S2R-T660 — Thrush Aircraft Llc S2R-T660

This document is a service bulletin (SB-AG-39) issued by Ayres Corporation, focusing on the inspection and fatigue life extension of wing spars in various S2R models. The bulletin outlines compliance requirements for inspections to detect cracks in the lower wing spar assemblies, particularly those with aluminum spar webs. It provides detailed instructions for inspection and rework procedures, including the necessary tools and parts. The bulletin is aimed at maintenance personnel and A&P mechanics, ensuring that aircraft are maintained to safety standards and operational integrity. The compliance intervals and procedures are crucial for extending the service life of the affected aircraft models.

• Models affected include various S2R types with specific serial numbers listed.
• Initial inspections should occur at 2000 hours TIS for Group 1 airplanes.
• If cracks are found, the spar cap or wing must be replaced before the next flight.
• Inspection requires 8 hours, while rework takes about 3 hours.
• Cold expansion procedures can eliminate the need for further inspections if done correctly.