What determines if an aircraft can be flown after maintenance?

The determination of whether an aircraft can be flown after maintenance is primarily based on the signing of a Release for Service. This document is a formal declaration, usually made by a licensed aircraft maintenance engineer, certifying that the aircraft has undergone necessary maintenance or repairs and is deemed airworthy for flight. The Release for Service confirms that all required inspections and necessary work have been completed satisfactorily.

Verbal confirmations or pre-flight inspections alone are insufficient. While a pre-flight inspection is an essential part of ensuring the aircraft's readiness for flight, it is not a formal indicator of maintenance compliance. Similarly, flight check results are important for verifying system performance, but they do not replace the need for official documentation concerning maintenance work completed. Thus, the signing of a Release for Service is a critical regulatory requirement that ensures safety and compliance before the aircraft can take to the skies.