Transport i lotnictwo · 09/12/2005

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-400 series airplanes. This proposed AD would require inspecting the support bracket of the crew oxygen cylinder installation to determine the manufacturing date marked on the support, and performing corrective action if necessary. This proposed AD results from a report indicating that certain oxygen cylinder supports may not have been properly heat-treated. We are proposing this AD to prevent failure of the oxygen cylinder support under the most critical flight load conditions, which could cause the oxygen cylinder to come loose and leak oxygen. Leakage of oxygen could result in oxygen being unavailable for the flightcrew or could result in a fire hazard in the vicinity of the leakage.