Why don’t modern airliners use tail-wheel?! (And why is it called taxiing?)

hi everybody welcome to mentor and general video podcast as always we'll be doing absolutely fantastic today on the video guys we're gonna be talking about no scare vs. tail drag why don't we see any tail drag modern airliners and also what does the word taxiing come from [Music] this video is brought to you in cooperation with brilliant now if you have found yourself just like I have during the last few months trying to homeschool your kids or trying to improve yourself well then I highly recommend you to go and check out brilliant you have more than 60 different courses in things like mathematical fundamentals or the physics of everyday or logic and what I've been doing lately is that my oldest son Lucas I tried to motivate him doing math and brilliant turns out to be really really effective in doing that so I'll put him in front of the logic course there's some brain-teasing kind of nuts to crack and he will keep working on them and when he comes up against something that he doesn't understand well then he can just click the explanation he get a really good explanation of how to think and then he'll be able to correct to kind of crack the next one which is really really motivating now those of you who uses this link here below will get a whopping 20% off the annual fee Oh brilliant but it's completely free to check it out so do that and let me know what you think [Music] alright guys so today I want to talk about tail drag which is the conventional landing gear against the no scare tricycle a configuration on aircraft so if you go back into the history you'll see that most older aircraft have the tail drag landing gear but the more modern they become the more we'll see the tricycle no scare configuration why is that well it turns out that it has a lot to do with the kind of runways that were in use and the way that aircraft was originally kind of utilized so if you go back to the birth of aviation and the first couple of decades of aviation the kind of runways that we use tend to be either big gravel fields or big grass fields okay when you were constructing an aircraft in order to fly on fields like that you wanted something sturdy and you also wanted something that gave a lot of clearance for the propeller it turns out that if you equip a aircraft with a tail drag the conventional landing gear principle where you have a big set of landing gear in front of the center of gravity and then you have a tiny little wheel or even just a drag hook at the end of the aircraft not only do you get a very sturdy kind of landing gear configuration that can take up a lot of potholes and a lot of uneven of uneven surfaces you also get a fairly light and easy it's constructed configuration because it's such a big distance between the center of gravity towards where the tail gear is you can make the tail wheel very very small and very lightweight all right so this is why you would see in the early versions of both smaller aircraft but also the early versions of airliners they will be using this principle you'd be taxiing out and here when you start to taxi on a conventional gear configuration with tail rag this is really where the problem start you need to have an enormous amount of skill as a pilot in order to taxi these aircraft in the first place because when you have the steering behind the center of gravity and the center of gravity behind this the main wheels what you get is a aircraft that on the ground is inherently unstable if you start to have the tail moving to the left or right instead of having kind of a stabilizing movement that you get on a nose gear you will have a destabilizing movement as in the more it moves the more it wants to move all right so this makes it really really hard to taxi the aircraft it also makes it really really hard to land especially when you're landing in CrossFit conditions because as you land with the crosswind and you have a run into the wind and the rudder becomes less and less effective as the speed decreases if you start to get any kind of movement of the tail it's very easy to end up with something called the ground loop which is where the that tail just come rushing from one side and it turns the whole aircraft 180 degrees around and if that happens that's very high speed well then the whole aircraft can kind of topple over the wing can dig into the ground and you can get some really bad damages to the aircraft and this happens quite often okay another problem you have is that you would obviously be breaking with the main landing gear and since you now not have a nose gear it means that if you brake suddenly very hard there is a potential of the aircraft to kind of just tip forward and bury your propeller or your nose into the ground ahead of you which is also happens quite a few occasions and here my friends is where we come to the origin of the word to taxi and aircraft because you think of it the two taxi an aircraft is what we say about aircraft that are moving on their own power on the ground but there are a lot of different vehicles out there who are moving by their own power on the ground a tractor is driving a truck is driving a car is driving but an aircraft is taxiing and why is that I've been digging into this and I found a really really compelling and interesting story the first time that you ever hear the word taxing about an aircraft movement on the ground is from back in 1911 where there was a French air school that's in a flight school that was using a very very peculiar type of aircraft to train its cadets now this aircraft was way too heavy and had way too small engine and actually had the wings configured so that it wouldn't take off but you could use it to practice to drive the aircraft on the ground so in the beginning of your flight training the cadets would get into this aircraft it would be driving out and then just drive up and down the airfield trying to make sure that it could handle this ground loop tendency and that it would be smooth on the brakes so they'll be just going up and down up and down now at 1911 seeing aircraft there was really something that's the general public like and the general public who was watching this happening they kind of laughed at this and I said listen look at that that looked like just one of these other new inventions the taxi mobile it looks like one of those taxi mobiles there are about two you know slowly going to pick up a new customer and drive it around so that's when they started to call this particular aircraft a taxi aircraft alright so it came from that people thought that it looked like someone was scouring for customers to pick up it it was also a fact that the cadets obviously were paying to be driving around on the ground and this is the origin of the word taxi and it came from the fact that tail drag aircraft or notoriously hard to maneuver on the ground fascinating a cool so as the these tail drag aircraft started developed they saw also that there were issues with for example maneuvering during strong crosswinds but recent I've already mentioned but also just taxing and strong winds was an issue because as you had fairly high inclination of the aircraft which gave an angle of attack effectively if there was very strong winds outside you could actually get a lot of lift being developed on one wing but maybe not the other and then the aircraft could have a tendency to start actually moving on the ground so because of all of this and because they wanted to start to get more forward visibility especially as there was more and more aircraft around on the ground they came up with the no scare configuration now the North kicker operation required a little bit more technology because it is less of distance between the the main gear and the nose gear the nose gear needed to take up a lot more weight which means that you have to have a nose gear struct for example so it became heavier but we did you also had much better for visibility you had much better much easier maneuvering on the ground it was easier to land and just generally easier to deal with so this is where you start seeing nose gear aircraft and nose wheel configuration undercarriage coming on you also see it on some of the earlier fighters that was flying on out of aircraft carriers because they had to land on a really really short distance on the carrier they noticed that you know there was a tendency otherwise to just get that head down motion so there were a lot of reasons for the nose gear sort of to appear but we have some airliners that have the tail drag and the carriage as well you look at the beautiful dc-3 for example it is flying with a tail gear configuration and it is an absolutely beautiful aircraft but if you've ever boarded one of those will come to one of the reasons why we don't see it in modern airliners and that is that it has a quite sharp incline seen you bore that from back obviously because you can't even reach up to the the front of it when it's standing on the ground and you're going to have to climb a fairly steep incline which is going to slow down boarding significantly if you had that on a modern airliner right so let's have a look now on modern airliners and whether or not we could actually have a modern airliner with a tail drag configuration so first of all when we are operating a modern airliner on the ground it's very important that we have good for visibility and that we have a low cockpit cutoff angle now a cockpit cutter bangle is the area behind the low the aircraft that the pilots cannot see because the nose is in the way and the higher of the angle we have on the aircraft the bigger this cockpit cutoff angle is so while we might not be able to see in the 77 maybe 15 meters ahead now if we would have a higher angle a higher incline as we're taxiing around on the ground it means that instead of having maybe 15 meters which we have today it would be maybe 18 meters right and this obviously would be a huge problem as we are you know taxing around on airport putting ourselves in a queue for example in order to get ready to take off so that's one thing the next thing which I think is really really important is that incline when you're standing by the gate like I've been saying already it would be hard to get the turnaround times if the passengers is going to be climbing up from one direction and possibly trying to call themselves going down the other direction but the main issue here is going to be the loading of cargo so in modern aircraft you load cargo either by a bulk which is individual items being thrown into different compartments in the in the holes or via container containers probably especially on the bigger airlines the most common thing and it's loaded in and then it's being pushed back using these kind of ball rails that wouldn't be possible in the same way if you had an incline in when you're standing at the gate you would need some kind of pulley system or some kind of thing that would pull or or hold the container sister were coming into place and it would be just a lot more potentially dangerous take a lot more time and be a lot heavier so that would be a clear downside of having a tail drag another thing is the jet blast so like we were saying when it comes to using taildraggers on propeller aircraft it's actually kind of a good thing because you have much more propeller clearance in most cases but the propeller works by taking a lot of air and kind of accelerating it a little bit backwards you don't really get that kind of jet blast from a propeller that you'd get from a jet aircraft so if you put jet engines on a tail dragger aircraft it means that that jet plus instead of being pointed straight backward it's now going to be pointed at an angle down to watch the ground and if you're trying to taxi a big heavy aircraft you have to use a little bit of trust these engines are extremely powerful those jet blasts are very powerful and it's very likely that those kind of jet blasts down into the asphalt is going to potentially damage the asphalt about the taxiways and the aprons if they do they're gonna be throwing up pieces of rocks and stone onto the horizontal and the vertical stabilizer so that would not be a good idea at all and then we come to just how to build the aircraft so if you look at the modern airline today they tend to have these huge main landing gear and they are always in center of the aircraft very close to the center of gravity around wings okay so in most cases the landing gear actuator unit is actually incorporated into the wings and the landing gear gets folded up into the belly of the aircraft but if you are going to use a term drag it means that the landing gear is going to have to be more forward it's gonna be have to be forward of the center of gravity in order for this to work and it's gonna be from just a structural point of view from how to build an aircraft point of view it's gonna be very very tricky to do so those are some of the main reasons why we're not seeing and a tail drag modern aircraft and while we won't see any tail drag modern aircraft in any time soon guys if you have more questions like this things that you've been wondering but no aces or why an aircraft looks like that whatever then make sure that you send me a message either you put them in here in the comments below I try to read through them as much as I can or you contact me in the event radiation app just tag at mentor in the chat or in the forums and I'll be checking that out I really appreciate the feedback that I'm getting from you that's what I'm building this channel on if you want to support me and the work that I'm doing and all of these videos that I'm churning out consider joining my patreon crew right my patron crew they get to preview my videos they convert suggestions of what I should and shouldn't talk about they you know give their opinions on thumbnails and many other things I also do su meetings with them and if you are at the $10 per month level or up then you also get a free premium membership inside of the Metro variation app as a perk so go and check out patreon have a absolutely fantastic day wherever you are and I'll see you next time bye bye right guys I really hope that you like that if you wanted 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 highlighted little notification valve see you inside of the mentor every Asian up and have an absolutely fantastic day bye bye [Music]

Channel: Mentour Pilot

Views: 192,206

Keywords: Tail wheel, tail drag, tricycle gear, conventional landing gear, Boeing 737, mentour pilot 737 max, mentour pilot landing, mentour pilot take off, Boeing 737 MAX, Boeing 787, ground loop, nose dive, flight training, how to become a pilot, fear of flying, pilot training, pilot life, aviation facts, fun facts about aviation, did you know, taxiing, taxying aircraft, nervous flyer, nervous flyer help, aviation news, breaking news, Airbus 380, Boeing 777

Id: np12Qy6NU7E

Length: 16min 25sec (985 seconds)

Published: Fri Jun 05 2020