Helios Airways flight 522 - WHAT happened?!

hi everybody welcome to mentor and yet another video podcast as always i hope you're doing absolutely fantastic in this video we are going to be talking about the tragic loss of helios airways flight 522 how default the position of one single switch in the cockpit led up to this accident now there will be mentioning of loss of life in this episode so if that's something that you are sensitive to i suggest you stop watching right now [Music] [Music] all right guys so this is the next episode in my series about famous incidents and accidents and what led up to them if you want to see more of this i have a playlist with all of the other episodes up here and as always all of the things that i'm going to tell you in this episode is taken straight from the final report which i have linked to in the description of this video so as always when it comes to major incidents and accidents in the aviation world there's always several components involved and that is definitely the case here as well now you might ask yourself why does he keep telling us about these things what's the point maybe you're a nervous flyer and you don't feel like listening to this at all the fact is that it is very important for you to understand that investigating any incidents and accidents out there and then sharing the information that comes out of those investigations is a cornerstone in what makes the aviation business so safe the fact that we never kick anything under the rug the fact that we always go to the bottom of why something negative has happened and we learn from it and we get better that's the reason that by far aviation is one of the safest ways of transport so this accident really started the day before so on the 13th of august 2005 the 737 300 which was going to become the accident aircraft came in after a normal flight the cabin crew had reported that they had heard some strange kind of bangs and noises from the right aft door and they had also noticed that the seal to the door looked like it was frozen which would indicate that there might be a pressurization issue here so the cabin crew wrote that up in their cabin logbook they then transferred that into the main aircraft logbook and the engineers were told about it the engineers took over the aircraft at night they did their normal maintenance inspections but they also did a pressurization check of the aircraft now to do this you have to follow very strict guidance boeing in this case has a maintenance manual and the maintenance manual tells you exactly step by step what you need to do in order to for example check the pressurization system the engineer on duty took help from an off-duty engineer that was awaiting a flight going home and they went on board and they started setting the aircraft up to pressurize it to see if there was any leak that they could notice a part of doing that is going into the cockpit and switching the pressurization mode selector from auto which is where the two pressurization computers in the aircraft takes care of the pressurization of the aircraft automatically to manual whereas where you have to toggle a little switch to open and close the alpha valve the reason they did that was because they needed to close the outdoor valve in order to pressurize the aircraft using the apu and to see if there's any leak that they could notice so this was done he stated that they couldn't find any leak and they also stated that after the procedure was done that they followed the maintenance manual guidance and reset the cockpit the way it was which would indicate that the pressurization mode selector will switch back from manual to auto however subsequent investigation showed that that was not the case the switch was most likely left in manual so this leads us to the morning of the fateful flight uh on the morning around five o'clock uh local time on the 14th of august 2005 the flight crew and cabin crew convened in order to do their pre-flight briefings captain 59 year old german citizen he has extensive flight experience more than 16 000 hours and there has been some reports from first officers in the airline that he is a little bit rough to fly with as in he can be very direct he's very standard operator procedure driven a little bit rigid and maybe not so friendly to fly with however other first officers seems to have no problem with him at all so this could be a cultural thing the first officer is 51 years old also very experienced a senior first officer with over 7000 hours and when they looked through his training records they found that there was mention about him skipping some standard operating procedures at times and sometimes skipping steps when operating the the qra the quick reference handbook non-normal checklist as well that could become important as we go forward anyway the crew did their preflight they went out to the the cockpit to start setting it up now what you need to understand is that when you set up a 737 there are specific areas of responsibilities so the first officer has certain parts of the cockpit that he is responsible for and the captain have other parts of the cockpit and then after they have done their duties then you run through a checklist to make sure that all of the switches are in their correct position right the first officer did his duties and part of that was setting up the pressurization panel so it was his responsibility to make sure that the the air conditioning packs and the air conditioning bleeds were in the correct position that the cruising altitude was set that the landing altitude was set but also that the pressurization mode selector was in auto it should be said at this point that sometimes when you do this you're under what we call perceived time pressure which means that you're looking at the clock seeing about we should take off in 10 minutes i need to do this quickly and the pressurization mode selector very rarely is touched right it is almost always in the auto position so there is a possibility here that when the first officer did this pre-flight check he just brushed past it without really looking too carefully on it okay so then after the preflight was completed they read the checklist now the way that the checklist is supposed to be read is by a by a technique called read look listen that means that the pilot monitoring was not going to be flying the leg reads the checklist items the pile of flying looks at whatever he's going to respond to responds and then the pilot monitoring checks that the response is correct and then you go to the next point so you read you look and then you listen to what the response is that's the way that checklist is supposed to be done now at this time the checklist response to air condition and pressurization was pax auto bleeds on set okay so the packs are auto makes sense leads are on also makes sense but set included three different things not only the pressurization mode selector but also the cruising altitude and the landing altitude set on the panel at this point they should have picked it up all right here they definitely should have caught that that switch is in the wrong position um there is a light when the preservation selector is in manual there's a green light illuminated to show that it's in the manual position and when it's in auto there are no lights so there should be something that would pick up here but once again if you rush the checklist or if there's something that you think that you know and you might be rhyming the checklist which is when you just answer what the right answer is and you don't look too carefully this could have been omitted and it was on this occasion so so the aircraft tax is out it takes off at time 0607 and it's a normal takeoff now you might be asking yourself how come that there's a green light for the preservation mode selector in in the manual shouldn't there be like a red light or an orange light or something the fact is that pressurization selector being in manual could be a normal thing right we are able to fly the aircraft in manual mode and using a toggle switch to keep the outflow vap open and close depending on what kind of cabin altitude we have so there is a supplementary procedure for how to do this and that is only really used in case the pressurization normal computers the controllers are not working okay but this is not a non-normal right it's it's a supplementary procedure and that's why it was green and not highlighted red or amber as it would with a non-normal situation the aircraft takes up normally in the of the takeoff checklist comes the next air conditioner pressurization check the reason that you see this coming in several checklists after each other is because the pressurization system is a life preserving system it's there to make sure that the people inside of the aircraft are kept alive so it's a very very important system so in the of the tech of checklist we should be looking through to make sure that the pressurization panel looks good but also that the indicators are indicating the correct values so we have differential pressure that should show a difference between the outside pressure and the inside pressure that div pressure should be increasing as we climb you also have the cabin altitude which would indicate what altitude the cabin is keeping in relation to the normal altitude that we have in this case if they would have looked careful at this they would have seen that the diff pressure was lower than normal that the cabin altitude was higher than almost almost the same as the altitude they were at and that the cabin climbed was much higher than normal in a normal climb about we would have about a thousand feet per minute rate of climb in the cabin and here it would be maybe two thousand two thousand three hundred so more than double the normal rate of climb some reason this was not done either all right now i really have to emphasize at this point if you are watching this because you want to become a pilot this shows how important application or procedures are you know the way that the procedures are written and described in our manuals has to be followed point by point exactly the way it's written because if we don't if we start omitting things if we start to kind of blur over and just do things quickly to get it over with you might miss some really really important clues anyway the aircraft continues to climb the outflow valve since it is now in manual was just stuck it was open at about 14 degrees did not move because that's what it was told to do as the aircraft climbed through about 10 000 feet of altitude there was the last communication with the previous air traffic controller the air traffic controller asked helios airways flight 522 which cruising altitude they wanted the captain responded with 34 000 feet of flight level 340 and then they were cleared to climb all the way up to their cruising altitude now sometimes we are cleared intermediate altitudes because of traffic but in this case there was likely little traffic so they got the clearance all the way up to their cruising altitude this was the last communication that air traffic control had with this aircraft because the next thing that happened was because of the now slow depressurization of the aircraft the cabin altitude warning horn [Music] now if you've heard the cabin outside volleyball you know that it's a really loud sound okay it's very very annoying and it is that for a purpose that warnings horn is there to tell you that you need to act on something really quickly this is crucial it's a really really important alarm right but now something happens that is hard to explain right now there are a couple of things that happen in very rapid succession that is going to lead to this disaster because since the crew has failed to identify the cause of this the uh pressurization mode selector not being in auto but being a manual instead at this point they now need to understand that okay we have a problem with our cabin altitude we need to take the appropriate steps and the appropriate steps that are hammered into every single pilot during training is that when you hear this alarm mask on first thing you do is you put your oxygen mask on you establish crude communication and then you start dealing with the problem and the reason that you need to do it in that order is because you might be climbing towards hypoxia you might be getting yourself in a situation where your body cannot take up enough oxygen to function properly and the first thing that's going to disappear is your ability to think straight all right it is your problem solving capacity your memory and your judgment so that's why it's so crucial to get the oxymethon but in this case something strange happened because after just a few seconds after this alarm goes off what the flight crew does is they disconnect the autopilot and then eight seconds later they connect the autopilot again followed by disconnecting the outer throttle and then engaging it again okay now this is a strange reaction but it becomes clear why they did that when they continue to climb and instead of doing the appropriate procedure for cabin altitude warning the captain decides to call up their dispatcher in their headquarters and the captain says that they're having an erroneous takeoff configuration warning now take off configuration warning you'll say the fact is that in the 737 the takeoff configuration warning horn and the cabin altitude horn sounds identical it's the same one the only difference here is the knowledge that is hammered into flight crew that the take-off configuration warning which is a warning that tells the pilots that the aircraft is not properly set up for takeoff maybe the flaps are not set or the stabilizer trim is not set the parking brake is set for example basically that the aircraft is not ready for takeoff that warning can only be heard on the ground right not in the air if you hear this warning in the air it's the cabin altitude warning now now in aircraft the same type today we also have a visual indication showing take off config warning or cabin altitude warning a red light just in front of us but that was as that came as a response to this accident it wasn't there on the accident flight so the captain has now started to go down the wrong path of thinking and once you've started going out on a different path confirmation bias is likely to set in and you might have a huge problem getting back to the right way of thinking the first officer seemed to just go along with the captain in this case there's no indication that he did anything or said anything different at this point unfortunately the voice recorder has not been preserved for this part of the flight because the flight became so long that it started overwriting itself so we don't know from the voice recorder what happened but we can see from the flight recorder what happened and what happened was that the aircraft continued to climb as the captain was now talking to the dispatcher as subsequently the engineer and what the captain said was that they had this problem take off config warning now at time 0614 okay there's another couple of things that happens in the cockpit and that is that the master caution light comes on now when the aircraft climbs up through a cabin altitude of 14 000 feet what will happen is that the passenger oxygen masks will fall down and when they fall down that's going to trigger a master caution overhead and if you look up then you'll see passenger oxygen on right that will indicate to any pilot that the passenger oxygen have fallen and it will be a clear indication that something is up with your pressurization system the problem is that another thing that happens is that the equipment cooling which is there it's a system there to cool the screens in the cockpit the electronics in the cockpit also the electronics down in the e and ebay where we have all of our computers and so on if that doesn't have enough air as in enough air density to cool the equipment properly it will also warn us and there will be an equipment cooling off light coming on now these things could potentially happen very close to each other depending on what kind of outside conditions we have the only thing we know here is that the master caution light came on it stayed on for almost a minute which means that if one of these warnings came on and this warning master caution wasn't reset it would not have popped up again if a secondary warning came on and if the first indication they had was equipment cooling off and then the passenger oxygen on came after that they would not have noticed it and this is what it looks like because when the captain is talking to the engineer he's mentioning that he has problems with the equipment cooling off he asks where the circuit breakers are because he thinks that this is what's causing the alarm and he wants to get up and start looking for them now remember all through this the aircraft is still climbing okay continuing to climb the engineer doesn't understand what he's talking about there's a little bit of a language barrier thing going on here but the engineer asks if he's checked that the presentation mode selector is in auto because he knows that he's been working on it but there's no response back from the captain to this so at the time 620 the aircraft has now reached an altitude of 28 900 feet that's the last time that the flight data recorder shows that someone is trying to communicate that's the captain still communicating with the engineer after that there's no more sounds there's no more indication that anything is happening inside of the cockpit from that point so there's a very high likelihood that somewhere after zero 620 both the first officer and the captain becomes incapacitated captain potentially on the floor looking for circuit breakers first officer as pilot flying in his seat none of them wearing their oxygen masks so what's going on in the cabin then well in the cabin at this point there would be huge confusion because the cabin crew is trained to deal with rapid depressurizations and the way that they they are supposed to deal with this is that as the passenger oxygen masks falls down they're supposed to sit down and put a masks or mask on and await a call from the captain that they can breathe again basically it's a call from the captain to get the purser up to the front to start briefing him or her and that indicates that yeah now we're down to a safe altitude so they are expecting when the mask drops down to just sit down put the masks on and the aircraft should level off and then start to descend and eventually they will get a call however in this case the masks falls down but the aircraft just continues to climb and there is no indication from the cockpit that anything is happening the issue here is that we don't know exactly what happened in the cabin what we do know is the way that the passenger oxygen system works is that that is chemically generated so in each unit over each passenger row there is a chemical generator that once the mask falls down and someone pulls the mask down the generator will start generating oxygen and it will generate oxygen for about 12 minutes after that there's no more oxygen coming out of that generator the reason it's 12 minutes is because it is built to enable an emergency descent and 12 minutes is more than enough for the aircraft to go from its maximum cruising altitude down to 10 000 feet not an issue but in this case the aircraft just continued to climb stayed at 34 000 feet 12 minutes would have come and gone oxygen would have ran out and the passengers would have become increasingly hypoxic you have a time of useful consciousness of a few minutes they think after having checked through the flight data recorder that the cabin altitude was probably around 24 000 feet but after that time of user's consciousness you become incapacitated becoming conscious now in the cabin there are oxygen cylinders these oxygen cylinders are there to give therapeutic oxygen in case a passenger would need it and they have several hours for one person in those oxygen cylinders and there was shown after the crash that at least three of the four oxygen bottles on board had been used we don't know how many of the cabin crew were actually using them this was just one or several but there's no indication that the cabin crew tried to enter the cockpit prior to later on in the flight so right now the aircraft has reached 34 000 feet and the flight management computer is set up and programmed to fly its route towards athens so if the autopilot is engaged and they have been cleared to 34 000 feet the aircraft will gladly climb up there and then it will fly on autopilot its programmed route which is exactly what happens air traffic control in nicosia which is the air traffic control unit they were talking to is trying several times to call them up to six times within the next five six minutes after their last contact no one is answering so they're starting to suspect that there's a problem with the radio here but when the aircraft flies into the next airspace this hunch the fact that they might have a problem here is not properly communicated to the next air traffic control unit they mention it that they haven't gotten in contact with them and that they would like the next unit to tell them if they do get into contact with them but the proper protocol for turning over a loss of radio aircraft is not followed properly which means that the next controller doesn't realize that there is a problem and actually highlights the aircraft as blue as in we have it in contact and it continues to fly and it continues to fly past its top of descent several calls are being made no response from the flight crew the aircraft flies in follows the approach procedure but still at 34 000 feet flies past the airport and into the holding pattern as part of its missed approach procedure and it sits there at 34 000 feet now here air traffic control knows that something is wrong and they hit the button that will scramble two f-16 fighters that will intercept the aircraft so these fighters they fly up and they take a close look at the aircraft and what they can see is that this appears to be a person in the first officer seat slumped over the controls there's no person in the captain's seat and they can see in through the cabin that there are some passengers slumped over wearing their oxygen masks but the problem here is that now the aircraft has been sitting and it's been flying for about six holding circuits in the holding over athens airport at times zero eight forty eight two hours and forty one minutes off the take-off the fighters in the f-16 aircraft are looking in and they see that someone is entering the cockpit okay they can see that a person wearing a vest looks like a cabin crew uniform gets into the cockpit and sits down in the captain's chair now this at this point we also have cvr voice recordings because this is just the last 30 minutes of the flight and on the voice recordings you can hear that someone takes out the oxymasks and puts it on the problem is though at only two minutes later the left-hand engine flames out because of fuel starvation they are sitting there for hours when the left engine flames out the aircraft starts turning towards the dead engine it's turning towards the left and it's also starts to descend now only two minutes after that the right engine also flames out due to fuel starvation on the voice recorder you can hear a voice calling mayday mayday mayday unfortunately the radius would have been set to the previous controller many hours ago so that message did not come out needed would it probably have made any difference because the person that was at the controls was most likely one of the flight attendants who had a commercial pilot license a cpl but did not have a 737 type rating and it would have been impossible for him to been able to fly this aircraft nor on one engine and definitely not without any engine it would have been on battery power at this point he would have had to use manual reversion to fly the aircraft which makes it very very heavy so the fighters followed the aircraft down as it descended um the person in the cockpit waved to them and when they signaled to him to follow them down towards the airport he just gave up kind of pointed downwards indicating that they were going down now there were indications that there was input to the flight controls during the very last seconds of the flight where this person tried to level the aircraft out to to reduce the impact forces of the aircraft but to no avail the aircraft impacted hills outside of athens with a tremendous force that destroyed the aircraft and anyone on board so um a very very tragic accident um now the accident investigation once again i'd like you to read the summary of the investigation here in the um in the link that i have provided in the description of the video but but basically the investigation came with the following courses so the direct courses to the accident was the non-recognition of the faulty um setting of the presentation mode selector from outdo to manual okay that was the direct cause of the accident also the fact that it wasn't recognized neither during the pre-flight nor during the use of the pre-start checklist or in the after takeoff checklist the next direct course was the non-understanding and misidentification of the cabin altitude warning horn and that led to the flight continuing decline and then eventually leading to the incapacitation of the flight crew due to hypoxia contributing forces here was uh deficiencies in the operations and quality management of the airline the safety culture in the airline they had had several um audits where this was indicated the years before these accidents there was some problems in the management managerial team of the of of helios airways at the time also they were they pointed at the regulatory authorities the fact that they weren't strong enough to adequately evaluate the uh safety of the operators that had to report to them so that's um that's another contributing factor and also inadequate use and application of crm because at any given point during this accident if someone would have spoken up one of the flight crew was going down the wrong path that misunderstood the problem the other one is supposed to pick that up it's supposed to at least come with the suggestion that maybe this has something to do with the pressurization or at least monitor the systems for ongoing development of the failure this didn't happen also the cabin crew could have intervened they could have contacted the flight crew or tried to contact them or try to gain access to the cab to the cockpit at an earlier point before the aircraft ran out of fuel all of this is indicative of lack of training lack of procedures and lack of crm unfortunately there were also mentions in the final report about the ineffectiveness of the manufacturer in this case boeing to implement measures taken after similar accidents or incidents there had been problems with this warning system and the pressurization issues in the 737 before um and there needed to be changes to procedures or these procedures need to be adequately communicated to flight crews and that was also finding in the fund report and finally a contributing factor was the fact that the engineers had not switched the switch back from manual to auto as part of the maintenance procedure um that the cabin crew procedures had not really taken into account what happens if you have a subtle depressurization what happens if the flight crew doesn't respond in the way that you expect it to um and that comes down to crm training and crew training ultimately so that's it guys that's the reason i wanted to do this video was i wanted to point at the how important it is that we follow and apply the correct procedures that we understand the correct procedures and also that we have this you know the needed technical knowledge to be able to determine one fault from another fault even though the indications might be similar depending on the phase of flight this is really important right and we've learned a ton from this there's been changes to how the cockpit is made on the 737 we now have warning lights that indicates if it's a take-off config warning and a cabin altitude warning we have added checklist items the precision mode selector is now a single item on our checklist there is clear training about hypoxia what happens if you have a subtle incapacitation or a subtle depressurization of an aircraft for example cabin crew training cabin crew procedures what if they don't hear anything from the cockpit how do they proceed all of this has been improved after this accident and it's made the aviation world a safer place to be and that's the point i wanted to make that's it guys i hope that you liked this episode uh if you like this kind of content and make sure that you have subscribed to the channel and that you've highlighted the notification bell have an absolutely fantastic day wherever you are and i'll see you next time bye right guys i really hope that you liked that if you want more content like that more aviation content but then check this out i hope that you have subscribed to the channel and that you've highlighted the little notification belt see you inside of the mentor aviation app and have an absolutely fantastic day bye

Channel: Mentour Pilot

Views: 1,293,380

Keywords: Helios Airways 522, Helios Flight 522, Ghost plane, Aviation accident, Aviation incident, Fear of flying, fear of flight, Fear of flight help, Nervous flyer, Nervous flyer help, How to become a pilot, Boeing 737, Boeing 737 300, Boeing 737MAX, Airbus A320, Airbsu A380, Breaking news, Aviation news, Final accident report, Boeing 747, Flight training, cockpit video, Aviation documentary, flight video, aviation documentary, Mentour pilot, Mentour pilot documentary

Id: pebpaM-Zua0

Length: 32min 27sec (1947 seconds)

Published: Sat Oct 31 2020