14 CFR § 25.1521

General. The powerplant limitations prescribed in this section must be established so that they do not exceed the corresponding limits for which the engines or propellers are type certificated and do not exceed the values on which compliance with any other requirement of this part is based.

Reciprocating engine installations. Operating limitations relating to the following must be established for reciprocating engine installations:

Horsepower or torque, r.p.m., manifold pressure, and time at critical pressure altitude and sea level pressure altitude for—

Maximum continuous power (relating to unsupercharged operation or to operation in each supercharger mode as applicable); and

Takeoff power (relating to unsupercharged operation or to operation in each supercharger mode as applicable).

Fuel grade or specification.

Cylinder head and oil temperatures.

Any other parameter for which a limitation has been established as part of the engine type certificate except that a limitation need not be established for a parameter that cannot be exceeded during normal operation due to the design of the installation or to another established limitation.

Turbine engine installations. Operating limitations relating to the following must be established for turbine engine installations:

Horsepower, torque or thrust, r.p.m., gas temperature, and time for—

Maximum continuous power or thrust (relating to augmented or unaugmented operation as applicable).

Takeoff power or thrust (relating to augmented or unaugmented operation as applicable).

Fuel designation or specification.

Maximum time interval between engine run-ups from idle, run-up power setting and duration at power for ground operation in icing conditions, as defined in § 25.1093(b)(2).

Any other parameter for which a limitation has been established as part of the engine type certificate except that a limitation need not be established for a parameter that cannot be exceeded during normal operation due to the design of the installation or to another established limitation.

Ambient temperature. An ambient temperature limitation (including limitations for winterization installations, if applicable) must be established as the maximum ambient atmospheric temperature established in accordance with § 25.1043(b).