Aeronautical Terms beginning with F
Feeder Route
A feeder route is a route depicted on IAP charts to designate courses for aircraft to proceed from the en route structure to the IAF. Feeder routes, also referred to as approach transitions,technically are not considered approach segments but are an integral part of many IAPs.
Field
See Database Field
Final Approach and Takeoff Area (FATO)
The FATO is a defined heliport area over which the final approach to a hover or a departure is made. The touchdown and lift-off area (TLOF) where the helicopter is permitted to land is normally centered in the FATO. A safety area is provided around the FATO.
Fix
A geographical position determined by visual reference to the surface,by reference to one or more radio NAVAIDs,by celestial plotting,or by another navigational device. Note:Fix is a generic name for a geographical position and is referred to as a fix,waypoint, intersection,reporting point,etc.
Flight Information Region (FIR)
A FIR is an airspace of defined dimensions within which Flight Information Service and Alerting Service are provided. Flight Information Service (FIS) is a service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. Alerting Service is a service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid,and assist such organizations as required.
Flight Level (FL)
A flight level is a level of constant atmospheric pressure related to a reference datum of 29.92 in.Hg. Each flight level is stated in three digits that represents hundreds of feet. For example,FL 250 represents an altimeter indication of 25,000 feet.
Floating Waypoints
Floating waypoints represent airspace fixes at a point in space not directly associated with a conventional airway. In many cases they may be established for such purposes as ATC metering fixes, holding points,RNAV-direct routing,gateway waypoints,STAR origination points leaving the en route structure,and SID terminating points joining the en route structure.
Fly-By (FB) Waypoint
A waypoint that requires the use of turn anticipation to avoid overshooting the next flight segment.
Fly-Over (FO) Waypoint
A waypoint that precludes any turn until the waypoint is overflown,and is followed by either an intercept maneuver of the next flight segment or direct flight to the next waypoint.
Four Corner Post Configuration
An arrangement of air traffic pathways in a terminal area that brings incoming flights over fixes at four corners of the traffic area,while outbound flights depart between the fixes, thus minimizing conflicts between arriving and departing traffic.
False Horizon
An optical illusion where the pilot confuses a row of lights along a road or other straight line as the horizon.
False Start
See HUNG START.
Feathering Propeller (Feathered)
A controllable pitch propeller with a pitch range sufficient to allow the blades to be turned parallel to the line of flight to reduce drag and prevent further damage to an engine that has been shut down after a malfunction.
Fixation
A psychological condition where the pilot fixes attention on a single source of information and ignores all other sources.
Fixed Shaft Turboprop Engine
A turboprop engine where the gas producer spool is directly connected to the output shaft.
Fixed-Pitch Propellers
Propellers with fixed blade angles. Fixed-pitch propellers are designed as climb propellers, cruise propellers, or standard propellers.
Flaps
Hinged portion of the trailing edge between the ailerons and fuselage. In some aircraft, ailerons and flaps are interconnected to produce full-span “flaperons.” In either case, flaps change the lift and drag on the wing.
Flat Pitch
A propeller configuration when the blade chord is aligned with the direction of rotation.
Flicker Vertigo
A disorientating condition caused from flickering light off the blades of the propeller.
Flight Director
An automatic flight control system in which the commands needed to fly the airplane are electronically computed and displayed on a flight instrument. The commands are followed by the human pilot with manual control inputs or, in the case of an autopilot system, sent to servos that move the flight controls.
Flight Idle
Engine speed, usually in the 70-80 percent range, for minimum flight thrust.
Floating
A condition when landing where the airplane does not settle to the runway due to excessive airspeed.
Force (F)
The energy applied to an object that attempts to cause the object to change its direction, speed, or motion. In aerodynamics, it is expressed as F, T(thrust), L(lift), W (weight), or D (drag), usually in pounds.
Form Drag
The part of parasite drag on a body resulting from the integrated effect of the static pressure acting normal to its surface resolved in the drag direction.
Forward Slip
A slip in which the airplane’s direction of motion continues the same as before the slip was begun. In a forward slip, the airplane’s longitudinal axis is at an angle to its flightpath.
Free Power Turbine Engine
A turboprop engine where the gas producer spool is on a separate shaft from the output shaft. The free power turbine spins independently of the gas producer and drives the output shaft.
Friction Drag
The part of parasitic drag on a body resulting from viscous shearing stresses over its wetted surface.
Frise-Type Aileron
Aileron having the nose portion projecting ahead of the hinge line. When the trailing edge of the aileron moves up, the nose projects below the wing’s lower surface and produces some parasite drag, decreasing the amount of adverse yaw.
Fuel Control Unit
The fuel-metering device used on a turbine engine that meters the proper quantity of fuel to be fed into the burners of the engine. It integrates the parameters of inlet air temperature, compressor speed, compressor discharge pressure, and exhaust gas temperature with the position of the cockpit power control lever.
Fuel Efficiency
Defined as the amount of fuel used to produce a specific thrust or horsepower divided by the total potential power contained in the same amount of fuel.
Fuel Heaters
A radiator-like device which has fuel passing through the core. A heat exchange occurs to keep the fuel temperature above the freezing point of water so that entrained water does not form ice crystals, which could block fuel flow.
Fuel Injection
A fuel metering system used on some aircraft reciprocating engines in which a constant flow of fuel is fed to injection nozzles in the heads of all cylinders just outside of the intake valve. It differs from sequential fuel injection in which a timed charge of high-pressure fuel is sprayed directly into the combustion chamber of the cylinder.
Fuel Load
The expendable part of the load of the airplane. It includes only usable fuel, not fuel required to fill the lines or that which remains trapped in the tank sumps.
Fuel Tank Sump
A sampling port in the lowest part of the fuel tank that the pilot can utilize to check for contaminants in the fuel.
Fuselage
The section of the airplane that consists of the cabin and/or cockpit, containing seats for the occupants and the controls for the airplane.
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.
Flight path
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.
FAASTeam
See Federal Aviation Administration Safety Team.
FAASTeam Program Manager
The person who designs, implements, and evaluates the FAASTeam within the FAA flight standards district office (FSDO) area of responsibility.
FAASTeam Representative
A volunteer within the aviation community who shares technical expertise and professional knowledge as a part of the FAASTeam.
Federal Aviation Administration Safety Team (FAASTeam)
An organization promoting safety standards and the reduction of aircraft related accidents. Each of the eight FAA Flight Standards regions have a dedicated FAASTeam office.
Flight review
A 14 CFR 61.56 requirement designed to assess and update a pilot’s knowledge and skills.
Flight training devices (FTDs)
A full-size replica of the instruments, equipment, panels, and controls of an aircraft, or set of aircraft, in an open flight deck area or in an enclosed cockpit. A force (motion) cueing system or visual system is not required.
Follow-up question
In the guided discussion method, a question used by an instructor to get the discussion back on track or to get the students to explain something more thoroughly.
Formal lecture
An oral presentation where the purpose is to inform, persuade, or entertain with little or no verbal participation by the listeners.
FTD
See flight training device.
Fixed Slot
A fixed, nozzle-shaped opening near the leading edge of a wing that ducts air onto the top surface of the wing. Its purpose is to increase lift at higher angles of attack.
Fixed-Pitch Propellers
Propellers with fixed blade angles. Fixed-pitch propellers are designed as climb propellers, cruise propellers, or standard propellers.
Flameout
A condition in the operation of a gas turbine engine in which the fire in the engine goes out due to either too much or too little fuel sprayed into the combustors.
Flaps
Hinged portion of the trailing edge between the ailerons and fuselage. In some aircraft ailerons and flaps are interconnected to produce full-span “flaperons.” In either case, flaps change the lift and drag on the wing.
Floor Load Limit
The maximum weight the floor can sustain per square inch/foot as provided by the manufacturer.
Fog
Cloud consisting of numerous minute water droplets and based at the surface; droplets are small enough to be suspended in the earth’s atmosphere indefinitely. (Unlike drizzle, it does not fall to the surface; differs from cloud only in that a cloud is not based at the surface; distinguished from haze by its wetness and gray color.)
Force (F)
The energy applied to an object that attempts to cause the object to change its direction, speed, or motion. In aerodynamics, it is expressed as F, T(thrust), L(lift), W (weight), or D (drag), usually in pounds.
Foreign Object Damage (FOD)
Damage to a gas turbine engine caused by some object being sucked into the engine while it is running. Debris from runways or taxiways can cause foreign object damage during ground operations, and the ingestion of ice and birds can cause FOD in flight.
Frise-Type Aileron
Aileron having the nose portion projecting ahead of the hinge line. When the trailing edge of the aileron moves up, the nose projects below the wing’s lower surface and produces some parasite drag, decreasing the amount of adverse yaw.
Front
The boundary between two different air masses.
Frost
Ice crystal deposits formed by sublimation when temperature and dewpoint are below freezing.
Fuel Load
The expendable part of the load of the airplane. It includes only usable fuel, not fuel required to fill the lines or that which remains trapped in the tank sumps.
Fuselage
The section of the airplane that consists of the cabin and/or cockpit, containing seats for the occupants and the controls for the airplane.
FEA/FCA
Flow Evaluation Area (FEA) / Flow Constrained Area (FEA) - FEA/FCAs provide reroutes using the Create Reroute capability and are published through a reroute advisory with an optional flight list attached. Stakeholders can monitor FEA/FCAs through reroute monitor in traffic situation display (TSD), web situation display (WSD) or collaborative constraint situation display (CCSD).
FSM
Flight Schedule Monitor. A tool used by Air Traffic Management Specialists to monitor air traffic demand at airports.
FSS
Flight Service Station. Air traffic facilities which provide pilot briefing, en route communications and VFR search and rescue services, assist lost aircraft and aircraft in emergency situations, relay ATC clearances, originate Notices to Airmen, broadcast aviation weather and NAS information, receive and process IFR flight plans, and monitor NAVAIDs. In addition, at selected locations, FSSs provide En Route Flight Advisory Service (Flight Watch), take weather observations, issue airport advisories, and advise Customs and Immigration of transborder flights.