background image

Pilot/Controller Glossary 

12/2/21 

weather information transmitted from ground 
stations. 

(See AUTOMATIC DEPENDENT 

SURVEILLANCE

BROADCAST OUT.) 

(See AUTOMATIC DEPENDENT 

SURVEILLANCE

REBROADCAST.) 

(See FLIGHT INFORMATION 

SERVICE

BROADCAST.) 

(See TRAFFIC INFORMATION 

SERVICE

BROADCAST.) 

AUTOMATIC  DEPENDENT SURVEILLANCE

 

BROADCAST OUT (ADS

B Out)

 The transmitter 

onboard an aircraft or ground vehicle that 
periodically broadcasts its GNSS

derived position 

along with other required information, such as 
identity, altitude, and velocity. 

(See AUTOMATIC DEPENDENT 

SURVEILLANCE

BROADCAST.) 

(See AUTOMATIC DEPENDENT 

SURVEILLANCE

BROADCAST IN.) 

AUTOMATIC  DEPENDENT SURVEILLANCE

 

CONTRACT (ADS

C)

 A data link position 

reporting system, controlled by a ground station, that 
establishes contracts with an aircraft’s avionics that 
occur automatically whenever specific events occur, 
or specific time intervals are reached. 

AUTOMATIC DEPENDENT SURVEILLANCE­
REBROADCAST (ADS­R)

 A datalink translation 

function of the ADS

B ground system required to 

accommodate the two separate operating frequencies 
(978 MHz and 1090 MHz). The ADS

B system 

receives the ADS

B messages transmitted on one 

frequency and ADS

R translates and reformats the 

information for rebroadcast and use on the other 
frequency. This allows ADS

B In equipped aircraft 

to see nearby ADS

B Out traffic regardless of the 

operating link of the other aircraft. Aircraft operating 
on the same ADS

B frequency exchange information 

directly and do not require the ADS

R translation 

function. 

AUTOMATIC DIRECTION FINDER

 An aircraft 

radio navigation system which senses and indicates 
the direction to a L/MF nondirectional radio beacon 
(NDB) ground transmitter. Direction is indicated to 
the pilot as a magnetic bearing or as a relative bearing 
to the longitudinal axis of the aircraft depending on 
the type of indicator installed in the aircraft. In certain 
applications, such as military, ADF operations may 

be based on airborne and ground transmitters in the 
VHF/UHF frequency spectrum. 

(See BEARING.) 
(See NONDIRECTIONAL BEACON.) 

AUTOMATIC FLIGHT INFORMATION SER­
VICE (AFIS) 

 ALASKA FSSs ONLY

 The 

continuous broadcast of recorded non

control 

information at airports in Alaska where a FSS 
provides local airport advisory service. The AFIS 
broadcast automates the repetitive transmission of 
essential but routine information such as weather, 
wind, altimeter, favored runway, braking action, 
airport NOTAMs, and other applicable information. 
The information is continuously broadcast over a 
discrete VHF radio frequency (usually the ASOS/ 
AWOS frequency). 

AUTOMATIC TERMINAL INFORMATION SER­
VICE

 The continuous broadcast of recorded 

noncontrol information in selected terminal areas. Its 
purpose is to improve controller effectiveness and to 
relieve frequency congestion by automating the 
repetitive transmission of essential but routine 
information; e.g., “Los Angeles information Alfa. 
One three zero zero Coordinated Universal Time. 
Weather, measured ceiling two thousand overcast, 
visibility three, haze, smoke, temperature seven one, 
dew point five seven, wind two five zero at five, 
altimeter two niner niner six. I­L­S Runway Two Five 
Left approach in use, Runway Two Five Right closed, 
advise you have Alfa.” 

(See ICAO term AUTOMATIC TERMINAL 

INFORMATION SERVICE.) 

(Refer to AIM.) 

AUTOMATIC TERMINAL INFORMATION SER­
VICE [ICAO]

 The provision of current, routine 

information to arriving and departing aircraft by 
means of continuous and repetitive broadcasts 
throughout the day or a specified portion of the day. 

AUTOROTATION

 A rotorcraft flight condition in 

which the lifting rotor is driven entirely by action of 
the air when the rotorcraft is in motion. 

a. 

Autorotative Landing/Touchdown Autorota­

tion. Used by a pilot to indicate that the landing will 
be made without applying power to the rotor. 

b. 

Low Level Autorotation. Commences at an 

altitude well below the traffic pattern, usually below 
100 feet AGL and is used primarily for tactical 
military training. 

PCG A

16