SPECIAL AIRWORTHINESS INFORMATION BULLETIN
Aircraft Certification Service
Washington, DC
U.S. Department of Transportation
Federal Aviation Administration
2023-04

March 15, 2023

This is information only. Recommendations aren’t mandatory.

Introduction
 
The Federal Aviation Administration (FAA) is issuing this Special Airworthiness Information Bulletin (SAIB) to alert owners, operators, maintenance technicians, and inspectors of an airworthiness concern for Hartzell Propeller Inc. (Hartzell) and McCauley Propeller Systems (McCauley) propellers, specifically, those returned to service by Trinity Specialized Services, LLC (Trinity) doing business as Specialized Propeller Services, LLC.  
 
At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39. 
 
Background
 
The FAA determined that Trinity did not maintain Hartzell and McCauley propellers in accordance with the current manufacturer’s maintenance manual or methods otherwise acceptable to the administrator and improperly returned propellers to service between the dates of January 29, 2016 and March 25, 2021. The following improper maintenance or overhaul practices were identified and may affect airworthiness of the propeller: 
 
- Trinity approved return to service propellers that were not maintained in accordance with the current manufacturer’s maintenance manual or methods otherwise acceptable to the administrator. 
- Trinity used parts that were not purchased from or traceable to an approved source.
- Trinity allowed unqualified personnel to perform nondestructive inspections, shot peening, and cold compression rolling of Hartzell propeller blades.
 
To date, the FAA has not received any in-fleet safety reports or failures related to Trinity return to service propellers, however, these discrepancies may affect the continued reliable operation of the propeller and related systems. 
 
Recommendations
 
The FAA recommends owners, operators, and maintainers of Hartzell and McCauley constant speed propellers which were returned to service by Trinity Specialized Services, LLC between January 29, 2016 and March 25, 2021 have their propeller overhauled or inspected for airworthiness by an authorized repair station holding a certificate issued by the FAA under Title 14 CFR Part 145. 
 
The FAA also recommends that any discrepancies which are found to be related to this safety issue be reported to one of the FAA contacts listed below and through the service difficulty reporting system. The FAA will continue to monitor the situation to determine if further action is warranted.
 
A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0731. Public reporting for this collection of information is estimated to be approximately one hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, completing and reviewing the collection of information. All responses to this collection of information are voluntary; the nature and extent of confidentiality to be provided, if any. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing t his burden to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.
 
For Further Information Contact
 
Tim Luckey, Program Manager, Chicago Aircraft Certification Office (AIR -7C3), Compliance & Airworthiness Division at Timothy.F.Luckey@faa.gov 
 
Bobbie Kroetch, Continued Operational Safety Program Manager, Program Management Section (AIR-722), Compliance & Airworthiness Division at Bobbie.Kroetch@faa.gov 
 
Kristi Bradley, General Aviation Safety Coordinator, Fleet Safety Section (AIR -723), Compliance and Airworthiness Division at Kristin.Bradley@faa.gov