How this Boeing 737 lost it’s ROOF! | Aloha Airlines flight 243

hi everybody and welcome to mentor yet another video podcast as always i hope you're doing absolutely fantastic now imagine yourself sitting as a passenger on a boeing 737-200 in cruise at 24 000 feet and suddenly a huge explosive decompression rips the roof of the forward part of the cabin this is exactly what happened on aloha flight 243 which i will be covering today and as a disclaimer there will be loss of life mentioned in this episode so if that's something that you're sensitive to you should probably stop watching right now point three one zero one six this video is brought to you in cooperation with nordvpn now if you haven't already started protecting yourself on the internet you really should be doing that and i have been using nordvpn for the last year or so that's great when i go traveling and i go to a training center sit in hotels and maybe using public wi-fi's in airport but to be perfectly honest the one thing that i use it for the most is because i live down here in spain but i still want to watch my favorite tv shows up in sweden but nowadays they're all these pesky regional restrictions so what i do is i just take up the nordvpn app i choose a server up in sweden and voila all of my favorite tv shows are available to me and this is great the nordvpn app is really really easy to use and if you sign up for this deal that i'm linking to down here then you can use six devices on one deal so that means that you can protect basically your whole household they're also incredibly fast they have more than 5 200 servers in 52 different countries scattered out of the globe and if you choose to use this link here below and the coupon code pilot well then you'll get 68 off the two-year deal which brings the price down to only 3.71 per month so go down click the link and start protecting yourself on the internet [Music] today [Music] okay guys so this is another episode in my series about famous incidents and accidents within the aviation industry and as always i am using the final report of the accident as the basis for this video if you are interested in knowing more exact details well then i'm linking to the final report here in the description of the video and i highly recommend you to go and check that out it's really really interesting the way that i would do this is i will first give you a full synopsis of what happened how the flight crew and the cabin crew and the passengers dealt with the incident and at the end i will go through the actual reasons behind this accident what caused it and what kind of recommendations came out from the final report so make sure you stay tuned i know it's a long episode but there are some really really nice details here that you probably won't find in any other way than reading the full report or listening to this video so this accident actually started early in the morning of the 28th of april 1988. at five o'clock in the morning the first officer of the day started doing his pre-flight work checking the weather nautums and in his base in honolulu he went out and he started doing the pre-flight inspections of the 737 200 that he was going to fly for the day and this preflight inspection was done in darkness the only light that was available was the kind of apron light and that's going to become important later on because at the time the pilots were not required to do preflight inspections between each flight you only need to do a pre-flight inspection in the morning and then you continue to fly throughout the day without doing any further inspections anyway the captain came out to the aircraft the first officer briefed him said the external inspection was good there was no findings and also the tech log was looking good so they just settled into the aircraft took on the passengers and started their duty now their first duty started with three round tip flights so six flights going out from honolulu to kilo moau inquire so this is the kind of operation that that aloha airlines did they were based on hawaii they flew intra flights within the islands obviously that would be really really short hops and climbing only up to a fraction of the maximum altitude of the 737 200. during these first six flights um the aircraft performed completely normal there was no problems with engine indications no pressurization problems nothing at all so completely normal day in the office basically now at 11 o'clock it was town time for a crew change so um i didn't see if the captain was changed but for sure the first officer did a crew change once again there was no external inspection done after the crew change but after the crew changed the captain was now captain rob schoensteiner and first officer madeleine tomkins they did the free flight they flew from honolulu to maui and then on to hilo so that's the first two flights of the day the third flight was flight 243 all right the accident flight on the accident flight there were these two in the flight deck there was three cabin crew which is the standard crew for 737 200. uh there was 89 passengers and there was one air traffic controller that was sitting in the cockpit on the jumpsuit was traveling back from um hilo to honolulu it was a perfect day really really nice weather over the hawaiian peninsula beautiful first officer madeline was the one that was flying and she took off from hilo at time 1325 climbed up manually flew the aircraft as you would uh up to 24 000 feet up in this point everything is normal but as they leveled off at 24 000 feet they heard this horrendous noise which was kind of like a pop and a tear imagine tearing a pair of jeans apart when that happened um first off the madeleine's testimony said that her head was sucked back into her seat and she could see parts of insulation and things starting to fly around inside of the cockpit so a huge pressure change obviously um captain rob looked over his side and realized that the cockpit door was gone and behind the top cockpit door he was looking out onto blue sky where the first class roof should have been right so obviously a major structural malfunction of the aircraft now when something like this happens and the aircrew was at 24 000 feet they're above the maximum of 10 000 feet cabin altitude that is required to be able to breed safely so when something like this happened the flight crew is trained to evaluate the situation first and do what we call an emergency descent now i have done a full video explaining all of the different parts of an emergency descend and if you're interested in watching that i'm going to link to it up here but what you need to realize is that the really most important thing is to get your oxygen masks on so the flight crew reach for the oxygen masks put it on including the jump seating air traffic controller and the flight crew oxygen worked fine okay so once you have the oxygen mask on you need to try to establish crew communication this was not possible because of the horrendous noise that was coming from the open gaping hall in the in in the aircraft structure and then you're supposed to try to rectify the situation so those are the first kind of memory items and obviously with this kind of structural failure of the aircraft there was nothing they could do about trying to restore pressurization so the next step is to initiate the emergency descent which is always done by the captain as pile of flying which meant they swapped roles the captain initiated the murders of the sand now here's something that's important to understand um if you watch the video about the emergency descent there is a point which basically says after you've initiated the initial descent that you can choose whether or not you want to increase the speed or not okay with a higher airspeed it means that you're going to be descending faster which means that you're going to be getting down into the breathable part of the atmosphere quicker however it's also stated that if structural integrity of the aircraft is in doubt you should not increase the speed and that's because you don't want to increase the forces on the aircraft you don't know what part of the aircraft has the structural damage so to increase the speed could potentially come with some real risk of an in-flight breakup however in this case the cab the the pilots did increase the airspeed so captain rob as part of his emergency descent procedure increased the speed between 280 and 290 knots which is not the maximum speed of the aircraft which is what it says that we should be doing but it's a fairly high airspeed okay uh he stated that the aircraft felt a bit sluggish in the controls and that it was initiating roles left and right and this is all kind of indicating that you know there's something wrong all right and the the it's likely that the uh the breakup of part of the cabin roof has had an effect either on the structural integrity of the aircraft as such or that part of the flight controls might have become damaged by the uh by the debris from the breakup anyway they initiated the sand uh they're now at 290 knots which means that the noise in the cabin is even higher so it was impossible for the hockey crew to communicate with each other instead they used sign language um to to kind of show what they were doing meanwhile in the back of the cabin there is absolute pandemonium as you might understand the fortunately all of the passengers were seated in their seats because at that point of the flight the the um see fast and seat belt sign was illuminated so everyone would sit down except the cabin crew when the breakup happened it started on the left hand side most likely of the aircraft forward approximately where the forward door is and very quickly as the um the structure started breaking up you had the decompression happening and the decompression just aggravated the breakup which meant that the little hole that's opened up in the beginning of the the cabin sewn to the left side now basically ripped 18 feet of the cabin apart over the top and then down to the window level on the right hand side and the porch let loose of the of the aircraft and disappeared now the purser the number one of the cabin crew she was standing at row five when the breakup happened and she did not have a chance right as soon as the breakup happened this happened in the matter of a second she was immediately sucked out of the aircraft um and disappeared and unfortunately her body was never recovered nor was any of the pieces that were actually ripped off the roof they fell down into the sea and they could never actually confirm her being dead she was just presumed being dead because of the nature of the accident the number two was standing at row 15 16 and she was struck down to the floor by the force of the depressurization but she managed to get up and she spent the rest of the flight crawling up and down the the middle aisle trying to comfort and help the passengers out and in the final report this was described as heroic like the fact that she would continue to do her duty and to help the passengers was considered an absolutely fantastic act of heroism the number three the most junior of the cabin crew was standing at road two which is just below the now open roof of the of the aircraft she was hit by debris as the depressurization happened it hit her in her head and she suffered uh severe head trauma um and was one of the the most badly hurt people in in the whole flight rest of the passengers especially the ones that were sitting below the now open roof suffered cuts lacerations um because of the debris flying around some of them actually had some electrical burns as well because of the the cables that was kind of hanging out now but since they were all seated with their seat belts fastened they were all safe in their seats and none of them actually died the only fatality in this whole accident was the person who was sucked out of the aircraft there was no communication from this point on with the cockpit crew obviously the a lot of the wiring goes through the roof of the 727 200 so the pa system was not working and the passenger oxygen system didn't work either but from 24 000 feet actually you can kind of still breathe there for a few minutes and the fact that they initiated the emergency design quickly also meant that they were quickly down in the breathable air however i just cannot even imagine the amount of sound and rushing air that must have come into the cabin especially during the high speed part of the emergency descent so now if we go back into the cockpit uh the the pilots are still doing the emergency set procedures and as part of that first of the madeleine has now put the transponder code 7700 into the transponder this is an emergency code that will immediately light up their radar blip on the air traffic controller's screens and she was also trying to call a mayday call into a traffic control but because of the ambient noise in the cockpit it was very hard for them to have any kind of communication going eventually they got down to about 14 000 feet and below and as they started to level off below the 10 000 feet captain rob reduced the speed back 210 knots and because of that the ambient noise now went down significantly and they could start to communicate and with that they could also communicate with their traffic control first off the madeleine was telling them that they had a rapid depreciation that they were in a emergency and that they needed emergency personnel now air traffic control did not understand how severe this problem actually was so they asked for the firefighting crew they did not ask for ambulance initially um there was continuing problems to to talk to air traffic control because even though the ambient noise level had gone down it still was extremely high there was continuous confusion happening but now the aircraft is diverting towards maui air traffic control can see them squawking seven seven zero zero they could hear them having a mayday situation and they could also see them turning towards maui so what the first officer did was she just um turned over the radius to maui approach control to tower and she continued to talk to tower throughout the rest of this incident as they're now getting closer towards the runway they have to start to prepare the aircraft for landing and the issue here and i've talked about this in previous videos as well is that when you have structural problems for the aircraft you don't really know how the aircraft is going to react when you start changing the configuration of the aircraft so they started slowing down if the captain asked for flaps 1 flaps 5 which he got he was still able to control the aircraft but as they went beyond flaps 5 he felt that the aircraft suddenly started to be harder to control so he decided that okay we will keep flaps five right that configuration seems to work let's keep it there flaps five will give you an approach speed of about 155 knots so on but when the captain reduced the speed below 170 knots once again the aircraft started behaving weirdly so he said all right we know that flaps 5 works we know that 170 knots works let's keep it at that speed so that's what it did and this is a show of good airmanship all right it's showing that it's better to know that you can control the aircraft at a certain speed knowing that you're gonna land with a higher speed now need more runway than to try to go further and potentially lose control of the aircraft at a lower altitude so they kept it at 170 knots now the selected gear down all right and here is where start where this scenario just if this scenario would happen in the in the simulator most pilots wouldn't even accept it all right because here's where it starts to get really silly as they selected the gear down um they got green indications on both main gear but they got no indication at all on the nose gear neither that it was down and locked so green light or a red light would indicate that it was unsafe so basically they had no idea what the nose wheel was doing this turned out to be a completely separate fold basically two bulbs had gone out in the in the light kind of structure but they didn't know this so they started doing the emergency gear extension procedure for the nose gear now once again i've done a video about how this emergency gear extension or alternate gear extension works if you're interested in seeing that it's up here but basically it just means that they pull a wire up to let gravity take care of the gear and let it fall into place and lock even after doing that they had no indication of the nose gear coming down so the first officer told that traffic control that there's a possibility that we might not have a nose gear now air traffic control is starting to understand that this is a much worse condition than just a rapid depressurization so at this point they're calling for ambulances to come to watch the airport as well when rob is now on approach remember up until this point they've done an emergency descent which means trust is set down to idle they're descending as quickly as they can and after they have descended down to 10 000 feet they will still be descending with idle thrusts down to their approach altitude basically so there has been no need for trust up until this point but as captain rob is now increasing the trust on the engines for uh for the approach which you're going to need to do to stabilize the proton or three degree glide slope he feels a yaw in the aircraft right the aircraft is joined to the left and he quickly realizes that he has no throttle response from the left-hand engine the number one engine he thinks the engine might have failed so he puts the storage switch to flight to try to reignite the engine if you put the storage switches to flight it means basically that both of the two ignitors inside of the engine is going to be continuously igniting to try to get the engine to start again this had no effect so now the aircraft is flying with a big part of the roof missing they have no indication of if the nose gear is extended and they also have only one engine responding so this is almost silly at this point but they managed to stabilize the aircraft on approach at four miles they decide they do not want to stay any longer they've been running through some non-normal checklist but at this point the captain is just focusing on getting the aircraft safely down to land at time 1358 the aircraft touches down on runway 02 in maui it's a completely normal landing the aircraft comes to a stop on the runway and as soon as they've stopped they set the flaps to 40 they run through the evacuation checklist and they evacuate the aircraft on the runway right this is an amazing feat they have managed to flown the stricken bird up from 24 000 feet with all of these failures down onto the runway the only thing that's left to do now is to try to figure out why this happened what have caused this problem so the national transportation safety board they go to work they come to to um to maui they have a look at the aircraft and they start the investigation into this and this is where it becomes really interesting and this is also why this accent is so important in um in improving the safety overall for all aircraft flying not only the 737 but every aircraft so what they find initially is that a section of the um of the overhead part of the structure of the aircraft has been ripped apart okay that they know they can see that uh the metal has been kind of shredded in v form below the left hand side and they can see that the structure is bent out to 90 degrees over the window level on the right hand side and this would indicate that the actual break started on the left hand side and it was opened like a can outwards to the right side where it was ripped off they find parts of the structure inside of the engines the engine fan blades for damage from both the left and the right hand side porch of the the structure it's from inside of the engines and and a big part of the structure is actually found wedged between the leading edge devices and the right-hand engine strut and this part this part of the structure is really the only thing that they have to go on when it comes to finding why the structure broke up in the first place they also found that the trust control cable that was running to the left-hand engine remember the one that failed on approach had been torn apart but we're gonna be talking about that later on so how is it possible that a 737-200 can lose part of its structure in an explosive decompression like that well this is the question that the ntsb had to answer and they started going to work into looking into the maintenance procedures and the overall manufacturing process of the 737 200 at the time now what's important to notice here is that aloha airlines they were flying very special types of fly into the 737 so when boeing constructed the 737 um it had given it a what we call a safe life so boeing was saying that up until this amount of hours this aircraft is going to withstand structurally everything that's needed and after that you need to go in and do proper inspections of it and throughout its entire life at regular intervals there are smaller medium and big inspections taking place so a b c and d checks the d checks includes basically stripping the aircraft down and going through looking at all structural components looking for fatigue cracks and things like that now the 737 200 the first couple of hundred um serial numbers of 200 was manufactured in a slightly different way okay so when you when you make a body of an aircraft it is made up from some space out uh circumferential kind of um frames so picture these round frames that comes on regular intervals they are held together by horizontal stringers that goes through the longitudinal part of the aircraft and then between those stringers and those frames what's actually taking up a lot of the load especially from the pressurization of the aircraft is actually the skin of the body so the skin has to be fastened and has to be manufactured in a way that can take up a lot of loads so on the earlier variants of the 737 200 the skin was manufactured out of sheets of metal that was 18 feet long and they were about 0.03 inches thick these sheets of metal the sheets of aluminium was done overlapping what we call lap joints with about three inches so the you have the upper skin and the lower skin and between these three inches when they overlap they put what we call a cold bonded adhesive and i know if you're an engineer out there you're gonna laugh at me now but i'm gonna make it simple picture a kind of glue strip okay now when we say that this glue strip cold bonded it meant that it was actually reactive in room temperature so they were kept these strips were kept on dry ice temperature until they were supposed to be used in a manufacturing process when they were taken out and then they were brought up to room temperature as soon as they're at room temperature they start to be sticky and then they were put in between these lap joints and then once they were in between then they were inserted three rows of rivets okay so what's keeping the lap joints together is the overlap the adhesive and three rows of um of rivets okay now after the manufacturing process and when these first 737 200s had been operating for a couple of thousand hours and they were going through these structural d-checks boeing started to realize that this cold adhesive that had been used it wasn't great especially if it was subjected to really humid conditions and it had a tendency to this bond okay that means basically that the glue doesn't work anymore it releases um and when it releases all of these forces that are being caused by the constant pressurization changes in the aircraft is now not taken up by the adhesive as was designed but it's been taken up entirely by the rivets okay so these three rows of rivets these rivets were fastened in a way to to make them flush with the aircraft body the only way to do that is you need to sink them in which means basically that you create a cone-shaped hole in this skin material so that the rivet can go down into that hole and create a flush surface but this also means that that cone shape creates a weakness in the upper part of the skin all right you're with me so far great so what happens if the adhesive stops working and the forces are now being subjected only onto these three rows of rivets is that you can kind of after many many thousands of cycles there could be cracks starting to propagate out from these rivets and the rivet road that had the most force on them was the top rivet row boeing knew about this right they had done extensive testing they have found this out they found these micro cracks and so they went out with what's called the service bulletin to all operators of these early uh versions of the 77 200 saying that okay we've noticed this is happening make sure that you do this thorough inspection of the adhesive make sure that you don't have this bonding and there's no corrosion going on in it if you find it this is the way that you fix it okay so this is exactly the way that a manufacturer need to do you know they create something they verify it and if they find something that is not operating to specifications well then they come up with a safe way of solving it and boeing did this however the maintenance guys at aloha airlines either did not understand the uh the significance of this service bulletin or they were on the time pressure they tended to do all of their maintenance during night for example and in any case it doesn't seem like this maintenance was being done now on top of this and to make this even more complicated is that the structure also contains a fail-safe principle called tear straps so tear straps are basically uh straps that are fastened to the skin at regular intervals throughout the entire body and they are also fastened with an adhesive this is a hot bonded adhesive so they're using a different adhesive and with rivets okay and the function of these tear straps is both to strengthen the overall structure of the aircraft but also if there would be a crack propagating from the rivets then when that crack came up and it met one of these tier straps but then at that point the structure is much much harder much more secure so a crack wouldn't be able to propagate past that tear strap instead it would potentially turn 90 degrees and move upward and what would happen then was in case these fatigue cracks would have gone unnoticed which they shouldn't be because they should be checked on regularly but if that would happen the crack would only propagate until it reached one of these uh tear straps move upwards and potentially the only kind of structural problem that would happen would be that a flap a small flap which would only be a couple of inches big would open up that would depressurize the aircraft still not great but it wouldn't be an explosive decompression it would be a control decompression the the forces on the overall body would disappear and then the um that part of the aircraft would be able to be fixed later on on the ground without any danger to human life so that was the fail-safe principle to make sure that you wouldn't have a kind of catastrophic structural issue with the body now the thing is though that also these tear straps needed to be properly monitored because as with any kind of adhesive in the kind of you know atmospheric situation that aloe airlines operated there was a possibility that those tier strap could this bond as well so as part of this service bulletin the maintenance personnel also had to go and check to make sure that these tier straps were properly fastened because if they weren't then a potential crack could continue to propagate from one rivet to the next rivet to the next rivet to the next rivet past the tier strap and on to the next and on to the next not the next and as you can see if that happens you could end up with a crack going along the whole side of the of the aircraft potentially leading to a much bigger decompression and as we could see on the lower flight 243 this seems to be what had happened so the combination of these problems they had on the manufacturing of the earliest 737 200s um actually they were the ones that came after about the first 200 they had a completely different manufacturing process together with the the lack of engineering practices at lower airlines and also together with the lack of oversight from the management of aloha airlines together with the fact that fva wasn't managing the aloha airlines properly all led to the fact that you had these uh these fatigue cracks appearing going unnoticed and leading ultimately to this catastrophic failure of the the lap joint leading to this accident after this aloha airlines went out and they checked the other three of their oldest 77 200s they found similar cracking happened on two of them or actually i think of three of them two of them were so bad that they were immediately decommissioned and sold for parts and scrap the third one they were actually managed man managing to to to rectify so it could continue to fly so this accident actually became incredibly important for the aviation industries ability to understand metal fatigue the importance of monitoring the amount of cycles that an aircraft is subjected to and how to monitor for and actually work with and fix fatigue cracking if it ever appears but you might ask yourself well what about that engine what happened what did the wire to the engine have anything to do with this well it turns out that inside of the pressure vessel the aircraft is pressurized both in the cabin where passengers are seated but also in the cargo bays because the difference is that in between the passenger compartment and the cargo bay you have a floor and that floor was never intended to be able to keep any pressure all right it was just there for you to be able to walk on but when this explosive decompression happen what happened was that the pressure immediately disappeared from the passenger compartment but it also needed to disappear from the cargo compartment and the way that it could do that was just trying to go and rush towards the hole in the front of the aircraft and it went with such a force when it rushed up towards the hall that it actually bent and cracked the floor beams underneath the hole of the body now inside of the floor beams you had uh the the wires running not only for the flight controls but also for the controls of the truss the left-hand side that's where the damage was the biggest because that's where the hole initiated and that meant that as the floorboards was now bent upwards it increased the tension a lot on the wire that was controlling the left-hand engine this wire was made out of carbon steel all right now it turns out that this carbon steel was susceptible to corrosion so the it was corroded and when the tension increased it snapped so boeing had issued a service bulletin on that as well several years ago saying that these carbon steel wires needed to be replaced by by stainless steel cables instead but once again for some reason the maintenance department at the low airlines did not do this so basically the final report came with several recommendations and most of these recommendations was aimed at the maintenance department and the management department at the lower airlines but also the faa was blamed partially for not having enough oversight over over the the work of the management and the maintenance procedures at aloha airlines so once again after this the airline industry became a much safer place to be because of this this is an amazing story all right and i i was i was so fascinated that i was reading through it and i hope that you liked this video now if you like videos like this i have a whole bunch of them now in my playlist about accidents and incidents you can go up and you can listen to other ones there will be more of these coming and i'd love to hear what you think about this what's your take on this whole story file it in in the comments below consider subscribing to the channel if you think that i've earned it and give a like and also highlight the little notification bell because like yesterday i did a spontaneous live stream at 11 o'clock at night yesterday if you have subscribed but you haven't put the notification bell on then you won't know when i'm doing live streams like that and you might miss it so for now thank you very much for watching consider checking out the sponsor of this episode which once again is nordvpn you'll get up to 68 on the two-year deal if you use this link here below and the coupon code pilot have an absolutely fantastic day and i'll see you next time bye-bye right guys i really hope that you liked that if you want more content like that more aviation content well then check this out i hope that you have subscribed to the channel and that you've highlighted little notification bell see you inside of the mentor aviation app and have an absolutely fantastic day [Music] bye

Channel: Mentour Pilot

Views: 654,064

Keywords: Aloha Airlines flight 243, Aloha Airlines, Boeing 737, Boeing 737 200, Boeing 737MAX, Aircrash investigation, breaking news, Aviation news, Seconds before disaster, Final accident report, How to become a pilot, pilot life, Pilot training, Mentour Pilot boeing 737, Mentour Pilot Boeing 737MAX, Mentour Pilot, Fear of flying, fear of flying help, Nervous flyer, Nervous flyer help, Boeing 787, Boeing 777X, Boeing 747, Airbus A320, Airbus A380, Airbus A350, Aviation

Id: sKs3ov6hFqM

Length: 38min 27sec (2307 seconds)

Published: Fri Oct 02 2020