5 ms·

Helo autorotation largely requires the momentum of the blades to keep going after engine failure (as well as the pitch and forward momentum). I don't think the

Helo autorotation largely requires the momentum of the blades to keep going after engine failure (as well as the pitch and forward momentum). I don't think the blades on small drones are heaby enough to store enough momentum for autorotation.

baddox 7y ago
More importantly, most drones cannot physically adjust the tilt of the rotor blades (which is called collective pitch control in helicopters). Helicopter autorotation requires rotors with a lot of angular momentum and usually an abrupt change in the collective pitch right before landing to turn that momentum into thrust and slow the helicopter down. There are RC aircraft with collective pitch controls, like most RC helicopters and even some multirotors. These RC aircraft generally can autorotate, as well as do things that are probably not practical for full-scale aircraft to do, like fly upside down. :) A collective pitch quadcopter flying upside down: https://youtu.be/MVL_Hf4ilLg?t=162 https://youtu.be/MVL_Hf4ilLg?t=162 An RC helicopter doing, well, all sorts of acrobatics that hardly make sense: https://youtu.be/KmPchrGW1TQ?t=48 https://youtu.be/KmPchrGW1TQ?t=48 An RC helicopter autorotating: https://youtu.be/bxQ5kwqiPN4?t=136 https://youtu.be/bxQ5kwqiPN4?t=136 (this one has an internal combustion engine, although that shouldn't make much of a difference for autorotation)
- cmurf 7y ago
  >that hardly make sense Just a guess: stronger strength to weight, and power to weight ratios, compared to the real thing. The tail rotor in particular appears to be quite a bit more powerful for the weight of the model than would be expected in a full size aircraft. And then also, these kinds of movements with a person inside? Haha! No!
  - baddox 7y ago
    Yeah, I've been pretty deep in the RC community, but what doesn't make sense to me is the physical skills of pilots like that! Handling orientation changes like that is insanely difficult. I practiced flying RC helis for a while in a simulator and even the basic orientation exercises are pretty challenging.

baddox 7y ago

More importantly, most drones cannot physically adjust the tilt of the rotor blades (which is called collective pitch control in helicopters). Helicopter autorotation requires rotors with a lot of angular momentum and usually an abrupt change in the collective pitch right before landing to turn that momentum into thrust and slow the helicopter down. There are RC aircraft with collective pitch controls, like most RC helicopters and even some multirotors. These RC aircraft generally can autorotate, as well as do things that are probably not practical for full-scale aircraft to do, like fly upside down. :) A collective pitch quadcopter flying upside down: https://youtu.be/MVL_Hf4ilLg?t=162 https://youtu.be/MVL_Hf4ilLg?t=162 An RC helicopter doing, well, all sorts of acrobatics that hardly make sense: https://youtu.be/KmPchrGW1TQ?t=48 https://youtu.be/KmPchrGW1TQ?t=48 An RC helicopter autorotating: https://youtu.be/bxQ5kwqiPN4?t=136 https://youtu.be/bxQ5kwqiPN4?t=136 (this one has an internal combustion engine, although that shouldn't make much of a difference for autorotation)

cmurf 7y ago
>that hardly make sense Just a guess: stronger strength to weight, and power to weight ratios, compared to the real thing. The tail rotor in particular appears to be quite a bit more powerful for the weight of the model than would be expected in a full size aircraft. And then also, these kinds of movements with a person inside? Haha! No!
- baddox 7y ago
  Yeah, I've been pretty deep in the RC community, but what doesn't make sense to me is the physical skills of pilots like that! Handling orientation changes like that is insanely difficult. I practiced flying RC helis for a while in a simulator and even the basic orientation exercises are pretty challenging.