Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A319, A320, and A321 series airplanes. This proposal would require replacement of a certain transformer rectifier unit (TRU) with a certain new TRU. This action is necessary to prevent ignition of the input filter capacitors of the TRU in position 2 of the avionics compartment, which could potentially result in smoke in the cockpit. This action is intended to address the identified unsafe condition.