EASA AD US-2024-12-10: Main Rotor Drive - Angle Gearbox Mount - Repetitive Inspections

What to do

Operators of affected Centerpointe Aerospace helicopters must perform the initial fluorescent penetrant inspection of the angle gearbox mount within 250 hours time-in-service starting August 26, 2024, and continue repetitive inspections at intervals specified in the AD. If cracks are found, the angle gearbox mount must be removed from service. Maintenance personnel must follow the inspection procedures outlined in the AD and may request alternative methods of compliance if necessary.

Summary

The Federal Aviation Administration's Airworthiness Directive 2024-12-10 is a final rule addressing all Centerpointe Aerospace Inc. Model S-58BT, S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters. It mandates repetitive fluorescent penetrant inspections of the main rotor drive angle gearbox mount to detect cracks and requires removal from service if cracks are found. This directive aims to mitigate the risk of structural failure due to fatigue cracking in the angle gearbox mount.

What changed

This new Airworthiness Directive introduces mandatory repetitive inspections using fluorescent penetrant inspection techniques on the angle gearbox mount of specified Centerpointe helicopter models. It requires inspection at specified intervals and removal of the mount if cracks are detected. The directive also clarifies inspection areas based on Centerpointe Aerospace Service Bulletin No. 58B75 and sets compliance requirements differing slightly from the service bulletin.

Why it matters

This AD is critical for aviation professionals as it addresses a safety risk involving fatigue cracks in a key structural component of several Centerpointe helicopter models. Operators and maintenance organizations must comply to prevent potential in-flight failures that could compromise flight safety. The directive ensures consistent inspection standards and timely detection of cracks, thereby supporting continued airworthiness and regulatory compliance.