Engine failure in a helicopter is not the disaster that many non-pilots think it will be.
If the helicopter’s engine fails while flying, the pilot normally enters what is known as ‘auto-rotation’. This means that he or she lowers the collective, putting the helicopter into a steep descent. The air coming up through the rotors keeps them turning, and the pilot can then aim for a safe site and land the aircraft.
However, if the engine fails while hovering, the technique required is somewhat different.
Why Would the Helicopter’s Engine Fail When Hovering?
Engine failure at any time is extremely rare. However, since it could be catastrophic if the pilot doesn’t know what to do, the recovery technique is practiced extensively during the helicopter private pilot’s course, and regularly afterwards. Engine failure in the hover due to mechanical failure is no more common or uncommon than in any other phase of flight; running out of fuel is one of the most usual causes of engine stoppage. This is probably more likely to happen in the hover than at any other time – for example, the pilot is trying to make it to the fuel tank (or bowser) on time, but gets held up or finds he miscalculated.
Also, though it is possible to troubleshoot in the air if the low rotor RPM warning light goes on or you receive some other sign of impending engine failure, when you are in the hover there is simply not time to look for what is wrong – you need to get safely on the ground.
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