Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Israel Aircraft Industries Model 1124 and 1124A series airplanes, and certain Model 1125 Westwind Astra series airplanes. This proposal would require a one-time inspection of the attachment bolts installed on the engine inlet cowl and aft nacelle attachment flanges to verify correct part numbers of the bolts, and replacement of any discrepant/incorrect bolt with a correct attachment bolt. This action is necessary to prevent failure of attachment bolts due to fatigue, which could result in separation of the engine inlet cowl and aft nacelle, and consequent damage to the horizontal or vertical stabilizer. This action is intended to address the identified unsafe condition.