14 CFR § 27.141

Except as specifically required in the applicable section, meet the flight characteristics requirements of this subpart—

At the altitudes and temperatures expected in operation;

Under any critical loading condition within the range of weights and centers of gravity for which certification is requested;

For power-on operations, under any condition of speed, power, and rotor r.p.m. for which certification is requested; and

For power-off operations, under any condition of speed and rotor r.p.m. for which certification is requested that is attainable with the controls rigged in accordance with the approved rigging instructions and tolerances;

Be able to maintain any required flight condition and make a smooth transition from any flight condition to any other flight condition without exceptional piloting skill, alertness, or strength, and without danger of exceeding the limit load factor under any operating condition probable for the type, including—

Sudden failure of one engine, for multiengine rotorcraft meeting Transport Category A engine isolation requirements of Part 29 of this chapter;

Sudden, complete power failure for other rotorcraft; and

Sudden, complete control system failures specified in § 27.695 of this part; and

Have any additional characteristic required for night or instrument operation, if certification for those kinds of operation is requested. Requirements for helicopter instrument flight are contained in appendix B of this part.