Jacob,
Great work on the video! I really enjoyed it.
The concept has a couple of significant problems, however. As the government found out with it's tail sitters, it is difficult it get the pilot into the aircraft. It sounds trivial, but you need a 5 story piece of ground support equipment to get the pilot into the airplane. In addition, the exhaust from the engines impinges on the ground and damages the runway and can cause debris to hit the aircraft and damage it. With the wing vertical it is subject to horizontal wind loads that try to topple it over. Lines attached to the front of the aircraft can resist this, but that again requires tall ground support equipment.
Any reason a tail-sitter wouldn't work for a drone though? It seems like everybody doing VTOL is using tilt-rotors.
I've been wondering, why not just take a quad-coptor and stick a wing on it oriented vertically? The COG would be somewhere near the wing when tilted horizontally. You would place the wing perpendicular to the wind during takeoff to minimize the loading. The coptor would take off normally, then begin moving foward. As it accelerates the wing would produce lift and it would transition, and likely turn into the wind.
Thinking about it a challenge would be the fact that the wing would produce way more drag than lift until the angle of attack was reduced. I guess you could transition by climbing high enough and then just pitching over and allowing the aircraft to drop considerably until it builds enough airspeed to maintain altitude.
Seems like the main downsides of a tail-sitting drone would be that short-takeoff wouldn't be an option for more payload, balancing the payload itself might be tricky, and the transition would be tricky since you have to build speed and reduce the angle of attack quickly.
The big upside of a tail-sitting drone would be that it wouldn't need motors/etc to tilt the rotors.
I'm not sure if it would be a pro or a con, but the behavior in wind during takeoff/landing would be different. You wouldn't get sudden gain/loss of lift during gusts, but you could get blown around laterally if wind direction shifts.
Replies
Great work on the video! I really enjoyed it.
The concept has a couple of significant problems, however. As the government found out with it's tail sitters, it is difficult it get the pilot into the aircraft. It sounds trivial, but you need a 5 story piece of ground support equipment to get the pilot into the airplane. In addition, the exhaust from the engines impinges on the ground and damages the runway and can cause debris to hit the aircraft and damage it. With the wing vertical it is subject to horizontal wind loads that try to topple it over. Lines attached to the front of the aircraft can resist this, but that again requires tall ground support equipment.
Keep up up the good work!!
Any reason a tail-sitter wouldn't work for a drone though? It seems like everybody doing VTOL is using tilt-rotors.
I've been wondering, why not just take a quad-coptor and stick a wing on it oriented vertically? The COG would be somewhere near the wing when tilted horizontally. You would place the wing perpendicular to the wind during takeoff to minimize the loading. The coptor would take off normally, then begin moving foward. As it accelerates the wing would produce lift and it would transition, and likely turn into the wind.
Thinking about it a challenge would be the fact that the wing would produce way more drag than lift until the angle of attack was reduced. I guess you could transition by climbing high enough and then just pitching over and allowing the aircraft to drop considerably until it builds enough airspeed to maintain altitude.
Seems like the main downsides of a tail-sitting drone would be that short-takeoff wouldn't be an option for more payload, balancing the payload itself might be tricky, and the transition would be tricky since you have to build speed and reduce the angle of attack quickly.
The big upside of a tail-sitting drone would be that it wouldn't need motors/etc to tilt the rotors.
I'm not sure if it would be a pro or a con, but the behavior in wind during takeoff/landing would be different. You wouldn't get sudden gain/loss of lift during gusts, but you could get blown around laterally if wind direction shifts.