Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Airbus Model A319, A320, and A321 series airplanes. This proposed AD would require modification of certain auxiliary power unit (APU) alternating current (AC) generators. This proposed AD is prompted by a report of an explosion in the APU compartment, which blew open the compartment doors. We are proposing this AD to prevent oil vapor leakage from the APU AC generator, which, when combined with an electric arc at the electrical receptacle, could result in a fire or explosion in the APU compartment during flight.