What should a pilot do if engine failure occurs at altitude?

In the event of an engine failure at altitude, lowering the collective pitch control to maintain rotor RPM is crucial. This action helps prevent the rotor from slowing down excessively, which can lead to a loss of lift and control over the helicopter. During an engine failure, maintaining adequate rotor RPM is essential for ensuring sufficient lift and facilitating a controlled descent.

When the collective pitch is lowered, it decreases the angle of attack of the rotor blades, reducing drag. This allows the rotor system to retain RPM, which is vital for managing the helicopter's flight characteristics and preparing for a potential landing. A controlled autorotation can then be carried out if necessary, enabling the pilot to execute a safe landing despite the engine failure.

While other actions may be appropriate in different situations, maintaining rotor RPM through collective pitch adjustment is a fundamental response that is critical in the scenario of engine failure at altitude.