The procedures described in this advisory circular are considered by the FAA to be acceptable data and can be submitted to them for approval for specific repairs.
AC 43.13-2. An advisory circular issued by the Federal Aviation Administration, giving examples of acceptable methods, techniques, and practices for aircraft alterations.
A-check. See maintenance checks.
acid. A chemical substance that contains hydrogen, has a characteristically sour taste, and is prone to react with a base, or alkali, to form a salt and to accept electrons from the alkali.
acid diluent (finishing system component). A component in a wash primer used to mildly etch the surface of a metal being primed. The etched surface provides a good bond between the finishing system and the metal.
acid-resistant paint. A paint used on the portion of an aircraft structure near the battery box. Some acid-resistant paints have a rubber or tar base, but polyurethane enamel is the most generally used modern acid-resistant paint.
“Acknowledge” (air traffic control). A request meaning “Let me know that you have received my message.”
ACLT (actual calculated landing time) (air traffic control). The frozen calculated landing time of a flight. ACLT is an actual time determined at freeze calculated landing time (FCLT) or meter list display interval (MLDI) for the adapted vertex for each arrival aircraft, based on runway configuration, airport acceptance rate, airport arrival delay period, and other metered arrival aircraft.