Flying WITHOUT Controls! United Airlines flight 232

hi everybody very welcome to mentor and yet another video podcast as always i hope you're doing absolutely fantastic today on the video guys an aircrew of a dc-10 finds themselves at 37 000 feet when suddenly an explosion renders their aircraft virtually unflyable we're going to be talking about heroic actions by flight crew and cabin crew about airmanship and how they work together as a team to avoid something that looked like a potential complete disaster this is the story of united airlines flight 232 and as a disclaimer there will be talks about loss of life in this episode so if you're sensitive to things like that then i recommend you to stop watching now win three one zero one six three one right hold on three one round guys before i start this video i just want to highlight that i have created an amazon page the reason i've done this is because i keep getting questions about like what my favorite aviation books are what you should be reading or doing before you start your flight training um what kind of material i'm using to do my youtube channel and just generally about things like my logbook and what kind of headsets i'm using and things like that so if you check out the link in the description below or up here i think i'll be able to do a link to it then you can go to that amazon page and you can check it out and also just remember as a disclaimer that this is my amazon page and if you do choose to buy something from there well then i will earn a little bit of money on the purchases you make so thanks for that guys [Music] all right guys so today i'm gonna be giving you the fascinating story of united airlines flight 232 all of the sources including the final report which i'm basing this on you can find in the description of the video so you can just go down and check it out um and i will be talking about this from my point of view from a pilot's point of view and what i think is really important in the way that the flight crew handled this so united airlines flight 232 started on the 19th of july 1989. it's flown by a dc-10 aircraft and the dc-10 is at this point a very modern airliner now as most bigger wide-body airliners at this time it doesn't have any physical connections between the flight controls to the rudder surfaces in the 737 the live fly we still have these um kind of the wires connected to the flight controls but in the case of the dc10 not so much uh instead you have hydraulic activators that's moving the flight controls around and because they don't have this backup system they have a much bigger redundancy built into the system so on the 737 for example we have two hydraulic systems and then a kind of a backup system that's built on the other two but on the dc10 they had three hydraulic systems one system for each engine and also a kind of an emergency turbine similar to what you'll find on the airbus the ramr turbine that could be extended into the airstream to provide electrical power to drive yet another pump in case they would lose complete engine power so these three hydraulic systems could all independently move the flight controls and they're spaced out so they go for example on the left hand side of the aircraft to watch the back end the right hand side and the center part of the aircraft in order to minimize the risk of any damage to the to the structure rupturing all hydraulic systems but one of the problems one of the weaknesses that we'll get to in this episode is of course that towards the back of the aircraft you have both the rudder and you have the elevator and the horizontal stabilizer and they're all condensed into a fairly small area anyway the flight in itself was a normally scheduled flight from denver to chicago and it took off at 1409 with three flight crew members in the cockpit captain alfred haynes a very very experienced captain with close to 30 000 hours on on different aircraft types you also had first officer william records which had about 20 000 hours and then you had second officer and flight engineer dudley dwark who had 15 000 hours so this is a very experienced flight crew all in all there were 296 people on board including passengers and crew and as the aircraft took off at the time or 9 everything was normal just flight just like any other they climbed up up to a cruising altitude of 37 000 feet where they were maintaining a speed of mach 0.83 which was a normal cruise speed now unbeknownst to anyone at this point especially from the flight crew during the manufacturing process of the number two endian fan disc there was a small imperfectional form a small metallurgical imperfection that metallurgical imperfection caused a tiny little cavity inside of the fan disc and during the life of this engine as the engine was constantly accelerated and decelerated that little cavity started creating fatigue cracks around it now these fatigue cracks were growing more and more and it went without being detected by the quality and engineering department of united airlines at the time and at time 1516 that fatigue crack became too big it expanded and the entire fan disk spread into two parts that immediately disintegrated the entire fan section of the number two engine which is the tail mounted engine on the dc10 and when that happened the fan basically shot out with so much energy that the housing that was made to contain the fan in case of a of a single failure of some sort had no chance of maintaining it so the the little shrapnel from the fan shut out into different parts of the the empanadas and it ruptured um hydraulic lines in both the right side and the left side of the horizontal stabilizer and it also completely shattered the hydraulic pump assembly on the engine number two so this meant that from this second as the aircraft was at 37 000 feet in a slight right hand turn the flight crew just noticed a sudden explosion and a shrubber to the aircraft and some warnings going off okay the autopilot disconnected obviously uh and captain haynes looked down saw the engine instrumentation and noticed that there was an engine failure on engine number two so he called for the engine failure checklist to be actioned by the second officer the flight engineer the flight engineer started working on it and realized quite quickly that he had no control over the thrust level of engine number two or the engine start lever the the fuel lever so he confirmed with the the captain and decided to pull the the fire warning handle in order to to stop fuel from going to default the engine and all of this the whole communication between these two took only about 14 15 seconds to do very very quick during this time as the first officer and captain is dealing with this problem they're now flying manually and first officer record which was the pilot flying for the flight is trying to keep the aircraft level but he finds to his confusion that no matter what he does with the the yolk or the elevator or the rudders nothing happens he gives full deflection in all directions and nothing happens he communicates this to the captain a captain tries to take control and try to do the same thing with exactly the same result at this time the the second officer who's been working on the engine failure is scanning the engine instrumentation and realizes that both the hydraulic pressure and the hydraulic quantity has dropped down to zero on all three system this means that the failure they have in the back has now punctured ruptured all three redundant hydraulic systems on the dc-10 so at this point the aircraft that was in a slight right-hand turn in level flight when the failure occurred is continuing its right-hand turn it's actually increasing the bank angle the flight crew very quickly discusses this and realizes that this is a potential fatal problem because if the aircraft continues to bank and they don't have any kind of flight controls to counteract it it might go into a diving spiral and it might actually go over inverted and if that happens it's going to be almost impossible to recover the aircraft so what can they do well the fact is that since the dc-10 has three engines two of the engines situated under the wings and when you have under mounted engines those engines and the truss that they produce is actually below the center of gravity of the aircraft so this means that if you add thrust on the engines it will cause the nose to pitch up subsequently if you take trust off you'll get a nose down moment okay so this gives the crew a little bit of control of pitch even though that it's very sluggish and it takes quite a lot of time to react also since you have the engines on both the left and the right of the center of gravity if you add thrust on one engine and reduce trust on the other it means that one engine will push one wing quicker than the other and if that happens you get a yaw and anytime that you get a yaw with any type of aircraft but especially a swept wing aircraft you will get more lift on the wing that is going quicker when you get more lift you get a little bit of a roll so this means that by using differential thrust the aircrew can actually kind of control the aircraft okay they realize this they take trust off on the engine number one they increase thrust to maximum on the engine number three and they manage to stabilize that right hand diving turn into almost level flight now at this point and this is only a couple of minutes into this disaster uh they call the cabin crew so they call the cabin crew in they tell the cabin crew that we're having problems with the flight controls you need to prepare the cabin for an emergency landing when the cabin crew comes in they relay a message from what turns out to be a line training captain a czech airman called dennis finch that's traveling as a passenger in the back dennis finch has about 23 000 hours and is a line training captain on the dc-10 and he has noticed that something is wrong and has told the cabin crew to relay information that he is there to help captain haynes immediately tells the cabin crew to to bring captain finch up to the flight deck because he realizes at this point that they are facing something that none of them have ever seen before okay this event where the flight crew loses all hydraulics and all flight controls is what is called a black swan event that is an event that has been rendered so unlikely that no one has even constructed any maintenance procedures for it and checklist for it and no one has been practicing this in the simulator because you know the thought of of losing all three hydraulic systems simultaneously was yeah it was just considered an impossible event hence there's been no training and captain haynes realizes that the more experience they can have in the flight deck the higher likelihood it is that they can figure something out so when captain finch comes up to the flight deck uh captain haynes tells him to please go back and have a look at the wings and see what he can see so finch goes back checks out comes back into the cockpit and says that um both the uh the inboard ailerons the two sets of ailerons on each wing on the dc10 the inboard ailerons are slightly up on both sides and the flight spoilers are flush with the wings they're locked down and there's no movement at all on them so that kind of confirms what they're already noticing the fact that no matter what they do with the flight controls nothing seems to be working and so they're starting to discuss how to deal with this now a really really interesting point which has come up here is that the czech airman captain finch he has actually previously been studying other accidents with other aircraft types where they have lost all hydraulics and he has kind of been curious about what he would do in a situation like that to the point of where he has actually been practicing flying the dc-10 in the simulator using differential trust and i really want to point out here guys how important this is and how that shows the kind of airmanship that we should all strive for because this is exactly you know what i've been talking about threat and error management when i'm talking about trying to to you know to see stuff coming up against you and have a plan for them this is an excellent example of that this means that captain finch have been so interested in doing his job well that not only has he been studying the non-normal checklist and the procedures for whatever failure that the you know the aircraft manufacturer think could happen he's also been thinking into what if something even worse happened and actually been training it that gives him a great advantage because instead of being put into a situation where you have no idea whatsoever what to do he can now use that uh experience that he has created himself to apply that to this situation and that will probably unlock a lot of extra um of extra capacity in both him and the rest of the flight crew so a very very good example of airmanship both on behalf of the three-man flight crew that invites the fourth man and on behalf of this czech airman that has taken this initiative anyway so right now the aircraft is descending down they contact air traffic control they call out a mayday call and they also contact their own maintenance control center they tell them what they have but since this is a black sworn event since no one has ever done anything like this before they don't really get any information from their maintenance control center because you know they've never seen anything like this before air traffic control is giving them vectors to whatever airport they want and they quite quickly decide that they're close to suicide and start to get vectors to that because the aircraft was in a slight right-hand turn when this failure happened the aircraft has a tendency of wanting to turn right and the flight crew now with captain finch handling the the trust levels are using this tendency to turn right to do several large right turns in order to kind of get the aircraft where they want it rather than trying to go opposite to the direction the aircraft want to go they just do several turns and try to roll the aircraft out close to the heading they want to go and this is smart because using differential trust will have a delay of about between 10 and 30 seconds so as you add trust is going to take that much time for the aircraft store rolling out if you do several turns like that you have a chance to practice to see how the aircraft is reacting because it's also going to make potentially different turns and different bank angles depending on the altitude and the speed that the aircraft is keeping so all of this they've never tried before they've never seen before and they're practicing and doing this for the first time they're getting closer to the city they managed to reduce the altitude they have constant communication with the cabin crew telling the cabin crew to you know prepare for a potential off-field landing make sure that the the passengers are briefed on how to do a proper brace position cabin crew is reacting to this and they're doing a great job with working with the passengers in the back they're also doing a very very quick pa because they don't really have time to focus on giving a long detailed pa and it's probably not even needed at this point so another motion that the aircraft is doing at this point is something called a pugoid motion now in order to understand what that is is that you need to know that all transport category aircraft basically all aircraft out there are built to be aerodynamically stable an aerodynamic disable around both its pitch plane it's your plane and it's role plane okay this means that if something happens to the flight controls if an aircraft is trimmed out and there is a disturbance to it the aircraft always try to get back to its stream position and it does so in the pitch plane by if the aircraft is starting to pitch down the speed automatically increases as the speed increases the aircraft pitches up and as it pitches up this speed decreases and it does a motion like this until it's stabilized again in the same way it was when it was trimmed now during this flight with united airlines by 232 the the aircraft is in a constant pugoid motion and it's only partially kind of rectified by the the change of differential thrust so the aircraft is descending increasing the sand and then decreasing descent and then increase in descendant decrease in descent and normally these pugoid motions tend to have a cycle of about one minute so it goes down for 30 seconds and up for 30 seconds like that so they're having to to deal with this pugoid motion as well now as they're getting closer to sewer city air traffic control wants them to try to line up for runway 3-1 that's the longest runway in sioux city but the aircrew at this point is visual with the airport and they've realized that on the track they currently have they're actually lined up with the now closed runway two two so they're just telling a traffic control we're just going to try to land on the runway straight ahead and air traffic control is being really helpful at this point and really trying to help the aircrew as much as possible they're discussing as well whether or not they want to extend the landing gear now there's a number of different reasons they're having that discussion they realize that they are going to be landing the aircraft at a much higher speed than usual and probably with a much higher vertical speed as well and if you do that having the landing gear out being able to absorb a lot of the energy with the landing gear is a really good thing now the downside if you're in a situation where you have very limited flight controls you want to try to avoid disturbing the equilibrium as much as possible and extending the landing gear could change the trim situation of the aircraft to such an extent that you might lose the pitch control of the aircraft however after having had this discussion once again they're all kind of putting their smart heads together and discussing this they realize that the benefits of getting the gear down is bigger than the potential loss of some of the pitch control and they do think that they will probably remain with positive pitch control anyway and also they have a little bit of a theory because the x the outboard ailerons are locked down in high speed flight they think that maybe there's a little bit of hydraulic fluid still locked in the output ailerons and if they do the um the manual extension of the landing gear which is an actual procedure where you use a crank in the in the floor i've done a video on this on how to do it on the 737 you can check it out by the way if you're interested if they're doing that that will also unlock the outboard ailerons and they think that maybe they might also get some aileron control if they extend the landing gear this way so all said and done they extend the landing gear uh they don't regain any kind of aileron control but they manage and i don't know how they do this they manage to end up on an almost three degree glide slope down towards runway two two and sioux city and i just cannot over emphasize how hard it would be to achieve this to actually get the aircraft from 37 000 feet down to an extended final to an actual runway without any kind of use of neither rudder elevator ailerons or horizontal stabilizer this is a feat that is almost unimaginable okay now the aircraft is on final approach they give four minutes warning to the cabin they get two minutes warning to the cabin and as they're coming on to absolute final approach here now the aircraft goes into one of these fugoid motions so the aircraft is starting a slight right-hand turn and it's starting to increase its vertical speed there's very little that the flight crew can do at this point the captain is calling for the czech airman to cut the trust in order to minimize the speed remember at this point they don't have any flaps they don't have any slats out which means that the speed at this point is 220 knots while a normal landing speed would be about 140 knots 220 knots is over 400 kilometers per hour and they're having a vertical speed now of 1600 feet minute while in a normal landing flare as we're getting into the flare we will maybe have about 300 feet per minute so they have a much much higher both horizontal and vertical speed but instead of taking the trust off to minimize the speed the czech airman captain finch realizes that if he cuts the trust it's likely that the aircraft is going to pitch down further so instead he is trying to add trust on the number three engine trying to stop this right hand turn from happening and add thrust in order to get the nose up and do something probably resembling a flare the aircraft touches down on the threshold runway two two it touches down with the right wingtip first followed by the right main landing gear and because the wingtips touch first the aircraft turns over and it breaks apart into several pieces but the key here is that there that this is happening this accident is now happening on the perimeters of an airport this is crucial the air crew has managed to get the aircraft down onto an airport which means that all of the emergency services everyone who's waiting for them can now quickly come in and help and they can start extinguishing the fire that broke out almost immediately after the touchdown and it can start helping passengers out out of the 296 people on board 185 people survived including all four members of the cockpit crew at this point this is still a horrendous loss of life don't get me wrong this is a terrible terrible accident but given the fact that this aircrew was sitting at 37 000 feet when this catastrophic engine failure happened and they lost complete control over all flight controls the fact that they managed to save so many lives is an incredible feat i cannot overemphasize how much the use of crm crew resource management played a role here in how captain haynes used all of his flight crew members and his cabin crew in order to maximize survivability in this catastrophic event okay the knowledge and the experience of all of these flight crew members was what made this possible after the event the investigation unit the ntsb in the united states put several flight crews into the simulator to try to reenact the event to see if there was a possibility to maybe create procedures for how to actually fly the dc-10 using differential trust none of them managed to do what this flight crew managed to do it was determined that something like this cannot be trained the variables are too many and the only way that something like this can be stopped in the future was some redesign of the dc-10 which happened for example they they introduced what's called hydraulic fuses into the hardware system what that is is basically a component that feels that if the flow of hydraulic fluid increases suddenly which would be indicative of a of a leak then the hydraulic fuse stops the fluid from going forward so it traps the fluid in the rest of the system making sure that all of the rest of the components can work and the part of the system that's been damaged that's that fluid disappears but it stops there also they introduced a feature in the number three hydraulic system that basically decided that if the hydraulic fluid dropped below a certain level well then there was a hydraulic stoppage of the fluid towards the back part of the aircraft that way you would have flight controls anyway and you'll be able to use the stabilizer trim in order to control the aircraft horizontally and the air alarms in order to control it vertically so those were some of the the things that came out of this accident the accident investigators praised the flight group for having done more than what could be ever expected they've gone up above and beyond what could be expected by any flight crew in that situation and the cause of the accident was of course deemed to be the rupture of the the fan disc that happened because of that fatigue cracks that were not noticed during the inspections and the quality inspections of the fan disc so it came down to the human factor on the engineering side and also partially on the manufacturing side of the titanium aisle alloy fan disc and that's it guys that's what i wanted the reason i did this video was that i wanted to really highlight how important it is with crm crew resource management to utilize all available resources in a flight crew cabin crew air traffic control and how if you do that the sum of your experience might actually become greater than just the individual experience by itself i also wanted to highlight the the importance of thinking ahead and preparing yourself for unexpected events that captain finch the czech airman showed by actually practicing something like this a black sworn event before it happened and how he could use that and if you like these kind of videos if you enjoyed this kind of content first of all i hope that i have earned a subscription and that you consider highlighting the little notification bell so you know when i do new videos like this and live streams and stuff like that and yeah i've done a playlist with more in this series about accidents and incidents you can you can click this one up here in order to see that have an absolutely fantastic day wherever you are 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 belt see you inside of the mentor aviation app and have an absolutely fantastic day bye [Music]

Channel: Mentour Pilot

Views: 223,814

Rating: 4.9627042 out of 5

Keywords: United Airlines flight 232, Sioux City disaster, Aircrash investigations, seconds from disaster, Loss of controls, DC10, Mentour Pilot, Mentour Pilot engine failure, Mentour Pilot Boeing 737, Boeing 737, Boeing 737 MAX, Airbus A320, Airbus A380, Airbus A50, Boeing 787, How to become a pilot, Aviation news, Breaking aviation news, Fear of flying, fear of flight, Nervous flyer, Nervous flyer help, Pilot training, aviation documentary, aviation video, aviation facts

Id: pT7CgWvD-x4

Length: 29min 30sec (1770 seconds)

Published: Sat Sep 12 2020