Aircraft Return to Service Statements: What You Need to Know

Returning an aircraft to service sends a green light to all stakeholders that the aircraft is “good to go” and safe to operate. When an aviation maintenance professional signs off on an official return to service statement, it’s a public acknowledgement of the soundness, safety, fit, form and function of the aircraft and its equipment. In fact, experts say, this act should be afforded no less attention to detail than the actual maintenance itself.

While aircraft maintenance technicians (AMTs) own the repair actions performed, aircraft owners are accountable for the airworthiness of the entire airplane. So, for them, knowing how to read and interpret maintenance logs is a must. Experts on NBAA’s Maintenance Committee offered their high-level guidance.

As always, safety is rule No. 1. The General Aviation Joint Safety Committee (GAJSC) discovered that fatal accidents occur when aircraft operate while still under maintenance and without the proper return-to-service approval. To assist, the FAA recently published Approval for Return to Service as a guide. The regulations are clear. Per 14 CFR section 43.9, those performing maintenance, repairs or alterations on an aircraft shall make an entry in the logbook with:

• A description of the work performed
• The work completion date
• The name of the person who performed the work
• The signature and certificate number of the person approving the work

Pay Attention to Advisory Circulars, Reference Data

However, gray areas still exist, and much is left to interpretation. For example, one cannot merely sign off and return an aircraft to service with the statement “IAW OEM guidelines.” Manufacturers typically disapprove of alternate maintenance practices such as supplemental type certificates, so-called “parts manufacturer approval” parts and “designated engineering representative” repairs.

“This is a job for advisory circular, accepted data out there that allows AMTs to incorporate OEM deviations,” said NBAA Maintenance Committee member Doug Gordon, maintenance manager at Executive Jet Management.

Also, it’s critical to correctly state the reference data used. “Best practices mean having a solid process; without it, important tasks get overlooked,” said NBAA member Jon McLaughlin, CEO of TBX Airworthy.com.

Put an Effective Process in Place

Implementing a process saves time, ensures details are recorded and avoids future problems. Joel Felker, a Gulfstream G650 manager, has just such a system. Felker uses a library of pre-drafted specific statements that cover various scenarios. One statement covers inspections and another covers repairs.

Felker also pointed out the importance of using Instructions for Continued Airworthiness (ICAs). ICAs establish a consistent and universal framework for maintenance data relating to aircraft, engines and propellers, effectively replacing the previously used diverse maintenance manual standards. When completing inspections IAW and ICA, this needs to be documented in the return to service statement, per FAR 43.11.

Beware of These 4 Common Pitfalls

1. Wrong Numbers
   NBAA Maintenance Committee member Bill Kamm, director of maintenance for Penn Aerospace, pinpoints the importance of accuracy, specifically regarding part and serial numbers. This situation often arises with complex components, such as aircraft wheels, which can have multiple part numbers for the wheel half versus the assembly. A common solution is to have the technical data present when completing the sign-off.
2. Not Using Backup Expertise
   “Don’t hesitate to seek another opinion or admit if you’re unsure,” said Kamm. “It’s always wise to contact the FAA for clarification.”
3. Being Verbose
   “People often make one of two mistakes in logbook entries: either they leave out important required information, or they overload the entry with excessive details, making it hard to read,” Felker said. He prefers log entries to serve as concise summaries, while full details should be in the work report.
4. Vagueness
   “When someone performs an inspection and finds the aircraft unairworthy, they must document their specific actions,” said Gordon. However, the determination of airworthiness can sometimes be ambiguous for the pilot or owner. A frequent issue in general aviation is failing to meet 91.417a(2)(v), which is commonly indicated by vague entries such as “all ADs complied with” without detailed information.

Use a Detailed Work Order

“If something incorrect ends up in a work order or logbook entry, no matter how unintentional, it’s considered dishonest and can have serious consequences,” said Gordon. For Part 135 operations, he uses a specific, mandated return-to-service statement every time an aircraft is signed off. One way to curtail a bloated logbook sign-off is to utilize a detailed work order (WO). Felker advises mechanics to use a WO and refer to it in logbook entries.

Overall, there’s one word that trumps them all: airworthy. The term “airworthy” carries tremendous weight, said Kamm. It can halt legal arguments and even derail aircraft sales. The FAA’s position is firm: An aircraft is either airworthy, or it isn’t.

When returning aircraft to service, ask the question: Does this component meet airworthiness criteria? As Kamm remembered one FAA inspector telling him: “True confidence, like sleeping through a storm, comes from a sound mind.”