other
The forces acting on the helicopter

# The forces acting on the helicopter, the concept of overload

During level flight at a constant speed to the helicopter, the following main forces: the main rotor thrust, drag X, the force of gravity G and the helicopter tail rotor thrust in, balancing on his shoulder reactive torque. Link HB tilted relative to the vertical forward to overcome aerodynamic drag, and right - for balancing the tail rotor thrust. Since the slope of the propeller thrust to the main modes is small, it can be assumed approximately:

To maneuver the pilot changes the magnitude and direction of thrust and tail rotor, which leads to the acceleration and the corresponding inertia forces. The result is a change in the direction or magnitude of airspeed.

When parking the force of gravity is balanced by the reactions of the helicopter ground acting on the landing gear. At the moment of impact the amount of planting soil reaction may be several times the weight of the helicopter as a result of inertial forces generated by the extinction rate of descent.

All the forces acting on the helicopter, can be divided into surface and mass. Surface forces are applied to the surface of the aircraft or a portion thereof. They can be distributed over the surface in the form of pressure or concentrated in selected nodes. By the distribution of surface forces are all aerodynamic forces, and to focus - power transmitted in the nodes mount units.

By the mass forces are gravity and inertial forces acting on each particle structure. Mass forces can act on the structure in the form distributed loads, such as gravity blades of the tail boom, the centrifugal force of the blade, or in the form of concentrated forces such as gravity suspension arms attached to the mounting assembly.

The greatest value and importance to the strength of the helicopter has overload. If the helicopter does not have wings, the only surface force in the direction of the OY axis is the vertical component of the thrust and then HB

Maximum overload resulting from the landing of the helicopter, shall not exceed the specified values.

The value to determine the allowable load to operate the helicopter, or any part thereof.