Summary
The FAA is revising an earlier proposed airworthiness directive (AD) for certain McDonnell Douglas Model DC-10-10, DC-10-10F, DC-10-15, DC-10-30 and DC-10-30F (KC-10A and KDC-10) airplanes; Model DC-10-40 and DC-10-40F airplanes; and Model MD-11 and MD-11F airplanes. The original NPRM would have required, for certain airplanes, modifying the thrust reverser command wiring of the number 2 engine. For certain other airplanes, the original NPRM would have required modifying the thrust reverser system wiring from the flight compartment to engines 1, 2, and 3 thrust reversers. The original NPRM also would have required installing thrust reverser locking systems on certain airplanes. The original NPRM resulted from a determination that the thrust reverser systems on these McDonnell Douglas airplanes do not adequately preclude unwanted deployment of a thrust reverser. This action revises the original NPRM by revising, for certain airplanes, the requirements for the modification of the thrust reverser system wiring from the flight compartment to engines 1, 2, and 3 thrust reversers. We are proposing this supplemental NPRM to prevent an unwanted deployment of a thrust reverser during flight, which could result in reduced controllability of the airplane.