Density altitude and helicopters (part 3 of 3)

Density altitude affects all aircraft equally, the higher the density altitude, the lower the performance of fixed and rotor-winged aircraft. In helicopters a higher density altitude will, among other things, translate to

(1) a lower hovering ceiling at a given gross weight, and

(2) the higher the density altitude the more power is needed for a vertical take-off and under certain weight and density altitude conditions, there may not be enough power for a vertical take-off. if that is the case, the helo pilot may need to do what is sometimes known as a running take-off.

For more information on the affects of density altitude on helicopters see this article