Expect-further-clearance (EFC). The time a pilot can expect to receive clearance beyond a clearance limit. 

FAA. Federal Aviation Administration. 

FAF.  See final approach fix. 

False horizon.  Inaccurate visual information for aligning the aircraft, caused by various natural and geometric formations that disorient the pilot from the actual horizon. 

Federal airways.  Class E airspace areas that extend upward from 1,200 feet to, but not including, 18,000 feet MSL, unless otherwise specified. 

Feeder facilities. Used by ATC to direct aircraft to intervening fixes between the en route structure and the initial approach fix. 

Final approach. Part of an instrument approach procedure in which alignment and descent for landing are accomplished. 

Final approach fix (FAF). The fix from which the IFR final approach to an airport is executed, and which identifies the beginning of the final approach segment. An FAF is designated on government charts by a Maltese cross symbol for nonprecision approaches, and a lightning bolt symbol for precision approaches. 

Fixating.  Staring at a single instrument, thereby interrupting the cross-check process. 

FL.  See flight level. 

Flight configurations.  Adjusting the aircraft control surfaces (including flaps and landing gear) in a manner that will achieve a specified attitude. 

Flight director indicator (FDI). One of the major components of a flight director system, it provides steering commands that the pilot (or the autopilot, if coupled) follows. 

Flight level (FL).  A measure of altitude (in hundreds of feet) used by aircraft flying above 18,000 feet with the altimeter set at 29.92" Hg. 

Flight management system (FMS).  Provides pilot and crew with highly accurate and automatic long-range navigation capability, blending available inputs from long- and short- range sensors. 

Flightpath.  The line, course, or track along which an aircraft is flying or is intended to be flown. 

Flight patterns.  Basic maneuvers, flown by reference to the instruments rather than outside visual cues, for the purpose of practicing basic attitude flying. The patterns simulate maneuvers encountered on instrument flights such as holding patterns, procedure turns, and approaches. 

Flight strips. Paper strips containing instrument flight information, used by ATC when processing flight plans. 

FMS.  See flight management system. 

Form drag. The drag created because of the shape of a component or the aircraft. 

Fundamental skills.  Pilot skills of instrument cross-check, instrument interpretation, and aircraft control. 

Glideslope (GS).  Part of the ILS that projects a radio beam upward at an angle of approximately 3° from the approach end of an instrument runway. The glideslope provides vertical guidance to aircraft on the final approach course for the aircraft to follow when making an ILS approach along the localizer path. 

Glideslope intercept altitude.  The minimum altitude of an intermediate approach segment prescribed for a precision approach that ensures obstacle clearance. 

Global landing system (GLS). An instrument approach with lateral and vertical guidance with integrity limits (similar to barometric vertical navigation (BRO VNAV). 

Global navigation satellite systems (GNSS). Satellite navigation systems that provide autonomous geo-spatial positioning with global coverage. It allows small electronic 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. 

GNSS. See global navigation satellite systems. 

Global positioning system (GPS). Navigation system that uses satellite rather than ground-based transmitters for location information. 

