Aircraft "Falling" - Emergency descend explained

hi everybody welcome back to mentor adult video podcasts I hope you're all doing great very welcome to all you new joiners to the channel it's always great to see you here so today we are going to be talking about rapid depressurization and emergency descent so this is the third video in my series about failure management within the aviation industry as always at the end make sure that you send in your questions and your suggestions about future content and what you thought about this video and also make sure that you share this video if you can on social media like Facebook Twitter or whatever you think that it would be appreciated because it's I really need to help to to kind of keep this channel growing and get more and more people involved and what we're going to be talking about so rapidly intersection what is it um well to keep it short I'm just going to explain a little bit about how things work so in order for people to be able to survive at higher altitudes we need to be able to breathe and you can do this in an aircraft in two different ways either you can be sitting with an oxygen mask breathing pressurized oxygen at higher altitude in order to to get the proper amount of oxygen into your blood or you could do what most modern airlines do which is to pressurize the air inside of the cabin in order to fix so that the pressure in the air inside the aircraft it's more or less the same as it would be on the surface it's not going to be exactly like on the surface but it's going to simulate it being at about seven or eight thousand feet so that's what we do that's what we do in an ordinary I know because it's you know is really hard to sit with an oxygen mask if you're going to be speaking to your wife or drinking a cup of coffee so this is by far the most easy way of of making me and have the environment habitable inside of an aircraft at 40,000 feet now the way that we do this is that we use pressurized air from the Indians to pump into the aircraft to fix that pressure at at the exact pressure that we want it to be and then we regulate how much air we're letting out of the aircraft to be in valve at the back of the aircraft called a delta valve and this system works great as long as the pressurization system is working well and as long as there is no big holes or any big ruptures in the aircraft structure from time to time there are failures with the pressurization system most of the time it has to do with the outflow valve functioning the way it should or one of the two controllers not working the way it should and most of the times it's perfectly fixable as with always you know I've been talking about this before we always have a redundant system so if one system failed the other system takes over and it's the same when it comes to the pressurization system controllers that's all but from time to time and I'm sure you've heard about this from time to time the system does fail or there is a catastrophic failure of the aircraft structure basically there's a hole somewhere or there's a door that blows out or something like that and if that happens we lose pressurization within the aircraft so what do we do first of all why is it important to do anything well like I've been saying before it's if the pressurization is lost very very quickly the pressure inside of the aircraft's can be designed as on the outside of the aircraft and if that happens people will be able to breathe but there will not be enough oxygen to to kind of fill you your bloodstream with you know the amount of oxygen that is needed and you will be suffering from hypoxia very quickly so how quickly does this happen well it differs with the altitude so if you're flying at about 40,000 feet you will have about 15 seconds before you will be rendered close to unconscious and not being able to do anything this time is called time of useful consciousness so forty thousand beats about fifteen seconds thirty five thousand feet about thirty seconds and then it increases the lower you gets around fifteen thousand feet you will have more than thirty minutes of time we lose consciousness so it's really really important if we would have a failure of the pressurization system to get down to lower altitudes as quickly as possible so what's the first thing that's going to happen well we in the cockpit have indications of the cabin altitude so we can see what the cabin altitude is doing and we know approximate where it's supposed to be we also can see the differential pressure which is the difference between the outside pressure and the inside pressure and this is something that we're monitoring regularly as we're climbing out we're looking at this every 10,000 feet we're climbing the making sure that thing is doing well and then we also have a system that is automatically controlling the pressurization so that if something will happen rapidly we would be warned about it so if we're sitting flying along as we do drinking a cup of coffee watching the beautiful views outside and then all of a sudden this system detects that the cabin altitude is rising and it's passing 10,000 feet 10,000 feet is important remember above 10,000 feet that's when people generally start having problems with hypoxia so at 10,000 feet there is a warning going off in the cockpit and it's a monotone warning a sound like Bam Bam Bam Bam continuously like that okay and the warnings might sound differently and different they're typed but they will all have a similar type of warning so whenever a pilot hears this while is or she is airborne there's the first thing to do there's only one thing to do and that is very very quickly get the oxygen mask on so we each have our own oxygen mask sitting on the side very readily be readily reachable and so whenever this warning goes off while we're airborne an important thing is to make sure that you get the oxygen mask on as quickly as possible because of that you know we're talking about 15 seconds it's very very little time you have in order to to get it on and get the oxygen selected 100% in order to get that precious oxygen company which practice this a lot in the simulator because in the simulator of course we can't simulate things like pain ear pain sinus pain thing but that will happen in the aircraft so of course if you ever had problems with sinuses if you've been in their craft you know that they can hurt very very badly the same thing can happen if you have a rapid depressurization because this will happen very quickly and you won't have time to kind of equalize the pressure as you used to so even if you don't have a cold it's very likely that you will feel a bit of pain another thing that might happen if we're talking about a rupture in the aircraft scheme for example is that if it's losing pressure very quickly it will also all the air will rush towards the opening and it will suck with it things like you know dust on the floor little grains sound things like that and I can very easily get into your eyes so all of this counted together and it can be a very very unpleasant experience okay so it's really important that we remember and seen our motoric memory that soon as you hear that warning first thing we do is put the masks on okay so that's the first thing whilst the masks are on the next thing is to establish communication between each other because it's really really hard communicate for these masks so generally we have intercom connected to our headsets and we can't really use in Tacoma this because it would be like to dart waiters trying to communicate with each other so we turn off the intercom can we switch over on our audio control panel which is the panel that controls our audio input we switch it over from boom to mask so that's the little microphone inside of the masks you've activated and we can start talking to each other so that's the first that's the second thing that we do establish crew communication now the next thing that we'll want to do is our memory items now remember I spoke to you about memory items in a previous podcast memory items are items of a non-normal checklist that needs to be actually quick the most of the time we we never need to do things very very quickly an aircraft you always have time to take a checklist up read exactly what you're supposed to do and why you're supposed to do it but there are a few occasions where we have to act quickly one of them is this so we want to try to now with molecular oxygen also we are now safe but we also want to make sure that the rest of the crew and the passengers are safe and this needs to be done fairly quickly which means we have memory items they are split between the captain and first officer so no matter who is panel fly and whose problem monitoring in this situation we will now divide our part into a captain part and first off support so the first officer goes immediately up to the pressurization panel which is located just above him or her on the overhead panel switches over the cancellation control from automatic to manual and then tries to close the outflow valve and the reason that he or she is doing this is because most of the time when we have pressurization problems it is because of that outflow valve opening and staying out by itself and it's a huge opening and can depressurize the aircraft very quickly so by doing this switching it from automatic to manual and then force closing elf about hopefully we can get regain control over the preservation system that's the priority here so obray the procession manuals the presentation selected over to manual Alphaville close and then evaluate situations the first ops will be looking up checking so that you know the pressurization system is doing what it's supposed to be doing and what he or she should be seeing at that point is a cabin descend okay it's supposed to if this action has sorted a problem out we now close the Alpha valve and the aircraft is supposed to start pressurized and when it pressurizes the cabin altitude goes down so if the and if the cabin is not descending it's actually staying the same or increasing in altitude then the problem has not been fixed it something else that's wrong this needs to be clearly communicated so the captain will generally ask do you have the cabin under control the first officer will look try to evaluate it and say yes it seems to be uncontrolled its descending or no I do not have the other control now the next step is fully dependent on whether or not you have control of because we want to try to avoid and avoid this of the Sun and emergence of the Sun is not something that you do lightly because it is a manoeuvre that we're going to scare the passengers it is also going to affect traffic around us so if we have traffic below for example our traffic on our sides they might be affected by the manoeuvre so we do not do an emergency descent unless we have a continuous problem with our pressurization and I want to stress this because in the simulator when this is being practiced then or normally practice together so you have a rapid depressurization and an ANOVA system but they do not have to come together if you have been to sort the problem out by closing the Alpha valve then there's no need for rapid difference they're afraid never see the Sun there might be a need for a descent anyway but on the more controlled forms ok so I want to make that point right now anyway in this scenario the first officer does not manage to sort the problem out so there's something else that is either keeping the alphabet open or there is some other rupture or open the war or something like that so the presentation is not normal then the captain will announce that we'll have to do an emergency descent then the memory items becomes goes from Rapid River Association which has now been done to emergency descent the first officer will then continue up and switch on the passenger oxygen the passenger oxygen should already be switched on in this case because that is automatically open that that's those masks that's falls out they open by themselves when the cabin altitude reaches around 13,000 feet but we do it anyway just to make sure that the Basques are actually down so that the passengers in the back have a chance to get our oxygen masks on the next thing is to switch the fasten seatbelts on that's also normally happen automatic when the system feels a rapid depressurization it will switch the belts on providing that the switch is in Auto however and we do it anyway to make sure that is on proceed down put the engine starts switches to continuous and then switch all of the lights on and the reason we're doing that is because we're now going to do a immerses Sun which means we've got to rapidly be descending we want to be able to to be as visible as possible for all aircraft around us then the first officer continues down onto the central pedestal where they switch the transponder over to our emergency cold and emergency cord on the transponder is 7700 a transponder is a little radio device that is sending out blips to the radar for the air traffic controllers and the air traffic controllers can see us as a little bit and depending what code we have they can identify us but whenever we switch it over to 7700 it lights up like a Christmas tree and the air traffic controllers can now see that someone is school the emergency and that won't give their full attention to that aircraft so once that is done the first officer will of course go up and communicate with ATC so they will say whatever the callsign is Mayday Mayday Mayday callsign wrap we have an emergency descent and we are descending to 10,000 feet Ward MSA if you're over a really high mountainous terrain you can't descend up to 10,000 feet so you might have to send to 12,000 feet or 13,000 feet you'd have your flight plan and flight plan generally the safety heights stated but you should have an okay situational awareness about where you are anyway so if you are over the Alps you know that you're gonna have to be careful with this ending but if you are over Germany somewhere you know only another side done 10,000 feet would generally be a safe altitude to the center so state that we can see and last ask for qnh local qh is the pressurization setting which is on the ground and we set that in order to make sure that the aircraft is descending down to ten thousand feet above the ground and not flight level 100 which might be more than two thousand feet of the ground we always set qnet once we have obtained the local community who set it on both sides and we continue our descent then the first officer is going for the qrh checklist start reading the checklist out loud so that the captain can listen to what's going on and actually in the rapid depressurization first and then once that's done into the emergency descent and proceeding with the checklist as far as possible he or she is also calling out every 10,000 feet descending and 2,000 feet to go to a level of 1,000 feet to go to a level of alright so that's the first officers job at this point we're doing all these things the first things are done fairly quickly and then the reading of the checklist is done while we're descending now but as of now we haven't started or descend yet because the captain is the one who is going to fly the aircraft so when the when he or she has announced that we're going to do a nice descent you see automatically the captain automatically becomes pilot of flying and does the actual manoeuvre the first thing that usually does before doing anything else it's going on to the PA system and calling out emergency descent ready to descend emergency descent three times the reason for this is that the cabin crew is supposed to react they probably reacted already because the masks dropping and soft but when they hear this means that they will be sitting down wherever they are there is a spare mask in each of the rows on each of the sides of the roads there's a spare mask they will take that mask so that they also get oxygen during the emergency descent maneuver so it's really really crucial that that call is being made the next thing to do is the captain will go up to his mode control panel which is what's controlling the outer outer planet which is up on top of the dashboard and they will point the altitude down they don't have to set it exactly just wind it down a couple of times we keep the autopilot engaged they will go the plus level change they would speed up normally speed up to our maximum speed which is close to 340 not so Mackay point 82 unless we have an idea that we think that there might be something structurally wrong with the aircraft if there's something in rehab we have heard a bang and we feel vibrations and stuff like that then we won't increase the speed just maintain the speed but if we don't think so if there's no indications of it put the speed up and the reason for that is but within level change the aircraft we want to try to achieve that speed by lowering the nose so when level change if you bring the speed back it's going to descend faster so find it down level change possibly speed up and then we go down to our central pedestal and we close the trust levers and we bring the speed break up to the flight intern position okay by doing that in this order we don't have to stress it but you do it fairly expeditiously the aircraft is now descending as quickly as possible okay then once this is done then we go up and we fine-tune the mCP which means that we're now setting 10,000 feet or the MSA whichever is higher we bring the speed back to what we have and were also and I've got the nationís in beginning we're contemplating a turn and a turn would do normally we turn 45 degrees left of white if we're on an airway and the reason for that is that we want to try to avoid any trip traffic that might be located on us if we're on a direct routing which means that the ATC has told us to go not following these Airways that I we have been filed up but we're going direct to a point then it might not be an idea to turn but generally speaking most airlines as a procedure to turn 45 degrees left to right and having to see that they're doing so so we're now descending quickly where we're turning off looking outside for traffic cause we want void flying to anyone else because this is another Avenue it hasn't been cleared by ATC something we'd do in order to get down into breathable air as quickly as possible it's an emergency maneuver as we're now descending the first officer the captain is listening to the first officer doing memory items making sure as well that we're not none of us is becoming incapacitated so we're checking out for each other looking everyone is doing what they're supposed to do and the captain is concentrating on flying the aircraft put the engine and the eyes only for entering cloud things like that while we're constantly communicating with each other to the best of our capacity when the captain here's two to go by the first officer we can start bringing back the speed bring back speed maybe something like 250 knots so which is the maximum speed below that 101 to go we're also lowering the speed break and while doing so the aircraft will now not descend as quickly we'll start to bring the nose up and do a nice level of at 10,000 feet when we level off we'll both look look up and we'll check what the cabin is doing the cabin is generally behind the aircraft because there's a bit of a leak rate but we'll evaluate if the cabin has actually reached 10,000 feet if it has them will continue to descend maybe down to nine 8,000 feet make sure that the cabin altitude is down below 10,000 feet okay once we are satisfied at the cabin altitudes below 10,000 feet then it's time to check if the air is breathable and the way that most airlines do this is the first sox2 strikes first so they will handle over whatever radio they have so they happen the telling case captain you have the radio I'm going to take your mask off and take the headset off again mask off check the air wait a little bit if they feel anything wrong with it they put the mask back on again if they feel that it's fine and is breathable done bringing the math back down switch the LD control panel back on - boom put the headset back on again and tell me captain that yeah it's fine I feel fine in which case the captain can do exactly the same so hand over the control to the first officer and radio take off the mask switch turret on the control panel and then they can stop communicating so at this point when the both of taking the masks often they realize everything is fine they want to complete what's left to check this to make sure that nothing has been forgotten and then the captain will let the first sauce maintain control and call number one to the flight deck in our company might be different calling different company but it will be something similar very important to make that call because that call in this particular situation means to the cabin crew that the air is breathable under they can take masks off and they can come forward into the forward galley to listen to the captain and await further instructions so when we do this in the scene the exercise is normally finished when you get to this point in reality it has just begun okay so the next thing that's going to happen is that the captain is going to talk to number one make sure that she is okay to the cruise okay and ask how is the status in the cabin very important to check this because they will be your eyes and ears in the cabin so they will be able to say you know if they've seen a hole in the cabinet there's a door missing do we have any injuries aboard the house people reacting and so on so you want to have a proper briefing with the cabin crew but what's going on how are they feeling so on because depending on what they say you might have to change your plan about how you forward so if we're going to this one this is this example here nothing really bad has happened so everyone is more or less okay there might be people complaining about airplanes and stuff but there's been no fatalities no no severe injuries so in that case the captain's alright I'm going to come back to you with the next brief remembering its nature intention time and special procedures they will happen later on because now we have to go in and we have to speak in the flight deck about how we are going to seed what are we going to do next so back into the flight deck inform the first ox about what's going on how's things going in the cabin so on and then we would start doing our procedure when it comes to decision making our lair lines have different modules of this we have something called PI OC which stands for what's the problem what kind of information do we have what kind options do we have we select the best option we execute it and then we continuously evaluated that's why it 4 PI OC so gather information that includes talking to the cabin clues taking weather for the airport around and disgusting what's best to do talk to ATC and then one who decided on where we want to go we can also go into our flight management computer or FM C and put long-range cruising because remember now we're down to 10,000 feet that we burn or fuel panel come out down there so we might not have as far of a range as we have before but we decide on an option and we once we have decided in lab we communicate we call the the person back again I will tell them so you're ready for an itch please please listen carefully I know that nature we've had a rabbit ear Association of emergency data centers you know intention is to go to this Airport here time we're looking at about 20 minutes into the land special procedures I want you to keep the cabin secure calm the passengers keep the scene as we get down onto the ground or something similar depending on how it works and and then I will make a PA to make sure you know to calm the passengers down let them know that everything is okay in the cockpit and that we're going to watch whichever airport that we have decided then as we're descending we can't descend as we normally do because normally we would sound with very high rates if you're doing that with an aircraft that doesn't have a functioning air conditioning system the cabin would descend at the same rate as the aircraft does so we might have to discern a bit slower in order to to make it feel more comfortable for people in the back and I'm basically just coming in doing a normal approach maneuver might be a good idea to have a look at pressurization system before you land make sure that the cabin is properly depressurized because depending on what fold it is you might need to actually manually depressurize it in order to be able to open the doors but generally also that just landing getting the emergency services to check the aircraft out and get the passengers off get any medical attention to anyone that might be feeling unwell and so on so from there on its its standard operating procedures but that's it that's how we do rapid depressurization versus isn't I'm just taking it straight over my my memory now so I might have been skipping in some small items but it gives you a little bit of a picture of how we're dealing with things so I hope you've enjoyed this as always make sure that you subscribe share this video with anyone you think might enjoy it and I'll see you next time thank you you

Channel: Mentour Pilot

Views: 152,584

Keywords: decompression, hypoxia, aircraft failure, aircraft, airplane, flight training, Flying, Airport, Airline (Industry), airliners, Boeing, Simulator, Microsoft Flight Simulator X (Video Game), Uncontrolled Decompression (Aircraft Accident Type), aircraft accident, pilot in command, captain, first officer, Landing, Airbus, Mentour, Mentour pilot, Boeing 737, How to fly, Fear of flight, bleeding from the ears, passengers bleeding, Jet Airways flight 697

Id: D7ECAgv-R48

Length: 28min 7sec (1687 seconds)

Published: Sat Oct 03 2015