Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to certain Pilatus Britten-Norman Ltd. (PBN) BN- 2, BN-2A, BN-2B, and BN-2A MK.III series airplanes that are equipped with a PBN Modification NB/M/256, 50A generator system. The proposed action would require inspecting the airplanes that are equipped with a 50A generator system for a 70A generator. If a 70A generator is installed, the proposed action would require replacing the 70A generator with a 50A generator, or (for the BN-2, BN-2A, and BN-2B series only) upgrading the airplane generator system to a 70A system to match the 70A generator. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by the proposed AD are intended to prevent damage to the components of the electrical system, which could result in electrical system failure during critical phases of flight.