Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-90-30 airplanes. This proposal would require a one-time inspection of the single-phase remote control circuit breaker(s) (RCCBs) in a certain area of the electrical/electronic (E/E) compartment to determine the part number and serial number of the RCCB(s), and replacement of certain RCCBs with new or serviceable RCCBs, if necessary. This action is necessary to prevent failure of an RCCB to trip during an overload condition due to a defective braze joint in the RCCB latch assembly, which could result in overheating of the RCCB load wire, and consequent smoke and possible fire in the E/E compartment of the airplane. This action is intended to address the identified unsafe condition.