By Paul 'BJ' Ransbury, CEO at Aviation Performance Solutions (APS)
This APS safety guide examines the risks of post-maintenance check flights and provides a practical framework for safer return-to-service decisions.
An aircraft may be cleared after maintenance, but is it truly ready to return to normal operations? When an airborne check is required, answering that question often necessitates more than a maintenance sign-off and a qualified flight crew.
Post-maintenance flights can expose pilots to unexpected aircraft behavior, particularly when maintenance has affected flight controls, aerodynamic surfaces, or stall-protection systems. In certain circumstances, these flights can introduce a serious risk of Loss of Control In-flight (LOC-I).
To help aviation organizations manage these risks, Aviation Performance Solutions (APS) has published At the Edge: Preventing Loss of Control In-flight (LOC-I) During Post-Maintenance Flights, a practical action guide authored by APS CEO Paul "BJ" Ransbury.
Post-maintenance check flights are intended to verify that an aircraft or its affected systems perform as required.
However, the flight may reveal unexpected handling characteristics, system malfunctions, or abnormal responses that were not detected during ground inspections.
The National Transportation Safety Board (NTSB) highlighted these dangers in its January 2026 report examining fatal Hawker stall-test accidents in 2024 and 2025. The pilots involved were qualified for normal aircraft operations but lacked preparation for the adverse stall behavior encountered during the tests.
These events highlight an important distinction: Being qualified to operate an aircraft does not necessarily mean a pilot is prepared to conduct every post-maintenance flight test.
The new APS guide outlines a coordinated return-to-service (RTS) process built around five essential safety priorities:
These measures help flight departments approach post-maintenance verification as a deliberate safety process rather than a routine extension of maintenance activity.
Upset Prevention and Recovery Training (UPRT) develops pilots' ability to prevent, recognize, and recover from aircraft upsets.
When post-maintenance checks create a credible risk of departure from controlled flight, recent, appropriately designed UPRT can be an important element of crew preparation. However, UPRT alone does not qualify a pilot to conduct specialized flight testing.
Effective preparation must account for the aircraft, the planned maneuvers, potential abnormal behavior, and the pilot's demonstrated competence. The quality and comprehensiveness of UPRT also matter, particularly when pilots may encounter conditions beyond those typically practiced during recurrent training.
At the Edge translates safety recommendations and lessons from NTSB investigations, WYVERN's Post-Maintenance Flight Check Guidance, and Flight Safety Foundation resources into actionable guidance for aviation organizations.
The 41-page guide includes:
Designed for flight department leaders, chief pilots, safety professionals, maintenance organizations, and pilots, the resource supports a more structured approach to managing post-maintenance flight risk.
The central message is simple: A successful return to service depends not just on completing the required checks, but on ensuring those checks are planned, conducted, and evaluated safely.
Explore the complete safety framework, real-world accident lessons, and practical planning tools in At the Edge: Preventing LOC-I During Post-Maintenance Flights.