r responsible for its content.

LOA

A - A Autotuned NAVAID  A At or Above (constrained altitude) 
AA American  AAATS Australian Advanced Air Traffic Services  
AAC Aeronautical Administration Communication (a class of communication
which supports administrative communication)  AAS Advanced Automation
System (the end systems for all FAA air traffic control, located at
the ARTCCs)  AATT Advanced Aviation Transportation Technology 
ABM Abeam  A/C Aircraft  AC Air Canada  ACARS Aircraft
Communications Addressing and Reporting System  ACARS ARINC communications
and address reporting system (digital communications system used primarily
for aircraft-to-airline messages)  ACARS MU ACARS Management Unit 
ACAS Airborne Collision and Avoidance System  ACF Area Control
Facility  ACFS Advanced Concepts Flight Simulator (a generic "glass
cockpit")  ACK Acknowledge  ACMS Aircraft Condition Monitoring
System   ACT Active   ADC Air Data Computer  
ADF Automatic Direction Finder   ADI Attitude Director lndicator 
ADLP Aircraft Data Link Processor (the Mode S subnetwork function onboard
the aircraft that implements the OSI network layer protocols) 
ADMA Aviation Distributors and Manufactureres Association  ADS
Automatic Dependent Surveillance   AECB Atomic Energy Control
Board   AERA Automated Enroute ATC   AFCS Automatic
Flight Control System   AFDS Autopilot Flight Director System
(also A/P F/D)   AFS Automatic Flight System  AGATE Advanced
General Aviation Transport Experiments   AGL Above Ground
Level   AHRS Attitude Heading Reference System  AIRS
Advanced Infrared Sounder   A/l Anti-ice  AI Artificial
Intelligence  AL Allegheny  Alert Indicator (visual or auditory)
which provides information to the flightcrew in a timely manner about
an event requiring pilot awareness.  ALPA Air Line Pilots Association  
ALT Altitude   ALT Alternate   ALTN Alternate  
ALT HOLD Altitude Hold Mode  AM Amplitude Modulation  
AM Aeromexico  AMSS Aeronautical Mobile Satellite Service  
ANA All Nippon Airways   AOA Angle-of-Attack  AOA Airport
Operations Area  AOC Aeronautical Operation Control (communications
which support safety and regularity of flight that normally take place
between aircraft and the operator)  AOCS Attitude and Orbit Control
System  AOM Aircraft Operating Manual  AOPA Aircraft Owners
and Pilots Association   A/P Autopilot  APA Allied Pilots
Association  APC Aeronautical Passenger Communication (a class
of communication which supports passenger communication)  APMS
Automated Performance Measurement System   APPR Approach/Approach
Mode   APR April   APRT Airport  APU Auxiliary
Power Unit  AQP Advanced Qualification Program  ARAC Aviation
Rulemaking Advisory Committee   ARINC Aeronautical Radio Incorporated 
ARPA Advanced Research Projects Agency   ARR Arrival 
ARTCC Air Route Traffic Control Center  ARTS Automated Radar Terminal
System   ASCII American Standard Code for Interface and Interchange  
ASI Air Speed Indicator  ASR Airport Surveillance Radar  
ASRS Aviation Safety Reporting System (aviation incident reporting system
run by NASA for FAA)  AT At (an altitude)   A/T Autothrottle 
ATA Air Transport Association  ATA Actual Time of Arrival 
ATC Air Traffic Control (a generic term for a joint civil/military system
for controlling traffic within a specific area)  ATCS Advanced
Train Control Systems   ATCSCC Air Traffic Control System
Command Center  ATHR Autothrust System  ATIS Automatic Terminal
Information Service (recorded voice message that provides weather and
airport services information)  ATM Air Transportation Management  
ATN Aeronautical Telecommunications Network (the collection of ground
subnetworks, air/ground subnetworks and airborne subnetworks interconnected
by ATN routers that support computer-to-computer, internetwork communication
and message transfer between host computers using the OSI ISO protocol
architecture)  ATS Automatic Throttle System  ATSC Air Traffic
Service Communications (Communications related to air traffic services.
This includes ATC, aeronautical and meteorological information, position
reporting and services related to safety and regularity of flight) 
AUG August  AV Avianca   AVAIL Available  AVHRR
Advanced Very High-Resolution Radiometer  AWACS Airborne Warning
And Control System   AWAS Automated Weather Advisory Station  
AWIPS Advanced Weather Interactive Processing System   Back
to Top   - B -   B At or Below (constrained altitude)  
BALPA British Air Line Pilots Association   BASIS British
Airways Safety Information System   BF MarkAir  
BIT(E) Built-ln-Test (Equipment)   BRG Bearing  
BRT Brightness   Back to Top   - C -  
C Centigrade   CAA Civil Aviation Authority (Great Britain)  
CAB Civil Aeronautics Board   CAAC Civil Aviation Authority
of China   CAS Calibrated (Computed) Air Speed  
CASE Computer Aided Software Engineering   CAT Clear Air Turbulence  
CAT Computer Aided Testing  CAT I Facility providing operation
down to 200 feet decision height and runway visual range not less than
2600 feet.  CAT II Facility providing operation down to 100 feet
decision height and runway visual range not less than 1200 feet. 
CAT II a Facility providing operation with no decision height limit
to and along the surface of the runway with external visual reference
during final phase of landing and with a runway visual range not less
than 700 feet.  CBT Computer Based Training   CDI Course
Deviation Indicator   CDU Control display unit (pilots' interface
to the FMS)   CDTI Cockpit Display of Traffic Information  
CENA Centred' Études de la Navigation Aérienne (France)  
CFIT Controlled Flight Into Terrain   CG Center of Gravity  
CGS Centimeter-gram-second   Cl Cost Index   CI
China Airlines   CIT Compressor Inlet Temperature  
CLB Climb Detent of the Thrust Levers   CLR Clear  
CMC Central Maintenance Computer   CNS Communications Navigations
and Surveillance   CO Continetnal   COM Cockpit
Operating Manual   CON Continuous   CO ROUTE Company
Route (also CO RTE)   COTR Contracting Officer's Technical
Representative   COTS Commercial Off The Shelf  
CP Control Panel   CPCS Cabin Pressure Control System  
CPDLC Controller Pilot Datalink Communications   CPU Central
Processing Unit   CRC Cyclic Redundancy Check  
CRITTER Civil Rotorcraft IFR Terminal-Area Technology Enhancement Research  
CRM Cockpit Resource Management   CRM Crew Research Management  
CRS Course   CRT Cathode Ray Tube   CRZ Cruise  
CSD Constant Speed Drive   CTA Controlled-Time of Arrival  
CTA Control Area (ICAO Term)   CTAS Center TRACON Automation
System   CTC Centralized Train Central   CTR Center  
CTR Civil Tilt Rotor   CTRL Control   CVSRF Crew-Vehicle
Simulation Research Facility (NASA Ames)   CWS Control Wheel
Steering   Back to Top   - D -   D Derated  
DA Descent Advisor   DBS Direct Broadcast Satellite  
DE-TO PR Derated Takeoff Engine Pressure Ratio   D-TO Nl Derated
Takeoff Engine Fan Speed   DADC Digital Air Data Computer  
DATALINK Digitized Information Transfer (air/ground)   DC
Direct Current Electricity   D/D Drift Down   DEC
December   DEC Digital Equipment Corporation   DECR
Decrement   DEL Delete   DEP Departure  
DES Descent   DEST Destination   DEV Deviation  
DFDAU Digital Flight Data Acquisition Unit   DFDR Digital
Flight Data Recorder   DFGS/C Digital Flight Guidance System/Computer  
DFW Dallas Fort Worth International Airport   DGPS Differential
GPS   DH Decision Height   DIR Direct  
DIR/INTC Direct Intercept   DIS Distance   DISCR
Discrepancy   DIST Distance   DL Delta  
DLP Data Link Processor (the FAA's ground automation system that supports
the Mode S subnetwork (GDLP), internetwork (ATN router) and non-ATC
data link application processes)   DLR German Aerospace Research
Establishment   DME Distance Measuring Equipment (ground navigational
aid that can provide display of distance to selected ground navigational
radio transmitter)   DMU Data Management Unit  
DNTKFX DownTrack Fix   DOT Department of Transportation  
DOD Department of Defense   DRU Data Retrival Unit  
DSPY Display (annunciation on CDU)   DTG Distance-to-go  
Back to Top   - E -   E East   EADI Electronic
Attitude Director Indicator   EAS Equivalent Airspeed  
ECAM Electronic Centralized Aircraft Monitor   ECON Economy
(minimum cost speed schedule)   ECS Environmental Control
System   E/D End-of-Descent   EDF Electricité de
France   EEC Electronic Engine Control   EFC Expected
Further Clearance   EFIS Electronic Flight Instrument System  
EGT Exhaust Gas Temperature   EHSI Electronic Horizontal Situation
Indicator   EICAS Engine Indicating Crew Alerting System  
EIU Electronic Interface Unit   ELT Emergency Locator Transmitter  
EMP Electromagnetic Pulse   EMS Emergency Medical Services  
ENG Engine   E/O Engine-Out   EPR Engine Pressure
Ratio   EPROM Erasable Programmable Read-Only Memory  
EST Estimated   ETA EstimatedTime of Arrival   ETX
End of Transmission   EXEC Execute   Back to Top  
- F -   F Fahrenheit   FA Final Approach  
FAA Federal Aviation Administration   FADEC Full Authority
Digital Engine Control   FAIL FMC Fail   Failure
The inability of a system, subsytem, unit or part to perform within
previously specified limits.   FAF Final Approach Fix  
FANS Future Air Navigation Systems   FAR Federal Aviation
Regulations (