Helicopters fly somewhat close to the ground. They fly near the troposphere. They fly at a lower altitude than planes.
The air gets thinner as you increase altitude, the same reason why only certain planes can reach high altitudes.
there can be any number of reasons for that.
no a helicopter is not a airplane because helicopter lifts but a plane takes off and a helicopters propeller is huger than a planes
36 000 feet
A helicopter needs a solid surface to fly over.
Helicopter engines require substantial power to propel the helicopter vertically from a standstill. With regards to planes, yes obviously planes need powerful engines, BUT planes speed up to 200km/h on runways before they start flying.
The helicopter's altitude, distance traveled, speed/rate of travel, etc.