Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Fokker Model F.28 Mark 0070 and 0100 series airplanes. This proposal would require a measurement of the resistance of the electrical connectors of the auxiliary power unit (APU) to detect a short circuit; an inspection to determine if the grommets or shrink sleeves are present; and modification, if necessary. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to detect and prevent a short circuit of a fire extinguisher electrical system due to a lack of shrink sleeves or grommets, and consequent disabling of the affected fire extinguisher system.