.
Great job on this one as usual!
It made my morning to see a new video post of this channel!
Another fantastic video, thank you.
Doesnt First officer an captain have same control over both elevators?
Yeah, that was a really strange line in the video. Each pilot doesn’t control one side of the elevators!
@@JamesDavidWalley yeah that would make a plane unflyable. Both pilots can have full control over every aspect of the plane. The whole concept of 2 pilots is about load management and redundancy, but in any event one pilot can control the whole plane. What he said in the video sounds so wrong.
Maybe (and it is just a guess) it was an attempt to explain the figure shown that has a "pitch uncoupling mechanism", so that (another guess) the configuration if one side of the elevator is utterly stuck only one pilot is in control of the unstuck side. It was a bit of an enigmatic explanation for sure. :-)
Alaska Airlines flight 261 is another classic example of a maintenance-related crash. The horizontal stabilizer failed because the jackscrew controlling it hadn’t been lubricated and was eventually stripped of its threads.
an iconic example
Regarding your comments at 07:30, you will find that any work that is carried out on critical systems (flying controls for example) will have mandatory independant inspections by someone not directly involved with the work, to make sure that the work has been done in accordance with the manufacturers maintenance instructions. This has been standard practice for decades, whether a particular company follows the manufacturers instructions is another matter.
Same goes for flight controls in Denmark, so even though DAT are Danish, the maintenance work must have been done outside Denmark. As a matter of fact, flight control work takes both 2 sets of eyes but also minimum 2 sets of sign offs. It would actually require more, since part of the final sign of, would be a test flight. In this case, it though should be clear, that the test flight would not have shown any indications of a faulty installation. I am not familiar with the ATR, but I am personally kind of puzzled that the apparent lack of bolt/nut, in at least one of the positions, had not been detected. I would guess that the bolts lube points must have been filled over 12 times since the apparent faulty installation. He says that it seemed to have been connected to work done in connection with it having been taken of and repainted, so - and this is pure speculation - maybe it was done in connection with a sale and a intermediate broker with maintenance capabilities. So part of purchase price are a "maintenance resetting" "D" check or above, and prep for operation for new owner (?), Would have been interesting with some more in-depth knowledge and analysis in the above clip. Out of the "whom, where, when, why", we only got the "when and why".
Best aircrash channel ever!!! Always so informative
Thank you so much!!
It sounds like the crew made two good calls. One, return to the airport. Two, return to the airport as soon as possible. No making a 180 degree turn, then get downwind of the airport, then another 180 degree turn and land into the wind, as usual. Instead, it was a simple 180 degree turn and land as soon as possible, with the wind. That may have made the difference. The risk of excessive ground speed during the landing with the wind, effectively making the runway shorter, just had to be accepted.
This Video is so nuts which makes it so good
I really enjoy these episodes. You do a great job.
Thanks Scott!
Thanks for sharing. Full watched. Have a great day.
Not to downplay anything. But honestly they probably would have been fine had that whole right elevator come off. The ATR has a clutch mechanism that can separate the left and right sides as you said. Though it's purpose is meant for a jammed elevator the result would be the same: only one elevator moving. Still, well done landing an airplane they had control problems with!
That's my thought too, as long as complete separation of the compromised flight surface doesn't damage the control cables it'd still be perfectly flyable. And they have shear linkages just for that reason
Great video as usual. Thanks
Love your reportability!
Seeing the wear on the bolt pictured. It Looks more like a bearing seizure and possible fusion with the bolt for some time, forcing the bolt to rotate each time the elevator is moved hence causing the nut to loosen.
You're absolutely right when you say their declaring an emergency, so quickly probably saved their lives. I don't know how long the single bolt would have stayed in tact, probably not long. You don't want to be trouble shooting elevator issues when you're missing 2 out 3 bolts. They obviously didn't know the extent of the problem but their quick decision to land immediately was most likely what saved them! Another great video! I especially like the one's where everyone survives!!
Another good one, thanks!
There is so much to learn even from incidents that don't result in crashes.
Honestly, I feel like this is also a very good example of how important redundancy is as well, because if not for the fact that that third nut could, at least temporarily, keep the elevator on, this would have ended much worse as well.
Great as always! I am from Norway, and I have not heard of this.
“The captain controls the left elevator and the first officer controls the right”
Funniest line from an accident report ever! Now to wipe up the coffee I spat out :-). Thank you.
I lost a friend on a maintenence flight that was not scheduled for that particular day. He happened to stop by the maintenance hangar, along with his new ground instructor and check airman, to pick up some items that were to be used as training aid, when the maintenance supervisor saw them in the shop, he asked the check airman "To fly the aircraft and to give it a test flight" so it was decided to make this maintenance flight a "Training flight", so it became Air Tahoma's flight 587.
The new hired captain who was acting as a first officer on this particular flight, was at the controls of the airplane. My friend who was also a new hired first officer, was seated as an observer on the cockpit's jumpseat. Lastly the instructor was seated on the left seat and was acting as a captain since this was to become maintenance/training flight. The aircraft was in the shop because it had undergone a C-check inspection. The crew of flight 587 took the aircraft on a short post heavy maintenance flight. Soon after take off, they crashed and burnt alive.
What brought down this Convair CV-580 aircraft, was the misrigging of the elevator trim cables making them to operate opposite of their intended direction of use. Air Tahoma was found guilty and liable for the life of these airmen and went out of business soon thereafter.
I watch every single one of your videos and have noticed the big difference between the old ones and the new ones that you make. Your videos have vastly improved with time. The quality of the graphics are excellent, the subject matter as always is very informative and educational. Two thumbs way up MACI, good job, keep up the great work you do and blue skies to you if you are a fellow aviator. Thank you for taking the time to make these videos as I am sure they are not easy to make.
Some aircraft require bolts (controlling the moving surfaces) visual inspection at every preflight. At least 5 annuals and no bolts inspection? Incredible negligence.
You do know they have panels hidding the bolts and that pilots do not have a skyjack to go to remove those panels. Not something you do at preflight but during a check
Doesn't the ATR 42 have one elevator on each side? It's even mentioned on the video. Both sides presumably have three bolts holding them to the horizontal stabilizer.
If the third bolt had failed and the elevator had fallen off, wouldn't there still be the other elevator on the other side of the aircraft, functioning as it should? A single elevator should be enough to control the aircraft within a limited flight envelope on a day of reasonably good weather. It would just require higher deflection to perform certain maneuvers.
Of course there are significant risk factors with one side elevator falling off and possibly breaking something on the way out, but in my opinion it's not entirely correct to say that the third bolt was the last thing keeping that plane aloft.
I agree. Assuming the damaged elevator separates cleanly and doesn't jam the opposite side on its way out, the aircraft should remain controllable.
@@TheLightningII he is putting hard work in and the videos are good. His original format was unwatchable...but he is not yet on a level with Alec Joshua Ibay or Flight Channel or Mentour Pilot
Thanks for elevating the humor of a situation that was nearly unhinged.
Interesting video, thank you.
Amazing job 👍👍👍
Merci for this video.
Wait... The captain controls the left elevator and the pilot controls the right elevator? Really?
If only one of them is manipulating the controls then both elevators follow that pilot. But if both pilots are commanding opposite inputs then each elevator is going to follow its respective pilot like what happened on Egypt air 990
Another good video. 👍
But, when you mentioned that the Captain's yoke controls the left elevator, and the First Officer's the right elevator, I was caught off-guard. It doesn't work that way. Both the yokes control both the left and right elevators. Please correct me if I am wrong. I work on flight control system on a modern fighter aircraft, which is fly-by-wire version, and hence haven't studied about the mechanical model of flight controls. Is what you said the general rule, or typical to this type?
I'm amazed at how far I had to scroll to find someone talking about this. A plane with only the left elevator working would be uncontrollable!
There’s actually a linkage in between so one pilot can control both elevators. But if needed each pilot can control their respective elevators. Kind of like what happened with Egypt air 990. I think it’s called splitting
All airliners that I am familiar with have the ability to split the controls for both the elevators and ailerons, and planes with dual rudders can probably split those as well. In the type I fly the controls are linked close to the yokes but there are red T-handles that we can pull to split the connections. This allows us a better chance to maintain control if the mechanism for either side should become jammed.
@@MiniAirCrashInvestigation I think you are missing the point the OP made. Yes you are right there are lots of splitters and linkage in a cable system, a simple example is on a car's brake system where the two independent cables connecting to each rear wheel drums come together attaching to a single cable via a splitter linkage, which means when you yank on the emergency brake equal pressure will be placed on the two rear brake mechanisms. The same kind of principle works on planes, whatever inputs a pilot puts into his yoke, the same kind of motion can be observed on the other yoke, which of course transmits directly to the control surfaces. Therefore your statement about how one pilot controls the left elevator and the other pilot controls the right elevator is incorrect. You obviously know what you are talking about, I think you just explained it is a clumsy way!
@@robbflynn4325 I think you are missing the point Mr Investigation made, which is that they are normally linked but can also be separated on purpose, a simple example is some aeroplanes' (such as the ones TheLightningII is familiar with) elevator system where the two independent cables connecting each rear elevator do not come together but connect to a separate control yoke, and then the control yokes connect together via a splitter linkage, which means when you yank on the splitter linkage the linkage splits.
I am only a PPL pilot, but do have aerobatic cert. taiilwheel and formation endorsement. During the Berlin airlift Operations.in the late 1940s, an aeroplane did take of with the elevator lock- jam still in place (control locks and tie downs were still in use then - usually external). The piloused engine speed, prop pitch and flaps to maintain just enough control to make a successful landing. The pilots on this plane might have been able to do likewise, If the passengers were prepared to cooperate, they could also have assisted with COG trim control by moving forward or aft. I would not however, have liked to try the latter - and I didn’t think mobile and unrestrained passengers would be or should be used in this crack-pot idea for several obvious reasons!
That's some fancy car the airport sent for inspection.
Only the best for runway inspections
“Basically, the Captain controls the left elevator and the First Officer controls the right.” SAY WHAT? Explain. (The pilot flying controls the all the flight surfaces!)
YES! This is a big miss by the narrator. Each pilot has a separate control circuit, but both circuits operate the two elevators in tandem.
@@dperreno didn't he already admit to that in his headline?
@@RichMcc Perhaps, but the detailed narration was clearly incorrect.
A fine pun! lmao Clearly I did see what you did there. Most excellent!
Must be 2nd then. Just glad to catch another video bro
When I was a maintainer in the Air Force a procedure like this would have had to be inspected by a second person when the job was complete. Anything that when removed or disconnected that would have not allowed the aircraft to be flown was considered critical. No pilot would fly an aircraft with only one functional elevator. One other note: the elevators work together with control inputs. They are not separated as to which pilot controls which. Input from either control column operates both at the same deflection and same time. The problem here is that they are operated by a common torque tube or bellcrank, so if one jambs they both are jammed, making pitch control difficult if not impossible.
GREAT SUMMARY !!!!!!!!!!
Your content is great and informative and I've been watching for quite a while now, however I have one feedback: Your narration volume seems to become quieter and quieter. I always have to turn up my speakers for your videos and if I forget to turn it down afterwards the next video or music is far too loud.
I think his voice in the very first videos he made is really muffled. His audio is a lot better now. If anything, it’s the “next” video that is poorer in quality as more often than not they’ve had the living bejeezus compressed out of them to make them sound artificially LOUD and it sounds terrible.
Another nice video 👍
Thank you!
Amazing that 1 out of 3 important bolts could depart from the plane, and it could keep on flying without a problem, but scary nobody noticed the redundancy was gone, until the 2nd bolt also fell off, and the plane could've ended up crashing.
That flight crew + passengers are lucky that whoever did the work at least managed to properly tighten the bolt which held.
This is a real problem with redundancy in general.
Good job!
I'm just a layperson here with limited experience even being a passenger on planes, but I can tell you with 100% certainty that EVERY repair done on the machine that keeps me tens of thousands of feet in the air is a "critical repair."
If the bolts in question had to be tightened to a specific torque then it is good practice to mark the bolt and the nut so that it can be immediately seen if it has come loose or was never tightened, this can also be applied to any bolt/nut that's fitted That procedure does not rely on whether the item is critical or not and should be in the common mindset of every maintenance engineer, even if its applied to say, an inspection hatch, there is no need to remember whether to tighten a bolt/nut as there is a clear visual identification of that..
I came for the incedent, I stayed for the pun. As a military maintainer, ALL of my work was double checked. There's a lot of stuff that goes on on the civil side that makes me nervous.
working in aviation, I always say everything elevator is always critical, it is THE most important control surface and control surfaces are always of prime importance
So it was a ONE BOLT that held on to save 25 people, and not one nut?
For a minute I though this was a happy end version of the accident of Conviasa flight 2350, on Sep 23th 2010 in Puerto Ordaz, Venezuela. It turned out to be something completely different, but may be worth it for you to have a look at that one too? In any case, thank you very much for your content.
The basic problem is the drive for cheapest price ... maintenance is always on the edge of failure due to the urgency of profit.
This ^^
Very fun mid air investigation
I saw what you did there.
😁 Nice!
These near miss MACI stories are gold.
Does the ATR42 not have some secondary locking on such bolts? On small aircraft I have flown, the flying controls have a split pin as well as a nut on the bolt. I am amazed that an airliner doesn't!
Yes, would have a lock pin or maybe a safety wire. SOP on flight control bolt/nut configs. I am not familiar with ATR´s but cant imagine an AC getting an airworthiness clearness with a design without this basic built in safety feature.
@@Mike-ox8sq As far as I could tell when reading the report, there arent any split pins or locking wire on these bolts, but the nuts are self locking
Glad they were able to safely land.
interestingly how you did a firetruck animation, is it added like a plane to some simulator but with a truck model ?
I'm super impressed that an individual bolt had a serial number traceable to that specific aircraft. Even a similar model aircraft would be impressive enough, but an individual airframe? Wow.
It dosent though. No bolt I have ever come across has had a serial number. Yes, they have batch numbers, but even those aren't imprinted on the bolt. And usually only a partial part number is written on the bolt because there isn't enough space
Brilliant CRM
where did you get the video from?I'm from Bergen and that was a film from the actual airport(Flesland).I even saw my mates house just south of the strip.I have landed and taken off from that strip thousands of times! By the way,I love your videos!
Do you mean the Microsoft Flight Simulator 2020 footage? It’s an amazing piece of software, there’s an outstanding 30 min video on RUclips on “How Microsoft Flight Simulator 2020 Recreated the Entire World”.
An Alaska Airlines DC 9 crashed near SF due to a failure of the elevator jack. Also on this aircraft could the non-compromised elevator allowed sufficient control had all of the bolts failed on the port (?) elevator?
I would have barfed my brains out if I saw my elevator looking like that! Sometimes it's good to see what is wrong with something, sometimes it's not! This is a definite not!! That is scary!! Great video!! So glad they all made it safely to the ground!!
Wow that's nuts!
To me as a pilot, ANY work on control surfaces is critical, and if the aircraft is small enough I will manually move them on my walk-around and check for locking wire or stiff-nuts. As my instructor taught me, if you have clean hands after a walk-around, you didn't do it right! I've sent a Cessna back to maintenance for lacking security (stiff-nuts, in that instance) on the rudder pivot. And the flying school owner, who was also the resident A&P tech, aerodrome operator and flight examiner, thanked me for checking his work. That is how it should be.
I think there is a design issue on that aircraft not to require some form of security for such important bolts. A loose bolt isn't a problem if there is a cotter-pin, lockwire, nylon insert, or some other security keeping it from completely coming off. I'm pretty appalled that a safety feature that is present on a Cessna light aircraft is absent on a transport category aircraft. Finally, does that bolt not have a specified torque setting? Some form of security is doubly important if the elevator (or any other flight control surface) is out of reach or too heavy to physically examine on a walk-around.
Am a little surprised they were not using castled nuts with cotter pin on such an important connection...
The hinges pun opened new doors to your style. I love it and also, see what I did there?
Yo whitch flight simulator game he using for the video?
Were was rge double inspectiin,it is flying controls/moving surface
I'm curious how they found the first bolt that fell out? The second one makes sense that it was laying on the runway, but were was the first one found. Also if the first one was found previously why wasn't it tracked back to the plane.
Yes, I'm curious about that too. I wondered if it had come out far enough to no longer connect the parts, but still be in the hole, but then surely whoever greased the joint would have noticed it ... unless the outer edges of the hinge are concealed and the grease nipple is accessible without seeing the bolt head or nut. In which case the bolt may have been lying inside the elevator or stabiliser until the investigators found it. But then why didn't the same happen to the outer bolt?
A lot of buts and guessing there 😣
The first bolt that fell out was found in "the elevator together with a washer in the leading edge box at the center hinge location". Another washer and nut were also found in the elevator close to the outboard hinge. Thats what the investigators assume anyways. They can't be 100% sure where the parts belong because none of these parts are marked with serial numbers. But due to the location the were found, they can assume beyond reasonable doubt where they were originally located.
I have spotted that aircraft in real life sometime ago!
60.2055° N, 24.6559° E
@@spanishinquisition3173 Why did you reply with coordinates to a place in Finland?
Great video. Not going to lie, though: when I saw the title involving a nut and a Danish, I honestly thought it was going to be a walnut or pecan on a pastry. Like that time my academic friends invited me to the Rubin for a lunch art thing, and I thought they were going to enjoy a delicious pastrami sandwich. I’m not really smart.
This incident flew under my radar and I live in Bergen. Not much was written about it at the time, only a few articles (that now only live in the Wayback Machine) in national and regional newspapers and a couple in a local one. Happy the outcome didn't warrant more coverage, though. One harrowing accident is more than enough. (Helicopter crash, 2013, just outside Bergen. 13 killed)