Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A300-600 and A310 series airplanes. This proposal would require replacement of certain symbol generator units (SGUs) in the electronic flight instrument system with new, improved SGUs, and modification of associated equipment and wiring. This action is necessary to ensure that the flightcrew has adequate flight information by preventing temporary loss of data from the primary flight and navigation displays. Inadequate flight information could result in reduced situational awareness for the flight crew, which could contribute to loss of control or impact with obstacles or terrain. This action is intended to address the identified unsafe condition.