What STOPPED this Airplane from flying? | Air Crash Investigation

this video has been brought to you together with the nord vpn use the link in the description below for your special deal an md-83 aircraft from ameristar air cargo is accelerating downro 2-3 left in willow run airport michigan united states in the back the local university basketball team the wolverines are getting ready for a tournament in washington dc but the weather outside is extremely windy so windy in fact the local air traffic control tower has had to be evacuated is there ever a situation where rejecting the takeoff after the decision speed of v1 is a good choice and what would happen if you do that stay tuned the extraordinary story about ameristar air cargo flight 9363 took place on the 8th of march 2017. now the aircraft being used is an md-83 which is a variant of the old dc-9 aircraft with a t-tail and two rear-mounted jet engines the aircraft had been parked for two days prior to the accident flights at the wileron airport in michigan they were awaiting the local sports team the wolverines for a shorter flight to washington dc during those two days the aircraft had been parked facing north next to a large hangar and the way that this aircraft was parked is actually going to have a quite significant importance later on during the night and the morning before the accident flight a low pressure had passed overhead michigan causing some really strong and gusty winds in fact at some point the wind became so strong that it knocked out the power supply to the local air traffic control tower causing the tower to be evacuated and that meant that as the flight crew arrived to the aircraft there was no way for them to contact the tower and also the automatic updating of the weather at the airport had stopped working under fva rules it's perfectly okay to operate a commercial flight out of an airport that doesn't have a working air traffic control tower however there are some rules applied to it and among those routes is that you need to be able to get your hands on your air traffic control clearance and also updated weather now the weather is extra important especially during really gusty strong winds like this in order to make some proper performance calculations the crew did exactly this they just used their mobile phones called the closest air traffic control center to get their clearance and also to get continuous updates on the weather now in the cockpit on the accident day are two very senior pilots the acting captain is 54 years old he's got 15 518 hours of total time and just under 8 500 hours on the dc9 however on this day he is going to fly the md 83 instead which is a variant of the dc-9 and since he has almost no experience at all on the md83 he needs to do something called difference training which is when you fly with a czech airman or line training captain so that they can point out what the differences between the different variants are now doing this difference training is a 41 year old czech airman he's got 9660 hours of total time of which 2462 is flown on the dc-9 and the md-83 now when you have two captains flying together there's always a potential for crm issues and that's because those two pilots those two captains are trained to take crucial decisions when there's very little time available an example of that is in the case of a rejected take-off when there's no time for discussion so it is really really important in a situation like that that both pilots have talked beforehand about who is going to do what during certain situations and in the case of a difference training like this the acting captain is being trained in his role as a captain which means that he is going to be the one that takes those decisions now the czech airman on the other hand he is designated the piloting command for this flight because he is the instructor but he is going to have to play the role of the first officer because otherwise the training of the captain is not going to be realistic and also if you start to kind of step on each other too much in the decision-making process there might be other crm problems coming in so it's very very important that a crew like this two senior captains flying together have worked this out and can play these roles and know what to do and when all the time at around 12 40 eastern standard time the pilots enter the cockpit for the first time and they start to discuss the weather outside obviously it is still really really windy and when it's windy we have some special procedures that we have to take into account now part of our performance calculation is calculating our v1 speed that's what we call decision speed it's the latest time that we can reject the takeoff safely and it's also the earliest speed in which we can continue the aircraft and fly it safely on one engine if we would have an engine failure but we also have to calculate our rotation speed and our safe climb speed our v2 speed okay when it is windy there is a possibility especially with gusty winds that the wind the headwind that we're calculating our performance on might dissipate right it might disappear and if that happens effectively the amount of air that's flowing over our wings and helping us to fly is going to be reduced and because there is a possibility that there might be a gust of wind that's dissipating just during the rotation stage sometimes we elect to continue past double rotation speed let the aircraft accelerate a little bit longer before we call rotate in order to make sure that we have enough speed for the aircraft to safely fly the czech airman who is going to be pallet monitoring for this first leg an acting first officer he suggests that they delay the rotation call until they reach the v2 speed the acting captain agrees with that seems like a very reasonable idea and they set the speed to v1 139 knots the rotate of 142 knots and v2 the safe climb speed of 150 knots now before the crew do their final flight deck preparation the acting pilot flying which is the captain is also having to do the walk around so he goes out he looks at all of the different parts of the aircraft and when it comes to the tail he looks up what you have to understand on the md-83 is that since it's a t-tail aircraft it means that the horizontal stabilizer and the elevator is about 30 feet above ground that's about 9 meters up now he looks at them and he sees that they're looking completely normal at this stage you also have to understand a little bit about the way that the elevators work on the md83 the elevator that is the flight controls that is primarily controlling the aircraft in pitch they are not directly connected to the flight controls in the cockpit okay on the 737 they are when you pull the yoke backwards that is going to deflect the elevators up directly but on the md83 that's not the case instead the flight controls in the cockpit is connected to something called a control tab that's a smaller rudder surface on the back of the elevator and the way that these control tabs work is that if the pilot would for example pull back in order to rotate the aircraft well then what they want to do is they want to get the elevators to pitch up thereby giving a force down on the tail making the nose of the aircraft rise and the aircraft climb away and with the control tabs the control tabs moves the opposite direction so they move down in order to true aerodynamic force the elevator to go up and that way get the aircraft rotating now that might sound like something that's a little bit complicated but in fact like quite a lot of aircraft especially older aircraft did things this way because there is considerably less force involved in order to use these control tabs than to move the entire rudder surface especially when the rudder surface is very big on top of these control tabs that are connected directly to the to the cockpit controls there's also something called a gear tab it's also named servo tab on other aircraft now this gear tab sits next to the control tab on the elevator and its job is to further kind of enhance the movement of the elevator so when the pilots move the control tab in order to move the elevator then this geared tab is connected to the elevator to further assist that movement right that also makes it easier to control the aircraft because now you only need to move the control tab the movement is going to start moving the elevator and the gear tab is going to further enhance that aerodynamic movement okay there's also another tab outside of that called a anti-float tab which i'm not going to go into too much because it doesn't have any bearing on what happens on this flight so the captain is now during his walk around looking up at these elevators and these elevators are not connected to each other so this means that one elevator can be pointing down another elevator can be pointed up okay so this is completely normal he sees nothing out of the ordinary so he just continues completes his walk around and goes in and joins up his colleague to continue to prepare the cockpit for flight now before we go into the actual accident sequence of this flight i just want to share this message with you this video is brought to you together with nordvpn now you know just as well as i do how important it is to protect you and your data in this day and age i use the nordvpn app whenever i'm out traveling so if i go into a cafe or an airport i want to use the public wi-fi well then i switch it on and it will tell me whether or not that network is actually safe and secure to use and if it's not i just don't use it it also helps me to encrypt my data and my position but probably what i use it the most for is to get past these pesky regional restrictions so if i'm out traveling somewhere and i want to watch my favorite netflix series well then by a click of a button i can be back in spain again which makes sure that all of the library in spain is available to me and you can use up to six different devices on one single deal if this sounds good to you then use the link in the description here below which is nordvpn.org pilot and the coupon code pilot to get 66 of the two-year deal plus an extra bonus gift go down click the link and start protecting yourself on the internet today the pilots now tell the cabin crew to begin boarding the passengers and the wolverines together where their cheerleaders some family members are all boarding at the same time at around 1400 eastern standard time all in all there's 110 passengers on board and six crew members once the boarding is complete the pilots start up their engines and they start to taxi out for takeoff and runway two three left during the taxi heart procedure the czech airman who is sitting in the first officer chair is doing all of the first officer's duties and that includes checking the flight controls all of the checks are done without the pilots noticing anything out of the ordinary at time 14 51 and 12 seconds the captain sets take of trust and his md83 starts accelerating down the runway for the first 40 seconds of the take-off roll everything is as normal there's no indications of anything being out of the ordinary the czech airman calls v1 and then as they had discussed previously they delay the rotation a little bit so six seconds after he calls v1 he calls rotate the captain starts trying to rotate the aircraft but after about three seconds he recognizes that something is severely wrong so he calls what what what's going on and then abort the czech airman looks over at him and says no not above and don't reject after v1 like that and he initially reaches for the flight controls as well the captain responds with it wasn't flying and he executes the rejected takeoff maneuver now when they start the rejected takeoff about 12 seconds has elapsed from the first v1 call remember v1 speed when the aircraft reaches that speed that's the last point which you normally can reject the take-off in order to safely stay within the paved runway this is now 12 seconds later which means that the aircraft has accelerated up to a speed of about 173 knots and while it's accelerating it's also eating up precious runway needed to stop so as the captain is now starting his rejected takeoff maneuver the czech airman realizes that the maneuver has already been started and even though he was initially reaching for the flight controls he now continues to do his part for the rejected take-off the rejected take-off maneuver includes items like closing the thrust levels disengaging the outer throttle making sure that you simultaneously have maximum braking manually raising the speed brake levers to make sure that your flight spoilers comes up in the wing and you get your weight down on the gear and then selecting reverse trust the czech airman is calling out speeds making sure that all of these items have been correctly executed the fact that you have maximum braking and doing everything that he is supposed to do in his role as a first officer but of course with the kind of speed that this aircraft is now keeping and you know as late as this is happening there's no way that they're going to be able to stop this aircraft within the runways so at time 14 52 and 20 seconds the aircrafts depart the paved part of the runway it goes into a runway safety area which is a grass field without any obstacle on it this safety area has actually been recently extended it used to be a smaller area but because of some upgrades during the beginning of the 2000s the faa had decided to try to increase this area so they go through that still breaking now they go through a perimeter fence and then they hit a slightly elevated paved road outside of the airport perimeter as they hit that that likely shears off the landing gear of the aircraft and the aircraft finally comes to a complete stop as soon as the aircraft comes to a complete stop the czech airman reaches over for the public address mic and starts the evacuation command which is evacuate evacuate evacuate when the cabin crew hears this they initiate the evacuation immediately uh they're doing so in a very professional way they have some initial problems with the right forward door where the slide wouldn't inflate also the aft evacuation door which is in the tail cone of the md-83 was jammed initially but after a few seconds the cabin crew managed to open that as well all in all all 110 passengers and six crew evacuate successfully from the aircraft there is just one passenger who suffers a small laceration of one of the legs the evacuation is a complete success both because of the professionalism of the cabin crew but also because the passengers the wolverines acted in a very professional way they followed the cabin crews command from the very beginning no one tried to take any of their personal belongings with them and evacuated as pure professionals did but what has actually happened well in interviews with the pilots when the captain was asked why he elected to reject the takeoff that far beyond the v1 call he said that as he heard the call rotate he started rotating normally now in both the dc-9 which he was very experienced on and in the md-83 there's about a three second delay from when you start putting inputs into the flight controls until the nose starts coming off the runway so during those first three seconds he wasn't that worried but he almost immediately realized that there was nothing happening the nose would not come off the ground and when he noticed that he continued to pull more and more not all the way until this dick was in his stomach but enough to realize that something was seriously wrong and when he realized that he immediately realized the situation they were in that he wouldn't be able to control the aircraft in pitch even if he did get it off the ground so he elected to reject the takeoff the czech airman when he was asked about his actions he said that his initial kind of backbone reaction was to reach for the controls when he realized that the aircraft was about to be rejected above v1 which is a known unsafe thing to do but obviously he couldn't feel the aircraft he had no idea why the captain was doing what he was doing but as he saw that the captain had already initiated the rejected takeoff he realized that there was nothing to do nothing he could do so the best thing to do in that situation is to continue with the rejected takeoff to try to make that as successful as possible so that is what he did but this doesn't explain why the aircraft wouldn't rotate as the accident investigation team came to the accident site they looked at the back of the aircraft and what anyone could see at the accident site if they looked up towards the horizontal stabilizer in the elevators was that the left elevator was in the full trailing edge up position which is what you would expect from an aircraft that is trying to rotate but the right elevator was in the full trailing edge down position as the investigators came up and started to try to move the elevator they realized very quickly that the right elevator was completely jammed and when they looked into it they realized that the geared tab remember that's the flight control that is next to the control tab on the back of the elevator the control rod that is normally controlling the movement that is connected to the elevator had moved past its maximum position and had gotten stuck in an over cooked position and because it was in that position it effectively jammed the stabilizer from movement the investigation team very quickly started honing in on the very strong winds that had been present at the aircraft during the previous night because they knew that boeing had put a restriction on the md-83 and on any other dc-9 and boeing 717 aircraft that if the aircraft was subjected to strong enough winds above 60 knots the nose of the aircraft needed to be parked into the wind and if at any time the winds exceeded 65 knots over the tail well then there was a maintenance procedure that needed to be in place where the engineers needed to go up and physically move the elevators to make sure that they weren't jammed but the interesting thing here is that at no time during the night nor during the hours before this accident flight had the wind even been close to 60 knots the highest recorded wind was 55 knots with the average wind gusts around 48 knots so why had the elevator jammed well in order to find this out they actually used some extraordinary investigation methods they mapped out using drones where the aircraft had been exactly parked and the drones also marked up the whole area including that big hangar that they were standing next to and because these strong gusty winds had come from the west and the new the direction of the winds they could use computer modelling to exactly show where those winds have been moving and how they had been moving and what they found out was that as the wind had been passing over this hanger not only had the hanger actually accelerated the wind it had also created these vortexes and those vortexes would have impacted exactly where this aircraft was parked now the way that these vortexes would have moved the elevators which didn't have any gust lock on them would have been up and down forcefully and when they contacted boeing to see how they had determined this maximum wind speed of 65 knots boeing said that they had been calculating on a straight wind without any acceleration in any kind of direction so if you had this very high wind with vortexes in it that could actually move the elevator up to its maximum deflection both up and down that could have caused enough force to get this gear tab into the overcooked position and effectively jam the elevator at a much lower wind speed and the investigation team actually tested this out with the actual flight controls and found that around 58 knots or so then that elevator could effectively be jammed so what about the pilot's actions and all of this then well this is a really interesting bit really because in any normal circumstances rejecting a takeoff above the v1 speed is not recommended not by boeing not by the company manual not by anyone because you know that there is a huge risk that the aircraft is going to exit the runway if that happens however there is a note from boeing in the flight crew operations manual that says that rejection of a takeoff above v1 is not recommended unless the captain deems that the aircraft is incapable of flight and in this case this is exactly what happened so we come to an extraordinary situation where the flight crew has been doing everything right they have done all of the procedures correct they have done the walk around correctly they have done the flight test correctly of course when they were doing the flight test the only thing that they could feel was how the control tab was moving but since the flight controls was not directly connected to the elevator the fact that the elevator was jammed could not be detected with the flight control check so they initiated their take-off role without any indication that anything was wrong with their aircraft the first time that these pilots would have noticed that something was wrong was when they started to rotate the aircraft finding out that the elevator was jammed at that point which was well beyond v1 so the accident investigation team actually commended the captain for his wise and timely decision to reject the takeoff even though it had passed v1 when he realized that the aircraft was unable to fly and they also commanded the czech airman who fought his urge to kind of over rule the captain even though he was the pilot in command on the flight instead following standard operating procedures he helped the rejected takeoff become as successful as possible the way that these two pilots work together in order to reject the takeoff and get the aircraft to stop in a relatively safe way is truly commendable the accident investigation team came to the following two causes of the accident number one a right jammed elevator caused by some very dynamic winds where the aircraft was parked number two the lack of means for the flight tech crew to identify this jam prior to the commencement of the takeoff they also added that contributing to the survivability of the event was the captain's timely decision to reject the take-off once he realized that the aircraft was unable to fly the extremely efficient crm and adherence to standard operating procedures shown by both flight crew members and also the extended runway safety area of the airport now there were a couple of recommendations that came out of this accident the first one was for boeing to change the design of the md-80 dc9 and boeing 717 aircraft to make sure that high winds couldn't cause this kind of jam to the elevator boeing subsequently did that as well by introducing a further stop to the geared balance tab to make sure that it couldn't get into this overcooked position and effectively jam the elevator number two was for new cockpit procedures to be implemented to make sure that while the pilots were doing their flight control check there would be some kind of means to effectively monitor the movement of the elevator as well to make sure that there weren't any jams in any of the flight controls before flight there was also a recommendation to the faa to determine the responsibility who needed to verify and check when an aircraft was subjected to high winds during it being parked at an apron guys i really hope that you like these type of videos and if you do that you have subscribed to the channel and that you've highlighted notification bell i have several other aviation incident and accident reports that i've done you can check out the playlist up here for your next one and also if you're liking this t-shirt that i'm using there's a link to my spring store here in the description of the video you can go there you maybe you like this one or this one or maybe this one in any case i hope that you're all doing absolutely fantastic wherever you are i hope that you will be enjoying my next coming video next week as well have an absolutely fantastic day and i'll see you next time bye [Music] you

Channel: Mentour Pilot

Views: 823,435

Keywords: Rejected takeoff, Ameristar Air Cargo flight 9363, aircraft accident investigation, aircraft accident documentary, aircraft accident investigation video, aircraft accident simulation, mentour pilot 737 max, mentour pilot crash, aircraft crash investigation, aircraft crash documentary, MD 83, DC 9, Boeing 717, Michigan, michigan wolverines basketball, Runway excursion, air crash investigation 2021, air crash investigation, Fear of flying, nervous flyer, Pilot life

Id: 61_TqeITE3I

Length: 27min 41sec (1661 seconds)

Published: Fri Jun 04 2021

Reddit Comments

[u/Naando_boi]

Petter’s videos are awesome

[u/Plane_n_Boom]

Reminds me of Air Moorea 1121.

[u/isnifmarkers1599]

Oh man, I live just North of YIP. Remember that day well. Definitely the windiest day we've had in a long time here in Southeast Michigan.