New answers tagged glider
4
votes
Minimum Sink Rate in Sailplane
How do gliders ascend at best rate of climb?
They do it by closely watching speed and stick forces.
You are right, when aspect ratio is high, the polar point of minimum sink is at a very high lift ...
- 229k
2
votes
Minimum Sink Rate in Sailplane
either with an engine or thermal?
Well, with an engine the best rate of climb is Vy. Lower angle of climb than Vx but faster. This results in a higher rate of climb.
With a thermal we use V min ...
- 18.9k
5
votes
Minimum Sink Rate in Sailplane
Usually, the designers make sure that the margin between the minimum sink speed and stall speed is larger. Take a look at a real example: the flight polar of the ASK21, one of the most common glider ...
- 4,332
0
votes
Accepted
How long can a foreign registry glider stay in the US before having to change the register to N or having to leave the country?
As far as I can tell, there is no explicit mention of this anywhere. The conclusion that foreign aircraft can remain in the US indefinitely is based on it not being forbidden anywhere, not it being ...
- 12k
3
votes
Accepted
Can new thermals be generated above a cloud layer?
Normally thermals used by glider pilots are driven by heating of the ground.
Thermals rise from the ground due to uneven heating from the sun, then
stop rising once they start condensing into cloud.
...
- 21.8k
0
votes
Design glider without aileron
Without ailerons you can get a bank angle only as a side effect of the sideslip introduced by the rudder.
This side effect mainly depends on the sweep and dihedral angles and on the position of the ...
- 9,489
2
votes
Accepted
Cruise-climb in glider with electric motor?
"Cruise climb" does have a definition regarding a cruising aircraft rising to a higher altitude as it loses weight from fuel consumption. This relates more towards long range aircraft such ...
- 18.9k
2
votes
Cruise-climb in glider with electric motor?
Reading the RFP one can easily see what is meant with "cruise-climb" (requirement 1.a.ii):
The self-retrieve begins with a self-launch and includes 30 minutes of soaring flight before the ...
- 9,489
1
vote
Cruise-climb in glider with electric motor?
Constant mass battery electric aircraft have no need to cruise climb.
Cruise climb is a technique where you allow the aircraft to slowly climb during cruise to keep the specific range at its optimal ...
- 7,184
1
vote
Accepted
Trailing edge tapered and leading edge straight
While sweeping a wing can change the shape of the load distribution and the pattern of stall (inboard vs. outboard), the amount of sweep you get by holding a high aspect ratio wing like this straight ...
- 7,184
3
votes
Effect of wing flexible in stall
Wing flex is an important consideration for most airplanes. Even the wing of a modern airliner will flex substantially, both in bending (tips up) and in torsion (tips twisted). Wing flex will also ...
- 229k
12
votes
Accepted
With existing tech and knowledge of meteorology, can aircraft be designed to reliably improve their range or loiter using updrafts to gain altitude?
Thermals are finite. This means they have a useful diameter which is smaller than the diameter of the smallest circle most airplanes can fly. The wing loading of a heavy (= full ballast tanks) glider ...
- 229k
6
votes
With existing tech and knowledge of meteorology, can aircraft be designed to reliably improve their range or loiter using updrafts to gain altitude?
You should not forget the infrared mongolfiers. This system was invented by French Centre National d'Etudes Spatiales (national spatial studies center) in 1977. It can fly between 18000 and 28000 ...
- 221
5
votes
With existing tech and knowledge of meteorology, can aircraft be designed to reliably improve their range or loiter using updrafts to gain altitude?
Yes it is certainly possible to extend flight times almost indefinitely by using atmospheric lift, but there is a trade off between duration and other factors such as a flight plan and movement of ...
- 1,637
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