United States Air Force | Royal Air Force | Canadian Pacific Railway | United States Army Air Forces | Great Western Railway | Royal Canadian Air Force | Indian Air Force | United States Air Force Academy | Special Air Service | Fleet Air Arm | Shanghai Railway Bureau | Canadian National Railway | National Air and Space Museum | Midland Railway | Grand Trunk Railway | Royal Australian Air Force | Strategic Air Command | London and North Western Railway | Delta Air Lines | Northern Pacific Railway | London, Midland and Scottish Railway | Air Canada | Israeli Air Force | International Air Transport Association | Great Central Railway | Air Training Command | United States Army Air Corps | French Air Force | Air National Guard | Edwards Air Force Base |
Air line is most commonly used for supplying compressed air to air tools in workshops and in road vehicle air brake or railway air brake systems on larger vehicles or rail cars.