Airworthiness Directives; McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30, DC-10-30F (KC-10A and KDC-10), DC-10-40, DC-10-40F, MD-10-10F, MD-10-30F, MD-11, and MD-11F Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain McDonnell Douglas transport category airplanes. This AD requires doing repetitive detailed inspections for accumulation of debris (blockage) in the drain holes of the pitot tubes, and cleaning the hole if any evidence of debris is found. This AD results from reports of blocked drain holes of the pitot tubes. We are issuing this AD to prevent blocked drain holes of the pitot tubes, which could result in the accumulation of water in the pitot-static system and consequent failure of that system. Failure of the pitot-static system could result in erroneous airspeed indications in the cockpit and consequent loss of airspeed control.