Until The Very END! The Tragic Story of Alaska Airlines flight 261

General Alaska 261 we are in a dive here but we've lost vertical control of our airplane as a pilot there are a few situations you hope that you will never ever have to experience and one of them is obviously a total loss of controls of your aircraft with no checklist available to help you solve it this is going to be a bone chilling account of one of the most consequential Aviation accidents in modern history but it's also a story of airmanship and a willingness to keep flying the aircraft no matter what stay tuned [Music] the story of Alaska Airlines flight 261 took place on the 31st of January 2000 but that's not when this story actually started now what happened here had its core deep inside something I call organizational creep and in order to understand that we will have to go back many decades all the way back to the certification of the aircraft involved and after that we must also take a look at the company operating it the accident aircraft was a McDonald Douglas md-83 which is a variation of the original dc9 introduced back in 1965. the dc-9 was in production up until 1982 and Was Then followed by the md-81 82 83 88 and then finally the Boeing 717 though the later types carried many upgrades the core design and systems could still be traced back to the original dc-9 the port of the aircraft which will become important in this story is the empanash or the back wing of the aircraft it consists of the vertical fin which together with the rudder stabilizes and controls the aircraft around the Euro axis and is therefore referred to as the vertical stabilizer on top of the vertical stabilizer the horizontal stabilizer is located now the horizontal stabilizer and elevators control the aircraft around the pitch Axis or in other words they are the controls who can point the nose of the aircraft either up or down and this pitch control is done primarily in two different ways if the pilot wants to get the aircraft to for example climb they can pull the control yoke backwards which will mechanically activate little control tabs on the back of the aircraft elevators these control tabs will then move down to force the main elevators up with the help of aerodynamic forces and that movement will in turn start pitching the aircraft's nose upwards the elevators provide the primary pitch control but pooling continuously on the Yoke will be very tiresome during long periods of flight and on top of that the amount of push or pull needed would also change depending on the configuration of the aircraft speed and changes in weight so there needs to be a way to neutralize those forces somehow and this is where we come to the use of the movable horizontal stabilizer which is basically the entire horizontal back Wing which the elevators are mounted on the movable horizontal stabilizer on the md-80 is about 40 feet wide and it's like I mentioned mounted on top of the vertical stabilizer via two hinges in the ACT Spar and in the front where a single Jack screw assembly which can raise or lower the angle of the stabilizer's Leading Edge by doing that the aircraft can be trimmed out so the control forces are alleviated for the pilots and this is also how the autopilot primarily controls the aircraft in Pitch when it's engaged now I will get a bit technical here but this explanation is absolutely crucial for you to understand what ultimately happened to this aircraft so stay focused to control the amount of stabilizer movements the pilots or the autopilot can do so in a few different ways on the control York there are two switches fondly known as Picton switches who when they're pressed simultaneously will activate a primary electrical trim motor which is mounted with its gearbox assembly connected to the front Spar of the horizontal stabilizer there's also a set of standby switches on the central pedestal who can activate a standby electrical motor mounted on the same location and this is also the motor that the autopilot is using now in case of an electrical failure of both of these switches a pair of trim handles next to the throttle quadrant known as the suitcase handles can also be used to activate the main motor manually but what does these motors do then well when any of the two Motors are activated they will start to rotate a torque tube inside of an Acme screw which run through an Acme nut connected to the vertical stabilizer below this means that as the Acme screw rotates in either direction the screw will either lower or raise the angle of the stabilizer in a uniform and smooth whale similar to the way that you lift your car up with a jack screw when you need to change the tire now obviously there are constraints to how much this screw is allowed to move and that's achieved by programmed maximum and minimum trim values that will stop the electrical Waters from running when those values are reached but if those would fail there are also mechanical stops at the top and the bottom of the Acme screw who serves as ultimate guarantees that the screw won't move beyond the ultimate maximum and minimum positions on top of that there is also a primary trim brake switch in the cockpit which can be used to stop any trim movement in case the motor will start to run away now those of you with engineering eyes will likely already have noticed that there's only one Acme screw and not in this system shouldn't A system that carries primary control loads of the aircraft be doubled up for redundancy well the way that McDonald Douglas initially approached the redundancy was to show to the authorities that both the Acme screw itself and the torque tube inside the screw was individually able to maintain the structural Integrity of the system this means that if one of them would break the other one would still be able to keep the screw assembly together and therefore accomplish the redundancy needed as far as the Ackman nut was concerned it was shown to be able to operate with up to 90 percent of the nut threads worn down and its redundancy was accomplished by inserting more screw threads than needed inside the knot as well as double spirals of thread the aquamanot was made out of a slightly softer alloy than the screw so any wear would naturally happen to the knot first initially the knot was certified to have a surface life of 30 000 flight hours but pretty soon after certification inspections revealed higher than expected wear on the nut threads and because of this inspections were put in place at regular intervals to measure this wear and when it reached a predetermined value the assembly was supposed to be replaced now as many of you will know whenever you have mechanical Parts moving up against each other there will be friction between them the more friction you have the quicker the wear will be and because of that the Ackman not unscrew needed to be lubricated at regular intervals using a certified Aviation approved type of grease and this is where we get to the operator Alaska Airlines and the FAA thank you initially off the certification of the original dc-9 McDonald Douglas recommended that lubrication interval of the Jack screw assembly every 300 to 350 flight hours this was then extended for the md-80 family up to every 900 hours but in 1996 a revision of the overall maintenance intervals instead included the lubrication in every C check which happened only every 3 600 hours or 15 months whichever came first now Alaska Airlines followed these recommendations and extended the interval for lubrication tube in their case every 8 months which was actually more conservative than the manufacturer's recommendation but obviously that's only if the actual lubrication procedures was done correctly when the airline applied to the FEA for this extension it was immediately approved as it satisfied the manufacturer's guidance at the time but it would later be found out that the inclusion of the lubrication in the c-check schedule had not actually been approved by or even explained to the original engineers at McDonald Douglas it had just been roped in there with several other maintenance checks without evaluation of every individual task now in terms of procedures according to McDonald Douglas the greasing of the nut was supposed to be done by pressing grease into a fitting on the knot until grease came flowing out on top and below the knot after that the screw itself needed to be properly greased up before the stabilizer was moved full up and down a few times to properly lubricate all of the involved components this was supposed to take about four hours to do every time but when the line engineer who was the last one to deal with the accident aircraft was asked how he would do that procedure he said that it would take him about one hour to do it and he couldn't account for each of the individual steps on top of this because of the higher than expected wear to the aquemonauts a procedure for measuring this wear had been designed using a tool that would tension the knot towards the agma screw and measure how much it would move this was supposed to be done using specific Boeing made restraining fixtures to set the correct tension but Alaska Airlines had decided to instead make their own ones which both looked and worked slightly differently from the Boeing designs these wear checks had been recommended to be performed every 30 months or 7 200 hours which ever came first but Alaska Airlines had written in their manuals that this check would need to be done every 30 months but with no hourly limit this meant that with the busy flying schedule that Alaska Airlines were operating at the time it would take close to 9550 hours between each of these checks and the accident aircraft was coming up towards the end of these 30 months can you see how the organizational cheese slices are starting to be crossed this takes us to the Fateful flight on January the 31st 2000 but before I get into the details there is this is everything you've heard so far making you a bit nervous but in that case you are a nervous flyer and you should send a special thank you to today's sponsor which is brilliant not because brilliant has anything to do with nervous flyers or helping them out they don't but because they are a fantastic interactive and fun learning platform which has helped me to create a app for you guys which includes an AI assistant now ai is based on large language models and neural networks and neural networks is actually one of the courses that brilliant provides together with courses in basic mathematics and physics and many many more things without brilliant I wouldn't have understood the theory behind the AI assistant Adam that I've created I can answer all of your questions about fear of flying and about aviation in general brilliant can be used by anyone whether you are a student a professional or someone who's just curious and want to learn new things if this sounds interesting to you which it really should well then you can click on the link below which is brilliant.org mentorpilot that will give you a completely free 30-day trial where you can check out all of the courses that brilliant has and the first 200 of you who clicks on that link will also get a 20 discount on brilliant one-year premium subscription which is really great and if you're interested in the fear of flying app then you can go to app.mentropilot.com thank you brilliant now let's continue in the afternoon of January 31st 2000 the accident aircraft with the tail number November 963 Alpha Sierra arrived on time to Le Santiago Gustavo Diaz International Airport in Puerto Vallarta Mexico the inbound crew had enjoyed a completely normal flight with nothing out of the ordinary and that's also what they reported when they handed the aircraft over to the next crew who was going to fly the aircraft back to Seattle via a short stop in San Francisco the new pilot said goodbye to the previous crew and started preparing the aircraft for the return flight in the new crew there were three seattle-based flight attendants who were getting things in order for the 83 booked passengers and two very senior Pilots in short was 53 year old Captain Ted Thompson who had been working for jet America and then Alaska Airlines since 1982. before he had started flying airliners he had flown for the U.S Air Force and at the time of this flight he'd flown little over 17 750 hours of Total time and over 4 000 hours on the md-80 he was flying together with 57 year old first officer Bill tansky who also has some previous military experience in his case from the U.S Navy he had accrued 8140 hours of which over 8 000 hours was flown on the md-80 making him very experienced on this type the aircraft looked like it was in good flying conditions and there was no problems or history or problems from the last few flights that the captain could see when he was looking through the technical logbook first officer bill was going to be Pilot Flying for the first flight with call sign Alaska 261 towards San Francisco and then Captain Ted would take over and fly the last leg home to Seattle it was a beautiful day for flying with light winds and good visibility conditions once all of the 83 passengers had been boarded the doors were closed and the engines were started as they were pushing back from the gates the takeoff trim had been calculated to 7 degrees nose up which was set without any problems and attired 1337 Pacific Standard Time Alaska Airlines flight 261 took off normally from Puerto Vallarta and started its climb towards Northwest off the bill flew the aircraft manually up to around 6 200 feet where he made sure that the aircraft was done properly trimmed and then engaged the autopilot after that point as the aircraft continued to climb to watch their planned Cruise altitude of 31 000 feet the autopilot continued to trim normally using the slower rate of the standby electrical motor just as it was designed to do but unbeknownst to the pilot things have now started to happen in the very back of the aircraft inside of the acumenat who was holding the exact screw assembly together for several thousand hours the screw had been grinding down on the softer not threads without hardly any grease to lubricate it and now only a sliver of the original thread was left to guide the screw as the autopilot was turning it when the aircraft climbed through 23 400 feet the last stabilizer trim movement was indicated on the five data recorder and after that it froze on a setting of 0.4 degrees nose down now we can't know for sure what caused it to freeze up but it is possible that the tips of what was left of the Acme nut thread now became so weak that they had started to bend under the load of the screw which just caused the screw to seize up in any case the way the pilots would have noticed this would have been by seeing that the autopilot was unable to keep speed and climb rate since it just couldn't move the stabilizer initially the aircraft continued to climb at a indicated airspeed of 330 knots but then it slowly began to level off as it reached around 26 000 feet as this was happening the speed started slowing down and then it restarted its climb again and the speed dropped further back to 285 knots around this point the trim enunciative warning light would have also illuminated giving a clear indication to the pilots that something wasn't quite right with the trim system so first off the build disconnected the autopilot and took manual control of the aircraft now we have no voice transcripts from this initial part of the flight since the cockpit voice recorder only gathered the last 30 minutes but we can assume that first off the build would have immediately noticed that he needed to pull as much as 50 pounds or 22 kilos of force in order for the aircraft to keep climbing and when he tried to trim it the stabilizer trim wasn't working like I mentioned in the beginning of the video the main reason for the stabilizer trim is to remove stick forces from the crew and since the aircraft was trimmed for a 330 knot climb and the speed now was back at 285 knots much more back pressure than normal would be needed to keep it climbing during the next few minutes the elevators were deflected upwards to continue the climb to 31 000 feet and after they had leveled off the amount of back pressure needed was reduced back to about 30 pounds or 13 kilos that's still a lot but it's clearly manageable this back pressure was also done further reduced by a speed increase and the gradual reduction in fuel weight so that eventually not much back pressure was needed at all to continue to fly in level flight as this was going on the crew would have also run through the stabilizer inoperative non-normal checklist in their quick reference handbook and that checklist would have told them to try utilizing the two standby systems in order to clear the problem and get the aircraft back in trim if that failed the checklist instructed the crew not to re-engage the autopilot because the fact that the trim wasn't moving with any of the motors indicated that something else was causing the jam and it would therefore be inadvisable to keep trying to activate the motors which the autopilot would definitely do spite of this after the aircraft had been flown manually for nearly two hours along the Route the autopilot was re-engaged at time 1547. the reduction of the aircraft's weight combined with the higher AirSpeed would have made the stick forces needed small enough to enable the autopilot to be re-engaged and it is possible that the crew just wanted the extra capacity to continue to troubleshoot the problem now you might be wondering why the pilots didn't just turn around and divert back to their departure airport as soon as they noticed the problem that they were having well with the information that they had at that time a straight return would have led to an overweight Landing with higher than normal approach on Landing speeds and from a strict handling perspective the problem that they thought they had wasn't that bad and the non-normal checklist didn't devise them to land at the nearest available airport but that doesn't mean that the pilots didn't think about diverting actually this was the very thing they were discussing on the CVR transcript eventually started at time 1549 and 49 seconds the pilots were down still troubleshooting the jam stabilizer and the captain was in contact with the Alaska Airlines maintenance and operations frequency the engineers had been going through the maintenance history and hadn't been able to find anything especially anything relating to the stabilizer in any case Captain Ted advice maintenance and operations that they wanted to divert to Los Angeles International Airport LAX instead of continuing towards San Francisco and when operations heard this they were clearly annoyed by this fact and wanted him to clarify why they couldn't just continue towards San Francisco instead now this is the kind of thing that just makes my blood boil a pilot never requests a diversion unless he or she deems it's absolutely necessary a diversion will always prolong the Working Day and it creates inconvenience for the passengers the crew and the company so a diversion is not something that a pilot would just ask for without proper course this seems to also have been the opinion of Captain Ted who explained to Alaska operations that he simply didn't want to fly past any suitable airport with this type of problem and that the winds and conditions in LAX normally were more suitable for Landings with issues like this the operations controller said that he should of course do what he thought was safest but he also informed the captain that this might cause delays for the flight back to San Francisco later on as well as issues with getting Landing clearance for an unscheduled international flight into LAX all of this just sounds like further ways to try and pressure the crew to continue to their original destination which wasn't lost on the captain who complained about it to his co-pilot one more thing that is important to remember here is that the flight was still well on the control at this point and no urgency or emergency call had been made this meant that the flight was treated just like any other aircraft in the airspace and that might also be an explanation to the relaxed attitude of the Alaska Airlines operations controller the pilots decided to continue following their route until they got closer to Los Angeles and then divert this way they could burn a little bit more fuel to reduce the landing weight and speeds and it would also allow them more time to continue troubleshooting and make a plan for their arrival from the conversations the crew was having you can clearly hear that these were two very experienced and well-trained pilots who were capable of thinking outside of the box they were even asking on the operations frequency if there was any instructor Pilots available as they might be able to think of something that the pilots had missed this is a very good idea but sadly there weren't any instructors available Captain Ted also advised operations that he intended to descend the aircraft down to a lower altitude and start configuring the aircraft to see how it behaved doing this is an excellent idea when you're dealing with flight control problems as it's much better to find out about potential additional control problems at a higher altitude when there is more time to rectify them and then make a new plan for the landing at time 1559 and 44 seconds the captain handed over the controls to the aircraft which was still being flown by autopilot at this point to First officer bill he then changed the frequency over to listen to the automatic terminal information service at LAX where the weather was good with winds almost straight down the runway good visibility and only some few clouds around once that was done he continued talking to the LAX operations about getting the landing performance figures calculated for them as well as an update on the winds in San Francisco to make sure that the weather was indeed better in LAX these were all standard diversion preparations and everything was still under control at this point but that was soon about the change at times 1607 and 51 seconds a new Engineers voice called up flight 261 on the operations frequency he said that he just wanted to know if they still had the same issue with the stabilizer and if they had indeed tried all of the different options including the pickle switches on the control wheel and the suitcase handles the captain responded that they had indeed tried everything even together and that they would love to hear if he had any other suggestions like hidden circuit breakers or something the engineer responded that he was double checking the CB guide but he just wanted to check that they had really tried everything Captain Ted said that they definitely had and that the AC meter which is an instrument that shows the alternating current load showed a big increase in electrical load when they were using the normal trim switches now this is important information because it clearly shows that the motor in itself was working but that it wasn't successful in actually moving the screw that's a sign of potentially serious damage to the whole Jack screw assembly but that would have been really hard for the pilots to figure out from the little information that they had at that point in later versions of the quick reference handbook checklist the crew will be clearly told not to retry operations of any trim systems if they didn't work after they were tried the first time and we will very soon see the reason for that now because of the repeated questions from the engineer the captain now seemed to have come up with an idea because at times 1608 and 59 seconds he said to the first officer I'm gonna click it off you got it and first officer Bill responded okay 10 seconds later the captain continued by saying let's let's do that and this will click it off followed by the autopilot being disconnected in all likelihood what the captain did here was to push both the pickle switches and possibly also the standby handles at the same time which disconnected the autopilot now a loud clunk could be heard on the cockpit voice recorder followed by two faint thumps from the back of the aircraft the next sound was the audible stabilizer movement tone followed by first officer Bill exclaiming holy the horizontal stabilizer now moved from its position of 0.4 degrees nose down which it had been jammed in for the last two hours to slightly Beyond its maximum nose down position of 3.1 degrees it's possible that the sudden engagement of the trim motor started moving the aquma screw again causing the remaining threads inside the Aquanaut to finally sheer completely off allowing the screw and the stabilizer to start moving freely inside of the knot the fact that the elevators were pulled upwards to try and counteract the dive just caused tension on the screw which moved it even further up making the situation even worse now the reason we can assume that this is what happened was because the movement of the trim during the seconds after the two thumbs were heard was not linear as it would have been if the screw was just rotating normally along the threads the upwards movement of the screw only stopped when the mechanical stopped slammed into the bottom of the acmonaut leaving clear indents and scrape marks on it the sudden stabilizer movement now caused the nose of the aircraft to pitch forward leading into a rapid dive and with that a big increase in speed the first officer shouted out what are you doing and the captain responded I clicked it off likely referring to the autopilot there was no way for the pilots to know what had just happened in the back of their aircraft but this call from the captain actually illustrates a very important point one of the main reasons we're not supposed to engage the autopilot when we have flight control problems is because the autopilot can actually mask the control issues and cause a very sudden pitch or role if it suddenly disconnects in this case the pilots now spent the next 80 terrifying seconds trying to pull the aircraft out of the dive the captain called Air Traffic Control telling them that they were in a dive and as he was doing so a strong vibration could be felt throughout the aircraft the captain called out you're stalled which was not the case but the vibrations together with the quick descent rate could possibly be interpreted as that this would also explain why here a few seconds later called out no no you got to release it you got to release it possibly referring to the way the first officer was pulling back on the controls there were several fourth and back course between the pilots until finally the overspeed warning started sounding this caused the pilots to extend the speed break and that seemed to improve the situation slightly but still took a combined effort of around 130 pounds or almost 60 kilos of force to pull the aircraft out of the 6000 feet per minute dive the crew finally managed to get the aircraft more or less on the controller as they reached about 24 000 feet they then asked our traffic control for a block altitude between 20 and 25 000 feet which would allow them clearance to other aircraft in case of another dive and then they started discussing what had just happened they both agreed to stay away from whatever switch they had touched they had initiated the dive and they also agreed that the situation was now significantly worse with the stabilizer in a Fool's nose down position they also started talking about how they needed to slow the aircraft down and get the slats and the flaps out to see if they could still control it but before they could do that Captain Ted went off the radio to again talk to maintenance and update them on the now much worse new situation when they answered the engineers didn't have much new advice to bring them they just said that it was up to him if he wanted to again try the trim system this advice sparked a conversation between the two pilots about whether or not they should maybe try it again but here the first officer spoke up clearly and he said that he didn't think that that would be a good thing to do first off the bill also at this point reminded the captain that he needed to make a PA today now likely terrified passengers in the back Captain Ted agreed and he made a short concise PA without giving too much detail but also without any type of a very well made PA given the extreme circumstances that they were in and hopefully that gave some reassurance to the passengers the Los Angeles air traffic controller now handed over flight 261 to the approach controller and when the captain called him up explaining the nature of their problems they were clear to proceed direct towards Los Angeles but here the captain made a truly heroic decision he likely knew that his yet was in a very bad shape so he declined the direct and instead asked to remain on radar vectors out of the bay in order to complete the configuration tests all the water rather than overpopulated land by doing so he would avoid third-party damage if something went further wrong and it shows extraordinary situational awareness under pressure once this decision was taken the captain asked for a further descent clearance down to 10 000 feet in order to complete the handling tests ATC initially told them to stand by and now again the first officer spoke up and suggested that they should run the test at their present altitude rather than descending down to 10 000 feet and do them there now I understand the captain's idea of doing it at a slightly lower altitude with the air is thicker and more similar to what they would face an approach but the first officer's suggestion to try it with more altitude margins also makes perfect sense it's great to see airmanship and CRM play out under such dire conditions control cleared the aircraft to descend to 17 000 feet initially which the crew read back and they also reminded the controller that they needed a block altitude they were clear to turn on to heading up to eight zero degrees out of the sea and then change controller frequency over to the next sector the Purser was now called into the cockpit and when she came in she informed the pilots that the crew had heard a large bang in the back of the aircraft just prior to the first dive the captain thanked her for the information and he told her to secure the cabin and strap everyone down because he was planning to unload the aircraft and see if he could get the trim working that way unloading the aircraft would mean pitching forward to reduce the back pressure and therefore the load on the stabilizer this type of maneuver has been known to be effective in fixing certain types of stabilizer gems in other aircraft types like the 737 for example where this was referred to as the roller coaster maneuver however trying that would again mean also trying to activate the trim system anyway the first thing they needed to do was to try and configure the aircraft and see if it was actually controllable they started with retracting the speed brake and then at times 16 17 and 54 seconds Captain Ted took control of the aircraft and asked for the slots to be extended first off the build moved the slot handle to the extend position and this apparently made the pitch down tendency even worse the captain then asks for the flaps to be extended to 11 degrees and when the flaps started to move the aircraft actually stabilized and became slightly easier to fly again now for some unknown reason once the test was complete the captain decided to retract the flaps and slats again even though the aircraft was flying reasonably well in that configuration he possibly did this because he had just wanted to try the configuration for the landing later on but wasn't planning to actually keep it all the way to LAX so here comes another lesson for you budding Pilots out there if you ever have flight control problems like this and fuel is not an issue don't change the configuration back after you have started configuring it it's generally better to just continue to fly the aircraft in this new configuration than trying to test your luck by reconfiguring more times anyway the next thing that the captain wanted to do was to try to unload the stabilizer and see if that would sort the trim problem out but here first officer Bill put his foot down he said that he didn't think it was a good idea to touch it again since the aircraft was flying and he also said I think that if it's controllable we order just try and land it Captain Ted listened to him and agreed again showing excellent CRM between the two but unfortunately this was just not supposed to be because only five seconds later a series of faint thumps could be heard from the back followed by the first officer saying you feel that the captain who had the controls responded yeah okay give me this is a indicating that he now required much more forces to keep the aircraft from pitching down what had likely happened at this point was that the torque tube inside of the Acme screw had been subjected to significant bending and pulling loads during the 10 minutes that had passed since the sharing of the actmann not threads those bending loads had activated existing fatigue cracks inside of the torque tube and now those cracks cause the torque tube to completely fracture into two pieces and therefore leave the knot and the backstop completely this meant that the stabilizer was now allowed to move almost freely around its aft hinges it now slammed up against the vertical stabilizer tip fairing brackets who now became the only thing holding it from moving even further upwards this caused the stabilizer angle to move from 3.1 degrees to 3.6 degrees nose down which explained the additional pitch down that the captain was feeling the captain almost immediately asked for these slots and flaps to be redeployed as the aircraft had been easier to control with those extended but this was sadly too late the vertical stabilizer tip fairing brackets were not made to hold the type of loads that the stabilizer was now exerting on it at time 16 19 and 35 seconds a horrible noise was recorded on the cockpit voice recorder and simultaneously several small radar returns could be seen on the air traffic control radar as the tip fairing was ripped off and saturated from the aircraft the stabilizer now moved upwards to an angle too high to measure on the flight data recorder and this caused an immediate and violent pitch forward this was a hopeless situation to recover from as the whole horizontal stabilizer was now completely out of control but that didn't stop Captain Ted from trying what he now did was to instead of trying to pull out of the 70 degrees Deep dive he pushed forward and rolled the aircraft left over to an inverted position effectively counteracting the downward pitch of the stabilizer he called out push push push and roll whilst the first officer called out Mayday but without actually transmitting it on the radio because of the role the pitch decreased from -70 degrees to 29 and then minus 9 degrees as they were now flying inverted out of the Bay at time 1619 and 54 seconds Captain Ted call out okay we're inverted and now we need to get it indicated that he wanted to get it rolled back into a normal position again then as he was trying this they were passing 16 400 feet still descending with a speed of 208 knots during the next few seconds the flight data recorded indicated ailera movement both in left and right direction as the flaps were being retracted Captain Ted called out push push push the blue side up indicating that he wanted to get the aircraft back on the right Keel again and that was followed by a call to kick Rudder kick left Rudder left rather first off the bill responded that he couldn't reach it and Captain Tad then called okay right Rudder right rudder this effort didn't work and 10 seconds later Captain Ted said gotta get it over again but at least upside down we're flying but sadly this call was almost immediately followed by the sound of several compressive stalls and the sound of the right engine spooling down likely because of the extreme angle of the oncoming air that was hitting the engine inlets from this point there was nothing more that could be done [Music] Captain Tad asked for the speed brakes to be extended but his last words could be heard on the corporate voice recorder at times 16 20 and 56 seconds when he said ah here we go less than a second later the aircraft impacted the Pacific Ocean and all 88 people on board were instantly lost [Music] several other aircraft in the area had witnessed flight 261's final descendant with the help of them and radar pictures the crash site was quickly found the the breeze was scattered over the sea floor and it took a week to salvage the majority of the pieces and among them was the flight data recorder the cockpit voice recorder and most of the Jack screw assembly from the horizontal stabilizer with the help of those pieces the ntsp investigators could relatively quickly start honing in on what had caused this horrible tragedy when they looked closer on the Acme screw and not they saw that the knot was almost completely smooth with only remnants of threads still left inside on the atmos group they found several spiral-formed pieces of thread which had been ripped out of the knot likely during that first dive but what really shocked everyone was that there didn't seem to be any grease at all left neither on the screw or on the knot the grease fitting on the knot was clogged with a gray mixture of old grease and wear material and the rest of the components were completely dry there was no lubricant at all on them this led the investigators to start scrutinizing the maintenance records of Alaska Airlines as well as interviewing mechanics and engineers big discrepancies were quickly found in both their maintenance manual and how the maintenance work was actually being carried out that their various technical centers on top of that important management functions were not filled in the airline which had caused real confusion about who was responsible for what this had happened over several years as the Alaska Airlines operation kept growing and this is what I was referring to as organizational creep it had all happened in small incremental steps the conclusion of the investigation was that the crash had been caused by a loss of control due to the in-flight failure of the horizontal stabilizer trim Jack screw assembly contributing to the course was Alaska Airlines extended lubrication schedule and wear checks which had both been approved by the FAA those two components combined with one or possibly several poorly executed lubrications meant that excessive wear went undetected and ultimately led to the complete failure of the threads inside of the akmenot and the subsequent failure of the torque tube there were 24 safety recommendations that came out of the investigation a few of them gave clearer guidance to Pilots about not repeating actions in checklist regarding the trim system and not using the autopilot with flight control problems but the vast majority of the recommendations were aimed at Alaska Airlines and the FAA regarding maintenance intervals lubrication and wear checks of the horizontal stabilizer after the accident the lubrication schedule was immediately changed to be completed every 650 hours on all md-80 aircraft there were also recommendations about not allowing certification of aircraft unless they could prove that they weren't susceptible to catastrophic single point failures like the one that had happened in this case the two pilots Captain Ted Thompson and first officer Bill tansky were posthumously awarded the airline pilots Association gold medal for heroism in recognition for their actions during the emergency and if you think that you recognize some of the scenes from this video that's likely because the same failure and similar pilot actions were used in the 2012 movie Flight starring damsel Washington now this was a very scary episode and I know that some of you watching this are probably nervous Flyers please know that even though things like this has happened it is tragedies like this one that has had the most profound impact on improving safety in the airline business and to stop things like this from ever happening again I have actually created an App precisely for you guys where you can ask your own questions check for turbulence on upcoming flights and listen to me explaining aircraft noises feelings and procedures it's available on all devices and you can check it out by going to app.mentropilot.com and just create a user I really hope it will help now check out these videos next and have an absolutely fantastic day bye

Channel: Mentour Pilot

Views: 989,753

Keywords: McDonnell Douglas, mad dog, maddog, MD-83, md83, stabiliser, horizontal, alaska, airlines, 621, alaska 621, alaska airlines 621, LAX, Mexico, Pacific ocean, water, mentour pilot, trending, plane crash, boeing, storytelling, true crime, full episodes, investigation, documentary, entertainment, mentour now

Id: gAYzBJxOeLw

Length: 42min 10sec (2530 seconds)

Published: Sat Jun 03 2023