Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-200B, 747-200C, 747-200F, 747-300, and 747SR series airplanes, equipped with GE CF6-45 or -50 series engines. This proposed AD would require modifying the side cowl assemblies on the engines by replacing existing wear plates with new extended wear plates and installing new stop fittings. This proposed AD is prompted by reports of a gap at the interface of the lower portion of the side cowl and the aft flange of the thrust reverser. We are proposing this AD to prevent an excessive quantity of air from entering the fire zone that surrounds the engine, which in the event of an engine fire, could result in an inability to control or extinguish the fire.