As an helicopter professional, I very liked your video. And loved the uranus joke :) Some contributions: - Autogyros are one of the most immune aircraft to engine failure. They have superiority to helicopters in engine-failure since they always fly (and designed to fly) in autorotation. Therefore, pilot doesn't need to do much when engine fails, whereas helicopter pilots have few seconds to lower the collective and put the helicopter into auto-rotation mode. So, they are very safe, if not the safest, for general aviation. Lack of hovering ability and lower performance that is why they are not very common for other purposes. - V22 can do autrotation technically but since the blades are much shorter, the descend rate would be much higher than that of a single main rotor helicopter. In fact, there is a term called "autorotation index" which is used in comparing autorotation performances of different rotors, which indicates that longer blades are better in auto-rotation. So V22 is not practical (meaning survivable) to autorotate, they are better off with gliding. Worth also mentioning that they have two engines and have less probability to loose both. - Autorotation is as effective as a parachute but still happens at a high descend rate (still survivable but risky) so pilots do one final thing named as flare, which is basically to raise the collective in exchange of the rotor rpm (lift creates drag). This slows down rotor but gives some moments of increased lift that further slows down the rate of descend. Edit:Typos
The funny thing is V-22 is also sucks for glide. It has smaller wing area and A/R ratios compared to normal fixed wing aircraft (because a larger wing area will blocked the downwash of rotor and causing the loss in the rotors' effective thrust, which you might already know.) And even worse, the huge rotors will obviously creating terrible drag when they're autorotating, it will make the glide ratio even worse. So V-22 is sucked when engine failure, because it can neither perform autorotation nor glide effectively.
Correct me if I'm wrong, but wasn't that what held up the Osprey's so much during testing? Not only can they not auto-rotate (safely), nor glide (well), but they also lack any sort of ejection system for the crew (due to the nature of the design). I imagine losing one engine would play havoc on your yaw control with all that torque on one side while struggling to produce enough lift from the edge of one wing - like trying to lift a barbell from one side!
A "glider" is just a spaceship engaging retro rockets in a low gravity environment. Rotors and wings are just environmental sensing equipment, and shouldn't be considered part of the physics package.
@@cabezadepija7318 not fake scientist, but people should remember that no "Expert" is an oracle with knowledge of everything. Ask him about his specific field, and even in that field there will be experts who disagree with each other. People should stop treating celebrities like gods.
The highest autorotation was performed at an altitude of 40,814 feet (12,440 meters) while also setting the highest flight record of a helicopter. At that altitude, the Aérospatiale SA 315B Lama (the helicopter used for this record), piloted by French aviator, Jean Boulet, had its engines flame out due to lack of oxygen.
that was one hell of a realization to make while so high in the air lmao. "oh shit, the engines gave out..." i know they likely kickstarted them again on the way down but still i bet some grey hairs were picked up on that mission
Ok this is actually hilarious... a "Boulet" in french literally means a cannonball. But calling someone a "Boulet" means they are an idiot. More precisely, it means they are a restraining factor, like having a cannonball attached to your foot.
@@Fantastic_Mr_Fox It can also mean to be head strong while never deviating from a path.... Like a cannonball once fired. It will stop inside a target or fly in a straight line until its out of energy... Kinda like how some people can't stop rushing at their problems in straight lines and smashing their heads on the wall until it crumbles instead of walking around it :D...
@@Captain_Cinnamon u seen the scott Manley video where he says Neil says u can't eject supersonic when we have already like he forgot supersonic flights aren't in lower atmosphere
Just a minor correction. Most autogyro craft can actually power the main rotor, however they generally don't have enough power to actually lift off purely by the power of the engine. The engine just serves to get the main rotor spinning fast enough so that the autogyro can actually take off within a reasonable distance, at which point it disengages from the main rotor and strictly powers the pusher and/or puller prop
@@NotWhatYouThink actually you should correct the first sentence to this shouldnt not happen. there where at least four crashes of civilian helicopter because of failing emergency systems.
“Why don’t helicopters land like a rock when the engine dies?” Well, they’re perfectly capable of landing like a rock, it just depends on how the pilot handles the situation.
I have to think the discrepancy between more crashes per 100k hours and fewer deaths per 100k hours is just down to helicopters not carrying as many people as airplanes.
He still makes a good point about the altitude and use cases of helicopters. I'd be very interested to see the statistics for survival rate by "altitude of engine loss" between the different types of aircraft. I'd still think airplanes are safer, but I've never seen the evidence, or really thought about it this way before.
@@usopenplayer Airplanes are way more dangerous at low altitude. They move much faster and the space requirement for a safe landing is much higher. But that's kind of like saying a bow is bad in a bar fight. It's actually a great weapon if used in the correct environment. Normal cruising altitude for airplanes (even general aviation airplanes) is high enough to give you several minutes to react to any problems and find a safe landing area. Commercial jets usually have several airports they can glide to if a problem happens. In fact I don't think it makes much sense to compare airplane and helicopters at all. Your alternative to helicopters is unlikely to be an airplane, but rather walking or climbing. You can't exactly fix a powerline from an Airbus and you're not flying across oceans in a Robinson.
@@djinn666Exactly. You’ve summarized the apples to oranges comparison here wonderfully. Stellar video though, I was hooked by how informative it was throughout. Gonna smash that subscribe button.
The quality of this channel's output has suddenly become exceptional! This was one of the most informative videos I've seen recently - superb! Please keep up this standard. Excellent!
V22 can't autorotate due to how short the propellers are in relation to the aircraft size, but they do share a drive shaft so in the event one engine fails the other engine can provide enough power for landing
I think you neglected to mention that part of an autorotation landing procedure is to "flare" just above the ground in order to soften the landing. This is usually accomplished by "aft cyclic" which means varying the blade pitch at the portion of its arc that causes the helicopter to tip back. In effect, use the fall to turn the blades, then in the final moments use the turning blades to slow the fall.
Hello Sir, This video was absolutely fantastic. I am a fixed wing pilot with multiple type ratings - single engine, multiple engine, turbine engine, Instrument rating, Commercial, CFI, and added the ATP a couple of yeas ago amassing a few thousand hours. I have always been fascinated by helicopters and finally got the rating last year. This video explains perfectly the wonder of autorotation. I have tried explaining this to others for years with no luck in their understanding the procedure. Your video will now make that so much easier. By the way - your English is simply excellent as well! I am now also a subscriber. All the very best to you and yours, Terry
My friend is a professional RC(Radio control) helicopter pilot, he uses a lot of autorotation in order to land because the thrust-to-weight ratio is exceptionally high so when the throttle is cut they can lower that ratio.
I like the part of RC vehicles comparing to a real ones. I drift with RC cars without crashing, but still not allowed to compete in a real track. I also fly RC helicopters, but nobody gives me license. Just their drivability isn't the same.
@@JustArmandsI think learning helicopters thru Rc is great to get and idea before learning to fly them. Same with learning to do a 360 drift in GTA and applying steering wheel and brake control to a real car. It's all to get an idea. Its how I started practising 360 drifts, then applied to open road practise, and I secceeded. ^_^
However, rc drifting is wack compared to videogames and real life. Rc cars have wayyy too central center of gravity compared to a generic front engine rwd car. Especially with plastic wheels and 4wd open diff rc car drivetrain.
Sounds like a 3D "stunt" copter. They may be the hardest flying machines in the world to master. And you might as well treat a large one like a real helicopter as they have plenty enough power to severely injure.
Out of curiosity, does that fatality figure account for the number of people onboard the helicopter/plane? I just wonder if the helicopter death figure is lowered because each fatal crash will only result in one or two deaths on average. I know that most fixed wing crashes will also be single seat or other small planes, but I imagine the average would be brought up by the occasional commercial crash of 100 or 200 people.
Mortality figures related to modes of transportation are routinely quoted in miles per person per hour(2) For example, an airplane with 100 people on board travels 1000 miles in 2 hours That’s 50,000 man miles per hour Whereas you spend two hours solo in a car our motorcycle going 60 mph you only logged 60 man-miles per hour The the best way to interpret this is death rates per trillion man miles Motorcycles come in at a whopping 200-ish Most commercial travel modes land somewhere between 4 to 12 and that includes trains, buses commercial airlines
People laughed at Douglass Adam's observation that flying is just a matter of falling and missing the ground, but that's more or less exactly what orbiting is.
The problem is that you need forward velocity at low altitude for auto-rotation. So if you're hovering and you back up into a tree branch or a power line, that loss of a tail rotor is probably unrecoverable, and you pretty much will just spiral into the ground.
@@RamadaArtistdepends on the dead man’s curve for the helo. But at power line height, you have had plenty of time for pre spin and once you feel the change in yaw, cut the engine power to eliminate torque and thus the spin. You will still be able to maintain your drag coefficient of ~1.4 but might now be able to flare much during the landing.
this channel feels like those old science shows I used to watch on TV. just a simple explanations unlike the weirdness of most internet content around.
The ejection system on Ka-52s is a bit different of classics ejection seats . A rocket behind the seat is attached to the crew member harness with a cable . When it's fired, it breaks the canopy and then extracts the crewman from his seat . It's similar to the Yankee extraction system .
I get you but this competition needs weight classes or something. The tesla valve is just as impressive (to me) but less flashy. Coconuts leave helicopters in the dust, they're solar powered self-replicating colony ships and they've probably killed more people than helicopters.
@@KoenZyxYssel I specifically said mechanical systems. That means non biological like a coconut. Also a teslavalve is a very simple thing that could have been invented at least 100 times by now if tesla himself didn't invent it first.
Definitely mechanical systems in vehicles are extremely impressive, like internal combustion engines in cars or jet engines on airplanes or like a closed cycle combustion engine on a rocket
@@monkaeyes3417 I'll agree to disagree on both of those issues. The more abstract definition of "mechanical" makes more sense to me. I also doubt anyone would have come up with the tesla valve but I guess we'll never know.
By using the mass of the rotor (autorotation). The bigger and heavier the rotor the more "lift potential in the tank" this is why big helicopters rarely crash when having only a engine failure given they have some altitude at least. Edit: 4:34 this is why this pilot had to do such a abrupt landing, the rotor has barely enough mass to do a 1 second "power up" 5:38 you can see how the mi8 has enough mass to do a gentle landing.
Technically it has to do with moment of inertia. While rotor (& transmission & engine) mass play a role, the distribution of the mass make a noticible diffference too. For example, for two rotors, one is three-bladed and the other two-bladed (assuming same lift and mass), the three bladed rotor would have less moment of inertia than the two-bladed rotor, because the three-bladed rotor will have a smaller diameter. In this case, the two-bladed rotor will have better autorotation characteristics.
I've heard that the venerable Bell UH-1 Huey has enough mass and momentum in it's rotor (Blades are nearly 12 inches wide IIRC) to land and with the engine off, lift off, turn 180 and land again. In contrast, the 2 seater Robinson R22 that I trained on, the pilot must IMMEDIATELY lower collective in the event of an engine failure (The handbook says 2 seconds or less). Essentially the blades slow down while lifting the helicopter. With no engine to speed them back up and if you don't lower collective and flatten the blades so they're no longer lifting, they'll get to a point where the air from the falling helicopter will push them up and break them off. There is no recovering from essentially losing your wings. Game over.
@@Quizzicality the huey blade is so wide it's more then the size of the shoulder width for a man, it's 53cm, or 21 inches, about 9cm thick at the root.
@@nicholaslau3194 this is why I stated "the bigger and the heavier" Mi8 has 5 blades but it's so big and heavy it can "go up instead of down" using autorotation.
@@Quizzicality the huey and ah1 cobra had another problem for the "loosing your wings" and it was mast bumping, if you went into low or negative G the heli started rolling, if you happened to correct the roll before applying back cyclic or collective to load the rotor again it would literally break away and fly off while you crashed.
Your explanation of autorotation was somewhat simplified but the actual physics is rather complicated (and potentially rather heavily technical for a short RU-vid video), involving three zones in the rotor disc - The driven portion, the stalled portion, and the driving portion - these zones are essentially concentric and offset slightly to the side of the retreating blade.
@@NotWhatYouThink - Probably a wise move. You'd have your audience falling asleep before the end of the video. It is rather interesting, though and the really nice thing about an autogyro over a helicopter is that we don't really need to pay close attention to our rotor RPM once we have it up to speed and have taken off. More weight, they spin faster. Thinner air, they spin faster. As long as the rotors are loaded, they spin at whatever is necessary to provide the lift we need and to ensure that we keep them loaded, we NEVER pull low- (or negative-) G manoeuvres. Autogyros are widely underestimated as they are incredibly capable aircraft and handle wind and turbulence better than the majority of GA fixed-wing aircraft. We go flying on days where the wind conditions have grounded everything else at our airport. I get envious looks as I am out warming up my engine when the folk at the flying school are racing to get their Pipers and Cessnas tied down. We don't need a lot of wind to be able to perform a zero ground-speed hover. We have around 90% of the capability of a small heli at about 10% of the operating cost. In your comparison between fixed-wing and rotorcraft when you were talking about safety, I think you might have missed a key detail. Whilst we cannot "glide" as far as a fixed-wing, we can put down in much smaller spaces which gives us many more options for an emergency landing. If you ever get the opportunity to go for a ride in one, I highly recommend it. You will land with a grin so large that the top of your head will be in danger of falling off.
@@mastershooter64 - I've never seen one. I'll have a look, though. I learned about autorotation because I fly a gyrocopter (just in case that wasn't obvious from my channel). If I cannot find a lecture on autorotation, perhaps I should put one together and upload it.... although, that would be a huge investment in time.
@@mastershooter64 Helicopter Lessons in 10 minutes or less does a great brief video on autos, and there are certainly plenty of exhaustive videos on the subject
To anyone confused as to how auto rotation works, they change the angle of the blades so that it starts spinning as they fall and then right whenever they're about to hit the ground they change the angle to start thrusting downward
Basically like flaring the flaps at the end of a glide. Giving it an extra boost in lift at the cost of forward momentum you are trying to get rid of anyway.
You sound somewhat confused, yourself. "so that it starts spinning" seems to imply that the main rotor stopped turning so that cannot be what you meant, right? Similarly, "they change the angle to start thrusting downward" seems to show a lack of knowledge of basic physics as well as aerodynamics. That being said, it appears that you have a little bit of understanding so perhaps you simply worded your comment incorrectly.
@@Tom-zs6bb The video never really explained how the driven and lifting sections of the rotor disk work during autorotation. He just says altitude is exchanged for rotor speed. That's true, but probably leaves a lot of questions for people.
@@CompTechs " The video never really explained how the driven and lifting sections of the rotor disk work during autorotation." No it didn't, but other than you attempting to prove you know something about the three regions of the disk during autorotation, a discussion that lies well outside the scope of this video, that is completely irrelevant to both my comment and the comment to which I responded. My comment was a response to a commenter who chose to provide instruction while he himself has no idea what he's talking about.
Well, that has really decreased my anxiety to step in a helicopter. Because I really thought it would fall like a brick if the motors failed. Thanks for explaining!
Autorotation is also a valid approach. Eg in New Zealand some locations require a auto rotate to get into. I always found autorotations more like a plane landing. Eg maintain a constant glide speed then flare near the ground. I guess keeping the rotors in the rpm range is slightly different.
I learned about this as a kid, thanks to the Discovery store. Got into model rockets with Estes rockets from walmart. When the discovery store opened at our local mall, it had a whole model rocket section. Rockets with cameras, rockets with multiple engine compartments, rockets that were inches long, rockets that were 5 feet tall, rockets with weird recovery systems. My dad was nuclear navy. He brought home a box labeled "helicopter rocket" one day. He explained the entire thing to me. I didnt get it till he showed me a maple seed. It blew my 6 year old mind.
While in the 82d Airborne Division, I had the experience to be aboard a UH-1H, C model that autorotated in, just off Sicily North dropzone. I knew, I NEVER wanted to do that again! I'm 74 now, thanks to two fantastic pilots. While I was soiling my shorts, they were being professional.
The only thing id guess at (and id love to be given a lesson if im wrong because this stuff is interesting) is that a plane might be easier/ more intuative to someone new than a helicopter. Planes just make more sense to me in general. I have no idea how to fly anything, but if i had to choose between being stucking in a plane or helicoper alone with a dead pilot, id pick the plane. I understand the basic physics of both, but the helicopter seems like it would take more skill and experience to operate.
10:07 Actually, depending on the "aircraft's" weight it would not require a pilot's license. "If unpowered, weighs less than 155 pounds", and "If powered, weighs less than 254 pounds empty weight, excluding floats and safety devices which are intended for deployment in a potentially catastrophic situation", weight does not include the pilot.
I knew right away this was gonna be about autorotation. Back in HS physics, I did a lot of research on it for our Egg Drop project. My idea was to copy those helicopter seeds. The major problem was our initial build volume was extremely restricted so at first we tried to make an expanding blade but because no initial rotation was allowed, it never spun fast enough for t he blade to expand out. So we ended up with a smaller but very wide surface area helical blades. Lemme tell ya, we felt like kings when we "won" the project but it felt so much better when we let go of our vehicle and it fell like a feather. Our physics teacher was so proud. It did sting a little that second place was literally an egg stuffed in a jar of peanut butter...
It should be noted that, while indeed engine failure isn't very deadly for a helicopter, gearbox failure absolutely is. If that thing locks up those blades ain't spinning anymore.
I would have to say, helicopters would definitely have a bit more challenge to it. Ive flown a plane and it really isnt that hard lol, for me at least, but anyways, the only thing that had a bit of difficulty twords flying a plane was landing. A helicopter has a whole lot of attention to detail, like if you accidentally pull that yolk a bit to hard you can enter a roll and it could be really hard to pull out of it.
I flew in H60R for 6yrs as a SAR Swimmer. I couldn’t wait until my enlistment was over. Terrified every day. Pilots we’re wreck less and lots of close calls. Glad I survived🙏
As a helicopterpilot I met said: "Helicopters are machines fucking with physics to kill you and you have to fight it" And of course they crash more often in relation. Airplanes have the task to fly from airport A to airport B. Helicopters have the task to land between traffic lights, land on rooftops, get someone from the side of a mountain and standing completely still while someone jumps into the ocean. Also its far more complex to operate, because it can hover and from there turn or move in every direction. a plane just moves forward.
Helicopter auto-rotation after engine failure requires two things: 1) reverse / negative pitch in the rotor blades 2) disconnect /uncouple the rotor from the engine, so the blades can spin freely. This way, the spinning rotor blades will function as a parachute. Both 1) and 2) be done QUICKLY, before the rotor speed slows. As you get VERY close to the ground, gradually feed in positive pitch to brake the descent speed for a comparatively soft landing.
@@dougadams9419 nope you actually don't, the torque to the helicopter delivered by the blades is delivered through the engine of the vehicle as it works against the drag the blades experience. when autorotating this simply cannot happen as the blades are not driven by the engine and will simply just reduce RPM. basically, the rotation the tail rotor compensates for can only happen if the main rotor is currently a powered rotor and is why gyro copters don't need any sort of tail rotor to maintain yaw control as the lifting rotor is purely driven by external forces and is not rotated by the engine.
Neil deGrasse Tyson is wrong about quite a lot of things that he preeches. I'm glad you pointed this one out because the public really needs to reconsider their view on his knowledge as well as intelligence.
I had a phase where I was a huge nerd over gyrocopters, so I basically knew all of this. When a helicopter's engine fails, it basically just turns into a gyrocopter.
The autogyro thing was really interesting. I went to Ken Wallis's house (who invented them) when I was a kid, and he flew one he made in a demo. I had no idea the top wasn't powered, but I do remember him getting up speed to take off. He was in his 90s back then and was basically dive bombing in it, or sitting with both legs out the same side. Zero fear.
4:01, As far as i know, this is how small propeller type blades work but I think the larger ones on the helicopter work like an aircraft wing not directly blowing air down but creating a difference in air pressure like a wing on an aircraft does. I think the mechanism may be similar with the auto rotation. I'm not very familiar with the technical nomenclature so correct me if i'm wrong.
I used to purposefully turn off my engine in my helicopters as I approached the trader zone and try to autorotate land for fun back in the day. Lost so many hinds and angered teammates lol, I miss arma 2
Autorotation is only possible if it has considerable forward motion. A hovering helicopter whose engine suddenly fails does fall exactly like... a brick. It takes considerable altitude to convert falling straight down into a blade rotation that provides lift. Often when you're hovering, you are NOT a such a high altitude, because you are raising or lowering something from the ground, landing, or taking off. In that situation, you're fucked, as autorotation won't help very much. ***crunch*** Score one for NDT.
1:15 To be fair - the F-4 Phantom II has a glide ratio of 6:1, meaning it glides six feet for every foot it drops. A typical helicopter has a glide ratio of 3:1, but the major difference is the ability to control the pitch of the "wing" at the moment of landing - so you can achieve a softer landing by flaring more than a fixed wing aircraft.
Woah! Honestly my favourite video of yourse I've seen! I mean, all are very intresting, but this one was sooo informative :D Helicopters are even more beautiful than I previously knew, and now I'm inspired to do my homework that doesn't have anything to do with this ❤
Ground Resonance doesn't happen randomly. Ground resonance happens when tie downs on an aircraft are not installed properly. Meaning they are too tight. If ground resonance does happen randomly without tiedowns installed, that is an issue with the helicopter, as that is not supposed to happen naturally with the bird sitting on the ground.
regarding the safety stats: if you separate aviation types (commercial vs general aviation), then planes fall into two distinct categories 1: Commercial aviation - extremely safe, chances of being injured or killed in a crash almost nonexistent 2: General aviation - on par with riding a motorbike in terms of deaths/injuries Statistically, Helos are a LOT safer than GA, less so than commercial aviation
