Low-Speed Tests, Altitude & Training...
There is a need for standards and training requirements from the authorities for operators/crews performing acceptance flights. We used to discuss/design our acceptance flight profiles with the help of the aircraft manufacturer and its test pilots. Our small team of acceptance flight crews underwent several special trainings and recurrent in the SIM with the acceptance program to be flown real later on. Excellent technical knowledge of all aircraft systems was required. Of utmost importance was the close cooperation of the acceptance pilots with base maintenance during the ground time of the aircraft and prior the test flight for any special items to look for during the test program. We had an internal standard and qualification program in order to "certify" new acceptance pilots.
On our non FBW aircraft, acceptance flights were allowed day only and special WX minima were defined. Low-speed tests were always performed in an altitude box between FL150 and FL190 in close coordination with ATC.