An unbelievable mistake | Yeti Airlines flight 691
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- Опубликовано: 21 фев 2023
- The preliminary report for Yeti Airlines flight 691 is released. The content of the report is shocking.
Preliminary accident report: www.tourism.gov.np/files/publ...
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My wife and I regularly took Yeti flights to Lukla as part of our exploration of Sagamartha National Park...we used to joke that they were a mess of an airline...it's so sad to see that it manifested in the worst possible way.
Hey, besides Yeti, had you taken any airlines or not? If you have, which airline in Nepal do you recommend?
U mean tara air
As a basic aircraft maintenance instructor, I feel proud to say that this video can be a human factors training and I'll surely share the details among the students which would greatly increase their curiosity to learn. It's only through mistakes one can learn max
😊😊😊😊😊😊
They thought they engine power is a thruster
Please show respect to others. Sadly, I have been forced to delete some comments because of harassment.
You should not censure people’s opinions. The point of accident investigations is to prevent future occurrences. I don’t know how you expect to do this when you are spoon feeding your our personal narrative.
I have deleted libelous comments targeting individuals. There's a clear line between discussing what has happened, and harassing people.
I'm from Nepal and you clear us why this accident happened thank you very much
@@FlywithMagnar Keep in mind that not all disputes are destructive. “Malicious compliance” is an actual thing. 90% of accidents could have been prevented by someone just speaking up, and your censorship does not help this at all.
@@mike48084, let me make this clear: I do not censor opinions. I remove comments that are attacking individuals as persons. This includes racism and hate messages.
Many years ago we had an incident where almost exactly the same thing happened. A training captain was also in the right hand seat. The pilot in the left hand seat asked for Flaps 40 and the RHS pilot shut down the right hand engine. The LHS pilot, a First Officer undergoing command training, noticed and decided to continue as Flap 25 is the standard configuration for a single engine approach.
The pilot flying also put a lot of faith in the instructor pilot.
Great report ... I was a passenger on this very same flight some years ago (absolutely loved this flight ... this ATR was in practically new condition, great service by cabin attendants and really nice views of the Himalayan ranges throughout the flight). It made me really sad when this flight crashed and was anxious about how this could have happened when nothing seemed seemingly wrong.
I flew in one of these aircraft a few times just a few days ago with Air New Zealand. I thank you for the sincerity with which you presented this tragedy.
Pete, I bet you had a few "butterflies", with this incident fresh in your mind?
Thank you for the explanation Captain Magnar, did happened to me when I act as PF and realized my FO as PM select CL number 2 instead of flap 30,
Immediately put back CL 2 to auto.
I believe fatigue was the main issue.
Because we’re doing 8 sectors on that time,just scan cross check and confirm we should be okay.
Thank you for your contribution and feedback! I have heard about a similar incident with a Dash 8. And as in your case, the mistake was discovered within seconds.
Yes pilot decreased condition lever instead of flaps to 30°
Engine turned off fuel supply due to that plane crashed - Cockpit Recorder
159,000 ?
@@jonathanhermansson4553 😂😂
@@jonathanhermansson4553it's still fu.cking 10 bucks who were giftet. Humans are stupid these days.
Thank you Captain Magnar,as an engineer working on this type I am deeply stressed seeing ATR crashed. Unbelievable mistake.
Perhaps making the feathering level into a wheel like a trim wheel will help with muscle memory? In low speed and low altitude trying to stay conscious of levers seem like it could go wrong somehow. Having a totally different feel and mechanism might help unconsciously differentiate controls.
@@manofcultura I think the levers are quite different enough. Humans do some crazy things under pressure. I though maybe adding an audible warning as in "Levers - Feather" would help, but there's no guarantee of that helping since hearing is one of the first things to go and numerous accident reports have noted pilots not hearing audible alarms when in a very stressful live or die situation.
@@pfsantos007 I agree with you. Some folks go completely "brainless" in high stress situations.
@@guitarhillbilly1482 This was not a stressful situation. Excellent weather conditions, light wind, good weather, excellent visibility.
Thankyou Captain for a sincere discussion of this accident. As someone who has flown ATRs for nearly 26yrs, I too find it unbelievable that the CLs may have been moved to the FX position.
Excellent walkthrough of that report, and your accompanying video and visuals. A real tragedy for certain. Thanks for the time you took to put this together.
Thank you for a greatly detailed video Captain Magnar. It is frightening to see this experienced Captain not realize such an enormous pilot error. The CVR will certainly reveal some important details about this tragic accident. Charles here, Airline Pilot in Los Angeles California.
Very interesting, educational video. That's just too bad this accident happened due to such a basic mistake. May I also point out that the quality of your videos went up when it comes to graphics and overall presentation, which is a great addition to your outstanding narration backed up by lots of flight hours and overall experience. Thank you!
Captain Magnar, thank you for your thoughtful, calm and professional presentation of the interim report and the circumstances involved with this aircraft loss. I look forward to seeing your future work when the final report is delivered.
You’re a wonderfully insightful person and a credit to your profession.
Thanks again.
Congratulations Capt Magnar. Very professional, following the official report and giving many examples with images. Good job.
I’ve been looking forward to your video about this matter, many thanks magnar!!
I'm not a pilot, but I wonder, given the degree of technology there is in modern avionics, why there isn't more verbal auditory feedback when controls are used. For example, “Both props feathered” or “Flaps 30”.
And read the altitude and squat switch for an immediate terse audio warning, ATR needs to alert pilots that make these deadly mistakes.
Perhaps not to the stage of flap warning, but yes it would not be easy to program in the backend with a rule. If aircraft is airborne and prop goes to feather, then audible warning in the likes of “feather” should be triggered. Same as in a simple piston like the baron, if flaps are down and throttle is reduced below a certain point it will alert for gear if not down.
It's really not necessary. Would compicate an already busy environment during a critical stage of flight
It doesn't help. People ignore it.
Listen to the Air France 447 crash. The stall warning was shouting "stall, stall" over 50 times and all three pilots ignored the fact it was stalling.
Engineers need to be aware of a thing called " nuisance information " which could be distracting to "trained" pilots.
I cannot stop thinking if the fact that the PM was a captain sitting in the right seat plays a role. Some captains have a habit of reaching the the flaps from beneath with two fingers, lift up with just two fingers and pull back (not to interfere with the first officer operation of the power levers). If the captain did this from the right seat as well, you can actually operate both flaps and condition levers without feeling the shape of the lever, which could explain why the mistake was not immediately corrected.
Can you explain further..with example
Thank you for this information! - Yes, this is plausible.
Point.
Good catch
Why is it not possible to take a quick glance at the lever before you pull it?
Thank you for the hard work and insight you bring to all your videos.
Thank you Capt. for your detailed description of this sad event and hard work on preparing this video.
1. Aviate, 2. Navigate, 3. Communicate
1. Check air-speed, power levers, flap position, attitude, etc.
2. Look out of the window to see where the airport is.
3. Talk to ATC.
It appears that they skipped parts of nr.1 to concentrate on 2. They got the priorities wrong.
Why this happened is a different story. I guess flying for decades give you too much confidence and you ignore and forget trivial tasks, especially in the first category. I am not a pilot, but when I took my car drivers license, I was very careful looking to the side, behind me etc. before turning. I will be lying if I say that I am that thorough today (25 years later); I am more confident when turning, but I do not always double check every angle as I used to.
Tudor, for not being a pilot well said!
One word can bring you down... Complacency 😮
Both are captains and they are overconfident I guess
Very well said. Makes a lot of sense.
Helps one understand how an experience pilot could make such a basic error. I was wondering how that could have happened.
So...props feathered...and therefore no thrust...therefore.. speed decayed....stall and spin..
Excellent explanation that even a lay person can understand with ease. Thank you.
Mr. Magnar does a great job explaining the ATR Quadrant and the Preliminary Accident Report.
Instead of the sad situation, is a very good content which enriches aeronautical safety culture. Tks Capt Magnar
Dear Captain,
Your video is a master's piece and most valuable in commenting on the accident, I share with you the noble feelings towards the lost lifes and their beloved ones, with hope to get a final report that will thoroughly analyze human factors that contributed to the fatal accident. Sure such final report will improve future ATR operations safety.
My observations on the accident on the Aviation Herald URL are below and would like to add them to comments on your video:
"Observations on Yeti AT72 at Pokhara
By Ghazi on Saturday, Feb 18th 2023 18:09Z
PM not moving flaps and acknowledging the PF’s call is weird, especially with both propellers speed decreasing simultaneously and Tq going to 0% without commenting, as per CVR findings. Cond Levers are Dual with releasable toggles while flaps lever is Single Aerofoil shape left to move type. PF not realizing change of attitude expected when extending landing flaps is also strange.
Master caution chime went neglected, instead a normal “Before Landing Checklist” was called for and carried out, no reference to Master Caution; again weird.
Discussing whether to continue turning and descending draws the question “had they considered landing straight ahead instead of going towards the runway?) this is vague. Seems that moving flaps to 30 degrees by the PM was prompted by reaching 500 feet AGL 22 seconds past the PF call needs thorough analyses.
Too late a call by the PF about lack of power and disparate attempts to increase power from disabled propellers, followed by control handover to the PM".
The role changing that occurred on the flight deck, I believe, contributed to the problem. The check airman moving to the right side still has muscle memory from the left seat. Muscle memory can help us or kill us.
Muscle memory from the seat ?
@@DearMe247 things you were doing with your right hand, you now do with your left
Excellent explanation of a truly sad incident.
The technical details particularly with the real life visuals and audio of the controls in operation really make it clear. And the timeline shows how it all happened in less than the time it takes to describe it.
Thanks for all the work you put into these videos.
Takk for at du la ut videoen, Magnar. Har ikke hørt om en dritt etter kræsj.
Veldig imponert ove din evalueringen.
Vanligvis tar det et halvt år før den første rapporten publiseres. Så dette er faktisk ganske så unikt at rapporten kommer så tidlig. Desverre mangler mange detaljer.
Thank You ! Watching from Nepal !
Nice report. As a crew trainer, 50 years of experience, the most overlooked, or perhaps overcooked, investigation response is the human brain and how it perceives “routine”. In this case you have a trainee pilot and a trainer. The trainer was PM, BUT, he is a trainer and always is thinking as a PF. So now you have 2 PFs and no PM. There is a reason for the PF/PM relationship. Every single CFIT is caused by the PM, why? Clearly he was not monitoring. No pilot flies into the ground intentionally. But when both pilots are looking at the same thing, they see the same thing and even when there is confusion (like this case when PF said more than once that there was no power), the workload was too high at that point to figure it out. The brain jut doesn’t see. This accident di not happen that day, it developed over the years by individuals who develop routines as PF. There is NO specific training for PFs. Every CFIT has been caused by experienced aircrew. It is obvious to me as to the cause of this accident. I have been able to make crews in the simulator to get into these positions. The solution is recognizing the way the brain operates. I recommend anything from Edward de Bono as reference
A very interesting Hypothesis. The Final Report is out now.
Very well said. As a fellow pilot, I can appreciate your objectiveness in having as much information as practical before offering any conclusions as to the final cause of the accident. It's quite easy to reach an answer based on the obvious outcome paired with the physical evidence collected. But as you mentioned, there's a percentage yet to be assigned from the standpoint of human factors. And that may be more than anyone can imagine. Bless those that lost their lives.
Wonderfully explained, Captain Magnar. Definitely workload management and situational awareness. Then STARTLE EFFECT kicked in when they realized they lost power. They needed at least 20 seconds to recover from the startle effect.
It hurts to think that the instructor was so oblivious to the scene that they did not notice the props feathered on 1. moving the lever 2. doing the checklist 3. setting flaps 4. receiving power loss comments from the PF. Receiving controls when the situation had already gotten so out of hand did not improve chances of recovery as the one closest to discovering the mistake was now in a recovery maneuver. Let's hope we will find out more to take some meaningful conclusions away from this tragedy. May the souls of those on board find peace.
It´s indeed obvious that more than one mistake was made during this short time of only 60 seconds.
Hi...Do you think it is normal thing to do to change the flight duties in the final moment when PF became the PM and PM became the PF ? Shouldn't the PF continue flying until Landing or Go Around Procedure is complete?
@@SurajUpadhyaya-kj8zi I believe they switched control to the more experienced pilot when it had already become obvious that there was some kind of problem. Remember the left seat was on a familiarization flight.
@@jerryweirdspeed8943 Indeed. But nevertheless it´s at least a point to discuss if this was a sensefull decision - both pilots had to find themselves in that new roles for what no time remained - and so far as I read the Preliminary Report no Control Inputs were made during the final 14 seconds of the flight.
@@NicolaW72 instructor did not check prop lever upon finally setting flaps. easy mistake to make even if it sounds unusual to have 4 occasions to miss the fact that the props are feathered and still not check the levers consciously. neither pilot did that in the end, it appears. and this is the tragedy of this incident. they did not perform checklists correctly nor did they show presence of mind when troubleshooting the issue. nor did they have much time at all whilst executing an approach to a new airport. and i'm not judging whether it was sufficient time. this is not up to me.
Hello Captain; I've been An ATR pilot for 8 years in Italy and that preliminary report sounded really unbelievable...
but as you say, this will surely be a "master case" in Human Factor, regarding workload and fixation and... a lot of other classic errors done in aviation crashes history.
I'm really really sad after watching your video... by the way... it's a really good video, keep going, I will follow your channel!
Best regards, Mauro
After a couple of month: Yes, indeed, exactly. And the "missing links" between what we know so far could contain some more bad surprises in this direction. It was really a very sad event.
The crew had several different methods to recognize the Props had been Feathered. What about the Torque Meter Indication? What about the Sound of the Engines/ Propellers?
What about the Airspeed?
The Flap handle does not need to be moved anywhere. It is shaped completely different that the other controls and located by itself on the far right side of the Pedestal/ Quadrant .
The Shape and Location separates it from every other control and there is NO EXCUSE for grabbing the Condition Levers instead of the Flap handle.
Lucid explanation. As a layman, I could comprehend everything. Thank you Captain.
Very clear explanation. It is sad that 72 people lost their lives probably due to an unimaginable error by the pilots. The high workload due to changing the approach direction to the runway probably led to such an error, if I understand right.
The family and the relatives of all those who perished deserve to know what happened, and knowing the truth will help avoid such accidents in the future, I believe.
May all those who passed away rest in peace.
Excellent overview of the initial report. I am reading through material for my ATPL exams at the moment, and your explanation of the set up of the turbo prop engine was a lovely addition, as I felt I had enough time to identify the parts of the engine layout before you clearly explained each piece. This was a very unfortunate accident, and it will be interesting to hear what was said in the cockpit during this sequence of events, once the final report in released. Thank you for putting this video together.
Thank you for your hard work in researching and making this video. An excellent tool to illustrate the many human factors that led to the crash. It will be good to analyse the full report in due course.
Thank you for this video. I am learning to fly the ATR, and that accident gave me Goosebumps.
Both pilots did not bothered themselves to look at the pedestal even for a second and check the flaps, condition and power levers. That is the most logical things. Even when I fly my Cessna 172 I keep monitoring all thing up to shut down the engine.
A comercial pilot flyies not just once a day or every vew days. If you fly like 5 different routes a day, you are in greater danger to become victim to a routine and so you maybe miss something. Most people are very carefull with everything that they don't do on a daily base b.c. they know that they can make misstakes and wan't to prevent them but if you do things regularly, you start to miss things b.c. the tension will become less each time.
@@friendlyreptile9931 in this case that is bad really specially when they know the life of many souls is in their hands.
@@noneNone-mw1px Yeah that's true.
@@friendlyreptile9931 That`s so true my friend. As the old saying goes, familiarity breeds contempt.
I call that good airmanship from your part. That is why piloting isn't for everyone. Equipments are getting better and better. Systems are put in place to assist pilots throught all stages of flight. Pilots need to be adamant towards check list and OPF. The ATR 72 is an awesome piece of equipment, which has achieved it's purpose 100%.
Captain your trainings and analysis videos are very excellent…
Many experienced pilots at times find themselves behind the airplane for many different reasons.
In this accident likely several factors contributed.
I alway like the landing gear switch up and away from the power console..also I prefer the flap switch to be away from the power console.
It’s easy to instantly grab the wrong lever thus a determined visual validation is critical. The flap switch up and away makes sense to me.
Yep. Anyone who drives a stick knows that one can put it into 4th gear instead of 2nd very easily because theyre side by side. I liken it to this. One has to be alert to the feel, the sound, or the instrument panel indication, to catch the error cuz it isnt obvious at first glance of the shifter.
Was waiting to watch your video on this tragic crash, Capt. So sad....
Hello. This is first time I have watched one of your videos. I REALLY like your no nonsense style, engineering accuracy and quality of graphics. Regarding this tragic, inexplicable accident, the elephant in the room is a deliberate act. I guess we may never know.
Thank you very much for this review! In fact more than one mistake was made in the very short time of only 60 seconds:
- the "basic" mistake of confusing flaps lever with condition lever
- the mistake not clearing it during Before-Landing-Check-List
- the mistake of Flaps 30 afterwards without a Callout (at least I readed the Preliminary Report in this way)
- the mistake not getting aware then that the Condition Levers were in the Feathered-Position
- the mistake not getting aware that the Condition Levers were in the Feathered-Position when the Power Levers were moved
- maybe also switching roles of PF and PM eventually in a very dangerous situation.
And not to forget: It was an unstabilized Approach!
Indeed incredible.
My impression from reading the Preliminary Report was, too, that the PM acted behind the back of the PF - what is the most disturbing part in this whole Crash Sequence. That was definetely more than only bad CRM.
The ongoing investigation will definetely have to take a closer look onto Human Factors, indeed.
I am not a pilot but in the work I do there is a saying "familiarity breeds contempt" and perhaps this played a part. God Bless the poor souls who perished
@@Johnlee0513 Both Pilots were of course familiar with the ATR 72 - the Pilot Instructor even very familiar. But the Approach they flew was new, therefore two Captains were seated on the Flight Deck, and the Pilot Flying did this particular Approach probably for the first time. As Magnar stated in the video: Both Pilots were probably looking out of the window for exact this reason and this contributed to the Crash.
The Sequence of this Event is nevertheless disturbing if you take a closer look. I hope the Final Report will answer the open Questions - and there´re still a couple of important ones.
It seems to be a really important investigation, not only one for this special case.
@timemachine194 Of course we don´t know if the Preliminary Report really contains everything what the FDR and the CVR are containing, as Magnar stated in the Video. But let´s take it for a moment as if everything is published what they´re containing.
The FDR than shows that between the switches of roles between the Pilot Flying and the Pilot Monitoring (10:57:18) and the Impact (10:57:33) there happened not a pull back of the Yoke instead of a move forward as it was the case in the Colgan Air - there was simply no Control Input at all - NOTHING! Even nothing when the Stick Shaker was going (at 10:57:24). THAT has to be explained.
The Aircraft was performing a difficult and for the Pilots NEW CIRCLE APPROACH. The Aircraft just turned from Base to Final and the Pilots tried to line it up with the Runway. Following the River was in this situation no option for them.
Then: This Aircraft stalled because the Propellers were - obviously unrecognized - in the Feathered Position - NOT because the Pilot Flying pulled the Yoke back instead of moving him forward, to repeat this! Short before the Role Switch of PF and PM the Power Levers were even set to Full Thrust - what would have been the absolutely right action in this situation - but what was useless with the Condition Levers in the Feathered Position.
Magnar explains this in great details. Please watch his video again.
This is a very different Story compared to the Colgan Air Crash.
@timemachine194 Thank you very much for your Work which you made yourself with this Post.
Not Loss of Engines - the Engines were in the Feathered Position. They were flying low and slow in the last turn from base to final when the stall happened. The Autopilot was off. Flaps 30 were only done at 10:56:56, not when the PF (left seat) called for it twenty seconds earlier. Did you anything read about Control Inputs between 10:57:18 and 10:57:32 in the quoted part of the text? Of course we must wait in this context for the Final Report as mentioned because we don´t know so far if the Preliminary Report really contains every available information about the Crash Sequence. But if we take for a moment as a complete description of that Crash Sequence what the Preliminary Report contains - because why should the investigators hide necessery informations for the understanding what happened? - then there was no control input from the IP at all when he became again PF, so no Nose Down, too - and that was of course another very serious mistake, adding up to all his other mistakes he made before. The Pitching up happened between 10:57:17 and 10:57.24, what matches perfectly to the Ground Observer Video and what happens when you´re turning with the Propellers in Feathered Position. With no control inputs => no nose down, gliding was impossible. When the Stick Shaker was going at 10:57:24, there were 2 seconds left - two! - before the Aircraft stalled. So at this Point the Game was probably anyway over: Too much too serious failure´s.
Openly said: I got the impression when reading the Preliminary Report that they could have glided two more hours, they wouldn´t had detected that the Condition Levers were in the Feathered Position. How much more best occasions did they needed to recognize this?
Maybe the Final Report will contain some more bad Surprises. He will surely deal much with Human Factors and will probably be from broader importance for Air Safety.
@timemachine194 That´s indeed possible, yes.
Thank you for this very detailed input.
Danke! I am getting into the ATR with msfs and your videos are amazing!
Vielen Dank!
Thanks for the analysis and for helping us to understand the condition lever and feather properties. As you stated, the Human Factors aspect will be very important in this investigation. To me, Crew Resource Management is just as important because it is necessary to understand how the crew was communicating, making callouts, and cross-checking their instruments and selections made. I also hope that the report highlights how the crew reacted to the problem of lack of thrust due to the feathered propeller.
The initial mistake of pulling the throttles back instead of the flaps control is bad enough. However as you said, work overload can cause strange things to happen. In Minnesota about a year ago during a traffic stop a police officer decided to use a Taser to subdue an uncooperative driver. She was also acting as an instructor for a new officer. However, although she announced "Taser" as per protocol she pulled out her pistol and killed the car's driver. This was despite the fact that the Taser was on the opposite side of her belt (she had to use her opposite hand to draw it) and was shaped differently than the pistol. So it can happen that situational overload can cause such a mistake even in an experienced police officer. I understand that both these pilots had lots of experience with this aircraft, although the airport was new to them. And as you said, the mistake was still recoverable and the plane could still have been landed safely at this point. However, the time it took these pilots to discover what the problem was apparently exceeded the time the plane could fly with no power and flaps in the wrong position. Here is where their training needs to be looked at. I hope the voice recording gives you the necessary information to avoid this happening again.
New video on police activity shows a shooting in Albuquerque grocery store and a one of the cops runs in on body cam wifj their taser out. Then realized after trying to pull the trigger and switched the pistol and starting shooting at suspect.
Many years ago, after we had landing and were clearing the runway, I called for the after landing checklist. The first thing the FO did was reach over and retract the gear lever!! Thank goodness the "squat" switches did their job and prevented retraction. I almost broke his knuckles when I reached across and slammed the gear lever back down so hard. Almost gave me a heart attack...Some people just don't look!
relative to your post he stated that the job of the "right seat" was to keep eyes on the controls and indicators for anything not normal....it was apparent you "saved the day" not the case here
@Fly with Magnar Just to point out the possible reason on the altitud they were flying at, I was on the understanding that it was not just a visual pattern but a cycling approach. If it were the case, cycling approach will be flown on landing configuration at the MDA for circle to land on the chart for runway 30. I can't find the charts for the airport but I'm almost certain that the MDA will be the one they were flying at.
Thanks for the excellent video and happy landings.
Thank you! That was a very good analysis! Keep them coming!
Isn't it ridiculous that in this day when local coffee shops have multiple cameras, that in these crucial investigations we're relegated to hunkering over a tape recorder guessing what certain 'clicks' may have been.
It's pathetic
pilots dont want to be filmed when they consume cocaine or play with the stewardess.
The data recorders can be upgraded to record what levers were pulled and buttons pushed without recording video.
Pilots are resistant to video recording for various reasons. One thing I've heard mentioned is that in worst cases, they don't want the video of their final moments to be circulated in the internet. They also don't want hourly micromanaging and micropunishing of their performance.
Many thanks for creating this educational content, captain!
Thank you so much! Highly appreciated!
@@FlywithMagnar Yes pilot decreased condition lever instead of flaws to 30°
Engine turned off fuel supply due to that plane crashed - Cockpit Recorder
Thank you for this heartfelt analysis of this accident. One thing I can say is due to the AUTO function of the Condition Levers, advancing the CLs(PROPS) to MAX is not in Muscle Memory! This makes it easier to not check the position of the CLs on Final Approach than in Aircraft without this function.
I felt so pity to departed soul and relatives to hear this very clear and important information , respect from Nepal 🙏
Superb analysis. Thank you.
I flew ATR’s for years. For something like this to happen is just unbelievable
is it possible that the investigation report was scripted to favour the airline and other stake holders. I mean its always a custom to blame the dead pilots rather taking any responsibility.
@@thomasgeorge5106 Absolutely not
Sabotage?
@@thomasgeorge5106 This Is The Report Of Nepal Investigator, there Is Still French Investigators are Ingestigating.
Thank you for such a thorough and detailed explanation that is easy to understand. Also really appreciate the cutaway diagrams of the aircraft engine you made here.
Excellent video. It brings back the good old memories when I was flying Seneca twin in the flight school.
This must have been a very difficult video for you to make.
Thanks.
Thank you so much fir this video! Really gives a very good insight in the working of the ATR engine/prop controls.
I have a question, in your experience, does the noise of the props change when they are feathered? I would assume the engine sound would be louder and probably drown out the prop noise, but maybe a prop (or two) that are not "biting" into the air will produce a different sound as compared to one that is working fine?
I ask this to understand if there could be a aural feedback to the pilots that they feathered the props by mistake instead of lowering the flaps.
Prop noise on a turboprop is definitely the prominent sound. Feathered engines produce considerably less noise but it is the same pitch, frequency or whatever. It would become suddenly quieter but with sound canceling headphones it might not be noticed as much.
@@thomasmaughan4798 I think for many pilots like myself the notion that the props were unexpectedly feathered in flight and NOT immediately noticed by either or both pilots is frankly perplexing. Noise cancelling headset would be irrelevant. As Capt. Magnar points out one does not easily confuse the prop condition levers with the flap lever, certainly not experienced pilots. This configuration of prop and flap lever is not unique to this airplane, on the contrary, it is very common. Feathered props would be noticed right away, it would sound different and would feel different, noticeably so on both counts not to mention that the airplane would fly differently. There were a lot of holes of the Swiss cheese model that lined up that day or in more modern terms the airplane quickly got into an undesirable (indeed unsafe) state and they did not notice much less correct it. Really bizarre.
Thank you for a thorough explanation of the engine, it's controls and indicators.
I suspect that feathering at idle would not produce much in the way of seat of the pants sensation, leading to the crew failing to catch the problem in time.
Very easy Capt:
1- PF……”Flaps 30”
2- PM….checks speed and announce “Flaps 30 selected”
3- PM…when Flaps REACHED desired setting announces “FLAPS 30 SET”
END OF DISCUSSION.
I flew ATRs for 17 years (9200hrs) and find this a CLEAR example of lack of discipline. Just 3 easy steps. But hey…there are many “astronauts” around….
Exactly This ⬆️
It's no longer needed to optimize RPM vs prop position because it's automated during flight. So the condition lever should move to a other position in the cockpit because it's only used at start/stop and emergency.
I don’t think it will happen, it is a perfect position, human stupidity will defeat any system
Apart from looking at the performance of the crew I believe another thing that should be considered is making the selection of “feather” on the condition levers a two handed operation. That can be either a warning inhibit or a mechanical interlock.
I'm surprised there isn't an indicator and a warning alarm when the props are feathered! Would make sense surely!
I'm wondering why the plane should even allow you to feather props mid-flight when there is power to the engines. I understand the desire to feather a prop if there is a stalled or dead engine, but the plane shouldn't even allow you to feather engines in flight that are receiving power from the turbine. Maybe i'm missing a situation where you would want this?
@@2760adeAn alarm sounds reasonable until you have a real engine failure. The you want the propeller to be feathered. The indication that this has been achieved is Np is zero. It must be therefore possible to cancel such an alarm however the propellor will still have been feathered.
@@robmausserOne such situation might be when you have a jammed engine control, a EEC/PEC failure resulting in a runaway engine/propellor, loss of oil pressure or an engine fire.
Thank You so much (from Argentina) for share this vid. Very clear and educative for those who love aviation. 🙏
Simple and straight up review of the report. Thank you.
It's absolutely possible - I pulled the mixture once in a PA28 instead of turning carb heat on in the landing pattern - two levers in different places, with different shapes. I was a student distracted by radio calls, and it took a good while to realise why the engine had "gone quiet".
Same here. Even in a case such as this, where it seems glaringly obvious that the pilot made a “stupid” mistake, I hesitate to use that word, since it is so human to be momentarily distracted and then do something completely different from what you intended to do.
Very valid point.
Sometimes we call this type of mistake "finger trouble". although this is an extreme example. We train crews to select then verify flap and other configuration changes which this crew didn't do. We also enforce the stabilized approach policy - if unstable, for any reason, we go around. It's never just one reason that an accident occurs.
Indeed. And here a couple of serious mistakes were made in the short time of only 60 seconds.
I can totally see myself making a mistake like this. Sometimes the mind just does weird things, especially when you're new (like on of the pilots was). Your mind gets blurred with too much stuff and you move the wrong lever.
But that's the point of having 2 pilots. The other person should say: "What are you doing?" And the mistake is corrected.
Trust but verify.
They should not put levers that are that important to be that similar and together. It's insane that you can even make that mistake
Thanks for your video, CPT. Safe flights and take care
You are a great analyst of the flight systems and procedures, a great detailed analysis
I was hoping you would make one video on this topic ever since you posted your comment on blancolorio channel. Thanks from Nepal 🇳🇵
I honestly believe that there was a breakdown in SOP’s, whether that be through the airline itself, or the individuals. Like you said however, let us wait for the final report.
If you are correct then this is the start of the investigation, not the end. Mashing up or totally ignoring SOP’s should not result in the aircraft being placed in a dangerous configuration.
@@Trevor_Austin Hey Trevor. I would have to respectfully disagree. There are many fatal accidents that have been caused as a result of the crew not following SOP’s. By drifting away from standard procedures, what you’re doing is exposing yourself to potentially dangerous errors that could adversely affect overall safety. Check out Mentor Pilot’s channel. He has several examples.
@@faganfit572 Hi...but I think we all are taught about the swiss cheese model....Fatal accidents happen due to series of mistakes. Just one mistake should not cause the crash to happen?
@@SurajUpadhyaya-kj8zi Very true Suraj. We can just aim to do our best as aviators.
could be watching tiktok instead of concentrating on the flight
Thank you for your excellent review of the preliminary report and the background technical information. I accept your suggestions but I feel as though the unfamiliar approach to the new airport and the lower than usual altitude and lack of response to the stick shaker were also significant factors. Very sad for all those involved.
Dear Magnar,
Thank you for your video and explanation of the accident, systems and possible causes.
Lets hope the investigation team will go deep into what has happened, as it is not 100% clear one could have done this inadvertently.
I find it amazing that there is no safety lock preventing selecting the feathered position on both engines at the same time while flying. I know they feather both engines after coming to a stop but to be able to operate the leavers together while flying should require a extra interlock to be overcome to prevent a no thrust situation.
You absolutely have to have full control over the Props at all times. In the unlikely event you suffer a double engine failure, then you would NEED to feather both props if the auto-feathering failed to operate, otherwise you will lose control of the aircraft. I hear what you’re saying, but it’s just not feasible. I’ve got thousands of hours flying ATR’s such as this, all be it many years ago now. Had an engine failure of my own on take off in one as well with an associated fire. Since flown most of the heavy jets and still do, but the ATR was a real handful at times, especially in strong cross wind.
This is a tragic accident, but it isn’t the first time in aviation history where mistakingly moving the wrong lever has caused a catastrophic accident, and sadly, it won’t be the last either.
@@GeeBeeMike in that case there should be a warning of "feathered props," once the leavers are moved or yellow warning light on the torque meters to highlight the prop condition.
@@shug831 You cant miss the props being feathered or unfeathered. The noise in the cockpit is unmistakable when you either feather or disc-out the props.
@@GeeBeeMike well two experienced captain's failed to hear the difference. 😢
@@shug831 Yes, indeed.
In my modest opinion, this mistake, as well the the Air Morocco in Sabiha few years back, could be the captains' over confidence. This make me now understand why in Japan, whether airlines or trains, operator must point at the task being done.
”Point and call out” has proven to be surprisingly effective. Even bus drivers in Japan use it when they come to a traffic light.
Point culture should be applied worldwide.
Could you quickly describe how it happens irl please? Thanks
Point and call is also implemented on some railroads in North America for example for approaching switches in the track - I can confirm it helps, especially if there is some fatigue issue.
Dear Captain, many thanks for publication, worth to be seen by everyone flying.
We’ve played this scenario at training cab 3 days ago.. 🤦🏻♂️😢
As a Pilot, I really appreciate your inform and deep knowledge about our plane, the excellent French ATR Series… God bless you!!!
Thank you for your thorough explanations. What I cannot understand: how could they not hear and feel the prop mushing / RPM drop? Can this not be heard in the cockpit in the ATR when wearing ANR headsets?
When the propeller is feathered in flights, the change in sound is more subtle than when feathering the propeller on the ground. And ANR headsets remove almost all sounds from the propellers and engines.
@@FlywithMagnar Thank you. May I ask another question? How long would it have taken the prop regulator to unfeather once the pilots would have recognized the mistake?
@@alw4755 yeah same qn
@@alw4755 I would say about 15 seconds.
@@alw4755it's faster than on the ground. So around 15 seconds sounds reasonable.
This is unbelievable that both CL were unlatched and brought back to feather position.
I have heard the design criticized on other videos
@@johngreydanus2033nothing wrong with the design, every aircraft type with condition levers has exact same configuration
@@johngreydanus2033 ATR is the most successful aircraft with most advance systems specially its propeller system. Mechanical failure or human factor could lead to such disaster. I will be very keen to know the actual position of CLs found after crash in final investigation report.
Nice to meet you Captain Magnar. Excellent analysis accident Yeti 691. I think ATR should review the checklist in BEFORE LANDING and add CL....AUTO POSITION.
Good breakdown of the report. Very tragic accident. Things go bad so quickly.Fatigue, stress, combination of factors clouding human judgement.
When I was learning to fly and seeing all the switches in the cockpit I asked the instructor "should I look at the switch before actioning it in case I flip the wrong switch?" to which the instructor replied "you could do that".
I am amazed that it's not standard procedure to look, reach and action rather than just reach and action when manipulating controls in an aircraft.
Of course this sort of thing happens - you need to look at what you are doing.
When at the end you say that you find it unbelievable that this could happen I think that is part of the problem - the problem is a human factor issue and as assumption that people do not make stupid mistakes - there should be some sort of warning if the props are feathered and if the engine speed is increased while the props are feathered there should be a further warning.
The point is people make mistakes, I don't care if someone is a highly trained pilot - they will still make dumb mistakes once in a while and in this case it led to loss of life.
Indeed, exactly.
I've never seen a first-world Airline that didn't explicitly train ACTUALLY verifying and confirming that all checklist items are performed correctly and the criticality of not becoming complacent. Especially so after all the high profile takeoff crashes of the 70s-90s that were the result of NOT performing critical checklists correctly. The takeoff/landing checklists in particular have the PM repeat command, visually confirm change, with the PF also verifying it afterwards. This is a huge part of training and has been a point of emphasis for decades now, and every cockpit video I've ever seen has the PM and PF both verifying checklist items
With that shocking control layout, it's frankly extraordinary that this exact scenario hasn't happened previously.
Let us wait for the final report thanks for the update captain.
Thank you for explaining!! A error in judgement caused so much grievance to people of Nepal
Both the flap lever and the condition lever involve a lift and retard motion. The condition lever requires lift to raise the interlock/detent, and the flap lever requires a lift action to clear the detent. If the same grip is applied to the flap lever as to the condition lever( i.e., hand wrapped over ), I can see how the fault could occur. Also, from the Capt seat, he must normally reach over the condition levers to get to the flap lever. If he does a similar over-reach from the co-pilot seat, he might over-reach to the condition lever instead of the flap lever. The levers are not necessarily as different as it would appear they are. Also, the arc through which the flap lever is moving from 15 to 30, is similar to the arc from auto to feather on the condition lever. Add in stress,boredom,distraction, etc and ......
And then there are 'senior' moments...
What you're saying makes the most sense , what a pity , things happened so fast not enough time to react.
Thanks!
Thank you so much! Highly appreciated!
I much prefer this style rather than the gimme gimme sponsored ones. Much more natural and told in a story-like matter. Well done.
Thank you for your excellent explanation of the tragic ATR loss. At the very least, it appears there needs to be a Level 3 Master Warning and CRC in the event both propellors are feathered with a functional gas generator in flight.
Great work
RIP to all those that perished in this crash. It can't be ruled out that the pilot monitoring deliberately moved both condition levers to feather for some reason. We can speculate on that reason but it's a bit suspicious that the CVR text hasn't yet been released.
I agree. Bringing both propellers into feather is so bizarre as to be suspicious of being an intentional act. But then later, the flaps were set to 30, so I suspect the pilot monitoring quietly tried to correct (or hide) his mistake?
@@m.f.m.67 Then why not restore the condition levers back to auto at that point also?
@@earthb67 That's the biggest question in my opinion. He must have realised he hadn't set the flaps to 30, but he must have ALSO realised that he had earlier accidentally moved something else? Makes no sense to me!
@@2760ade It´s indeed so that after the "basic" mistake of confusing Flaps Lever with Condition Lever five or six more crucial mistakes were made in just 42 seconds: 1.) The "basic" mistake was not cleared when the Pilots worked the Before-Landing-Checklist. 2.) When the Flaps were finally set to 30 there was no Call-Out made by the Pilot Monitoring (at least I readed the Preliminary Report in this way), so that the Pilot Flying stayed unaware of this action at that time. 3.) When the Flaps were eventually setted to 30 the mistake that the Condition Levers were in the Feathered Position stayed undetected - or at least uncorrected. 4.) When the Power Levers were moved first to 62% and then to Full Power the mistake of the Condition Levers being in the Feathered-Position was also not detected or at least not corrected by BOTH Pilots . 5.) The Pilots switched the Roles of Pilot Flying and Pilot Monitoring in that now very dangerous situation, so that they wasted time with accomodating to their new Roles instead of FLYING THE AIRCRAFT. 6.) That all happened during an unstabilized approach (= Checklists were not completed and Landing Configuration was not finished above 500 feet AGL), so that the Pilots were during this whole Accident Sequence always behind their Aircraft.
And then finally - again: at least I readed the Preliminary Report in this way - the former Pilot Monitoring and now Pilot Flying made no Control Inputs during the final 14 seconds of the Flight, even not when eventually the Stick Shaker was going. That means, he was NOT flying the Aircraft when he became Pilot Flying.
To type all of this mistakes in lasted nearly half an hour - the real Crash Sequence lasted only 60 seconds all-in-all. That is to remember. But nevertheless: There was seldom a Crash were in such a short time such an amount of really crucial and weird mistakes were made. So there remains really the need for the ongoing investigation to find an answer to the question: Why?
I've been saying that ever since the report came out, there's no way he mistakenly moved the lever instead of the flaps!!!!! It seems he was an experienced pilot.
"Thank you for your great effort, it is truly appreciated."
REALLY excellent video! I flew turboprops (Dash7) years ago and had forgotten how the systems (props) worked… The human factors in this accident will be very interesting….
I had checked 12 days of flight performance about this particular aircraft in radder. Altimeter and Speedometer have not been working properly for many days. So i presume maintenance history should be examined to find the clue.
At 10:56 there was a click sound. Like you said it can be come from a lot of things, can't it be possible to detect the pitch of the click sound and compare it with another same model aircraft? If you notice in the video demonstration every click is not in the same pitch.
Note 4 says it was assumed to be them turning off Master Caution.
@@steve6375 Indeed.
For the folks on this thread saying the crew had such a short time to correct the "mistake" just sit down in a chair and Count fast:
1000 and one
1000 and two
1000 and three
And do that to 52. [Cut it in half to 26 seconds and there still was time to make corrections and get the propellers producing thrust again]
The number of seconds they had to look at the Engine and Propeller settings on the Quadrant and the TORQUE METERS.
Something really smells about this whole report and story.
The crew had plenty of time to correct their mistake before the Stick Shaker and stall / crash.
Gotta say that is a great presentation and explanation of information. God rest the souls of those who lost their lives.