Contents
What is the purpose of autorotation?
It is analogous to the gliding flight of a fixed-wing aircraft. The most common use of autorotation in helicopters is to safely land the aircraft in the event of an engine failure or tail-rotor failure. It is a common emergency procedure taught to helicopter pilots as part of their training.
What would cause a helicopter to nose dive?
If timing is not correct and a landing attitude not set at the appropriate time, the tail rotor may contact the ground causing a forward pitching moment of the nose and possible damage to the helicopter. This could result in a hard landing with corresponding damage to the helicopter.
How much does it take to fill a helicopter?
Cost Example
| Helicopter Type | Average Fuel Burn | Cost To Fill |
|---|---|---|
| Bell 206 Jetranger III | 27 gph | $383 |
| AS350 B3 Astar | 50 gph | $600 |
| Bell 212HP | 100 gph | $903 |
| Bell 205A-1++ | 90 gph | $925 |
Why does a helicopter yaw during autorotation?
Essentially, the pilot is consuming the energy stored in the aircraft’s altitude to maintain rotor rpm. Generally, this will result in a 1,500-foot-per-minute descent. While this is happening, the loss of engine torque will cause the helicopter to yaw severely to the left because the tail rotor is still producing thrust.
How does the rotor system work in autorotation?
To fully understand how autorotation works, we need to review some basic aerodynamics. The rotor blades spin to produce airflow and consequently lift and drag. The rotational speed of the rotor system is held constant, and lift is created by increasing each rotor blade’s angle of attack.
How is lift created in an autorotation system?
The rotational speed of the rotor system is held constant, and lift is created by increasing each rotor blade’s angle of attack. This is accomplished by raising the collective pitch control in the cockpit. Basic aerodynamic theory tells us that an increase in lift will be accompanied by an increase in drag.
What makes the tail rotor spin faster than the main rotor?
Gearing allows it to spin faster than the main rotor, and its rpm varies in direct relation to main rotor rpm. To rotate the fuselage around the main rotor axis, the pilot changes the tail rotor blades’ angle of attack, and hence thrust, with anti-torque pedals in the cockpit.