NCAA PPL Aircraft General Knowledge flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Semi-monocoque construction

A structural design where the skin carries a large share of the load, supported by stringers and frames. It is light and strong but dents or cracks in stressed skin reduce strength and require inspection.

Aileron function

Ailerons move in opposite directions to raise one wing and lower the other, producing roll about the longitudinal axis. Adverse yaw results from the descending wing producing more induced drag.

Elevator function

The elevator is hinged to the horizontal stabilizer and controls pitch about the lateral axis. Moving the control yoke or stick aft raises the elevator and pitches the nose up.

Rudder function

The rudder is hinged to the vertical stabilizer and controls yaw about the vertical axis. It is used to coordinate turns and counteract adverse yaw and slipstream effects.

Flap purpose

Flaps increase lift and drag at lower airspeeds for takeoff and landing. They have a maximum extended speed (VFE) that must not be exceeded, and they change the stall speed.

VFE

VFE is the maximum speed at which flaps may be extended. Exceeding VFE risks structural damage to flaps and hinges, so pilots must slow before selecting flap settings.

Trim tab

A small movable surface attached to a primary control surface. It moves opposite to the control surface to reduce the force needed to hold a control position, relieving control pressure in steady flight.

Retractable landing gear

Gear that folds into the airframe to reduce drag. It requires position indicators, a warning horn, and respect for VLE and VLO limits before extension or retraction.

VLE

VLE is the maximum speed at which the landing gear may be extended. It differs from VLO, the speed for operating the gear in transit, and both limits must be observed.

Hydraulic system

A system that transmits force through incompressible fluid under pressure. It typically powers gear, flaps, or brakes, and a leak or pump failure causes loss of the affected function.

Alternator purpose

The alternator generates electrical power in flight and recharges the battery. If it fails, the ammeter or voltmeter shows discharge and the battery supplies limited power until depleted.

Battery function

The battery supplies power for engine starting and emergency electrical loads. It does not carry the normal in-flight load when the alternator is functioning properly.

Pitot tube

The pitot tube faces into the airflow and supplies ram or impact pressure to the airspeed indicator. A blocked pitot tube causes erroneous or zero airspeed readings, especially in climbs or descents.

Static port

The static port supplies ambient pressure to the airspeed indicator, altimeter, and vertical speed indicator. A blocked static port freezes the altimeter and VSI and errors the airspeed indicator.

Airspeed indicator

The airspeed indicator shows the difference between pitot ram pressure and static pressure. It displays indicated airspeed, which must be corrected for position and installation error.

Altimeter

The altimeter converts static pressure into altitude using a pressure scale. It must be set to the correct pressure setting, and it reads incorrectly if the static port is blocked.

Vertical speed indicator

The VSI shows the rate of climb or descent by sensing changes in static pressure over time. It lags briefly during changes and freezes if the static port is blocked.

Rigidity in space

A spinning gyro resists changing its orientation in space. This principle keeps the attitude indicator and heading indicator stable as the aircraft maneuvers around them.

Precession

The response of a spinning gyro to an applied force, tilting it at a right angle to that force. This principle drives the turn coordinator and turn-and-slip indicator.

Attitude indicator

A gyroscopic instrument showing pitch and bank relative to the horizon. It uses rigidity in space and typically becomes unreliable when its vacuum or pressure source fails.

Heading indicator

A gyroscopic instrument showing the aircraft's heading. It uses rigidity in space, must be set to the magnetic compass before flight, and drifts due to precession and friction.

Turn coordinator

A gyroscopic instrument showing rate of turn and coordination. It is often electrically driven, so it may remain usable if the vacuum system fails.

Four-stroke cycle

A piston engine cycle of intake, compression, power, and exhaust strokes. The crankshaft turns twice per cycle, and the spark plug fires near the end of compression to start the power stroke.

Mixture control

The mixture control adjusts the fuel-to-air ratio entering the engine. Leaning reduces fuel flow for high-altitude or cruise operation, while enriching adds fuel for cooling and power.

Carburetor heat

A control that routes heated air into the carburetor to prevent or clear carburetor ice. Applying it typically causes a slight power loss and enriches the mixture, so it is used as needed.

Carburetor ice

Ice that forms in the carburetor due to fuel vaporization and pressure drop. It can occur at temperatures well above freezing and is indicated by a gradual loss of RPM or manifold pressure.

Manifold pressure gauge

An engine instrument showing absolute pressure in the intake manifold in inches of mercury. It reflects power output in a constant-speed propeller aircraft and drops when the throttle closes.

Tachometer

An instrument showing engine crankshaft speed in revolutions per minute. It is used to set power and monitor limits, and a sudden change may indicate a propeller or engine problem.

Exhaust gas temperature

The EGT gauge measures exhaust temperature and is used to lean the mixture. Peak EGT indicates a specific fuel-to-air ratio, and leaning beyond peak reduces power and fuel flow.

Oil pressure gauge

An engine instrument showing lubrication system pressure. Low or zero pressure indicates a serious problem that can lead to engine damage and requires immediate attention.

Oil temperature gauge

An engine instrument showing the temperature of the engine oil. High temperature can indicate low oil quantity, cooling problems, or excessive power, and it affects oil viscosity and lubrication.

Constant-speed propeller

A propeller whose blade angle is adjusted by a governor to maintain a selected RPM. Increasing blade angle increases load and reduces RPM, and the system allows efficient operation across power settings.

Magnetic compass

A non-gyroscopic instrument showing magnetic heading. It is subject to magnetic dip and turning errors, so it is read level in smooth flight and used to set the heading indicator.