June 2009

Advisory Circular Updated to Provide Further Guidance on Repair Station Outsourcing of Maintenance

Holland & Knight Newsletter
Marc L. Antonecchia

FAA Oversight of Aircraft Maintenance

The Department of Transportation (DOT) and the Federal Aviation Administration (FAA) continue to focus on aircraft maintenance practices, emphasizing that air carriers and maintenance providers need to ensure the performance of maintenance tasks by trained and qualified personnel.

In 2008, the DOT released a report concerning air carriers’ outsourcing of aircraft maintenance, concluding that the FAA needed to enhance its oversight of outsourced aircraft maintenance.1 Shortly thereafter, the FAA issued Advisory Circular 120-16E (AC 120-16E), which updated the recommended scope and content of an air carrier aircraft maintenance program.2 That Advisory Circular addresses an air carrier’s responsibility for maintenance provided by third parties, emphasizing that the air carrier remains primarily responsible for all of the maintenance performed by any maintenance provider.

AC 120-16E recommends that, when possible, the air carrier and maintenance provider should define the performance of maintenance through a written contract. A March 2009 update to Advisory Circular 145-9 (AC 145-9), titled “Guide for Developing and Evaluating Repair Station and Quality Control Manuals,” provides guidance concerning the outsourcing of maintenance work by a repair station certificated by Part 145. In cases where the maintenance provider is a Part 145 repair station, it would be prudent for the written contract to address such outsourcing.

Advisory Circular 145-9 Provides Guidance on Maintenance Performed for Air Carriers

AC 145-9 was originally issued in 2003 to provide information for all repair station certificate holders and applicants under Part 145 to develop and evaluate a Repair Station Manual (RSM) and Quality Control Manual. The AC recognizes that repair stations perform maintenance, preventive maintenance, and alterations for air carriers conducting operations under Parts 121, 125, 129 and 135. As such, the RSM must describe procedures to ensure that maintenance is performed in accordance with the air carrier’s program and maintenance manual.

The RSM’s procedures must ensure that the air carrier has provided the repair station with the information necessary to comply with the air carrier program and maintenance manual. The AC provides the following guidance:

“The air carrier may provide the repair station with the applicable sections of its maintenance programs or manuals at the time the work is performed. On the other hand, the purchase order or other contractual documents from the air carrier could clearly state the source of the data (manufacturer’s or air carrier’s manual) used to perform the requested maintenance along with any other requirements of its program or maintenance manual.”

AC 145-9 emphasizes the importance of defining responsibilities within the repair station. For instance, the RSM must identify the location of applicable maintenance manuals and who at the repair station is responsible for keeping the operators’ data current. It must also explain what air carrier or commercial operator information should be available to maintenance personnel when the work is performed. When the repair station transfers requirements from an air carrier to its maintenance personnel by special instructions on the work order, the RSM’s quality control section must clearly explain how to accomplish this task.

AC 145-9 identifies several key areas to aid the repair station’s development of procedures for performing air carrier maintenance:

  • maintaining a file of the air carrier’s procedures, including necessary technical data
  • reviewing purchase orders for complete and correct instructions
  • maintaining a current list of Required Inspection Item (RII) inspectors
  • RSM procedures to ensure that necessary equipment, trained personnel, and technical data are available for line maintenance
  • coordinating training programs with air carriers
  • authorization for individuals performing line maintenance and RII
  • compliance by all repair station personnel, regardless of location, with RSM.

In addition to these considerations, repair stations, and, by extension, the air carriers with whom they contract, should account for the outsourcing of repair station maintenance. Part 145.217 permits a certificated repair station to contract any maintenance, preventive maintenance, or alteration for which the repair station holds a rating. AC 145-9 suggests that the types of maintenance functions for which a repair station may want approval to outsource fall into two categories. The first type is maintenance functions for which the repair station does not have the housing, facilities, materials, or equipment available on its premises and under its control. The second type is maintenance functions that need to be outsourced because of workload or emergency situations. The March 2009 update to AC 145-9 provides additional guidance concerning such outsourcing.

March 2009 Update to AC 145-9

The updated AC 145-9 states that a repair station can contract with an FAA certificated or non-certificated entity provided that the “repair station takes responsibility for the work scope performed by issuing an approval for return to service.” In order to exercise the contracting privilege, the repair station must, in accordance with Part 145:

  • make a list of maintenance functions that it: (a) is certificated to perform but requests approval to contract out; and (b) takes regulatory responsibility for issuing an approval for return to service for the exact same work under its rating
  • obtain approval of the listed functions and provide the list to the FAA
  • ensure that it qualifies the entities to which it contracts the maintenance functions
  • maintain a current list of contractors and provide the list to the FAA
  • ensure that the repair station has procedures to perform the incoming inspection, final inspection, and return to service
  • provide a procedure that confirms by inspection or test that the work was performed satisfactorily

In addition, although not required, the updated AC suggests that the RSM identify the name of each outside contracted source, the maintenance function contracted to each source, and the type of certificate and ratings held by each source.

The updated AC provides separate requirements when outsourcing to FAA-certificated facilities and non-certificated entities. When outsourcing to FAA-certificated facilities, the repair station may issue an approval for return to service of a maintenance function contracted to the third-party repair station if the repair station determines that the third party repair station is properly rated to perform the maintenance. When outsourcing to non-certificated entities, the repair station must remain directly in charge of the work performed, and verify by inspection or testing that the work was performed satisfactorily and that the item is airworthy before approving it for return to service.

The Updated AC Is Important to Both Air Carriers and Repair Stations

Despite any regulatory duties imposed on repair stations, each air carrier remains primarily responsible for all maintenance performed on its aircraft and the recordkeeping concerning that maintenance. Thus, in determining whether a repair station has the capability of performing the work, an air carrier should be mindful of the potential for outsourcing of repair station work to either FAA-certificated and non-certificated entities. Repair stations must not only comply with requirements set forth by the air carrier, but also exercise proper oversight over entities to which they outsource maintenance work. Given these circumstances, it is extremely prudent for air carriers and repair stations to constantly evaluate and, to the extent necessary, define their rights and responsibilities concerning the performance of maintenance tasks.



1 U.S. Department of Transportation, Office of Inspector General, “Air Carriers’ Outsourcing of Aircraft Maintenance,” Report No. AV 2008 90, Sept. 30, 2008.

Advisory Circular 120 16E, Air Carrier Maintenance Programs, issued September 11, 2008.

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