14 CFR § 136.13

Each operator that uses a rotorcraft must complete a performance plan before each commercial air tour or flight operated under § 91.146 or § 91.147 of this chapter. The pilot in command must review for accuracy and comply with the performance plan on the day the flight occurs. The performance plan must be based on information in the approved aircraft flight manual for that aircraft taking into consideration the maximum density altitude for which the operation is planned, in order to determine:

Maximum gross weight and center of gravity (CG) limitations for hovering in ground effect;

Maximum gross weight and CG limitations for hovering out of ground effect; and

Maximum combination of weight, altitude, and temperature for which height/velocity information in the approved aircraft flight manual is valid.

Except for the approach to and transition from a hover for the purpose of takeoff and landing, or during takeoff and landing, the pilot in command must make a reasonable plan to operate the rotorcraft outside of the caution/warning/avoid area of the limiting height/velocity diagram.

Except for the approach to and transition from a hover for the purpose of takeoff and landing, during takeoff and landing, or when necessary for safety of flight, the pilot in command must operate the rotorcraft in compliance with the plan described in paragraph (b) of this section.