Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F27 Mark 050 and Model F28 Mark 0100 series airplanes. This proposal would require an inspection to verify that adequate clearance exists between the insulation screen and the two adjacent terminal bolts, and replacement of the circuit breaker terminal bolts with new bolts, if necessary. This proposal is prompted by a report that circuit breaker terminal bolts that were too long were discovered installed in the circuit breaker panels. The actions specified by the proposed AD are intended to prevent damage to the insulation screen between adjacent rows of circuit breakers, as the result of a circuit breaker terminal bolt being too long; this condition could lead to electrical arcing and loss of the associated electrical system, which could result in the potential for an electrical fire.