How this Aircraft lost BOTH engines and landed!

this video has been made possible together with brilliance the fun way of learning science technology engineering and mathematics it's the 17th of january 2008 and a boeing triple 7 200 from british airways is on final to run with 2-7 left at london heathrow united kingdom the pilots are getting ready for what they believe to be a standard landing after a more than 10-hour long flight from beijing china but suddenly the engines stop responding to outer trust commands instead they're starting to roll back to flight idol the aircraft pitches up to try to follow the ils glideslope signal but without the help of the engines it's impossible to do so the pilots are now faced with a scenario that they've never seen before nor have they been trained for and they do their absolute best to try to rectify the situation but the aircraft ends up slamming into the ground 330 meters prior to the threshold of runway 2-7 let's together now have a look at the final report and try to figure out why this happened and also how well the pilots actually dealt with this situation stay tuned british airways flight 38 was a scheduled flight from beijing in china over to london heathrow in the uk it is flown by a boeing triple seven two three six with two uh voice royce engines they are rb211 trent 895 17 engines the aircraft was built back in 2001 which makes it about seven years old at the time of the incident and it had no recorded snags for this flight the flight crew consisted of three pilots it was captain peter burkhill who was 43 years old at the time of the incident he had about 12 700 hours and 8430 on type together with him was senior first officer john coward who was about 41 years old and had 9 000 hours in total and 7 000 hours on type and it was also our third pilot called conor mcgenis he's 35 years old has 5 000 hours in total and 1 120 hours on type and he was there as a cruise pilot someone who comes in and relieves the other pilot so that they can go and rest during the flight so it's very normal that we are three pilots or even more if you do very long whole legs in the cabin there's 13 cabin crew taking care of the 136 passengers which is very little for a boeing triple 7 which makes this aircraft very light and that's actually going to have some impact later on the previous flight was operated from london heathrow over to beijing and when the aircraft landed the fuel in the tanks was recorded at about minus 20 degrees celsius and after the refueling for the return leg to heathrow the fuel temperature was still minus two degrees now in the preflight stage the pilots have been reviewing their flight plans and they realized that they were going to fly through some very very cold air masses on their way over specifically russia and scandinavia so typically the air temperatures at those latitude tends to be maybe minus 50 to minus 60 degrees centigrade but on this date the temperatures was recorded to be as low as minus 70 which was unusually low but not extremely low but because of that the flight planning department of british airways had actually planned flight 38 to do a step descend on route in order to get into warmer temperatures now you might ask yourself why is this even an issue you know what does it matter that it is cold outside where the aircraft is flying and that's a fair question because the aircraft in itself does in the components of the aircraft the engines the body and so on can take very very cold temperatures but the limitation comes to the fuel okay because yet a1 fuel has a freezing temperature of about minus 44 degrees celsius and yet a fuel which can also be used has an even higher freezing temperature of minus 37 degrees if the fuel is allowed to get down to those temperatures it will turn into a wax-like substance that wax-like substance has a much lower kind of fluidity than the fuel and it can start clogging up things like fuel filters and pumps and because of that the boeing triple seven actually has a fuel temperature warning system so if the fuel temperature comes within three degrees of the freezing temperature of the fuel well then the crew will get a low fuel temperature warning and they need to do something about it most of the time you just need to descend in order to get out of this now those of you who have been paying attention so far would have noticed that i said that it was going to be about minus 70 degrees centigrade on route but the fuel freezing temperature is only -44 so how does that work well here is where you need to start understanding a little bit about the physics of light and the temperatures that we're dealing with so when we fly we basically deal with two different temperatures okay we have the static air temperature sat which is basically the temperature you get if you are standing in a room holding a drop thermometer okay right just the temperature now if you instead would hold that thermometer up in the air and then you would start running at mach 0.02 or faster you would notice that the temperature actually starts rising okay this has to do with something called ram rise okay and it is a little bit of compressibility in the air as the air gets compressed at higher speeds it actually rises a little bit in temperature and this leads to another temperature which is called the total air temperature tat and the total air temperature when we are up at our cruising speed of mach 0.08 for example is actually going to be significantly higher now this is not to be confused with the temperature rise you get due to air friction because the air friction temperature increase will come at much higher speed so if you're flying at the speeds of the concorde or the sr-71 blackbird well then that is going to be what rises the temperature the most but up until the normal cruising speeds of normal airliners the ram rise it's what's causing this and this means that if we are at the temperature of maybe minus 70 degrees of static air temperature the total air temperature which is what's actually affecting the fuel in the tanks is going to be closer to maybe minus 35 minus 40. and on top of that the fuel temperature will never be as cold as the temperature outside because even though the fuel is stored in the wings and this really really cold air is flowing over the wings making a heat transfer from the fuel out to the cold air inside of the fuel tanks we have several components that actually heats the fuel so on the triple 7 for example there is hydraulic heat exchangers two in the right hand wing and one in the left hand wing which heats the fuel continuously and because of that the fuel metering stick the actual temperature meter is situated in the left hand tank because theoretically that's where the fuel temperature is going to be the lowest now guys if you are interested in things like thermodynamics all right or physics mathematics technology then you should definitely check out the sponsor of this episode which is brilliant right brilliant is a fantastic learning tool that makes learning actually both interactive and fun there are loads of different courses in there but scientific thinking is a course that i really recommend you if you're interested in these things i have been working on these courses together with my 11 year old son lucas he loves the little brain puzzles and stuff that are in there and if you come across something that you don't understand they will have great ways of explaining how to think about it and to bring you forward in your learning if you think that this sounds like something you want to try out then use the link here in the description below or up here and it will give you a whopping 20 discount on the annual fee of brilliant i really recommend you to just click the link check out if it's something for you and if it is get it okay so the next thing we need to discuss when we're talking about temperatures in the fuel is water in the fuel basically it's impossible to keep water completely out of the fuel right we do our best we make sure that there's not a lot of water in the fuel that is being uplifted from the fuel trucks we also do daily inspections of the aircraft fuel tanks to make sure that there's not much fuel in there but you know air will come into the tanks through these ventilation docks it will contain moisture as the temperature goes down it's going to start forming water droplets which will eventually end up inside of the fuel so a little bit of water in the fuel is absolutely normal right and water can exist in the fuel in three different states either it is dissolved water right the salt water is when water molecules basically attach to hydrocarbon molecules in the fuel and in this case it doesn't really matter right it just exists there however as the temperature drops in the fuel you will start to get something called suspended water instead and this is basically little water droplets that is suspended inside of fuel travels around freely in the fuel eventually they are going to start meeting up to each other crashing into bigger water droplets and since the water is of a higher density than the fuel they are going to fall down to the bottom of the tanks and form little puddles and typically at the lowest points in the tanks that's where we have our fuel drainage in order to actually find these little puddles of water and get them out of fuel the problem can occur when you have a bit of suspended water moving around in the tanks and the fuel temperature drops to you know between minus five and the minimum temperature because what happens then is that the suspended water will turn into ice crystals these ice crystals they will move around and in that temperature range between -5 and -20 the these ice crystals have a tendency to start sticking together right they stick together with each other and they can stick to things like fuel lines for example or fuel tanks right this is what the scientists refer to as the sticky range as the temperature go even lower than that then they're so cold that they don't really stick to anything they just get sucked with the fuel into the engines and burn up but ice crystals in the sticky range can be an issue right because they have a tendency to kind of stick to each other and create larger volumes of this slushy icy substance and this is going to become important later on let's now also talk a little bit about the fuel system on the boeing triple 7. so as the fuel is taken from the tanks it goes through piping okay and it first goes through a low pressure pump and then it goes into something called the fuel oil heat exchanger the fuel oil heat exchanger serves two purposes one it cools down the engine oil right and two it heats up the fuel before it goes into the the later components and enter the engine for the combustion chambers the way that the fuel oil heat exchanger is made this is basically a cluster of over a thousand very thin pipes now the fuel is pushed through these pipes and the oil is routed around these pipes thus having a good heat exchange okay the fuel oil heat exchanger is going to become important for this incident but that's enough technical information for now the crew made a completely normal pre-flight they started pushing back taxiing out and then took off on their flight towards heathrow they had briefed thoroughly about the temperature being an issue they were well aware of it and they basically said that throughout the flight they were going to be monitoring the fuel temperature and if the fuel temperatures started to get too low well then they would descend they started their climb out to their initial cruise altitude of 35 000 feet and the initial climb was flown in an autopilot mode called v nav now when you're in v nav basically the aircraft will drive the trust to full climb trust and the aircraft will try to climb as quickly and efficiently as possible they continued at 35 000 feet until they were about 350 nautical miles north of moscow at that point they were giving a step climb to 38 000 feet now this depth climb they didn't use v-navin alright they used a another autopilot mode called vertical speed now vertical speed is an autopilot mode that will basically prioritize the vertical speed of the aircraft so as the pilots put in for example four five six hundred feet per minute well then the aircraft is going to try to achieve that climb rate and just add as much trust as they need in order to achieve it and the reason why this is a preferred climb mode during cruise is because it doesn't you know it doesn't disturb the passengers they're hardly going to notice as the engines kind of slowly increase in thrust and then it's a nice calm soft climb up to the new crowd cruising altitude and they did two of these cruise climbs so one as i said slightly north of moscow and then another one up the flight over 400 as they passed over sweden the temperature in the tanks never went colder than minus 34 degrees and that's well above the freezing levels of the the fuel so the crew was happy the aircraft proceeded normally on route and they started their descent in towards london heathrow as the aircraft now descends toward heathrow the temperature outside is starting to warm up right so the temperature of the fuel goes up from minus 35 degrees down to minus 22 degrees during the descent the aircraft flies into a holding pattern over lamborn at flight level one one series at 11 000 feet which is completely normal for heathrow there's always a lot of traffic coming in there so you can always expect a few turns in the hold before you start to approach during the cruise and the sand here the captain is flying but they have planned for the senior first officer to be doing the landing and they're going to do something called the monitored approach which is where one of the pilots flies the approach which is flown on instrument and the other pilot who got one that's going to actually land is starting to look out for visual cues at an earlier stage and as soon as that pilot is happy to take over he will basically take controls and complete landing the reason you want to do this is because it doesn't force one pilot to go from instrument flight to visual flight right and it takes away all of the risks associated with this so this was standard operating procedure for british airways at the time the triple seven is now vectored for an eyelash approaching for runway two seven left in heathrow everything looks completely normal they couple with the eyelash approach just stealing out the pilot at this point and everything looks completely normal down to about a thousand feet above ground at this point the aircraft shoots through the clouds right they become visual and they transfer the controls over to the first officer and also as they come through the clouds there are a bit of wind changes right and when the wind changes you will also have speed changes and the outer pilot and the outer throttle is engaged which means that the outer trust is starting to try to counteract these speed changes and it does so by increasing the thrust and decreasing it cyclically about four times okay now on the fourth increase of trust the aircraft is about 720 feet above ground the first officer is looking out getting ready to disconnect but now something strange happens first the right-hand engine start suddenly spooling down right the truss levers remain in the same position but the trust just comes back gently back to just above idle trust it doesn't fail but it's a title trust seven seconds later the same thing happens to the left-hand engine the first officer starts to notice this because they're starting to see a split in the trust level position but he doesn't really understand what it is he's seeing he's kind of muttering a little bit about it as the aircraft passes 500 feet now the aircraft is completely set up for landing at this point with flaps 30 and basically all of the checklists completed so the captain calls out stabilized and the first officer responds with just and the reason he responds that is because he sees that the speed is now starting to deteriorate right there's still no warnings about any engine failures the engines are still running they're producing trust but just at a very very low amount now they had planned to disconnect the autopilot at this point but it's likely that the first officer have just you know it's just preoccupied with what it is that he's seeing so he has not disconnected which means that the autopilot is now trying to keep the glide slope the electronic glide slope keeps it at the right path towards the runway but as the speed is now deteriorating and going lower and lower the aircraft needs to increase its nose attitude continuously in order to maintain the same amount of lift to maintain the glideslope coming down at this point there is recordings of the flight crew starting to discuss why the engines are at idle and trying to troubleshoot but this is only about 30 seconds prior to impact so we have very little time at this point at 115 knots the first low speed master caution warning comes up the captain responds in a slightly unusual way here so as he recognizes this low speed event he moves over and moves the flap lever from the landing flat position of lap 30 to flaps 25 he also reaches up and switches on the engine start switches and he starts the apu now the attitude of the aircraft is really high and the stall speed for flaps 30 is about 104 knots with this weight for flaps 25 is 106 knots and just about here they get the first stick shaky warning right as the six shaker comes on the first officer reacts immediately by lowering the nose attitude and as it does so that disconnects the autopilot the captain realizes what's about to happen now and he calls in a mayday call on the radio aircraft is descending quickly towards the ground here now the first officer tries to arrest the descent rate by pulling back on the yoke but the speed is too low and it's too late the aircraft crashes into the ground with about 1400 feet per minute producing about 2.9 g's and as it does so the main gear impacts first it bounces a little bit and then the right main gear collapses separates from the aircraft and as it separates it goes up and it punches a hole in the right-hand side of the aircraft as it flies it branches through about row 30 where there's a passenger seated and it breaks the leg of the passenger the left-hand main gear also collapses but it stays attached to the aircraft and it actually bends open the fuel tank a little bit on the left hand side rupturing the fuel tank nose gear collapses and the aircraft skids off to the right and it ends up basically just slightly to the right of the threshold markings of runway 27 left but the aircraft is intact the crew is stunned immediately but after a few seconds they initiate on the command from the captain a orderly evacuation all of the evacuation exits works some of them can see a little bit of debris outside so they redirect passengers to other exits but all in all this is a very successful evacuation okay everyone survives there's one serious injury and that's the passengers that were seated next to the hole in the cabin from the right main gear but all of the others only have some minor injuries and this is a complete miracle the evacuation itself very smooth there were however reports of some passengers bringing their personal belongings with them and even one passenger that after the evacuation was complete decided to climb up one of the evacuation slides to retrieve the personal belongings and this is of course a complete no-no if you ever end up in an evacuation yourself just make sure that you and your loved ones in an orderly way progress towards the nearest exit leave everything behind you're gonna get it later on and then just get yourself out and follow the directions of either the crew or the fire chief who might be down on the ground now a really thorough investigation takes its start and it's the air accident investigation board in the uk together with the ntsb in the us and many other participants that are starting to try to find out how something like this could happen how come that the engines reacted this way and what they came up with after many months of testing including setting up a mock engine and introducing water and checking all of the different involved components was that the most likely cause of this was that these free-flowing ice crystals had started to amount up inside of the tubing for the engine and because the flight was flown but very low for the triple seven fuel flows the entire flight all the way down until final it was really only when the engine started to ask for trust with flaps 30 hanging out that the fuel flow increased okay and when it increased it sucked with it all of these ice crystals that had been stuck inside of the tubing and it ended up inside of the fuel oil heat exchanger right remember that's the part that is situated just prior to the engines in order to heat up the fuel and cool down the oil now it was expected that this ice had basically formed into a slush that had temporarily stopped the transfer fuel through the fuel oil heat exchanger and that is likely what has caused this and they've actually found another incident where an american registered triple 7 had a very similar incident happening a flight of a 390 also after cool temperatures in the fuel where they tried to do a step climb and when they did so just after the step climb the right engine rolled back in a very similar way took a few minutes and then it came back again as the uh the ice probably melted off inside of the fuel oil heat exchanger so the investigation came to several different safety recommendations one of the safety recommendations actually made sure that royce royce had to redesign this part of the fuel system the fuel oil heat exchanger so that all the triple sevens that are using the rb211 trent 800 engines now have a fuel oil heat exchanger that can actually take this amount of slush even though that it was shown through some extensive data gathering for more than 775 000 flight that these two flights that suffered this were the only ones that had this combination of circumstances so how did the crew respond to this incident then well the final report goes into some detail when it comes to this and if we start looking at the flight crew as a team um the fund report basically says that they think that they worked in an effective and professional way giving the circumstances they take into consideration the fact that none of them had been trained for a dual engine run back at such a low altitude they say that the actions taken by the crew were effective and had a positive effect on the outcome of the incident and if we look at the aircrew separately the captain's decision to move the flaps from 30 to 25 was a little bit unorthodox however it did extend the glide of the aircraft and the final report basically said that even though it had very little effect the aircraft would have touched down inside of the airport boundary even if he hadn't done that it extended the glide with approximately 50 meters and that could have had a major impact because at about 40 meters before the touchdown point there was an ils antenna and if the aircraft would have hit that antenna as part of the landing it could have caused even further damage to the aircraft so that was seen as a positive thing and it would probably would have had even more positive influence on the glide distance if it would have happened at an earlier stage further out but this brings us to the actions of the first officer now the first officer was the pilot flying during this event and he was responding in a way that could be expected when faced with a very quickly developing situation like this the really important thing here is that once he was faced with the stick shaker even though he was really close to the ground he did what his training had taught him which is to push the nose down to make sure that you offload the wings and keep the aircraft flying now that might sound obvious but when you are at 400 feet of the ground and you see the runway coming up i can tell you that the the feeling of wanting to keep the nose up in order to kind of stretch the glide to get it down on the runway is going to be almost overwhelming and the fact that he just focused on what he was trained to do got the nose down pitched it down towards the ground it enabled the aircraft to continue to fly had he not done that if we would have tried to stretch it it is likely that the aircraft would have stalled and it would have basically touched down in an uncontrolled way possibly even outside of the airport boundary so well done great great to see how the training kind of kicks in even during an extreme situation like this once the aircraft had come to a stop on the ground the captain initially initiated the evacuation command over the vhf frequency so he called the tower rather than calling on the pa he then very quickly was made aware of that and made a secondary pa to start evacuation that's why it took a few seconds for the evacuation to start but it had no impact on the safety on the outcome of this incident the cabin crew did a fantastic job even though they had not been made aware of this obviously the pilots didn't even know about it until it was about 35-40 seconds prior to touchdown once it happened they reacted according to the training and they facilitated a really effective evacuation of the aircraft so all in all a great job under the circumstances by the operating crew guys i hope that you are finding this um series about famous incidents and accidents in the aviation history fascinating and if you are i hope that i have earned a subscription from you now if you want to subscribe then click the subscribe button and also highlight the notification bell so you make sure that you get a notification anytime that i send out a new video and i would also love to hear from you what do you think you know what is the next incident you would like me to cover put it into the comments below or contact me in the mentor aviation app or the free discord server right i'm going to link to it up here you can just click on it get either the app or discord server and contact me i love hearing from you guys until next time have an absolutely fantastic day wherever you are and i'll see you next time [Music] bye [Music] you

Channel: Mentour Pilot

Views: 962,120

Rating: 4.9143968 out of 5

Keywords: Engine failure, Aviation, crash, Aircrash, air crash investigation, aircrash confidential 2021 new series, mentour pilot engine failure, mentour pilot crash, Final report, British Airways, british airways flight 38, boeing 777 denver, Boeing 777, Boeing 777 Heathrow, Dual engine failure, Fear of flying, fear of flying help, Nervous flyer, Engine icing, Aviation fuel, rolls royce trent 800, Aviation explained, Pilot life, Aircrash explained, plane crash, Flight simulator

Id: GmNnmyLbPDE

Length: 28min 58sec (1738 seconds)

Published: Fri Mar 05 2021

Reddit Comments

[u/MidnightWineRed]

The plane very much didn't survive that.