Hard landing
From Wikipedia, the free encyclopedia
The term hard landing is used to describe an especially rapid or steep descent. The term is commonly used in aviation.
[edit] Aviation
Landing is the final phase in flight where the vehicle returns to the ground. A hard landing occurs when the vehicle impacts the ground with a greater speed and force than in a normal landing. Hard landings can be caused by weather conditions, mechanical problems, pilot decision and/or pilot error. The term hard landing usually implies that the pilot still has total or partial control over the vehicle, as opposed to an uncontrolled descent into terrain (a crash) which usually results in the destruction of the vehicle. Hard landings can vary in seriousness from simply causing mild passenger discomfort to situations resulting in serious vehicle damage, structural failure, and loss of life. When an aircraft has experienced a hard landing it has to be checked for damage before next flight.
The term hard landing can also be applied to helicopter landings after mechanical failure and/or damage caused by hostile fire. A helicopter can often return to the ground after engine failure more safely than a fixed-wing aircraft provided that the rotor(s) are still intact and free to turn. Unpowered helicopter rotors exhibit autorotation in which airflow over the rotors keeps them turning and provides buoyancy and limited pilot control during descent. As an unpowered descent, it requires considerable pilot skill and experience to safely execute. Autorotations can also be impeded by obstructions on the ground.
