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19 votes

Can quadrotors be used for commercial passenger flights?

The three most important factors in passenger air travel are safety, safety & safety. So that is where most of the questions will focus on, and where most of the engineering effort will be put ...
Koyovis's user avatar
  • 61.8k
18 votes

Can a passenger drone perform auto-rotation?

That drone has fixed-pitch rotors, and that pitch is optimized for thrust, not for autorotation. In the absence of power, those rotors won't autorotate. They will stop rotating 'in the right way' and ...
xxavier's user avatar
  • 11.1k
16 votes

Is possible to stick two '2-blade' propellers to get multi-blade propeller?

Sure, this is not only possible, but even has some advantages over single-plane propellers. The catch is you ideally want the two to spin in opposite directions to cancel out torque and vibration. You'...
TypeIA's user avatar
  • 14.4k
13 votes

What‘s the thrust of two stacked propellers?

There's a really interesting paper by Manikandan Ramasamy (Hover Performance Measurements Toward Understanding Aerodynamic Interference in Coaxial, Tandem, and Tilt Rotors, Journal of the American ...
Marius's user avatar
  • 3,671
12 votes

Is possible to stick two '2-blade' propellers to get multi-blade propeller?

It's done sometimes, for ultralight aircraft and paramotors. Like this:
xxavier's user avatar
  • 11.1k
11 votes

Can a passenger drone perform auto-rotation?

Simple answer. No. A drone with fixed wing propellers such as the one you describe can not autorotate. For autorotation to work the pitch of the blades needs to be variable. At the instant of engine ...
JensB's user avatar
  • 211
9 votes

Can I fly this six motor drone?

No, you may not fly this drone. It weighs much more than 55 lbs. At least in the United States, you have to have an FAA clearance and hold an FAA Part 107 Certificate to operate anything that heavy.
Grayson Bertaina's user avatar
8 votes

Can quadrotors be used for commercial passenger flights?

What are the advantages that quadrocopters have over conventional helicopters? Super cheap flight control achieved via electronic control of individual electric motors. (Basically, it means avoiding ...
Agent_L's user avatar
  • 1,392
7 votes

Could a tilt quadcopter use turbofan engines?

In a way, this has been done already half a century ago. When NATO decided to try a VTOL strategy, the Harrier was not the only result. There was even a supersonic VTOL fighter, and it used ...
Peter Kämpf's user avatar
7 votes

Can a passenger drone perform auto-rotation?

I am a career helicopter pilot who enjoys watching the development of drone technology. I can tell you for certain that this aircraft is incapable of autorotation. A parachute would be it's best ...
user27970's user avatar
7 votes
Accepted

Must quadcopters have the same propeller sizes?

The main point of a quadcopter is that it can be controlled by engine power using much simpler fixed-pitch rotors¹. Assuming this construction, you need to be able to separately adjust power of ...
Jan Hudec's user avatar
  • 56.3k
7 votes

What are the failure mode(s) for flying cars in case of power loss?

As I am closely working on some of these projects, I think I can answer. Let me start from: if the power fails this is a rather extreme situation, since everyone is including emergency ...
Federico's user avatar
  • 32.6k
5 votes

Does the direction of rotation of the propeller affect the direction of the thrust generated?

It depends. For that simple kind of a fan with flat blades, yes. For anything that was ever installed on a full scale airplane, it will generate no or very, very little thrust, more likely backward. ...
Jan Hudec's user avatar
  • 56.3k
5 votes

If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID?

You can use PID algorithms to control quite complex systems. After all, it's just a feedback system, which in itself is a robust concept. The problem is rather to control them in an optimal manner; or ...
Zeus's user avatar
  • 9,083
5 votes
Accepted

If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID?

If the Quadcopter is a MIMO Nonlinear System, How Can it be Controlled using PID? Exactly as you mention later: Does the model need to be linearized so that PID algorithms can be used? Yes, that'...
Federico's user avatar
  • 32.6k
5 votes
Accepted

How is the flight of a tricopter controlled?

There are few examples of three-rotor helicopters. On of them is the Cierva W.1 Air Horse. According to Wikipedia, torque balance, and hence, yaw control 'was provided by slightly inclining each rotor ...
xxavier's user avatar
  • 11.1k
5 votes

Can quadrotors be used for commercial passenger flights?

An important point is that that type of aircraft can't glide in autorotation, as helicopters are able to do in case of engine trouble. It will drop like an stone...
xxavier's user avatar
  • 11.1k
5 votes

Could a tilt quadcopter use turbofan engines?

The main reason V-22 uses propellers is efficiency. To get high thrust for power, you need to affect a lot of air and that requires a large propeller. The V-22 has huge propellers, closer to ...
Jan Hudec's user avatar
  • 56.3k
5 votes

Can quadcopter-like UAVs ever get significantly quieter? Any candidate technology?

A quiet fan is a large fan. (This should be understood in relation to either mechanical power or lift. Of course, a multi kilowatt industrial turbine is way noisier than the fan cooling your computer.)...
fraxinus's user avatar
  • 1,543
5 votes
Accepted

What happens if one or more rotors are stopped during autorotation on a quadrotor?

After watching the video the problem he was having was in keeping it horizontal. It appears that the software isn't able to control the unpowered motors. I know absolutely nothing about quads but I'm ...
TomMcW's user avatar
  • 28.6k
5 votes
Accepted

Could a quadcopter fly if its propellers were encased in cylindrical tubes?

Yes. It would be able to turn. Of your 4 propellers, 2 spin clockwise and 2 spin counterclockwise. The torques cancel out. To make it spin, you run the 2 clockwise propellers a little faster and the ...
Daniel K's user avatar
  • 5,508
5 votes

What disadvantages does flying a drone close under a ceiling have?

For a quadcopter, flying close underneath a flat surface will increase the amount of lift produced, but this will make it harder to control (unless the quadcopter is equipped with appropriate control ...
Tanner Swett's user avatar
  • 5,781
5 votes

Is possible to stick two '2-blade' propellers to get multi-blade propeller?

Any propeller 'unit' has been designed for a certain set of conditions: rotational-speed/air-speed/power/etc. If you then double-up in any way, then you can be assured that for the same conditions, ...
MikeB's user avatar
  • 785
4 votes

Why haven't quadcopters been scaled up yet?

There's a number of comments above about the various reasons that quadcopters don't exist in full size, but there's one I don't see mentioned. The quadcopters themselves use 4 rotors that have a ...
Tom K's user avatar
  • 611
4 votes

Why haven't quadcopters been scaled up yet?

They have been scaled up - perhaps not in rotor size but in number of rotors. If this can be done, I can see no practical limit to producing a manned platform with four rotors. Controllability seems ...
Koyovis's user avatar
  • 61.8k
4 votes
Accepted

How can this single-prop drone maintain stable (rotating) attitude and position?

You can read all about it in their paper (which actually reads quite nicely) http://flyingmachinearena.org/wp-content/publications/2016/zhaIEEE16.pdf First, the parameter space (so, location of ...
Sanchises's user avatar
  • 13.4k
4 votes

Can quadcopters save energy by flying in formation?

Yes, drag can be reduced by formation flying. Geese using a low drag "V" formation. The authors of a 2001 Nature article stated that pelicans that fly alone beat their wings more frequently and ...
jwzumwalt's user avatar
  • 11.5k
3 votes
Accepted

Is the rotor described in this Kickstarter new?

The rotors on that drone are of the centrifugal fan type. They are not new in design (don't know about aircraft use though) and can be found in all kinds of everyday appliances: hairdryers, vacuum ...
MadMarky's user avatar
  • 669
3 votes

Why haven't quadcopters been scaled up yet?

In my mind there is only one thing standing in the way of this form of transportation. Power density
Jim's user avatar
  • 737

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