FLAG ALARM-
(See FLAG.)
FLAMEOUT- An emergency condition caused by a loss of engine power.
FLAMEOUT PATTERN- An approach normally conducted by a single‐engine military aircraft experiencing loss or anticipating loss of engine power or control. The standard overhead approach starts at a relatively high altitude over a runway (“high key”) followed by a continuous 180 degree turn to a high, wide position (“low key”) followed by a continuous 180 degree turn final. The standard straight‐in pattern starts at a point that results in a straight‐in approach with a high rate of descent to the runway. Flameout approaches terminate in the type approach requested by the pilot (normally fullstop).

FLIGHT CHECK- A call‐sign prefix used by FAA aircraft engaged in flight inspection/certification of navigational aids and flight procedures. The word “recorded” may be added as a suffix; e.g., “Flight Check 320 recorded” to indicate that an automated flight inspection is in progress in terminal areas.
(See FLIGHT INSPECTION.)
(Refer to AIM.)
FLIGHT FOLLOWING-
(See TRAFFIC ADVISORIES.)
FLIGHT INFORMATION REGION- An airspace of defined dimensions within which Flight Information Service and Alerting Service are provided.
a..
Flight Information Service. A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.

b..
Alerting Service. A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid and to assist such organizations as required.

FLIGHT INFORMATION SERVICE- A service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights.
FLIGHT INSPECTION- Inflight investigation and evaluation of a navigational aid to determine whether it meets established tolerances.
(See FLIGHT CHECK.)
(See NAVIGATIONAL AID.)
FLIGHT LEVEL-A level of constant atmospheric pressure related to a reference datum of 29.92 inches of mercury. Each is stated in three digits that represent hundreds of feet. For example, flight level (FL) 250 represents a barometric altimeter indication of 25,000 feet; FL 255, an indication of 25,500 feet.
(See ICAO term FLIGHT LEVEL.)
FLIGHT LEVEL [ICAO]- A surface of constant atmospheric pressure which is related to a specific pressure datum, 1013.2 hPa (1013.2 mb), and is separated from other such surfaces by specific pressure intervals.
Note 1: A pressure type altimeter calibrated in accordance with the standard atmosphere:
a.
.When set to a QNH altimeter setting, will indicate altitude;

b.
.When set to a QFE altimeter setting, will indicate height above the QFE reference datum; and

c.
.When set to a pressure of 1013.2 hPa (1013.2 mb), may be used to indicate flight levels.

Note 2: The terms `height' and `altitude,' used in Note 1 above, indicate altimetric rather than geometric heights and altitudes.