D
DECISION ALTITUDE/HEIGHT (DA/H) (ICAO)
A specified altitude or height (A/H) in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established.
NOTES:
Decision altitude (DA) is referenced to mean sea level (MSL) and decision height (DH) is referenced to the threshold elevation.
The required visual reference means that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path.
DECISION HEIGHT (DH) (USA )
With respect to the operation of aircraft, means the height at which a decision must be made, during an ILS or PAR instrument approach, to either continue the approach or to execute a missed approach.
NOTE: Jeppesen approach charts use the abbreviation DA(H). The decision altitude “DA” is referenced to mean sea level (MSL) and the parenthetical decision height (DH) is referenced to the TDZE or threshold elevation. A DA(H) of 1,440 ft (200 ft is a Decision Altitude of 1,440 ft and a Decision Height of 200 ft.
DEPARTURE CLEARANCE VIA DATA LINK (DCL)
Provides assistance for requesting and delivering information and clearance, with the objective of reducing aircrew and controller workload. The DCL service shall be initiated by the aircrew at a suitable time between Ti and Tt where:
Ti –the earliest time at which a DCL service can be initiated;
Tt –the latest time after which an aircrew, having not completed the DCL service, is still able to receive by voice procedures and in due time, the vocal departure clearance.
The third time parameter of the DCL acknowledge procedure is T1 where:
T1–timer implemented in the ATS ground system between the sending by ATS ground system of the DCL clearance message and the reception by it of the read-back of DCL clearance message.
DIRECT ROUTE
A requested route published on a Jeppesen Enroute or Area chart to assist pilots who have previous knowledge of acceptance of these routes by ATC. Use of a Direct route may require prior ATC approval and may not provide ATC or Advisory services, or be acceptable in flight plans.
DISPLACED THRESHOLD
A threshold that is located at a point on the runway other than the designated beginning of the runway.
E
ENROUTE FLIGHT ADVISORY SERVICE (FLIGHT WATCH)
A service specifically designed to provide, upon pilot request, timely weather information pertinent to the type of flight, intended route of flight, and altitude. The FSSs providing this service are indicated on Jeppesen Enroute and Area charts.
F
FAA AIR CARRIER OPERATIONS SPECIFICATIONS
Document issued to users operating under Federal Aviation Administration Regulations (FAR) Parts 121, 125, 127, 129, and 135. Operations Specifications are established and formalized by FARs. The primary purpose of FAA Air Carrier Operations Specifications is to provide a legally enforceable means of prescribing an authorization, limitation and/or procedures for a specific operator. Operations Specifications are subject to expeditious changes. These changes are usually too time critical to adopt through the regulatory process.
FEEDER FIX
The fix depicted on instrument approach procedure charts which establishes the starting point of the feeder route.
FEEDER ROUTE
Routes depicted on instrument approach procedure charts to designate routes for aircraft to proceed from the en route structure to the initial approach fix (IAF).
FINAL APPROACH COURSE
A published MLS course, a straight line extension of a localizer, a final approach radial/bearing, or a runway centerline all without regard to distance.
FINAL APPROACH (ICAO)
That part of an instrument approach procedure which commences at the specified final approach fix or point, or where such a fix or point is not specified,
at the end of the last procedure turn, base turn or inbound turn of a racetrack procedure, if specified; or
at the point of interception of the last track specified in the approach procedure; and ends at a point in the vicinity of an aerodrome from which:
a landing can be made; or
a missed approach procedure is initiated.
FINAL APPROACH FIX (FAF)
The fix from which the final approach (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated in the profile view of Jeppesen Terminal charts by the Maltese Cross symbol for non-precision approaches and by the glide slope/path intercept point on precision approaches. The glide slope/path symbol starts at the FAF. When ATC directs a lower-than-published Glide Slope/Path Intercept Altitude, it is the resultant actual point of the glide slope/path intercept.
FINAL APPROACH FIX (FAF) (AUSTRALIA)
A specified point on a non-precision approach which identifies the commencement of the final segment. The FAF is designated in the profile view of Jeppesen Terminal charts by the Maltese Cross symbol.
FINAL APPROACH—IFR (USA)
The flight path of an aircraft which is inbound to an airport on a final instrument approach course, beginning at the final approach fix or point and extending to the airport or the point where a circle-to-land maneuver or a missed approach is executed.
FINAL APPROACH POINT (FAP) (USA)
The point, applicable only to a non-precision approach with no depicted FAF (such as an on-airport VOR), where the aircraft is established inbound on the final approach course from the procedure turn and where the final approach descent may be commenced. The FAP serves as the FAF and identifies the beginning of the final approach segment.
FINAL APPROACH FIX OR POINT (FAP) (ICAO)
That fix or point of an instrument approach procedure where the final approach segment commences.
FINAL APPROACH POINT (FAP) (AUSTRALIA)
A specified point on the glide path of a precision instrument approach which identifies the commencement of the final segment.
NOTE: The FAP is co-incident with the FAF of a localizer-based non-precision approach.
FLIGHT INFORMATION REGION (FIR, UIR)
An airspace of defined dimensions within which Flight Information Service and Alerting Service are provided.
Flight Information Service (FIS) – A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.
Alerting Service – A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required.
FLIGHT WATCH (USA)
A shortened term for use in air-ground contacts to identify the flight service station providing Enroute Flight Advisory Service; e.g., “Oakland Flight Watch.”
FLY-BY WAYPOINT
A fly-by waypoint requires the use of turn anticipation to avoid overshoot of the next flight segment.
FLY-OVER WAYPOINT
A fly-over waypoint precludes any turn until the waypoint is overflown and is followed by an intercept maneuver of the next flight segment.