The objective of this Opinion is to mitigate the risks linked to maintenance check flights (MCFs). In MCFs, the pilots check the adequate functioning of aircraft systems that cannot be fully tested on the ground. This Opinion proposes to establish safety requirements to adequately select pilots and apply procedures for MCFs while distinguishing between MCFs with complex aircraft and MCFs with non-complex aircraft. The proposed changes are expected to increase safety of MCFs. Operators conducting the higher risk category of these MCFs with complex aircraft will have to develop their own procedures and ensure coordination between the operation, the continuing airworthiness management organisation (CAMO) and the involved maintenance organisation.