First Post-Maintenance Flight Should Be Treated With Caution and Respect

NTSB accident reports back up the importance of aircraft testing in return to service.

Meg Godlewski

Tuesday, June 10, 2025 at 01:00 PM ET

Verified

Edited By:

Travis Tingle

There are many instances in NTSB accident reports where something bad happened during the first postmaintenance flight. [Credit: FLYING Magazine Archives]

Key Takeaways:

The most risk-prone flight for an aircraft is the first one after significant maintenance, a fact supported by experienced mechanics and NTSB accident reports, and mandated by FAR 91.407(b) for operational checks.
An NTSB accident report highlighted the dangers of flying an aircraft against a mechanic's advice after post-maintenance issues, leading to engine failure due to a loose fuel pump fitting, with the pilot's decision to ignore warning signs being a contributing factor.
Pilots conducting post-maintenance test flights should meticulously check flight controls for correct rigging and full travel, ensure seats and seat rails are secure, and thoroughly inspect the engine compartment for any foreign objects.

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If you ask a seasoned aviation mechanic what flight is the most risk-prone for an aircraft, you may be surprised to hear that it’s the first flight after significant maintenance, such as the annual inspection. I learned this when I worked at a flight school that had the CFIs do the “return to service test flights.”

This follows FAR 91.407 (b), which states “[if] the aircraft has been maintained, rebuilt, or altered in a manner that may have appreciably changed its flight characteristics or substantially affected its operation in flight, it cannot be released for rental until an appropriately rated pilot with at least a private pilot certificate flies the aircraft and makes an operational check of the maintenance performed or alteration made, and logs the flight in the aircraft records.”