Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-90-30 airplanes. For some airplanes, the proposal would require replacing one 3-phase limiter block assembly, 6 current limiters, and hardware for 9 electrical cables with new parts. For other airplanes, this proposal would require inspecting 6 current limiters and 3 spare current limiters and replacing any defective current limiters with new current limiters. These actions are necessary to prevent overheating of the terminal studs on the 3-phase limiter blocks and associated current limiters, which could cause a fire in the airplane. This action is intended to address the identified unsafe condition.