HOW This Aircraft FELL 30 000 Feet in Less Than 2.5min! | China Airlines 006

this boeing 747 is literally falling out of the sky the crew are performing some quite terrifying aerobatic maneuvers and if you've ever wanted to know how much forces it would take to start ripping an aircraft apart midair this video is going to give you an indication stay tuned a huge thank you to the airline pilot club for sponsoring this video it's late in the morning on the 19th of february in 1985. a boeing 747 sp from china airlines is cruising at 41 000 feet over the north eastern part of the pacific ocean about 300 nautical miles northwest of san francisco the flight is a scheduled passenger service from taipei in china over towards los angeles in the united states and it took off at 1622 taipei time and has now been flying for about 10 hours onboard the aircraft is 251 passengers at 5 pilots and 18 cabin crew the flight crew operating this flight is very experienced the captain is a 55 year old male with 15 494 hours of total time assisting him is a 54 year old male first officer with 7 734 hours and a 55 year old flight engineer with 15 510 hours also augmenting the flight crew as a relief captain and an extra flight engineer and both of those were actually resting during the time of this event the aircraft being flown is a relatively new boeing 747sp it has four prattan whitney jt9 delta seven alpha engines rated at forty six thousand one hundred and fifty pounds of thrust now there had been some issues on the previous two flights for this aircraft with the number four engine that's the engine situated on the right-hand wing the furthest out what had happened was that the crews had reported a loss of thrust on the number four engine and a subsequent need to re-light it in cruise and because of that it had been taken down and it had been thoroughly examined on the ground by an engineering team some part had been replaced and then the engine had been ground tested and been found to work satisfactorily the weather in the area which the aircraft is flying through is a little bit unstable they've just flown through a cold front and associated with that cold front is something called a jet stream a jet stream is a quite narrow band of very strong winds and where those strong winds rub up against slower moving air particles it creates these vortexes which creates turbulence and the aircraft was experiencing turbulence just before this event occurred that prompted the captain to switch on the foster seatbelt sign and that's going to turn up to be a very good move indeed at this point the aircraft was flying on autopilot and the autopilot was connected to its performance management system pms which is very similar to the more modern variant fms flight management system that we're using on aircraft today the performance management system was also connected to the outer throttle which was set to maintain an airspeed of mach .85 as the aircraft got closer to a mandatory reporting point called redo the clear air turbulence suddenly got a little bit worse now the issue with clear air turbulence is that sometimes it can start fluctuating the airspeed of the aircraft in this case the speed started going up so it reached as high as mach point 88 and because the auto throttle was engaged the auto throttle wanted to keep a speed of mach 0.85 so it started reducing the trust on all four engines to achieve that speed the speed started reducing and when it hit mach point 84 the outer truss started telling the thrust levers to increase again but here's something happen even though the auto trust was now commanding all four trust levels to move forward the epr the engine pressure ratio on the number four engine didn't increase and this indicates that the trust is not increasing either because the aircraft was already flying through turbulence the flight engineer had put the engine start switches to in-flight start that provides continuous ignition to all four engines and it's normal procedure to do so when we're flying through turbulence but when the flight engineer realized that the number four engine wasn't responding he started actioning the hung or slow engine acceleration procedure now this procedure is not an emergency procedure so it doesn't have a non-normal checklist connected to it it is a supplementary procedure and because of that the flight engineer is allowed to do this procedure by heart so what he does is that he once again reduces the trust on the engine 4 trust level and then slowly starts bringing it back up again hoping that it will solve the problem unfortunately he forgets one crucial thing and that is in this procedure you also have to switch the bleed air on that engine to off and the reason that's important is because what's likely happening to the number four engine right now is something called bleed load hogging during normal circumstances all four engines will be providing high pressure lead air to the pressurization system of the aircraft this is done by a high pressure and a low pressure bleed air valve on each engine when the engine is operating at low thrust both of these valves are open but as the engines start to accelerate up to higher trust settings well then the high pressure bleed air valve will close and only the lower pressure of the data valve will be open the problem is if one engine is accelerating slower than the others you might get into a situation where the three engines that have accelerated will close their high pressure bleed air valve but the slower engine has both high pressure and low pressure bleeder valve open and in that case that engine will take up much more of the bleed air load when bleed air is being sucked from the engine that will actually take some of the thrust away from it hinder its acceleration so it might become a kind of a self-playing piano where it's slow to begin with and it just keeps becoming slower and harder for that end to work that's why it's so important to switch that bleed air valve off in this procedure but the flight engineer forgets to do this as this is happening remember that the outer pallet and the outer throttle are still engaged well as the number four engine which is situated on the furthest out position on the right hand wing starts delivering less thrust it means that a thrust asymmetry is starting to develop where on the left hand wing both engines are producing trust and on the right hand wing essentially only one engine is producing trust this means that the aircraft is going to start to yaw towards the right the autopilot doesn't have any authority over the rudder okay this is the same on the 737 i'm flying so the only thing that the autopilot can do in order to counteract this yaw is to start inputting aileron towards the left putting in a bank toward the left to counteract the yaw that is forcing it to the right now the flight engineer also notices that the generator of boss light has popped up on the number four engine and this is actually an indication of the engine not just struggling to accelerate but that it's actually failed so he calls this out to the captain tells him we have now an engine failure on engine number four and he starts getting ready to issue the engine failure checklist which is a normal checklist and he also starts getting ready to calculate the aircraft's tree engine cruise altitude because the aircraft cannot sustain 41 000 feet with only three engines so it's very important that you very quickly figure out what altitude you can maintain because otherwise the speed is going to start reducing at this point the captain also asks the flight engineer to try to restart the engine even though the aircraft is still at 41 000 feet and the highest altitude for a restart attempt is actually 30 000 feet the first officer has heard and seen all of this happening and he heard the flight engineer calling out the engine failure as this is happening he's looking back and he realizes that the supplementing flight engineer has popped his head into the cockpit and first also tells him to come in and start helping the flight engineer to try to re-light the engine first officer is also looking down onto his instrumentation and he realizes that the speed is starting to decrease so he calls this out to the captain the captain responds to this by telling the first officer to contact oakland air traffic control and ask for lower levels so they can initiate the descent and keep the airspeed to keep themselves safe at time 10 14 and 11 seconds the first of the calls up auckland atc and asks them to descend he doesn't declare a mayday he doesn't declare a pan and he doesn't tell them about the engine failure at this point oakland atc tells them to stand by and this is a good reminder for any pilot out there who's watching why it's so important to state at least a pan pattern because then you will get the attention of our traffic control it's very likely that they won't tell you to stand by that they will issue an immediate descent clearance which is what you want in a situation like this the first officer later testified that he didn't hear anything else coming back from oakland atc but the atc transcript shows that between the time 10 15 13 and 10 1828 atc both came in and cleared air china flight 06 to descent flat level 270 and they then called them a further six times without any response back from the flight crew it's very likely that the reason that the crew couldn't respond to that was that they were in the middle of this horrifying upset which is about to happen the captain meanwhile is monitoring his airspeed and he does not like what he sees the speed is going lower and lower which is to be expected when you're maintaining 41 000 feet and you've lost one engine so the captain decides that he's going to switch off his pms system that's going to release the aircraft out of altitude hold and then he's going to turn his pitch control wheel on the autopilot control panel down to initiate a descend but still in autopilot but remember how the autopilot does not have any rudder authority well what's happening right now as the captain is trying to get the aircraft to descend and is focusing on his airspeed is that the thrust on remaining engines have been increased to maximum continuous this has also increased the asymmetry between the left and the right wing so the aircraft is really starting to yaw towards the right the autopilot itself has now inputted its maximum control wheel input towards the left which is 22 degrees on the control wheel this doesn't mean that the aircraft is actually rolling 22 degrees to the left it just means that this is as much as the outer pilot can do in fact what the aircraft is doing is it's starting to roll slightly towards the right and this is all because of that asymmetric trust what needs to be done right now is that the captain needs to start inputting left rudder in order to straighten the aircraft out and be in control of the aircraft but for some reason this is not done he is concentrating more on his airspeed there's no rudder input and the aircraft starts to roll more and more towards the right the captain keeps monitoring his airspeed and realizes that the aircraft is still decelerating and he decides that he's now going to disconnect the autopilot in order to pitch the nose down and get the speed under control what he doesn't realize is that as he disconnects the autopilot he's now going to be faced with the full effect of the asymmetric trust the thing that he has not yet compensated for at time 10 14 and 50 seconds the aircraft has rolled right 64 degrees and is now pitching down with four degrees only 10 seconds later they are at a roll angle of 92 degrees and they're pitching down 27 degrees the aircraft continues to roll at a really high roll rate and this causes the captain to believe that there's something wrong with this instrumentation he just cannot believe what it is that he's seeing same is happening to the first officer they communicate about this they think something is wrong with our instrumentation but there's no indication that anything is wrong with them all three of their primary adis are indicating the same there are no warning flags on them indicating that they're actually showing the horrifying truth of what's happening to the aircraft they continue to roll a full 360 degrees around the roll axis as the pitch is going near vertical as it's doing so the speed is also increasing and it's getting close to its maximum certified limit captain realizes this but since they're now inside of a cloud layer and he doesn't trust his instrumentation he just does not know what to do and they have now completely lost their situational awareness as this is going on the flight engineer realizes that the aircraft is going into an upset attitude he reaches over and he increases the thrust on the engines but he also notices that the engines are not responding immediately now this is likely because they are still at a fairly high altitude up there the air is very thin and it takes a while for the jet engines to respond to trust lever inputs but because things are now accelerating and getting worse so quickly it's likely that he just does not think about that he assumes that all four engines have flamed out the flight engineer now reaches up and puts the standby igniter switch to on in order to try to re-light the engines that he thinks have failed but as he's doing so the captain who's desperately trying to stop this increasing the center rate is now pulling hard on his yoke while he's doing that at this high airspeed he's actually subjecting the aircraft to extreme g-forces in the first pull-up he does he pulls 4.8 g's this is so much g-forces that the flight engineer who is trying to re-light the engines gets forced with his face and hands down towards the center pedestal the standby captain and flight engineer has now also entered the cockpit to see what's going on and they get pushed onto the floor and cannot get up from there just by the g-forces eventually the captain manages to arrest the descent rate and he continues to pull remember he's still in clouds he still doesn't trust his instrumentation which means that the aircraft is now pitching up and the airspeed comes rushing off and it reaches as low as 80 to 100 knots indicated airspeed when the captain sees this he panics and he pushes forward in order to get the speed back on the control and this once again accelerates the aircraft up to above the maximum certified speed what happens next is that the captain and first officer would use their combined force to try to pull the aircraft out of this dive and while doing so they create a soul-crushing 5.1 gs that last several seconds and just to put that into perspective the kind of g-forces that astronauts will be subjected to during a launch or during re-entry is around 3gs at 11 000 feet the aircraft comes out of the cloud layer which means that the pilots now have a real horizon that they can use to orient themselves this means that they manage to level the aircraft off at about 9500 feet they bring the trust back up in order to stabilize the flight and it looks like they have the aircraft now under control but they have descended more than 30 000 feet in under two and a half minutes now you might think that that's going to be the end of this horrifying story but you couldn't be further from the truth and i will tell you all about what happens next to this aircraft just after this short message i have some really exciting news for you guys it is now 100 free for anyone who has even the smallest inkling that they want to become a professional pilot to join the airline pilot club using the link here below the club will offer you things like professional airline aptitude testing that will show you what if anything that you might need to improve before you start your training this test can also be used during or after your training to prepare yourself for that airline application process it will also give you access to airline quality e-learning like threat and error management and crew resource management and access to a great community of people just like you who might be on your way up to start your training or people who are already in training or people like me that can give you feedback of how it's actually like in the industry this and a lot more is now available absolutely for free and if this sounds interesting to you we'll then use the link in the description here below it's the airlinepilotclub.com register and let's start working on getting you into that right seat right now now back to the video so the boeing 747 house now level off at about 9500 feet and the pilots are starting to get their bearings back the flight engineer reaches over and checks whether or not the engines are operating and he finds that yes engines one two and three are operating normally they respond normally to truss lever input but engine number four is still failed he uses the engine inflight restart non-normal checklist in order to start ending number 4 and it starts up so they now have all four engines back again working at time 10 1705 the first officer calls up air traffic control and he reports we have experienced a flame out we have emergency and we are at 900 000 feet the first officer also asked to get radar vectors onto the course back towards los angeles air traffic control provides this and also gives them a clearance to climb to flight over 200. during the climb the first officer calls our traffic control and says uh we can we can control the aircraft which i bet is a nice thing to hear if you're in air traffic controller oakland atc also comes in and asks the aircraft if they want to divert towards san francisco which is the closest available major airport on their route but the crew responds to that that the conditions are now normal we would like to continue to watch los angeles soon after this they get further clearance to climb to flight level 3-5-0 but during the climb the flight engineer is doing a panel scan and he realizes that the main body landing here doors are open and that's the main body gear is actually down and locked when they realize this they level off at 27 000 feet because the maximum altitude they can fly with gear out is 29 000 feet and they start looking into their fuel figures whether or not they can actually continue the flight with the remaining fuel and reach los angeles on top of this the flight engineer also realizes that the number one hydraulic system is completely depleted it's indicating zero somewhere around here the crew must have also contacted the cabin crew in the back because at time 10 38 and 39 seconds they call a traffic control up again declares an emergency and say that they have injured persons on board and that they would like to divert towards san francisco air traffic control obviously gives them a direct vector toward san francisco and give them a descent unknown discretion basically that they can descend however they want in order to get into runway 2-8 left in san francisco the aircraft initiates its descent all engines are operating normally at this point and they're using the outer pilots as they're initiating their approach they also realize that they need to take the gear down manually because they've lost hydraulic system number one so they do this and they proceed to do a normal successful landing runway two eight left after landing uh the captain steers off on one of the high speed taxiways but because he is lacking hydraulic system one he has only limited nose wheel steering so he decides to stop the aircraft on the taxiway shut down the engine and ask for a tog to bring them into the terminal but what has happened in the back and to the aircraft well it turns out that when it came to the passengers and crew it was actually not that bad one of the cabin crew members had strained his back so bad he needed to go to the hospital but he was released about three days later and one of the passengers had fallen and broken his right foot but those were the only injuries to people in the cabin there was also a big mess because the overhead lockers had opened up and stuff had fallen out and people were scared but the real scope of the seriousness of this accident actually came to light when the engineer started looking at the aircraft because what they found was that first of all both wings had been permanently bent upward to about two to three inches at the wingtips now that was still within the kind of tolerance of the aircraft manufacturer but the left-hand aileron had been permanently damaged in several places and when they came to the landing gear section of the aircraft they realized that both the left and right body gear upload assemblies had separated from their attachments because of the huge g-forces this in turn had forced the main body landing gear out and knocked out the landing gear doors which had separated and just fallen off the aircraft this is why the landing gear doors were indicated open and the gear was down and locked when the engineers came to the back part of the aircraft the epinaut they were horrified of what they found because large sections of the horizontal stabilizer had been completely ripped off on the left hand side the outer part of the horizontal stabilizer and the outer elevator was completely gone and it had also ripped with it the hydraulic line to the actuator for the elevator which was connected to the number one hydraulic system so that's where the number one hydraulic fluid had drained out and on the right hand side there was very similar damage with the outer part of the horizontal stabilizer gone as well and only a small bit of the outer elevator still remaining the engines were in surprisingly good condition there was some minor scrubbing on the fan rotor rub strips but except for that they were reasonably intact the number four engine was once again removed and subjected to testing and this time they found some fuel feed anomalies that was likely the cause of the in-flight engine shutdown in my view this just goes to show how incredibly durable these aircraft are and how much punishment they are able to take and still continue to fly safely it's absolutely amazing in my view the conclusion of the final report was that a single engine failure had led to asymmetric trusts that asymmetric trust had been masked by the autopilot who tried to keep the aircraft wings level flying straight forward the captain had been fixating on the airspeed and failed to input any rudder to stabilize the aircraft that in turn led to a loss of control once he disconnected the autopilot and complete lot of situational awareness because both him and the first officer did not believe what they saw on their flight instrumentation this loss of situational awareness was only solved when the aircraft came out of the cloud and they got access to a natural horizon that they could use to stabilize the aircraft with interestingly enough there was no recommendations that came out of this accident but i think that there's a few things that we can still learn from it for example know your situation know your aircraft understand what it's showing you so that if you find yourself with for example an engine failure you know what to do also if you don't really understand what your automatics are doing well then disconnect and fly the aircraft manually and do so at an early opportunity then you can always engage the autopilot again once you have everything under control and also trust your instrumentation all right unless there is a failure flag or an obvious indication that the instrument is not working it's still going to be better than you and your vestibular system now if you want to see a crazy video about pilots who had to fight with their aircraft and losing control of it for over two hours well then check out the video up here it's truly amazing if you want to support me and my channel then consider becoming a patreon or maybe buying a t-shirt have an absolutely fantastic day and remember check out the airline pilot club down here it's now absolutely free [Music]

Channel: Mentour Pilot

Views: 1,164,489

Keywords: mentour pilot, air, plane crash, air crash investigation, air china 006 incident, china airlines flight 006, rapid descent airplane, fear of flying, roll, yaw, asymmetrical thrust, landing gear failure, boeing 747, boeing 747sp, los angeles airport, LAX, pratt and whitney, airplane engine, aircraft engine, 747 engine, engine failure, explained, scary, Mentour Pilot crash, Fear of flying help, Nervous flyer, Nervous flyer help, Jumbo accident

Id: DWhZWtDinLg

Length: 24min 59sec (1499 seconds)

Published: Sat Nov 06 2021