Summary
We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -300 series airplanes, and Model A340-200 and -300 series airplanes. This proposed AD was prompted by a report of contact between certain electrical harnesses and the hatrack rod that could cause chafing between the harnesses and surrounding structure. This proposed AD would require modifying the routing of certain electrical harnesses. We are proposing this AD to prevent chafing and possible short circuit of two oxygen chemical generator containers in different wiring routes, which could result in malfunction of the electrical opening of all the containers connected to these routes. Such conditions, during a sudden depressurization event, could result in lack of oxygen and consequent injuries to airplane occupants.