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I've read that Gyroplanes are dangerous to beginners because if you get in trouble the instinct to pull back on the stick like a traditional aircraft can be fat

I've read that Gyroplanes are dangerous to beginners because if you get in trouble the instinct to pull back on the stick like a traditional aircraft can be fatal to gyro pilots. They have to un-learn one of the most basic skills they learned as pilots. Edit: I mean push on the stick. Sorry, had a brainfart. Good thing I'm not a pilot.

garaetjjte 6y ago
>in trouble the instinct to pull back on the stick like a traditional aircraft You mean push on stick? (that's what is done to avoid stall in normal aircrafts) Anyway, https://xkcd.com/1972/ https://xkcd.com/1972/
elihu 6y ago
That was alluded to in this old xkcd commic, though it doesn't go into the details: https://xkcd.com/1972/ https://xkcd.com/1972/ I kind of assumed that "the one thing you instinctively do to escape a stall" is to push forward on the stick. Some answeres here seem to confirm that: https://aviation.stackexchange.com/questions/49865/why-does-xkcd-say-that-autogyros-will-crash-if-the-pilot-reacts-to-a-stall-as-in https://aviation.stackexchange.com/questions/49865/why-does-...
- phkahler 6y ago
  The comic says it never stalls, but then says if it does you should not do the instinctive thing. ;-)
  - elihu 6y ago
    It says it crashes if you do the thing that you would do in a normal aircraft to prevent stalling. From the other discussion I linked, it sounds like the issue is that the rotor normally creates forward drag, and earlier designs have the engine/thrust propeller mounted pretty high. Pushing the stick forward causes the rotor to have less forward drag than it normally does, so the engine thrust effectively causes the whole craft to pitch forward. Which is sort of what you'd expect to happen when you push forward on the stick, but I guess it happens in a way that's hard/impossible to correct from.
    - taneq 6y ago
      The issue is that the drag is what spins the rotor, and the rotor's rotation is what makes your controls work. So when you get close to a stall, the rotor's already going slowly, and then you push forward and it slows even further. Now you have almost no control authority and the only major force acting on the aircraft is the thrust from the propeller, which pitches you rapidly forward. I'm not sure why (given sufficient altitude) you can't cut the engine and recover using autorotation the way a normal helicopter can, but I imagine it's pretty hard to do this in a normal helicopter too if you're falling upside-down.
    - Kiro 6y ago
      I still don't understand. If it can't stall why would you ever try to prevent stalling?
      - krisoft 6y ago
        It’s a reaction trained to fixed winged airplane pilots to the point where it becomes instinctual. If your airspeed is dropping low you push forward the stick. You don’t do it because you have run a fluid dynamics simulation which warned you about the approaching stall, but rather as a reflex to a set of sensory cues.
minieggs 6y ago
FWIW during my PPL pulling back during (un?)expected situations instinctually was very much discouraged. edit: this parent comments makes more sense if instead the author meant push on the stick, as another pointed out.
deleted 6y ago
[deleted]
Wistar 6y ago
Not sure about gyrocopters but fixed-wing pilots who later transition to, or add, a rotary wing license are intensely counseled to resist the baked-in urge to push the nose over to counteract a stall or imminent stall. In almost all single-rotor helicopters, pushing the nose over — fixed wing style — runs a high risk of causing the tailboom to rise and collide with the main rotor. The rare rigid rotor ships (BO-105s, mostly) are less likely to have this happen.
abeppu 6y ago
Should a lot of vehicles have fundamentally different controls now than when they were first invented? In particular, should we move away from controls which map onto how control surfaces or other physical parts move, and instead focus on controls that describe the desired motion? Quad-copters are pretty easy to fly, but they would be really really hard to fly if you were supposed to manage the thrust on each motor. I've never flown one, but I understand helicopters are challenging to fly, and controls do map onto actually actuating the swashplate and tail rotor. I don't understand how a gyroplane flies, or why pulling back on the stick causes immediate problems. But ... should autogyros have controls where you describe the motion you want, and let a computer figure out the actuation? I think there's an analogy to software here, where generally we're less error-prone and more productive if we can specify what we want by expressing higher-level, declarative relationships, rather than demanding that humans always think in terms of the low-level operations that will need to occur.
- tjohns 6y ago
  In aviation you want to avoid unnecessary complexity. You really want to avoid single points of failure. Most small aircraft are controlled via cables and pulleys because they're simple, can be redundant, easy to verify, and unlikely to fail. What's your backup plan when your flight control computer crashes? Or if you have an electrical failure? (There's an argument to have computers provide additional assistance on top of the manual systems, but we usually stop short of fundamentally remapping flight controls. And even then, we have to be careful otherwise we end up with situations like MCAS.)
  - taneq 6y ago
    I think what you really want to do in aviation (or anything safety-critical) is reduce risk of failure. Avoiding risk of mechanical failure at the expense of controllability is simply pushing the blame onto the pilot. The general approach for critical hardware like flight controllers is triple redundant systems with two-out-of-three voting, driving redundant actuators. MCAS is a prime example of this NOT being followed, because it relied on a single sensor input to generate a significant control output.
- 6y ago
rectang 6y ago
Here's a video of a Gyroplane "bunting over" or "pushing over" once the rotors become unloaded... the final impact is not shown but it's implied the pilot died: https://www.youtube.com/watch?v=CfjBzrSDrV0 https://www.youtube.com/watch?v=CfjBzrSDrV0 An explanation: https://www.kitplanes.com/gyroplane-safety/ https://www.kitplanes.com/gyroplane-safety/ > Fatal Sequence > As the rotor is unloaded, both control thrust and the drag of the rotor disc fall off rapidly. With a high engine thrustline (relative to the vertical c.g. and center of drag) and/or with a momentary gust that can increase fuselage drag, the gyro can pitch forward and tumble. Such tumbling, also known as bunting over, can occur almost instantly. There is no possible recovery, and bunting over is invariably fatal.
- taneq 6y ago
  From the description there, it seems like a simple "oh shit" lever to tilt the engine (or at least prop) upwards could fix this issue?
simonebrunozzi 6y ago
I'm not an expert, but yesterday I've heard from a pilot that most US gyros don't have a tail stabilizer (is that how it's called?), unlike the Magni models (Magni is a small Italian manufacturer of gyros), which don't have the problem you are describing. If there's an expert, I'd love to hear if what I just wrote is correct.
- foxyv 6y ago
  Since there is no torque on the rotor (Except for maybe the part the spins up the rotor before takeoff) there is no need for a tail rotor. Typically autogyros will have a rear elevator and rudder like a traditional airplane. Since most have a pusher propeller that gives you even more control in a low velocity takeoff or landing which is what gyros are good at. A good picture of this setup: https://en.wikipedia.org/wiki/Autogyro#/media/File:AutoGyro_Calidus_-_Shuttleworth_Season_Premiere_2016_(26422815634).jpg https://en.wikipedia.org/wiki/Autogyro#/media/File:AutoGyro_... Edit Addendum: Typically loss of control in a nose down situation for autogyros is because they don't have ailerons to control roll. They rely on the cyclic of the rotor disk.

garaetjjte 6y ago

>in trouble the instinct to pull back on the stick like a traditional aircraft You mean push on stick? (that's what is done to avoid stall in normal aircrafts) Anyway, https://xkcd.com/1972/ https://xkcd.com/1972/

elihu 6y ago

That was alluded to in this old xkcd commic, though it doesn't go into the details: https://xkcd.com/1972/ https://xkcd.com/1972/ I kind of assumed that "the one thing you instinctively do to escape a stall" is to push forward on the stick. Some answeres here seem to confirm that: https://aviation.stackexchange.com/questions/49865/why-does-xkcd-say-that-autogyros-will-crash-if-the-pilot-reacts-to-a-stall-as-in https://aviation.stackexchange.com/questions/49865/why-does-...

phkahler 6y ago
The comic says it never stalls, but then says if it does you should not do the instinctive thing. ;-)
- elihu 6y ago
  It says it crashes if you do the thing that you would do in a normal aircraft to prevent stalling. From the other discussion I linked, it sounds like the issue is that the rotor normally creates forward drag, and earlier designs have the engine/thrust propeller mounted pretty high. Pushing the stick forward causes the rotor to have less forward drag than it normally does, so the engine thrust effectively causes the whole craft to pitch forward. Which is sort of what you'd expect to happen when you push forward on the stick, but I guess it happens in a way that's hard/impossible to correct from.
  - taneq 6y ago
    The issue is that the drag is what spins the rotor, and the rotor's rotation is what makes your controls work. So when you get close to a stall, the rotor's already going slowly, and then you push forward and it slows even further. Now you have almost no control authority and the only major force acting on the aircraft is the thrust from the propeller, which pitches you rapidly forward. I'm not sure why (given sufficient altitude) you can't cut the engine and recover using autorotation the way a normal helicopter can, but I imagine it's pretty hard to do this in a normal helicopter too if you're falling upside-down.
  - Kiro 6y ago
    I still don't understand. If it can't stall why would you ever try to prevent stalling?
    - krisoft 6y ago
      It’s a reaction trained to fixed winged airplane pilots to the point where it becomes instinctual. If your airspeed is dropping low you push forward the stick. You don’t do it because you have run a fluid dynamics simulation which warned you about the approaching stall, but rather as a reflex to a set of sensory cues.

minieggs 6y ago

FWIW during my PPL pulling back during (un?)expected situations instinctually was very much discouraged. edit: this parent comments makes more sense if instead the author meant push on the stick, as another pointed out.

deleted 6y ago

[deleted]

Wistar 6y ago

Not sure about gyrocopters but fixed-wing pilots who later transition to, or add, a rotary wing license are intensely counseled to resist the baked-in urge to push the nose over to counteract a stall or imminent stall. In almost all single-rotor helicopters, pushing the nose over — fixed wing style — runs a high risk of causing the tailboom to rise and collide with the main rotor. The rare rigid rotor ships (BO-105s, mostly) are less likely to have this happen.

abeppu 6y ago

Should a lot of vehicles have fundamentally different controls now than when they were first invented? In particular, should we move away from controls which map onto how control surfaces or other physical parts move, and instead focus on controls that describe the desired motion? Quad-copters are pretty easy to fly, but they would be really really hard to fly if you were supposed to manage the thrust on each motor. I've never flown one, but I understand helicopters are challenging to fly, and controls do map onto actually actuating the swashplate and tail rotor. I don't understand how a gyroplane flies, or why pulling back on the stick causes immediate problems. But ... should autogyros have controls where you describe the motion you want, and let a computer figure out the actuation? I think there's an analogy to software here, where generally we're less error-prone and more productive if we can specify what we want by expressing higher-level, declarative relationships, rather than demanding that humans always think in terms of the low-level operations that will need to occur.

tjohns 6y ago
In aviation you want to avoid unnecessary complexity. You really want to avoid single points of failure. Most small aircraft are controlled via cables and pulleys because they're simple, can be redundant, easy to verify, and unlikely to fail. What's your backup plan when your flight control computer crashes? Or if you have an electrical failure? (There's an argument to have computers provide additional assistance on top of the manual systems, but we usually stop short of fundamentally remapping flight controls. And even then, we have to be careful otherwise we end up with situations like MCAS.)
- taneq 6y ago
  I think what you really want to do in aviation (or anything safety-critical) is reduce risk of failure. Avoiding risk of mechanical failure at the expense of controllability is simply pushing the blame onto the pilot. The general approach for critical hardware like flight controllers is triple redundant systems with two-out-of-three voting, driving redundant actuators. MCAS is a prime example of this NOT being followed, because it relied on a single sensor input to generate a significant control output.
6y ago

rectang 6y ago

Here's a video of a Gyroplane "bunting over" or "pushing over" once the rotors become unloaded... the final impact is not shown but it's implied the pilot died: https://www.youtube.com/watch?v=CfjBzrSDrV0 https://www.youtube.com/watch?v=CfjBzrSDrV0 An explanation: https://www.kitplanes.com/gyroplane-safety/ https://www.kitplanes.com/gyroplane-safety/ > Fatal Sequence > As the rotor is unloaded, both control thrust and the drag of the rotor disc fall off rapidly. With a high engine thrustline (relative to the vertical c.g. and center of drag) and/or with a momentary gust that can increase fuselage drag, the gyro can pitch forward and tumble. Such tumbling, also known as bunting over, can occur almost instantly. There is no possible recovery, and bunting over is invariably fatal.

taneq 6y ago
From the description there, it seems like a simple "oh shit" lever to tilt the engine (or at least prop) upwards could fix this issue?

simonebrunozzi 6y ago

I'm not an expert, but yesterday I've heard from a pilot that most US gyros don't have a tail stabilizer (is that how it's called?), unlike the Magni models (Magni is a small Italian manufacturer of gyros), which don't have the problem you are describing. If there's an expert, I'd love to hear if what I just wrote is correct.

foxyv 6y ago
Since there is no torque on the rotor (Except for maybe the part the spins up the rotor before takeoff) there is no need for a tail rotor. Typically autogyros will have a rear elevator and rudder like a traditional airplane. Since most have a pusher propeller that gives you even more control in a low velocity takeoff or landing which is what gyros are good at. A good picture of this setup: https://en.wikipedia.org/wiki/Autogyro#/media/File:AutoGyro_Calidus_-_Shuttleworth_Season_Premiere_2016_(26422815634).jpg https://en.wikipedia.org/wiki/Autogyro#/media/File:AutoGyro_... Edit Addendum: Typically loss of control in a nose down situation for autogyros is because they don't have ailerons to control roll. They rely on the cyclic of the rotor disk.