Air Transport Association 
Advanced Technology Attachment 
Actual Time of Arrival 
Allen Telescope Array 
Automatic Trouble Analysis 
American Trucking Association 
Ammonia Tank Assembly 
AT Attachment 
Analog Terminal Adapter 
atmospheres absolute 
Airport Traffic Area 
American Telemarketing Association 
Avionics Test Article 
Abort Timing Assembly 
Air Transport Association of America 
American Translators Association 
Analog Telephone Adapter 
Analogue Terminals and Access 
ARCNET Trade Association 
AT Attachment interface 
Auto-Tracking Antenna 
Address Translation Agent 
Advanced Technology Adapter 
Air Traffic Alliance 
Air Transport Associaton 
Air Transport Auxillary 
Airline Transport Association 
Airlock Test Article 
American Trans Air 
Analog Telephone Adaptor