Pilot/Controller Glossary 

10/5/23 

b. 

Nonstandard formations are those operating under any of the following conditions: 

1. 

When the flight leader has requested and ATC has approved other than standard formation dimensions. 

2. 

When operating within an authorized altitude reservation (ALTRV) or under the provisions of a letter 

of agreement. 

3. 

When the operations are conducted in airspace specifically designed for a special activity. 

(See ALTITUDE RESERVATION.) 
(Refer to 14 CFR Part 91.) 

FRC

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(See REQUEST FULL ROUTE CLEARANCE.) 

FREEZE/FROZEN

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Terms used in referring to arrivals which have been assigned ACLTs and to the lists in 

which they are displayed. 
FREEZE HORIZON

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 The time or point at which an aircraft’s STA becomes fixed and no longer fluctuates with 

each radar update. This setting ensures a constant time for each aircraft, necessary for the metering controller 

to plan his/her delay technique.  This setting can be either in distance from the meter fix or a prescribed flying 

time to the meter fix. 
FREEZE SPEED PARAMETER

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 A speed adapted for each aircraft to determine fast and slow aircraft. Fast 

aircraft freeze on parameter FCLT and slow aircraft freeze on parameter MLDI. 
FRIA

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(See FAA

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RECOGNIZED IDENTIFICATION AREA.) 

FRICTION MEASUREMENT

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 A measurement of the friction characteristics of the runway pavement surface 

using continuous self-watering friction measurement equipment in accordance with the specifications, 

procedures and schedules contained in AC 150/5320

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12, Measurement, Construction, and Maintenance of Skid 

Resistant Airport Pavement Surfaces. 
FSDO

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(See FLIGHT STANDARDS DISTRICT OFFICE.) 

FSPD

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(See FREEZE SPEED PARAMETER.) 

FSS

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(See FLIGHT SERVICE STATION.) 

FUEL DUMPING

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 Airborne release of usable fuel. This does not include the dropping of fuel tanks. 

(See JETTISONING OF EXTERNAL STORES.) 

FUEL REMAINING

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 A phrase used by either pilots or controllers when relating to the fuel remaining on board 

until actual fuel exhaustion. When transmitting such information in response to either a controller question or 

pilot initiated cautionary advisory to air traffic control, pilots will state the APPROXIMATE NUMBER OF 

MINUTES the flight can continue with the fuel remaining. All reserve fuel SHOULD BE INCLUDED in the 

time stated, as should an allowance for established fuel gauge system error. 
FUEL SIPHONING

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 Unintentional release of fuel caused by overflow, puncture, loose cap, etc. 

FUEL VENTING

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(See FUEL SIPHONING.) 

FUSED TARGET-

(See DIGITAL TARGET) 

FUSION [STARS]- the combination of all available surveillance sources (airport surveillance radar [ASR], air 

route surveillance radar [ARSR], ADS-B, etc.) into the display of a single tracked target for air traffic control 

separation services. FUSION is the equivalent of the current single-sensor radar display.  FUSION performance 

PCG F

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