Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all McDonnell Douglas Model MD-11 and -11F airplanes. This proposed AD would require revising the maintenance inspection program that provides for inspection of principal structural elements (PSEs) and replacement of safe-life parts, to incorporate a new revision to the MD-11 Airworthiness Limitations Instructions. The revision would reduce inspection intervals for fatigue cracking of certain PSEs, and expand the inspection area for a certain other PSE. This proposed AD results from a revised damage tolerance analysis. We are proposing this AD to detect and correct fatigue cracking of certain PSEs, which could adversely affect the structural integrity of the airplane.