1. As one of the most distinctive creations of aviation technology in the 20th century, helicopter has greatly expanded the application range of aircraft.
 2. Helicopter is a typical dual-use product, which can be widely used in transportation, patrol, tourism, ambulance and other fields.
 3. The maximum speed of the helicopter can reach more than 300km/h, the diving limit speed is nearly 400km/h, the practical ceiling can reach 6000m (the world record is 12450m), and the general range can reach about 600-800km.
 4. The flight range of carrying in and out auxiliary fuel tanks can reach more than 2000km.
 5. Helicopters have different takeoff weights according to different needs.
 6. At present, the largest heavy helicopter in use in the world is the Russian Mi-26 (the maximum takeoff weight is 56t, and the payload is 20t).
 7. At present, the actual application is mechanical driven single rotor helicopter and dual rotor helicopter, of which the number of single rotor helicopters is the largest.