14 CFR §33.7
Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
- (a)Engine ratings and operating limitations are established by the Administrator and included in the engine certificate data sheet specified in § 21.41 of this chapter, including ratings and limitations based on the operating conditions and information specified in this section, as applicable, and any other information found necessary for safe operation of the engine.
- (b)For reciprocating engines, ratings and operating limitations are established relating to the following:
- (1)Horsepower or torque, r.p.m., manifold pressure, and time at critical pressure altitude and sea level pressure altitude for—
- (2)Fuel grade or specification.
- (3)Oil grade or specification.
- (4)Temperature of the—
- (5)Pressure of—
- (6)Accessory drive torque and overhang moment.
- (7)Component life.
- (8)Turbosupercharger turbine wheel r.p.m.
- (c)For turbine engines, ratings and operating limitations are established relating to the following:
- (1)Horsepower, torque, or thrust, r.p.m., gas temperature, and time for—
- (i)Rated maximum continuous power or thrust (augmented);
- (ii)Rated maximum continuous power or thrust (unaugmented);
- (iii)Rated takeoff power or thrust (augmented);
- (iv)Rated takeoff power or thrust (unaugmented);
- (v)Rated 30-minute OEI power;
- (vi)Rated 2 1/2-minute OEI power;
- (vii)Rated continuous OEI power; and
- (viii)Rated 2-minute OEI Power;
- (ix)Rated 30-second OEI power; and
- (x)Auxiliary power unit (APU) mode of operation.
- (2)Fuel designation or specification.
- (3)Oil grade or specification.
- (4)Hydraulic fluid specification.
- (5)Temperature of—
- (i)Oil at a location specified by the applicant;
- (ii)Induction air at the inlet face of a supersonic engine, including steady state operation and transient over-temperature and time allowed;
- (iii)Hydraulic fluid of a supersonic engine;
- (iv)Fuel at a location specified by the applicant; and
- (v)External surfaces of the engine, if specified by the applicant.
- (6)Pressure of—
- (7)Accessory drive torque and overhang moment.
- (8)Component life.
- (9)Fuel filtration.
- (10)Oil filtration.
- (11)Bleed air.
- (12)The number of start-stop stress cycles approved for each rotor disc and spacer.
- (13)Inlet air distortion at the engine inlet.
- (14)Transient rotor shaft overspeed r.p.m., and number of overspeed occurrences.
- (15)Transient gas overtemperature, and number of overtemperature occurrences.
- (16)Transient engine overtorque, and number of overtorque occurrences.
- (17)Maximum engine overtorque for turbopropeller and turboshaft engines incorporating free power turbines.
- (18)For engines to be used in supersonic aircraft, engine rotor windmilling rotational r.p.m.
- (1)Horsepower, torque, or thrust, r.p.m., gas temperature, and time for—
- (d)In determining the engine performance and operating limitations, the overall limits of accuracy of the engine control system and of the necessary instrumentation as defined in § 33.5(a)(6) must be taken into account.