AD NUMBER: 2011-12-04

MANUFACTURER: BRP-Powertrain GmbH & Co. KG Rotax 912 F3, 912 S2, 912 S3, 912 S4, 914 F2, 914 F3, and 914 F4 Reciprocating Engines
SUBJECT: Airworthiness Directive 2011-12-04

SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: During a production process review, a deviation in hardening of certain Part Number (P/N) 944072 washers has been detected, which exceeds the hardness of the design specification. The affected washers are part of the magneto ring flywheel hub installation and have been installed on a limited number of engines. No defective washers have been shipped as spare parts. This condition, if not corrected, could lead to cracks in the washer, loosening of the magneto flywheel hub and consequent ignition failure, possibly resulting in damage to the engine, in-flight engine shutdown and forced landing, damage to the aeroplane and injury to occupants. We are issuing this AD to prevent engine in-flight shutdown, and damage to the airplane.

FMI: www.faa.gov/regulations_policies/airworthiness_directives/