Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-200C and -200F series airplanes. This proposed AD would require, among other actions, installing mounting brackets, support angles, and moisture curtains in the main equipment center. This proposed AD results from reports of water contamination in the electrical/electronic units in the main equipment center. We are proposing this AD to prevent water contamination of the electrical/ electronic units, which could cause the electrical/electronic units to malfunction, and as a consequence, could adversely affect the airplane's continued safe flight.