How Helicopters Differ from Airplanes
We often see both airplanes and helicopters in the air, and perhaps you’ve taken a ride in both. It’s easy enough to visually see how they vary from each other, but you may still wonder about how helicopters differ from airplanes in other ways. We present some of the subtler features that set helicopters and airplanes apart.
How They Achieve Flight
Since airplanes and helicopters are heavier than air, they maintain their airborne position through the utilization of an upward force called lift. The way they go about generating lift, however, is where they diverge. Airplanes fly forward, and as air blows over and under their curved wings, air pressure decreases above and increases underneath them. This pressure difference raises them up. Helicopters use a similar principle by creating more air pressure beneath each rotor. Since the rotors are spinning above the aircraft, helicopters do not need to move forward to create this pressure difference.
The Way They Fly
The methods by which airplanes and helicopters achieve lift, in turn, affects the way they fly. Airplanes must always keep moving forward, or they will lose their lift. Their fixed wings and linear travel make them more stable, though. Helicopters can lift off the ground straight upwards and move in any direction by tilting towards said direction. They may also hover over a fixed spot. For this maneuverability, they trade some stability. The increased amount of moving components and the fact that they have more controls make them more difficult to operate.
The Rules They Follow
As you know, airplanes are much more commonly used as passenger aircraft than helicopters. Consequently, they are often built much larger and are not as agile as helicopters. This compounds their already lower maneuverability. Since the lives of so many people are cradled in their frames and they cannot easily dodge oncoming objects if they suddenly show up close by, airplanes have different rules governing their flight than helicopters. They cannot drop below certain heights which vary depending on the area, for instance. Helicopters are given more flexibility to move closer to the ground and air traffic controllers direct them to fly under airplanes when nearing an airport.
