29.45—General.
(2)
The power absorbed by the accessories and services at the values for which certification is requested and approved.
(d)
For reciprocating engine-powered rotorcraft, the performance, as affected by engine power, must be based on a relative humidity of 80 percent in a standard atmosphere.
(e)
For turbine engine-powered rotorcraft, the performance, as affected by engine power, must be based on a relative humidity of—
Between these two temperatures, the relative humidity must vary linearly.
(f)
For turbine-engine-power rotorcraft, a means must be provided to permit the pilot to detemine prior to takeoff that each engine is capable of developing the power necessary to achieve the applicable rotorcraft performance prescribed in this subpart.