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Yacht Approach	A yacht approach is a non-standard landing approach used in emergency or unique situations where traditional runways are unavailable. This term is rarely used and refers metaphorically to a precise, controlled approach, akin to maneuvering a yacht into a harbor.
Yaw	Yaw refers to the rotation of an aircraft around its vertical axis, controlled by the rudder. Yaw movements affect the aircraft's nose direction and are essential for coordinated turns. Pilots use rudder inputs to counter adverse yaw during turns or to maintain a straight path during crosswind conditions, ensuring stability and control.
Yaw Angle	The yaw angle is the angle between an aircraft’s longitudinal axis and its actual flight path or relative wind. A positive yaw angle indicates a nose-right deviation, while a negative yaw angle shows a nose-left deviation. Managing yaw angle is crucial for precise navigation and stable flight.
Yaw Axis	The yaw axis is the vertical axis of an aircraft, running perpendicular to the longitudinal and lateral axes. Movements along the yaw axis are controlled by the rudder and affect the aircraft’s heading. Proper control of the yaw axis is critical for stable navigation and coordinated turns.
Yaw Braking	Yaw braking uses differential braking on the main landing gear to assist with directional control during ground operations, such as sharp turns or crosswind taxiing.
Yaw Control	Yaw control refers to the use of rudder inputs to manage an aircraft's rotation around its vertical axis. Pilots adjust yaw control to maintain coordinated turns, counteract crosswinds, or stabilize the aircraft during engine-out scenarios in multi-engine aircraft.
Yaw Coupling	Yaw coupling describes the interaction between yaw and other aircraft axes during maneuvers. For example, yaw can induce roll or pitch changes due to aerodynamic effects. Proper design and control inputs mitigate these effects, ensuring predictable handling characteristics.
Yaw Damper	A yaw damper is an automatic system that minimizes undesirable yaw oscillations, known as "Dutch roll," in aircraft. It improves passenger comfort and reduces pilot workload during flight. By applying corrective rudder inputs, the yaw damper enhances stability, especially in larger or swept-wing aircraft prone to such oscillations.
Yaw Damper System	A yaw damper system automatically detects and counters undesirable yaw movements. It prevents Dutch roll, improves directional stability, and enhances passenger comfort during turbulence. Yaw damper systems are essential for modern commercial aircraft.
Yaw Induced Drag	Yaw-induced drag occurs when yaw movements disrupt smooth airflow, increasing drag and reducing fuel efficiency. Pilots minimize yaw-induced drag through coordinated controls and precise navigation.
Yaw Induced Roll	Yaw-induced roll occurs when yaw movements create an unintentional roll due to aerodynamic forces. This effect is most common in swept-wing aircraft. Pilots and autopilot systems correct yaw-induced roll using ailerons or rudder inputs to maintain level flight.
Yaw Mode	Yaw mode is an autopilot function that controls the aircraft's yaw movements. It maintains heading or corrects for yaw deviations caused by turbulence, crosswinds, or asymmetric thrust. Yaw mode simplifies directional control, especially during long-haul flights or adverse weather conditions.
Yaw Moment	The yaw moment is the turning force around an aircraft’s vertical axis. Generated by rudder deflections or aerodynamic asymmetries, it impacts the aircraft’s heading. Understanding yaw moments is essential for designing stable and controllable aircraft.
Yaw Oscillation	Yaw oscillation refers to repetitive side-to-side movements around the vertical axis. This phenomenon, known as Dutch roll, can be uncomfortable for passengers and challenging for pilots. Yaw dampers automatically correct oscillations to stabilize the aircraft.
Yaw Out-of-Trim	Yaw out-of-trim refers to a flight condition where the rudder is not properly aligned, causing the aircraft to deviate from its intended heading. Pilots use yaw trim adjustments to restore balance and stability.
Yaw Rate Indicator	The yaw rate indicator measures the rate at which an aircraft rotates around its vertical axis. It helps pilots maintain coordinated turns and is also used in flight testing to evaluate yaw dynamics.
Yaw Rate Sensor	A yaw rate sensor measures the rate of rotation around an aircraft’s vertical axis. It provides input to flight control systems, autopilots, and yaw dampers, ensuring precise adjustments to maintain stability and prevent excessive yaw movements during flight.
Yaw Resistance	Yaw resistance is an aircraft’s ability to resist undesired yaw motions caused by external forces, such as wind gusts. High yaw resistance improves stability and control, especially in challenging flight conditions.
Yaw Roll Stability	Yaw roll stability describes the relationship between yaw and roll movements, ensuring the aircraft maintains level flight during coordinated turns. Proper stability design minimizes coupling effects between yaw and roll.
Yaw Rollout	Yaw rollout occurs during the landing phase when rudder inputs are used to align the aircraft with the runway centerline. Pilots carefully manage yaw rollout to prevent skidding or side loads on the landing gear.
Yaw Rudder Authority	Yaw rudder authority describes the effectiveness of the rudder in controlling yaw movements. Adequate rudder authority is critical for handling crosswinds, maintaining stability, and executing coordinated turns in all flight phases.
Yaw Skid	Yaw skid describes an uncoordinated flight condition where excessive yaw causes the aircraft to slide sideways. Pilots correct yaw skid using coordinated rudder and aileron inputs to restore straight and level flight.
Yaw Stability	Yaw stability refers to an aircraft’s ability to resist unwanted yaw movements and maintain directional control. This characteristic is critical for ensuring smooth flight in turbulent conditions and during maneuvers. Swept-wing aircraft typically require yaw dampers to enhance yaw stability.
Yaw String	A yaw string is a simple, lightweight device attached to a glider’s windshield or fuselage to indicate yaw. The string points directly into the airflow, showing whether the aircraft is flying straight or slipping/skidding. It provides a visual cue for proper rudder control during flight.
Yaw Trim	Yaw trim adjusts the rudder’s neutral position to counteract persistent yawing tendencies, such as those caused by asymmetric thrust or crosswinds. It reduces pilot workload during long flights, ensuring smoother and more efficient operations.
Yaw Torque	Yaw torque refers to the rotational force applied to an aircraft around its vertical axis. It is generated by rudder inputs or asymmetric thrust, such as in engine-out conditions. Pilots balance yaw torque to maintain heading and prevent uncoordinated flight.
Yellow Arc (Instrument Marking)	The yellow arc on an aircraft instrument indicates cautionary operating ranges. For example, on an airspeed indicator, the yellow arc represents speeds requiring extra care, such as during turbulence. Staying within this range ensures structural integrity and safe operations, provided the pilot avoids exceeding limitations.
Yellow Warning Light	A yellow warning light in the cockpit indicates a cautionary condition requiring pilot attention but not immediate action. Common examples include system malfunctions, weather radar anomalies, or anti-ice system activation. Pilots monitor these warnings to address issues before they escalate.
Yield Strength	Yield strength is the stress level at which an aircraft material begins to deform permanently. Engineers design aircraft components to remain below their yield strength under normal operating conditions, ensuring structural safety and integrity. This property is critical for selecting materials in high-stress areas like landing gear and wings.
Yoke	The yoke is the primary control device used by pilots to steer an aircraft. It controls both the roll (ailerons) and pitch (elevator) axes. Pulling or pushing the yoke changes altitude, while turning it adjusts the aircraft’s bank angle, making it a vital component for manual flight.