The facilities covered in this document are: a. Navigational equipment which makes use of radio or other devices b. Equipment for weather surveillance@ anti-collision devices@ etc. c. Air traffic control equipment d. All air-borne communications equipment both for communication within the aircraft and to points outside the aircraft. PURPOSE This document presents a recommended standard for commercial transport for the manner in which information from electronic navigation and communication aids are portrayed in the cockpit. It also recommends a standard arrangement for the cockpit controls used to operate and receive information from this equipment. The basic factors considered@ not necessarily in the order of importance@ are: a. Ability of the crew to use the equipment. b. Flexibility combined with safety to provide optimum use of the equipment. c. Degree of accuracy necessary. d. Simplicity. e. Economy of the installation. Since all of these items are not always compatible@ certain compromises have been made. It is desired to obtain the maximum possible use out of the installed equipment; however@ some compromise in flexibility may be accepted when the degree of complication required for accomplishment creates a probability of error above an acceptable limit.