Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all McDonnell Douglas Model MD-90-30 airplanes. This proposed AD would require replacing existing dual anti-skid control manifolds (DACM) with new, improved or reworked and reidentified DACMs; inspecting the inlet filters and other components of the DACMs for damage; replacing any damaged DACM components with new or serviceable components; and flushing/cleaning the braking system prior to replacing the inlet filters. This proposed AD is prompted by reports of multiple incidents of blown tires on landing while using maximum autobrake. We are proposing this AD to prevent metallic fibers from the first stage filter of the servo valves inside the DACM from becoming lodged in the first stage nozzle of the servo valve, which could lead to tire failure during high speed/high energy braking and possible subsequent runway departure.