14 CFR § 29.79

For Category A rotorcraft—

The landing performance must be determined and scheduled so that if the critical engine fails at any point in the approach path, the rotorcraft can either land and stop safely or climb out and attain a rotorcraft configuration and speed allowing compliance with the climb requirement of § 29.67(a)(2);

The approach and landing paths must be established with the critical engine inoperative so that the transition between each stage can be made smoothly and safely;

The approach and landing speeds must be selected by the applicant and must be appropriate to the type of rotorcraft; and

The approach and landing path must be established to avoid the critical areas of the height-velocity envelope determined in accordance with § 29.87.

It must be possible to make a safe landing on a prepared landing surface after complete power failure occurring during normal cruise.