FAA Flight Engineer key terms

The speed at or above which a takeoff must be continued after an engine failure, and below which the takeoff should be rejected. It is chosen so that accelerate-stop and accelerate-go distances both fit the runway.

The speed at which the pilot begins raising the nose to lift off. It is high enough that the aircraft reaches V2 by 35 feet above the runway with an engine failed at V1.

The minimum speed that must be maintained with one engine inoperative during the takeoff climb. It guarantees directional control and the required climb gradient until the aircraft is cleaned up.

The lowest airspeed at which the aircraft can be controlled with one engine failed and the other at takeoff power, using no more than a specified rudder force and bank angle.

The engine whose failure most adversely affects performance and control, usually the one whose loss produces the greatest yawing moment because of P-factor and accelerated slipstream on the opposite side.

The yawing and rolling moment created when one engine produces more thrust than the other. It must be countered with rudder and bank, and it sets the control problem behind Vmc.

The runway length at which accelerate-stop distance equals accelerate-go distance, giving the shortest field from which a given weight can safely be flown after an engine failure at V1.

The total runway distance needed to accelerate to V1, recognize an engine failure, and bring the aircraft to a full stop. It includes the distance covered during pilot recognition time.

The height gained per unit of horizontal distance, expressed as a percentage, with one engine inoperative. Required gradients vary by segment and guarantee obstacle clearance along the departure path.

The altitude an aircraft can maintain with one engine inoperative at a given weight, found where single-engine available thrust equals drag. It determines the level-off altitude after an engine failure at cruise.

The maximum altitude at which an aircraft can still climb at a specified rate, typically 100 feet per minute for reciprocating aircraft. It reflects the loss of power and lift as air density drops.

Pressure altitude corrected for nonstandard temperature. It represents the altitude the aircraft 'feels' and drives engine power, propeller efficiency, lift, and true airspeed, so hot days degrade performance sharply.

The altitude indicated when the altimeter is set to the standard datum of 29.92 inches of mercury. It is the base value from which density altitude is computed.

The range of allowable CG positions, from forward to aft limits, within which the aircraft can be safely controlled. Loading outside it affects stability, trim, and rotation.

The weight of the aircraft plus payload but without usable fuel. It is a structural limit because all fuel beyond it must be carried in the wings, which relieves bending loads.

The heaviest weight at which the aircraft may begin the takeoff roll. It is limited by structure, runway length, climb performance, and obstacle clearance, whichever is most restrictive.

The horizontal distance from the reference datum to a loaded item's center of gravity. Multiplying weight by arm gives the moment used to compute the aircraft's total CG.

A piston engine in which fuel-air mixture is ignited in cylinders to drive a crankshaft. In aircraft it is usually air-cooled, horizontally opposed, and drives a propeller through a reduction gear or directly.

The absolute pressure of the fuel-air mixture in the engine's intake manifold, read in inches of mercury. It indicates the power being developed and is the primary power reference for a constant-speed propeller aircraft.

An exhaust-driven compressor that packs denser air into the intake, allowing an engine to hold power at high altitude. Its wastegate controls how much exhaust energy reaches the turbine.

A valve that routes exhaust gas around or through the turbocharger turbine. Closing it sends more exhaust through the turbine, raising boost, while opening it limits boost and protects the engine.

Exceeding the manufacturer's maximum manifold pressure limit, which can cause detonation, high cylinder pressures, and structural damage. It is often caused by mishandling the throttle or wastegate.

Explosive, uncontrolled burning of the fuel-air charge after ignition, producing a sharp pressure spike and possible engine damage. It is promoted by high manifold pressure, high temperature, and low fuel octane.

Ignition of the fuel-air mixture before the spark plug fires, usually caused by a hot spot such as a glowing carbon deposit or overheated plug. It raises temperatures and can lead to detonation and piston damage.

Ice buildup in the carburetor throat caused by fuel vaporization and pressure drop cooling the air. It can occur at outside temperatures well above freezing and causes a gradual power loss.

A control that routes heated air into the carburetor to melt ice. Applying it enriches the mixture and reduces power, so it is used as a preventive and corrective measure with mixture adjustment.

The cockpit control that sets the fuel-to-air ratio entering the engine. It must be leaned as altitude increases to preserve power and economy, and enriched for high power settings to control temperatures.

The temperature of the exhaust gases leaving the cylinders, used to judge mixture strength and engine stress. Peak EGT marks the chemically ideal ratio, with richer or leaner settings chosen for cooling or economy.

The gas temperature entering the turbine section of a turbojet or turboprop engine. It is a primary limit because excessive values shorten turbine blade life or cause immediate damage.

A powerplant in which air is compressed, mixed with fuel, burned continuously, and expanded through a turbine. The turbine drives the compressor and either a propeller or a fan and exhaust nozzle.

A disruption of smooth airflow through the compressor, causing a loud bang, vibration, and loss of thrust. It can be triggered by abrupt throttle changes, disturbed inlet air, or exceeding surge limits.

Loss of combustion in a turbine engine, causing thrust to fall to zero. It may result from fuel starvation, icing, or extreme airflow disturbance, and usually requires an in-flight relight procedure.

A propeller whose blade angle is automatically adjusted to hold a selected rpm as power and airspeed change. The pilot sets rpm with the propeller control and power with throttle and manifold pressure.

Rotating the blades of a failed engine's propeller to the streamlined position, minimizing drag and windmilling. It reduces asymmetric drag and improves single-engine performance and control.

The rotation of an unpowered propeller or turbine driven by air flowing through it. It creates drag and can cause a failed engine to keep turning, so feathering or shutdown procedures may be needed.

The effective use of all available resources, including crew, equipment, and information, to achieve safe flight. It covers communication, leadership, workload sharing, and decision making under pressure.

A rule that restricts nonessential conversation and activity during critical phases such as taxi, takeoff, and approach. It keeps attention on flying and monitoring when workload and risk are highest.

A framework in which crews anticipate threats, detect errors, and trap or mitigate them before they cause an undesired state. It treats error as normal and focuses on resilience rather than blame.