Unstabilized Aircraft approach - Explained!

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 we're gonna be talking about unstabilized approaches what are they what leads up to them how do we mitigate against them and towards the end we're gonna be looking at an accident an actual case study where unstabilized approach was one of the reasons why the aircraft ultimately crashed [Music] [Music] this video is brought to you in cooperation with my patron Cru the patron Cru all the ones that really supports the channel they helped me preview my videos they helped me to choose which thumbnails I should be using and which I shouldn't be that tell me if something is off and they provide financial support for the channel now if you are interested in joining the crew and taking part of these discussions then click the link up here and go in and see what it's all about thinking thank you slapping a bird switch to flopping in between you can put the Terrain inhibitors as well so guys unstabilized approaches being hot and high these are all things that you would have heard about in the media during the last few weeks and I felt that it's probably a good idea to explain what it is and what leads up to it and how we the pilots are actually trained to make sure that it doesn't happen in order to understand on established approaches you need to understand that the aircraft basically has three different forms of energy when it's flying you have potential energy that's the aircraft's altitude so the higher the aircraft climbs the more potential energy it has then you have kinetic energy kinetic energy has to do with the movement of an object so in the case of an aircraft as the aircraft accelerates which it does thus were climbing up higher and higher then the kinetic energy also increases and the third energy states is the chemic energy state IC and that's what we have in our tanks the fuel because the fuel has the potential to be converted into energy and that's what we're using in order to increase our potential and our kinetic energy so as we are cruising along at a cruising altitude we might be at 450 knots of true airspeed and around 38,000 feet that's when we have the maximum amount of energy now all of that energy needs to be taken away in one way or another until we get down and stop at the end of the runway so we do this in several different ways obviously when it comes to descending we need to be aware of these energy states because you need to know how far away from your airport you need to start to descend if you start to descend too late it means that you're going to be too high when you're getting close to the airport this has been the case in some case and it has led to high energy rotor so we'll get to that in a second so the way that we calculate when to start a descent is using our onboard computer most of the time our FMC so the FMC knows how heavy the aircraft is obviously that's gonna have an impact on the overall energy state of the aircraft the heavier the more energy we have it knows how fast we're flying it also knows what winds that we are likely to encounter during the descent because in our pre briefing material we will have gotten a wind short and as part of our preparation for the descent we would sit and we would put the descend Vin's in at at least three different altitudes during our descend and based on all of this plus temperature outside pressure outside and all of the different parameters that we get through our different probes it will calculate the most efficient descent right so most of the case is just a matter of us seeing where the top of descent is prior to that we ask air traffic control for descent clearance hopefully we'll get it and then we will just descend according to what air traffic control is telling us but there are potential faults in here there are potential things that can happen that can influence this so for example we tend to program the FMC with an anticipated arrival route so this tends to be the standard arrival route the star that comes in to an airport but in some circumstances air traffic control might elect for efficiency for example to give us shortcuts right so quite a bit of the pre descent planning goes into discussing between the pilot what are not we anticipating to get any shortcuts and if we are then we need to reflect that in the FMC either by putting in an altitude restriction that enables the aircraft to take the shortcut or by just taking part of the route away because we know from experience of that Airport that we're never going to fly it in that case you also know how to put it back in if we would need to right but sometimes we still kind of get a surprise shortcut and the problem with that is that if we have this if we have calculated with a much longer route then the aircraft thinks that it has much more time to dissipate the potential energy the altitude and if it doesn't get that route if it doesn't get those track mouths well then the energy state is going to be too high and if we accept that shortcut in that case when we get closer to the approach we're gonna be way too high in order to just get down because the across you can't just push a button and have the aircraft descending down to the altitude you need to think energy and in the case of the 737-800 that I fly it is a really really aerodynamically efficient aircraft so it just does not descend and decelerate well at this both at the same time you need to kind of plan pre-planned where you can do this so this is one of the I would say one of the biggest reasons that aircraft ends up hot and high that is because air traffic control will offer a shortcut to the flight crew flight crew will take that shortcut without thinking and then you will end up much higher as you're trying to intercept the glide slope later on ok now the way to mitigate against this is a being aware of it so that you pre plan for it be turning down the shortcut if you see that you can't make it you know air traffic control are trying to help by giving shortcuts but sometimes it is not helpful like in this case for example in that case the only thing you need to do is flight crew is tell them negative would like to continue on the planned arrival route or can we get a few more track miles an air traffic control always knows what that means and they would always comply if you can't do that you'll have to tell that of control listen can we go in to this fix and do one turn in a holding pattern perfectly okay alright it does not matter why you want to do this air traffic control will make sure that it happens alright so never feel forced to take a shortcut and then start to chase because that will bring us into the next problem here and that has to do with pilot workload alright so if you get one of these shortcuts and you accept it and you start realizing that you are a thousand or two thousand feet high and profile be able to see that normally on our veena pause display which tells us that if you do this you're gonna be really really high well then you're gonna need to start doing things you can for example use your speed break you can also use you can also slow down and start taking flaps because remember the flaps have speed restrictions too all right you cannot take flaps at every given speed and if we're coming in that's 280 knots for example then we're not allowed to take any flaps which means we can't get that extra drag out so that means that you need to slow down first but of course remember the different energy states if you take away the kinetic energy which is what you're doing when you slow down well in that case you would probably have to increase your potential energy because you're not destroying any energy here you're just changing in between them in order to destroy energy you need to add drag and that's what we're trying to do when we're extending flaps so you see your high bring the speed back this will just make you higher now because the aircraft will not descend and decelerate at the same time it will go cut almost level and then the speed will come rushing off as you're sitting with the closed thrust levers maintaining the altitude the speed comes down and as it comes down below the limit speed you can start taking flaps and as you do so now you're adding drag now you're actually destroying energy okay but now you are ending up even higher than that and if you have too little track months to go until you're supposed to get stabilized on the approach you might not be able to make it so once again here's the time to tell air-traffic control that you need more track mouth all right nothing wrong with that so now you're sitting here you can use speed breaks together with flaps down to in the 77 to flaps 10 above elapsed and you're not allowed to use speed breaks anymore right there's too much air that's gonna separate over the the trailing edge flaps if you do so there's gonna be too much buffeting it's not safe so we don't do that but you also have the landing gear the landing gear is not designed to be used at the speed break but if you are below the safe speed and you do extend the landing gear it will provide you with an enormous amount of drag all right so that can be used in certain circumstances but generally what we are teaching is that if you find yourself in a situation where you need to take the gear especially lower down closer to your stabilized criteria altitude which is a thousand feet and 500 feet will get done a second if that's the case it's probably better just to ask for track miles rather than taking the gear because you're now coming into the zone where you can't start making some serious mistakes f as you're taking gear down now and flaps and reducing the speed your descent rate is going to increase quite a lot all right perfectly okay if you're far out but the closer you get to the ground the less include that is and we were talking about workload since the pilot flying now is most likely solely kind of trying to chase the and the altitude getting down onto the profile his or her attention span is gonna go way way down the higher you are the more stressful it will become the more the pile of flying is going to try to do whatever he or she can to get the aircraft down all right pilot monitoring is likely going to do the same pallet monitoring it's gonna sit there and come try to calculate and see what's going on also talking to our traffic control and the workload for the crew goes up as the workload goes up some strange things happens to us humans right and one of the things is that with the stress is really high we stop hearing things we stop hearing warning sounds we stop hearing voices from air traffic controller even from our pilot monitoring so when you're deep down into the stress cone you might start doing things and not notice it noticing things that would be perfectly impossible to understand when you're listening to for example voice recordings how come that they didn't hear the stall warning or the too low flaps too low gear warnings and that's because the stress is down so high and they're so far down into the stress cone that hearing has disappeared now they only see and they only react to what they see right so this can happen if you drive yourself really far down into the stress cone and the way to mitigate against this is that someone need to come in and say stop all right you can be the part of line you can be the pilot monitoring in some cases can be a traffic control but it has to be down to the flight crew and at some point you need to say no not further I'm not going to continue this now in order to help pilots take these decisions we have put in force something called stabilized approach criteria okay sterilized approach criteria means I'm gonna get to the individual points very soon but at a certain point if we are in clouds as in IMC in instrument metrological conditions we need to be stabilized on the approach at a thousand feet above ground level if we are in VMC so visual metrological conditions we need to be stabilized at five hundred feet and these are the latest point we should be sterilized way outside of that but the point is that at these points the pilot monitoring has the ability to say go around right if we are not within these criteria and they are very very clear strict criteria you cannot continue prove you're not allowed to you have to go around and it's the palate monitoring job to verify this and say okay one thousand feet not stabilized go around and if the palate flying does not kind of listen to that the palate monitoring has the chance to actually either call a second time you have to call a second time but if you continue after that you could potentially take control as well however that's very rare so what are these criteria then well the aircraft needs to be on the correct flight path right this means that you need to be if you're flying an instrument landing system and I laughs you need to be within one dot localizer or glide slope reflection means that it's very very minimal flight path changes needed so in the example that we were given before if you're chasing from above and you haven't gotten down to your glide slope yet you're not stabilized right so you need to be pretty much where you're supposed to be you also need to make sure that you're at the correct speed because remember the different energy states so if you're on the ILS you're on the glide slope you've chased it down you're on it but your speed is way too high you're still not stabilized you're sitting with the thrust levers closed you probably have not been able to achieve the is the configuration that you need with flaps and gear and so on so you're not stabilized and the speed window that we have that we're allowed to be is between V Ref which is the reference approach speed to the rap plus 15 up to a maximum of VF plus 20 right you have 20 knots that you need to be inside if you're not you're not stabilized you go around the next thing that you need to make sure that you have is your configuration being correct this means the gear down the flaps where they're supposed to be the stablish criteria they need to be at the landing flaps so at the thousand feet IMC you have flaps 30 or flaps 14 depending on what you're going to do on the same at 500 feet VMC all right and the way obviously to know that your is that your check list needs to be complete the only point that can be missing from the landing checklist at this point is the landing clearance because the landing clearance can come later on especially if you're coming into a busy airport like London Heathrow or Los Angeles or something like that so landing checklist complete all the way down to clear to land basically also your descent rate needs to be correct this means that you cannot be sitting with 1500 2000 feet in recent rate you shouldn't be sitting with 200 feet mint descent rate either all in ILS 3° glides you should be around 750 feet a minute okay if you're more than a thousand feet per minute it needs to be in pre-brief because there are some approaches which are steeper because of surrounding terrain for example in that case you can have a final descent rate of more than 1000 feet but it needs to be pre briefed right it cannot be something you're sitting on a normal eye less and you have a really high descent rate because you could be on a faulty glide slope there are different ILS lobes I say in the way that the glide slope works is that you have two different frequencies that intersect with each other and when they intersect perfectly you know you're on the right glide okay but the problem with these radio lows is that they reproduce several times so you have lobes at 3 degrees 6 degrees 9 degrees and so on if you're on if you have been chasing the part from above there is a possibility that you might latch on to an incorrect ILS law and the way one of the ways to find that out is that you might have an extra hi descent rate even though the it looks like we were perfectly on the glide okay so that's another thing now the last thing is that you need to have appropriate trust for the configuration you have right so why they say appropriate trust is because that differs with your weight so for example if you have flaps forty on a 60-ton 737 you should be about sixty percent than one if you have flaps 30 on sixty tone aircraft it's about three percent less about fifty seven something like that and it follows the weight quite closely so that means that if you're flying an almost empty aircraft you can be as low as 48 49 it's not like that would be perfectly possible to do and the reason we're saying that is because if you have once again come in really hot and high you might be sitting with thrust up as closed okay and it takes a while even from a pro title where the idle under engines a little bit higher than normal it still takes a while for the trust to kind of spool up and give you full go or on trust if you need it so if you're sitting dead sticking as we call it trust completely closed well then you are not in the safe zone you should be sitting and approach trust so if you need to go around add thrust and the aircraft responds almost immediately to it all right so all of these criteria have to be fulfilled right if any single one of these criteria is not fulfilled the pilot monitoring calls go around you execute to go around and no one will ever blame you that's another thing that you need to understand about the airline world you're never blamed for a go-around you might have to write a report about it if it's below a certain altitude but that's more for statistical purposes to know and also to track does this happen often at one particular Airport well then maybe there's something weird the airspace so the airport that needs to be sorted out but you as a crew will never be blamed for doing and go around under any circumstance right under no circumstance a go-around is in 99% of the cases the absolute safest thing to do all right so remember that if you feel weird something looked looks odd if you have a warning if you have a failure if you why not just feel a bit off you go around sort out to go around you have more time you can sort out whatever problem you have and you can come in and do a perfectly safe approach on the second attempt okay now we touched a little bit on emergencies here and in most cases where you see really severe mistakes being made it is because something in the aircraft is not working it might be a technical issue or it might be something that the flight crew has done you know which has caused a technical issue and in any case a technical malfunction on approach if you're coming in hot and high takes away even further the ability of the crew to take rational decisions because some of the attention is going to be trying to figure out what a fault is and do something about it and this is yet another reason what you have to go around okay you need that time to go through the non normal checklist to make sure that that issue is solved and then come in and do a landing you don't want to sit on approach especially if you're hot and high trying to deal with something because then you might miss something else and this brings us to today's case study now the video that you're about to see it's an animation coming from the final report of the National Transportation Safety Board NTSB in the United States and it will reenact the last couple of minutes of flight 82 84 of Empire Airlines it's an ATR 42 flown in to Lobeck International Airport it's very early in the morning 0 for 30 local time it's in freezing fog the pilot flying is the first officer she has about 2100 hours a total time in about 130 hours on the type and the captain has about 14,000 hours and about 1900 hours on type so let's have a look and see what happens here now as the video starts here we are about 1500 feet above ground flying about 160 knots of airspeed the trust is that normal stage for this stage of flight there is no flaps out okay there just received a clearance Landen runway so at this point everything looks fine as you can see the speed is sitting more or less stable at about 160 knots where it should be and now we're asking for gear down and flaps 15 and as you can see on the right side of the screen there it's only the left flap that comes out not the right so you have some kind of technical malfunction here a call they're asking for landing checklists and they're referring to something called glide slope star here which is likely the glide slope indication on the primary flight display at this point you can tell that the crew is starting to feel a little bit uneasy about something this is an altitude alert and the first officer is asking what's going on here captain is trying to figure out what's going on and as you can see the airspeed is now crept down almost 20 knots or 25 knots from where we were in the beginning but the flaps has not changed so this means they're coming closer to a stall now depositing a thousand feet so this is where they're in IMC they should go around if they're not happy with the situation the flaps are not out and now they're getting into intermittent stall warnings as well the captain tells the first officer to fly the aircraft the first officer wants to go around and ask for it but the captain tells her to keep descending first officer clearly not happy with this and the captain takes over the controls struggles with the controls remember flaps are still not out now reduces thrust to idle pauses 500 feet and getting continuous stick shaker here now I have to remind you that the continuous stick shaking means and a stall escape maneuver no matter where it happens but here the captain sees the runway so start aiming for the runway instead continues to descend the speed is now down to 125 knots stick trick it comes on the aircraft comes into an aerodynamic stall and at this point the aircraft impacts the runway or impacts prior to the runway skids about 1000 M nature's ends up to the right of the runway and the aircraft catches fire right both crew members survived this incident with minor injuries the aircraft was completely written off and when the National Transportation Safety Board came out with a final report it said that the the likely causes of the crash was the air crews inability to monitor their instruments and realizing that you know that they were descending with too low speed to high descent rate and inability to follow the standard operating procedures which stipulated to go around in case of a unstabilized approach together with a few other items okay the air crew was continued to fly after this but they were changes to how airlines were practicing flight in icing conditions and re-emphasis on the stabilized approach criteria and the fact that you need to go around if you find yourself in an unstable ice approach no matter what the reason is right guys I hope you like these type of videos if you do consider subscribing to the channel and highlighting the notification bell make sure you highlight the all notifications because I do sometimes video spontaneously that might not come out on Fridays or I do live streams and I do interviews with other pilots and if you have the little notification bell on that means that you will get a notification whenever I do this okay a huge thank you once again to my patreon crew if you're interested in joining my patron crew there are links here basically patreon.com slash mentor pilot queen check it out and see if it's something for you have an absolutely fantastic day and I'll see you next time bye bye right guys I really hope that you like that if you want more content like that more radiation content but then check this out I hope that you have subscribed to the channel and that you've highlights little notification valve see you inside of the mentor evasion app and have an absolutely fantastic day bye-bye [Music] [Applause] [Music]

Channel: Mentour Pilot

Views: 168,139

Keywords: Unstabilized, Aircraft to high, Breaking aviation news, aviation news, unstabilized approach, unstabilised approach, Boeing 737, Airbus 320, breaking news, Boeing 737MAX, Mentour pilot, Mentour pilot B737, Nervous flyer, Nervous flyer help, nervous flyer tips, aviation explained, ILS, Aircraft too high, False glideslope, Flight school, aviation training, pilot life, pilot training, Boeing 747, Boeing 787, Airbus 380, Airbus 350, Aviation youtuber, Airplane approach

Id: ZiNHsukIkCg

Length: 25min 36sec (1536 seconds)

Published: Fri May 29 2020