R Ramp weight. The total weight of the aircraft while on the ramp. It differs from takeoff weight by the weight of the fuel that will be consumed in taxiing to the point of takeoff.

R — масса на стоянке. Общая масса воздушного судна на стоянке. Отличается от взлётной массы на массу топлива, которое будет израсходовано при рулении к точке взлёта.

Rate of turn. The rate in degrees/second of a turn.

Скорость поворота. Скорость поворота в градусах в секунду.

Reciprocating engine. An engine that converts the heat energy from burning fuel into the reciprocating movement of the pistons. This movement is converted into a rotary motion by the connecting rods and crankshaft.

Поршневой двигатель. Двигатель, преобразующий тепловую энергию сгорания топлива в возвратно-поступательное движение поршней. Это движение преобразуется во вращательное движение шатунами и коленчатым валом.

Reduction gear. The gear arrangement in an aircraft engine that allows the engine to turn at a faster speed than the propeller.

Редуктор. Механизм в авиационном двигателе, позволяющий двигателю вращаться с большей скоростью, чем воздушный винт.

Region of reverse command. Flight regime in which flight at a higher airspeed requires a lower power setting and a lower airspeed requires a higher power setting in order to maintain altitude.

Область реверса. Режим полёта, при котором полёт с более высокой скоростью требует меньшей мощности, а при меньшей скорости — большей мощности для поддержания высоты.

Registration certificate. A State and Federal certificate that documents aircraft ownership.

Регистрационное свидетельство. Государственный и федеральный сертификат, подтверждающий право собственности на воздушное судно.

Relative wind. The direction of the airflow with respect to the wing. If a wing moves forward horizontally, the relative wind moves backward horizontally. Relative wind is parallel to and opposite the flightpath of the airplane.

Относительный ветер. Направление воздушного потока относительно крыла. Если крыло движется горизонтально вперёд, относительный ветер движется горизонтально назад. Относительный ветер параллелен траектории полёта самолёта и противоположен ей.

Reverse thrust. A condition where jet thrust is directed forward during landing to increase the rate of deceleration. G-12

Реверс тяги. Состояние, при котором реактивная тяга направлена ​​вперёд во время посадки для увеличения скорости замедления. G-12

Reversing propeller. A propeller system with a pitch change mechanism that includes full reversing capability. When the pilot moves the throttle controls to reverse, the blade angle changes to a pitch angle and produces a reverse thrust, which slows the airplane down during a landing.

Реверс воздушного винта. Система воздушного винта с механизмом изменения шага, включающая возможность полного реверса. Когда пилот переключает рычаги управления двигателем в положение реверса, угол наклона лопастей изменяется на угол тангажа и создаёт обратную тягу, которая замедляет самолёт во время посадки.

Roll. The motion of the aircraft about the longitudinal axis. It is controlled by the ailerons. Roundout (flare). A pitch-up during landing approach to reduce rate of descent and forward speed prior to touchdown.

Крен. Движение самолёта вокруг продольной оси. Управляется элеронами. Закругление (подвал). Подъём тангажа при заходе на посадку для уменьшения скорости снижения и поступательной скорости перед касанием земли.

Rudder. The movable primary control surface mounted on the trailing edge of the vertical fin of an airplane. Movement of the rudder rotates the airplane about its vertical axis.

Руль направления. Пара управляющих поверхностей на хвосте самолёта, расположенных в форме буквы V. При совместном перемещении штурвалом эти поверхности выполняют функции рулей высоты, а при дифференциальном перемещении педалями руля направления — функции руля направления.

Ruddervator. A pair of control surfaces on the tail of an aircraft arranged in the form of a V. These surfaces, when moved together by the control wheel, serve as elevators, and when moved differentially by the rudder pedals, serve as a rudder.

Руль направления. Пара управляющих поверхностей на хвосте самолёта, расположенных в форме буквы V. При совместном перемещении штурвалом эти поверхности выполняют функции рулей высоты, а при дифференциальном перемещении педалями руля направления — функции руля направления.

Runway centerline lights. Runway centerline lights are installed on some precision approach runways to facilitate landing under adverse visibility conditions. They are located along the runway centerline and are spaced at 50-foot intervals. When viewed from the landing threshold, the runway centerline lights are white until the last 3,000 feet of the runway. The white lights begin to alternate with red for the next 2,000 feet, and for the last 1,000 feet of the runway, all centerline lights are red.

Осевые огни ВПП. Осевые огни ВПП устанавливаются на некоторых ВПП для точного захода на посадку для облегчения посадки в условиях ограниченной видимости. Они расположены вдоль осевой линии ВПП с интервалом 15 метров (50 футов). При взгляде с порога ВПП осевые огни ВПП белые до последних 900 метров (3000 футов). На следующих 600 метрах (2000 футов) белые огни чередуются с красными, а на последних 300 метрах (1000 футов) ВПП все осевые огни красные.

Runway centerline markings. The runway centerline identifies the center of the runway and provides alignment guidance during takeoff and landings. The centerline consists of a line of uniformly spaced stripes and gaps.

Разметка осевой линии ВПП. Осевая линия ВПП обозначает центр ВПП и служит ориентиром для выравнивания при взлете и посадке. Осевая линия состоит из ряда равномерно расположенных полос и промежутков.

Runway edge lights. Runway edge lights are used to outline the edges of runways during periods of darkness or restricted visibility conditions. These light systems are classified according to the intensity or brightness they are capable of producing: they are the High Intensity Runway Lights (HIRL), Medium Intensity Runway Lights (MIRL), and the Low Intensity Runway Lights (LIRL). The HIRL and MIRL systems have variable intensity controls, whereas the LIRLs normally have one intensity setting.

Боковые огни ВПП. Боковые огни ВПП используются для обозначения границ ВПП в темное время суток или в условиях ограниченной видимости. Эти системы освещения классифицируются по интенсивности или яркости, которую они способны обеспечить: огни высокой интенсивности освещения взлетно-посадочной полосы (HIRL), огни средней интенсивности освещения взлетно-посадочной полосы (MIRL) и огни низкой интенсивности освещения взлетно-посадочной полосы (LIRL). HIRL

Runway end identifier lights (REIL). One component of the runway lighting system. These lights are installed at many airfields to provide rapid and positive identification of the approach end of a particular runway.

Runway incursion. Any occurrence at an airport involving an aircraft, vehicle, person, or object on the ground that creates a collision hazard or results in loss of separation with an aircraft taking off, intending to takeoff, landing, or intending to land.

Выезд на ВПП. Любое событие в аэропорту с участием воздушного судна, транспортного средства, человека или объекта на земле, которое создает опасность столкновения или приводит к потере эшелонирования с воздушным судном, которое взлетает, намеревается взлететь, приземляется или намеревается приземлиться.

Runway threshold markings. Runway threshold markings come in two configurations. They either consist of eight longitudinal stripes of uniform dimensions disposed symmetrically about the runway centerline, or the number of stripes is related to the runway width. A threshold marking helps identify the beginning of the runway that is available for landing. In some instances, the landing threshold may be displaced. 

Маркировка порога ВПП. Маркировка порога ВПП бывает двух видов. Она либо состоит из восьми продольных полос одинакового размера, расположенных симметрично относительно осевой линии ВПП, либо количество полос зависит от ширины ВПП. Маркировка порога помогает обозначить начало ВПП, доступной для посадки. В некоторых случаях порог ВПП может быть смещен

safety (SQUAT) switch. An electrical switch mounted on one of the landing gear struts. It is used to sense when the weight of the aircraft is on the wheels.

Scan. A procedure used by the pilot to visually identify all resources of information in flight.

Sea level. A reference height used to determine standard atmospheric conditions and altitude measurements. Segmented circle. A visual ground based structure to provide traffic pattern information.

Service ceiling. The maximum density altitude where the best rate-of-climb airspeed will produce a 100 feet-per-minute climb at maximum weight while in a clean configuration with maximum continuous power.

Servo tab. An auxiliary control mounted on a primary control surface, which automatically moves in the direction opposite the primary control to provide an aerodynamic assist in the movement of the control. Shaft horse power (SHP).

Turboshaft engines are rated in shaft horsepower and calculated by use of a dynamometer device. Shaft horsepower is exhaust thrust converted to a rotating shaft. Shock waves. A compression wave formed when a body moves through the air at a speed greater than the speed of sound.

Sideslip. A slip in which the airplane’s longitudinal axis remains parallel to the original flightpath, but the airplane no longer flies straight ahead. Instead, the horizontal component of wing lift forces the airplane to move sideways toward the low wing.

Боковое скольжение. Скольжение, при котором продольная ось самолёта остаётся параллельной первоначальной траектории полёта, но самолёт больше не летит прямо. Вместо этого горизонтальная составляющая подъёмной силы крыла заставляет самолёт двигаться боком к низко расположенному крылу.

Single engine absolute ceiling. The altitude that a twin engine airplane can no longer climb with one engine inoperative. Single engine service ceiling. The altitude that a twin engine airplane can no longer climb at a rate greater than 50 fpm with one engine inoperative.

Skid. A condition where the tail of the airplane follows a path outside the path of the nose during a turn.

Занос. Состояние, при котором хвостовая часть самолёта во время поворота следует траектории, выходящей за пределы траектории носовой части.

Slip. An intentional maneuver to decrease airspeed or increase rate of descent, and to compensate for a crosswind on landing. A slip can also be unintentional when the pilot fails to maintain the aircraft in coordinated flight.

Скольжение. Преднамеренный манёвр для снижения скорости или увеличения скорости снижения, а также для компенсации бокового ветра при посадке. Скольжение также может быть непреднамеренным, когда пилот не может поддерживать координированный полёт самолёта.

Specific excess power (PS). Measured in feet per minute or feet per second, it represents rate of energy change—the ability of an airplane to climb or accelerate from a given flight condition. Available specific excess power is found by dividing the difference between power available and power required by the airplane’s weight.

Удельная избыточная мощность (PS). Измеряется в футах в минуту или футах в секунду и отражает скорость изменения энергии — способность самолёта набирать высоту или разгоняться из заданного состояния полёта. Доступная удельная избыточная мощность определяется путём деления разницы между доступной мощностью и потребляемой мощностью, исходя из веса самолёта.

Specific fuel consumption. Number of pounds of fuel consumed in 1 hour to produce 1 HP.

дельный расход топлива. Количество фунтов топлива, потребляемое за час для выработки 1 л.с. мощьности

Speed brakes. A control system that extends from the airplane structure into the airstream to produce drag and slow the airplane.

Воздушные тормоза. Система управления, которая простирается от конструкции самолёта в воздушный поток, создавая сопротивление и замедляя самолёт.

Speed instability. A condition in the region of reverse command where a disturbance that causes the airspeed to decrease causes total drag to increase, which in turn, causes the airspeed to decrease further.

Нестабильность скорости. Состояние в области обратного управления, когда возмущение, вызывающее уменьшение воздушной скорости, приводит к увеличению общего сопротивления, что, в свою очередь, приводит к дальнейшему снижению воздушной скорости.

Speed sense. The ability to sense instantly and react to any reasonable variation of airspeed.

Чувствительность к скорости. Способность мгновенно определять и реагировать на любые разумные изменения воздушной скорости.

Speed. The distance traveled in a given time.

Spin. An aggravated stall that results in what is termed an “autorotation” wherein the airplane follows a downward corkscrew path. As the airplane rotates around the vertical axis, the rising wing is less stalled than the descending wing creating a rolling, yawing, and pitching motion.

Spiral instability. A condition that exists when the static directional stability of the airplane is very strong as compared to the effect of its dihedral in maintaining lateral equilibrium.

Spiraling slipstream. The slipstream of a propeller-driven airplane rotates around the airplane. This slipstream strikes the left side of the vertical fin, causing the airplane to yaw slightly. Vertical stabilizer offset is sometimes used by aircraft designers to counteract this tendency. Split shaft turbine engine. See free power turbine engine.

Spoilers. High-drag devices that can be raised into the air flowing over an airfoil, reducing lift and increasing drag. Spoilers are used for roll control on some aircraft. Deploying spoilers on both wings at the same time allows the aircraft to descend without gaining speed. Spoilers are also used to shorten the ground roll after landing.

Spool. A shaft in a turbine engine which drives one or more compressors with the power derived from one or more turbines.

Stabilator. A single-piece horizontal tail surface on an airplane that pivots around a central hinge point. A stabilator serves the purposes of both the horizontal stabilizer and the elevator.

Stability. The inherent quality of an airplane to correct for conditions that may disturb its equilibrium, and to return or to continue on the original flightpath. It is primarily an airplane design characteristic.

tabilized approach. A landing approach in which the pilot establishes and maintains a constant angle glidepath towards a predetermined point on the landing runway. It is based on the pilot’s judgment of certain visual cues, and depends on the maintenance of a constant final descent airspeed and configuration. Stall strips. A spoiler attached to the inboard leading edge of some wings to cause the center section of the wing to stall before the tips. This assures lateral control throughout the stall.

Stall. A rapid decrease in lift caused by the separation of airflow from the wing’s surface brought on by exceeding the critical angle of attack. A stall can occur at any pitch attitude or airspeed.

Standard atmosphere. At sea level, the standard atmosphere consists of a barometric pressure of 29.92 inches of mercury ("Hg) or 1013.2 millibars, and a temperature of 15 °C (59 °F). Pressure and temperature normally decrease as altitude increases. The standard lapse rate in the lower atmosphere for each 1,000 feet of altitude is approximately 1 "Hg and 2 °C (3.5 °F). For example, the standard pressure and temperature at 3,000 feet mean sea level (MSL) is 26.92 "Hg (29.92 – 3) and 9 °C (15 °C – 6 °C).

Standard day. See standard atmosphere. Standard empty weight (GAMA). This weight consists of the airframe, engines, and all items of operating equipment that have fixed locations and are permanently installed in the airplane; including fixed ballast, hydraulic fluid, unusable fuel, and full engine oil.

Standard weights. These have been established for numerous items involved in weight and balance computations. These weights should not be used if actual weights are available.

Standard-rate turn. A turn at the rate of 3º per second which enables the airplane to complete a 360º turn in 2 minutes.

Starter/generator. A combined unit used on turbine engines. The device acts as a starter for rotating the engine, and after running, internal circuits are shifted to convert the device into a generator.

Static stability. The initial tendency an aircraft displays when disturbed from a state of equilibrium.

Station. A location in the airplane that is identified by a number designating its distance in inches from the datum. The datum is, therefore, identified as station zero. An item located at station +50 would have an arm of 50 inches.

Stick puller. A device that applies aft pressure on the control column when the airplane is approaching the maximum operating speed.

Stick pusher. A device that applies an abrupt and large forward force on the control column when the airplane is nearing an angle of attack where a stall could occur.

Stick shaker. An artificial stall warning device that vibrates the control column.

Stress risers. A scratch, groove, rivet hole, forging defect, or other structural discontinuity that causes a concentration of stress.

Subsonic. Speed below the speed of sound. Supercharger. An engine- or exhaust-driven air compressor used to provide additional pressure to the induction air so the engine can produce additional power.

Supersonic. Speed above the speed of sound.

Supplemental Type Certificate (STC). A certificate authorizing an alteration to an airframe, engine, or component that has been granted an approved type certificate.

Swept-wing. A wing planform in which the tips of the wing are farther back than the wing root.

Tailwheel aircraft. See conventional landing gear. Takeoff roll (ground roll). The total distance required for an aircraft to become airborne.

Target reverser. A thrust reverser in a jet engine in which clamshell doors swivel from the stowed position at the engine tailpipe to block all of the outflow and redirect some component of the thrust forward.

Taxiway lights. Omnidirectional lights that outline the edges of the taxiway and are blue in color. Taxiway turnoff lights. Flush lights which emit a steady green color.

Tetrahedron. A large, triangular-shaped, kite-like object installed near the runway. Tetrahedrons are mounted on a pivot and are free to swing with the wind to show the pilot the direction of the wind as an aid in takeoffs and landings.

Throttle. The valve in a carburetor or fuel control unit that determines the amount of fuel-air mixture that is fed to the engine.

Thrust line. An imaginary line passing through the center of the propeller hub, perpendicular to the plane of the propeller rotation.

Thrust reversers. Devices which redirect the flow of jet exhaust to reverse the direction of thrust.

Thrust. The force which imparts a change in the velocity of a mass. This force is measured in pounds but has no element of time or rate. The term, thrust required, is generally associated with jet engines. A forward force which propels the airplane through the air.

Timing. The application of muscular coordination at the proper instant to make flight, and all maneuvers incident thereto, a constant smooth process. Tire cord. Woven metal wire laminated into the tire to provide extra strength. A tire showing any cord must be replaced prior to any further flight.

Torque meter. An indicator used on some large reciprocating engines or on turboprop engines to indicate the amount of torque the engine is producing.

Torque sensor. See torque meter.

Torque. 1. A resistance to turning or twisting. 2. Forces that produce a twisting or rotating motion. 3. In an airplane, the tendency of the aircraft to turn (roll) in the opposite direction of rotation of the engine and propeller. Total drag. The sum of the parasite and induced drag.

Total energy error. An energy error where the total amount of mechanical energy is not correct. The airplane has too much or too little total energy relative to the intended altitude-speed profile. When this error occurs, the pilot will observe that altitude and airspeed deviate in the same direction (e.g., higher and faster than desired; or lower and slower than desired). An example would be an airplane on final approach that is above the desired glide slope and at a faster airspeed than desired. Total mechanical energy. Sum of the energy in altitude (potential energy) and the energy in airspeed (kinetic energy). Touchdown zone lights. Two rows of transverse light bars disposed symmetrically about the runway centerline in the runway touchdown zone. Track. The actual path made over the ground in flight. Trailing edge. The portion of the airfoil where the airflow over the upper surface rejoins the lower surface airflow. Transition liner. The portion of the combustor that directs the gases into the turbine plenum. Transonic. At the speed of sound. Transponder. The airborne portion of the secondary surveillance radar system. The transponder emits a reply when queried by a radar facility. Tricycle gear. Landing gear employing a third wheel located on the nose of the aircraft. Trim tab. A small auxiliary hinged portion of a movable control surface that can be adjusted during flight to a position resulting in a balance of control forces. G-15 Triple spool engine. Usually a turbofan engine design where the fan is the N1 compressor, followed by the N2 intermediate compressor, and the N3 high pressure compressor, all of which rotate on separate shafts at different speeds. Tropopause. The boundary layer between the troposphere and the mesosphere which acts as a lid to confine most of the water vapor, and the associated weather, to the troposphere. Troposphere. The layer of the atmosphere extending from the surface to a height of 20,000 to 60,000 feet depending on latitude. True airspeed (TAS). Calibrated airspeed corrected for altitude and nonstandard temperature. Because air density decreases with an increase in altitude, an airplane has to be flown faster at higher altitudes to cause the same pressure difference between pitot impact pressure and static pressure. Therefore, for a given calibrated airspeed, true airspeed increases as altitude increases; or for a given true airspeed, calibrated airspeed decreases as altitude increases. True altitude. The vertical distance of the airplane above sea level—the actual altitude. It is often expressed as feet above mean sea level (MSL). Airport, terrain, and obstacle elevations on aeronautical charts are true altitudes. T-tail. An aircraft with the horizontal stabilizer mounted on the top of the vertical stabilizer, forming a T. Turbine blades. The portion of the turbine assembly that absorbs the energy of the expanding gases and converts it into rotational energy. Turbine outlet temperature (TOT). The temperature of the gases as they exit the turbine section. Turbine plenum. The portion of the combustor where the gases are collected to be evenly distributed to the turbine blades. Turbine rotors. The portion of the turbine assembly that mounts to the shaft and holds the turbine blades in place. Turbine section. The section of the engine that converts high pressure high temperature gas into rotational energy. Turbocharger. An air compressor driven by exhaust gases, which increases the pressure of the air going into the engine through the carburetor or fuel injection system. Turbofan engine. A turbojet engine in which additional propulsive thrust is gained by extending a portion of the compressor or turbine blades outside the inner engine case. The extended blades propel bypass air along the engine axis but between the inner and outer casing. The air is not combusted but does provide additional thrust. Turbojet engine. A jet engine incorporating a turbine-driven air compressor to take in and compress air for the combustion of fuel, the gases of combustion being used both to rotate the turbine and create a thrust producing jet. Turboprop engine. A turbine engine that drives a propeller through a reduction gearing arrangement. Most of the energy in the exhaust gases is converted into torque, rather than its acceleration being used to propel the aircraft. Turbulence. An occurrence in which a flow of fluid is unsteady. Turn coordinator. A rate gyro that senses both roll and yaw due to the gimbal being canted. Has largely replaced the turn-and-slip indicator in modern aircraft. Turn-and-slip indicator. A flight instrument consisting of a rate gyro to indicate the rate of yaw and a curved glass inclinometer to indicate the relationship between gravity and centrifugal force. The turn-and-slip indicator indicates the relationship between angle of bank and rate of yaw. Also called a turn-and-bank indicator. Turning error. One of the errors inherent in a magnetic compass caused by the dip compensating weight. It shows up only on turns to or from northerly headings in the Northern Hemisphere and southerly headings in the Southern Hemisphere. Turning error causes the compass to lead turns to the north or south and lag turns away from the north or south. U Ultimate load factor. In stress analysis, the load that causes physical breakdown in an aircraft or aircraft component during a strength test, or the load that according to computations, should cause such a breakdown. Unfeathering accumulator. Tanks that hold oil under pressure which can be used to unfeather a propeller. UNICOM. A nongovernment air/ground radio communication station which may provide airport information at public use airports where there is no tower or FSS. Unusable fuel. Fuel that cannot be consumed by the engine. This fuel is considered part of the empty weight of the aircraft. Useful load. The weight of the pilot, copilot, passengers, baggage, usable fuel, and drainable oil. It is the basic empty weight subtracted from the maximum allowable gross weight. This term applies to general aviation aircraft only. Utility category. An airplane that has a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for limited acrobatic operation. G-16 V V1. Critical engine failure speed or takeoff decision speed. It is the speed at which the pilot is to continue the takeoff in the event of an engine failure or other serious emergency. At speeds less than V1, it is considered safer to stop the aircraft within the accelerate-stop distance. It is also the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance. V2. takeoff safety speed, or a referenced airspeed obtained after lift-off at which the required one engine-inoperative climb performance can be achieved. VA. The design maneuvering speed. This is the “rough air” speed and the maximum speed for abrupt maneuvers. If during flight, rough air or severe turbulence is encountered, reduce the airspeed to maneuvering speed or less to minimize stress on the airplane structure. It is important to consider weight when referencing this speed. For example, VA may be 100 knots when an airplane is heavily loaded, but only 90 knots when the load is light. Vapor lock. A condition in which air enters the fuel system and it may be difficult, or impossible, to restart the engine. Vapor lock may occur as a result of running a fuel tank completely dry, allowing air to enter the fuel system. On fuel-injected engines, the fuel may become so hot it vaporizes in the fuel line, not allowing fuel to reach the cylinders. V-bars. The flight director displays on the attitude indicator that provide control guidance to the pilot. Vector. A force vector is a graphic representation of a force and shows both the magnitude and direction of the force. Velocity. The speed or rate of movement in a certain direction. Vertical axis. An imaginary line passing vertically through the center of gravity of an aircraft. The vertical axis is called the z-axis or the yaw axis. Vertical card compass. A magnetic compass that consists of an azimuth on a vertical card, resembling a heading indicator with a fixed miniature airplane to accurately present the heading of the aircraft. The design uses eddy current damping to minimize lead and lag during turns. Vertical speed indicator (VSI). An instrument that uses static pressure to display a rate of climb or descent in feet per minute. The VSI can also sometimes be called a vertical velocity indicator (VVI). Vertical stability. Stability about an aircraft’s vertical axis. Also called yawing or directional stability. VFE. The maximum speed with the flaps extended. The upper limit of the white arc. VFO. The maximum speed that the flaps can be extended or retracted. VFR Terminal Area Charts (1:250,000). Depict Class B airspace which provides for the control or segregation of all the aircraft within the Class B airspace. The chart depicts topographic information and aeronautical information which includes visual and radio aids to navigation, airports, controlled airspace, restricted areas, obstructions, and related data. V-G diagram. A chart that relates velocity to load factor. It is valid only for a specific weight, configuration, and altitude and shows the maximum amount of positive or negative lift the airplane is capable of generating at a given speed. Also shows the safe load factor limits and the load factor that the aircraft can sustain at various speeds. Visual approach slope indicator (VASI). The most common visual glidepath system in use. The VASI provides obstruction clearance within 10° of the extended runway centerline, and to 4 nautical miles (NM) from the runway threshold. Visual Flight Rules (VFR). Code of Federal Regulations that govern the procedures for conducting flight under visual conditions. VLE. Landing gear extended speed. The maximum speed at which an airplane can be safely flown with the landing gear extended. VLO. Landing gear operating speed. The maximum speed for extending or retracting the landing gear if using an airplane equipped with retractable landing gear. VLOF. Lift-off speed. The speed at which the aircraft departs the runway during takeoff. VMC. Minimum control airspeed. This is the minimum flight speed at which a twin-engine airplane can be satisfactorily controlled when an engine suddenly becomes inoperative and the remaining engine is at takeoff power. VMD. Minimum drag speed. VMO. Maximum operating speed expressed in knots. VNE. Never-exceed speed. Operating above this speed is prohibited since it may result in damage or structural failure. The red line on the airspeed indicator. VNO. Maximum structural cruising speed. Do not exceed this speed except in smooth air. The upper limit of the green arc. VP. Minimum dynamic hydroplaning speed. The minimum speed required to start dynamic hydroplaning. VR. Rotation speed. The speed that the pilot begins rotating the aircraft prior to lift-off. G-17 VS0. Stalling speed or the minimum steady flight speed in the landing configuration. In small airplanes, this is the power-off stall speed at the maximum landing weight in the landing configuration (gear and flaps down). The lower limit of the white arc. VS1. Stalling speed or the minimum steady flight speed obtained in a specified configuration. For most airplanes, this is the power-off stall speed at the maximum takeoff weight in the clean configuration (gear up, if retractable, and flaps up). The lower limit of the green arc. V-speeds. Designated speeds for a specific flight condition. VSSE. Safe, intentional one-engine inoperative speed. The minimum speed to intentionally render the critical engine inoperative. V-tail. A design which utilizes two slanted tail surfaces to perform the same functions as the surfaces of a conventional elevator and rudder configuration. The fixed surfaces act as both horizontal and vertical stabilizers. VX. Best angle-of-climb speed. The airspeed at which an airplane gains the greatest amount of altitude in a given distance. It is used during a short-field takeoff to clear an obstacle. VXSE. Best angle of climb speed with one engine inoperative. The airspeed at which an airplane gains the greatest amount of altitude in a given distance in a light, twin-engine airplane following an engine failure. VY. Best rate-of-climb speed. This airspeed provides the most altitude gain in a given period of time. VYSE. Best rate-of-climb speed with one engine inoperative. This airspeed provides the most altitude gain in a given period of time in a light, twin-engine airplane following an engine failure. W Wake turbulence. Wingtip vortices that are created when an airplane generates lift. When an airplane generates lift, air spills over the wingtips from the high pressure areas below the wings to the low pressure areas above them. This flow causes rapidly rotating whirlpools of air called wingtip vortices or wake turbulence. Waste gate. A controllable valve in the tailpipe of an aircraft reciprocating engine equipped with a turbocharger. The valve is controlled to vary the amount of exhaust gases forced through the turbocharger turbine. Weathervane. The tendency of the aircraft to turn into the relative wind. Weight and balance. The aircraft is said to be in weight and balance when the gross weight of the aircraft is under the max gross weight, and the center of gravity is within limits and will remain in limits for the duration of the flight. Weight. A measure of the heaviness of an object. The force by which a body is attracted toward the center of the earth (or another celestial body) by gravity. Weight is equal to the mass of the body times the local value of gravitational acceleration. One of the four main forces acting on an aircraft. Equivalent to the actual weight of the aircraft. It acts downward through the aircraft’s center of gravity toward the center of the earth. Weight opposes lift. Wheelbarrowing. A condition caused when forward yoke or stick pressure during takeoff or landing causes the aircraft to ride on the nose-wheel alone. Wind correction angle. Correction applied to the course to establish a heading so that track will coincide with course. Wind direction indicators. Indicators that include a wind sock, wind tee, or tetrahedron. Visual reference will determine wind direction and runway in use. Wind shear. A sudden, drastic shift in wind speed, direction, or both that may occur in the horizontal or vertical plane. Windmilling. When the air moving through a propeller creates the rotational energy. Windsock. A truncated cloth cone open at both ends and mounted on a freewheeling pivot that indicates the direction from which the wind is blowing. Wing area. The total surface of the wing (square feet), which includes control surfaces and may include wing area covered by the fuselage (main body of the airplane), and engine nacelles. Wing span. The maximum distance from wingtip to wingtip. Wing twist. A design feature incorporated into some wings to improve aileron control effectiveness at high angles of attack during an approach to a stall. Wing. Airfoil attached to each side of the fuselage and are the main lifting surfaces that support the airplane in flight. Wingtip vortices. The rapidly rotating air that spills over an airplane’s wings during flight. The intensity of the turbulence depends on the airplane’s weight, speed, and configuration. It is also referred to as wake turbulence. Vortices from heavy aircraft may be extremely hazardous to small aircraft. Y Yaw string. A string on the nose or windshield of an aircraft in view of the pilot that indicates any slipping or skidding of the aircraft. G-18 Yaw. Rotation about the vertical axis of an aircraft. Z Zero fuel weight. The weight of the aircraft to include all useful load except fuel. Zero sideslip. A maneuver in a twin-engine airplane with one engine inoperative that involves a small amount of bank and slightly uncoordinated flight to align the fuselage with the direction of travel and minimize drag. Zero thrust (simulated feather). An engine configuration with a low power setting that simulates a propeller feathered condition.