EASA SIB NE-20-11: Hamilton Sundstrand Corp. 568F Propeller Blades — Inspection Under the Compression Wrap

What to do

Owners, operators, and maintenance facilities should perform all tasks in the CHECK/Major Propeller Inspection section of Hamilton Sundstrand CMM 61-13-12, specifically removing and replacing the compression wrap during major inspections. They should also contact the FAA engineer listed in the SAIB if any propellers have not received a complete major inspection. No specific compliance deadline is stated, but adherence is recommended at the next major inspection.

Summary

Hamilton Sundstrand Corp. 568F Propeller Blades — Inspection Under the Compression Wrap is a Special Airworthiness Information Bulletin (SAIB) issued by the FAA to alert owners, operators, and maintenance facilities of Hamilton Sundstrand 568F-1, 568F-5, 568F-7, and 568F-11 model propellers. The bulletin addresses misinterpretations of the Component Maintenance Manual (CMM) 61-13-12 that have led to incomplete major inspections by not removing and replacing the propeller blade's compression wrap. This SAIB provides guidance to ensure proper inspection procedures are followed to maintain propeller airworthiness.

What changed

This SAIB clarifies that during the Major Propeller Inspection of Hamilton Sundstrand 568F model propellers, the compression wrap must be removed and replaced to properly inspect the blade tulip section, even if no surface damage is visible. It highlights that some maintenance facilities have been performing inspections without removing the compression wrap, which is contrary to the CMM requirements. Hamilton Sundstrand plans to revise the CMM 61-13-12 to prevent future misinterpretations.

Why it matters

Proper removal and replacement of the compression wrap during major inspections is critical because corrosion has been found under the wrap despite no visible surface damage. Failure to perform this step could lead to undetected damage, potentially compromising propeller safety and reliability. This SAIB helps maintenance professionals ensure compliance with inspection requirements and supports continued airworthiness of affected propellers.