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 first flight after significant aircraft maintenance, such as an annual inspection, is considered the most risk-prone due to potential oversights, a fact corroborated by mechanics and NTSB accident reports.
FAR 91.407(b) mandates an operational check flight after maintenance that could alter flight characteristics, emphasizing the pilot's role in verifying airworthiness post-service.
Pilots conducting post-maintenance test flights must perform exceptionally thorough preflight inspections, specifically checking for correctly rigged flight controls, secure seats and seat rails, and the absence of foreign objects in the engine compartment.
A critical incident illustrates the danger of disregarding mechanical warnings, where a pilot's decision to fly against a mechanic's advice after an initial engine anomaly led to an engine failure shortly after takeoff due to a loose fuel connection.

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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.”