Glossary

Frise-type aileron. Aileron having the nose portion Global positioning system (GPS). Navigation system projecting ahead of the hinge line. When the trailing edge that uses satellite rather than ground-based transmitters for of the aileron moves up, the nose projects below the wing’s location information. lower surface and produces some parasite drag, decreasing the amount of adverse yaw. GLS. See global landing system. Front. The boundary between two different air masses. GNSS. See global navigation satellite system. Frost. Ice crystal deposits formed by sublimation when Goniometer. As used in radio frequency (RF) antenna temperature and dewpoint are below freezing. systems, a direction-sensing device consisting of two fixed loops of wire oriented 90° from each other, which separately Fuel load. The expendable part of the load of the airplane. sense received signal strength and send those signals to two It includes only usable fuel, not fuel required to fill the lines rotors (also oriented 90°) in the sealed direction-indicating or that which remains trapped in the tank sumps. instrument. The rotors are attached to the direction-indicating needle of the instrument and rotated by a small motor until Fundamental skills. Pilot skills of instrument cross-check, minimum magnetic field is sensed near the rotors. instrument interpretation, and aircraft control. GPS. See global positioning system. Fuselage. The section of the airplane that consists of the cabin and/or cockpit, containing seats for the occupants and GPS Approach Overlay Program. An authorization for the controls for the airplane. pilots to use GPS avionics under IFR for flying designated existing nonprecision instrument approach procedures, with G the exception of LOC, LDA, and SDF procedures. GAMA. General Aviation Manufacturers Association. GPWS. See ground proximity warning system. Gimbal ring. A type of support that allows an object, such Graveyard spiral. The illusion of the cessation of a turn while as a gyroscope, to remain in an upright condition when its still in a prolonged, coordinated, constant rate turn, which base is tilted. can lead a disoriented pilot to a loss of control of the aircraft. Glideslope (GS). Part of the ILS that projects a radio beam Great circle route. The shortest distance across the surface upward at an angle of approximately 3° from the approach of a sphere (the Earth) between two points on the surface. end of an instrument runway. The glideslope provides vertical guidance to aircraft on the final approach course for Ground adjustable trim tab. Non-movable metal trim tab the aircraft to follow when making an ILS approach along on a control surface. Bent in one direction or another while the localizer path. on the ground to apply trim forces to the control surface. Glideslope intercept altitude. The minimum altitude of an Ground effect. The condition of slightly increased air pressure intermediate approach segment prescribed for a precision below an airplane wing or helicopter rotor system that increases approach that ensures obstacle clearance. the amount of lift produced. It exists within approximately one wing span or one rotor diameter from the ground. It results Global landing system (GLS). An instrument approach with from a reduction in upwash, downwash, and wingtip vortices, lateral and vertical guidance with integrity limits (similar to and provides a corresponding decrease in induced drag. barometric vertical navigation (BARO VNAV). Ground proximity warning system (GPWS). A system Global navigation satellite system (GNSS). Satellite designed to determine an aircraft’s clearance above the Earth navigation system that provides autonomous geospatial and provides limited predictability about aircraft position positioning with global coverage. It allows small electronic relative to rising terrain. receivers to determine their location (longitude, latitude, and altitude) to within a few meters using time signals transmitted along a line of sight by radio from satellites. G-13