Atlas/ Glossary/ APU Abbreviation APU — auxiliary power unit. APU auxiliary power unit. Source 14 CFR § 1.2 → Related — Abbreviation. ABEAM ABEAM ABORT ABORT — To terminate a preplanned aircraft maneuver AFM AFM — airplane flight manual AGL AGL — above ground level ALS ALS — approach light system ASR ASR — airport surveillance radar
