FAA multi-engine airplane class-rating foundations key terms

The engine whose failure has the most adverse defined effect on handling or performance under the stated conditions, requiring actual configuration and rotation references.

A minimum-control-speed concept under its specified engine-out conditions, distinguished from stall speed or a guarantee of available climb performance.

An unequal propulsion condition producing moments dependent on thrust magnitude and geometry, combined with the actual drag and control forces.

The angle between a stated blade-section chord and the plane of rotation, distinguished from its aerodynamic angle relative to the local airflow.

The actual forward advance per revolution at the stated operating condition, distinguished from the geometric screw-advance model of the blade.

The difference between geometric and effective advance per revolution in the defined comparison, requiring a stated denominator when expressed as a percentage.

A specified measurement location relative to the propeller reference, used to make geometry and inspection results repeatable under the applicable data.

Useful propulsive output calculated from thrust multiplied by forward speed in a consistent model, distinguished from the engine shaft input power.

A state where the actual rotational speed matches the selected governor setting within the system behavior, distinguished from a fixed universal blade angle.

Actual rotational speed above the selected or specified reference, whose correction and limits depend on the actual governor and installation.

The governor element providing the selected reference force against the speed-sensitive mechanism, rather than a direct measurement of aircraft forward speed.

Moving blades toward the defined low-drag alignment with axial airflow, using the actual control forces and angle references of the installation.

A pitch-change arrangement using hydraulic action in both movement directions, distinguished from a single hydraulic direction opposed by other forces.

Matching propeller rotational speeds in the defined control arrangement, distinguished from independently establishing blade phase, track or structural condition.

Controlling a specified relative angular blade relationship in addition to speed, with permitted operation and authority determined by the actual system.

A rotating electrical contact surface used with the specified brush arrangement to transfer electrical power or signals across the rotating interface.

The controller-defined order and timing of electrical element operation, assessed against the actual system rather than an assumed universal cycle.

A rotating distribution method using centrifugal action to direct the specified fluid along the intended delivery paths rather than a generic fuel-supply function.

Best rate-of-climb speed with one engine inoperative in the applicable aircraft condition, not a universal landing approach speed or proof of positive climb.

The defined condition where single-engine rate of climb reaches zero, distinguished from a service-ceiling criterion and from required terrain clearance.

A specified training power condition approximating a defined engine/propeller effect, requiring the actual aircraft or approved training data rather than a guessed setting.

The defined cross-check of a suspected condition before acting, distinguished from treating one mnemonic, sensation or unconfirmed indication as proof.

The applicable aircraft-class qualification within the certificate framework, distinguished from a separate operator approval, currency or personal medical assessment.