Why can airplanes fly higher than helicopters?

A jet has two wings that develop equal lift and move at the same speed as the aircraft. A helicopter has 2 to 5 or 6 rotor blades, half of which are in some part of a backward motion (retreating). read more

If you can get more air over the wing by changing its shape in a certain way, as well as increase the power of the thrust from the engines, it'll go even higher. Some planes with powerful engines can fly very high, over 100,000 feet. So planes = thrust from engines and lift from wings. Efficient. But helicopters depend on the rotors for all its lift. read more

As the aircraft gets lighter (burns fuel), the minimum (safe) speed it can fly decreases, and then it can climb a little higher during a flight. The maximum speed is limited by the speed of sound, or rather, a factor of the speed of sound. read more

As you can see, the lift that is produced is proportional to the density of air; the higher the density, the more lift is produced and the more comfortably the helicopter can fly, and vice-versa. Less air density means less lift. The air density at sea level is 1.225 kg per cubic meter . read more