Beechcraft 76 Duchess — Weight And Balance

This document is an Alert Service Bulletin issued by Hartzell Propeller Inc., specifically addressing the inspection and maintenance of propeller hubs used on various aircraft, including the Beechcraft 76 Duchess. The bulletin outlines critical inspection requirements for left-hand rotating propellers installed on Lycoming 360 series engines, detailing the necessary actions to ensure airworthiness and safety. It includes information on compliance timelines, inspection procedures, and potential modifications to propeller hubs. The bulletin is essential for maintenance personnel and operators of affected aircraft to prevent incidents related to propeller hub failures.

• Perform eddy current inspections within 50 hours or 12 months of the effective date.
• Installation of a two-blade hub with 'B' suffix increases weight by 0.50 lb.
• Installation of a three-blade hub with 'B' suffix increases weight by 0.80 lb.
• Modification to oil-filled configuration increases weight by 0.50 lb for two-blade and 1.0 lb for three-blade propellers.
• Compliance with this bulletin is critical to prevent propeller hub failures.