Glossary

Turbocharger. An air compressor driven by exhaust gases, Underpower. Using less power than required for the purpose which increases the pressure of the air going into the engine of achieving a faster rate of airspeed change. through the carburetor or fuel injection system. United States Terminal Procedures Publication (TPP). Turbofan engine. A fanlike turbojet engine designed to Booklets published in regional format by FAA Aeronautical create additional thrust by diverting a secondary airflow Navigation Products (AeroNav Products) that include DPs, around the combustion chamber. STARs, IAPs, and other information pertinent to IFR flight. Turbojet engine. A turbine engine which produces its thrust Unusual attitude. An unintentional, unanticipated, or entirely by accelerating the air through the engine. extreme aircraft attitude. Turboprop engine. A turbine engine which drives a Useful load. The weight of the pilot, copilot, passengers, propeller through a reduction gearing arrangement. Most of baggage, usable fuel, and drainable oil. It is the basic empty the energy in the exhaust gases is converted into torque, rather weight subtracted from the maximum allowable gross weight. than using its acceleration to drive the aircraft. This term applies to general aviation aircraft only. Turboshaft engine. A gas turbine engine that delivers power User-defined waypoints. Waypoint location and other data through a shaft to operate something other than a propeller. which may be input by the user, this is the only GPS database information that may be altered (edited) by the user. Turn-and-slip indicator. A flight instrument consisting of a rate gyro to indicate the rate of yaw and a curved glass V inclinometer to indicate the relationship between gravity and V . See takeoff decision speed. 1 centrifugal force. The turn-and-slip indicator indicates the relationship between angle of bank and rate of yaw. Also V . See takeoff safety speed. 2 called a turn-and-bank indicator. V . See maneuvering speed. A Turn coordinator. A rate gyro that senses both roll and yaw due to the gimbal being canted. Has largely replaced Vapor lock. A problem that mostly affects gasoline-fuelled the turn-and-slip indicator in modern aircraft. internal combustion engines. It occurs when the liquid fuel changes state from liquid to gas while still in the fuel delivery TWEB. See Transcribed Weather Broadcast. system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor or fuel injection system, U resulting in transient loss of power or complete stalling. UHF. See ultra-high frequency. Restarting the engine from this state may be difficult. The fuel can vaporize due to being heated by the engine, by the Ultra-high frequency (UHF). The range of electromagnetic local climate or due to a lower boiling point at high altitude. frequencies between 300 MHz and 3,000 MHz. Variation. Compass error caused by the difference in Ulitimate load factor. In stress analysis, the load that the physical locations of the magnetic north pole and the causes physical breakdown in an aircraft or aircraft geographic north pole. component during a strength test, or the load that according to computations, should cause such a breakdown. VASI. See visual approach slope indicator. Uncaging. Unlocking the gimbals of a gyroscopic instrument, VDP. See visual descent point. making it susceptible to damage by abrupt flight maneuvers or rough handling. Vector. A force vector is a graphic representation of a force and shows both the magnitude and direction of the force. Uncontrolled airspace. Class G airspace that has not been designated as Class A, B, C, D, or E. It is airspace in which Vectoring. Navigational guidance by assigning headings. air traffic control has no authority or responsibility to control air traffic; however, pilots should remember there are VFR VEF. Calibrated airspeed at which the critical engine of a minimums which apply to this airspace. multi-engine aircraft is assumed to fail. G-32