Function and reliability flight testing is an important trial for civil aircraft airworthiness certification, and is a part of the qualified acceptance flight tests that confirm that the aircraft, components, and equipment are reliable and functioning properly. This article studies the airworthiness requirements for function and reliability flight testing in CCAR21 and Appendix B of AC25-7D, and combines practical experience with civil aircraft models to analyze the requirements for flight testing time, configurations, procedures, and problem requirements, and provide recommendations for civil aircraft function and reliability flight testing.