A flight shall not be commenced until flight preparation forms have been completed certifying that the pilot in command is satisfied that:
• the aircraft is airworthy;
• the instruments and equipment for the particular type of operation to be undertaken, are installed and are sufficient for the flight;
• a maintenance release has been issued in respect of the aircraft
• the mass of the aircraft and centre of gravity location are such that the flight can be conducted safely, taking into account the flight conditions expected;
• any load carried is properly distributed and safely secured;
• check has been completed indicating that the aircraft performance operating limitations can be complied with for the flight to be undertaken;
• the standards relating to operational flight planning have been complied with.
Completed flight preparation forms shall be kept by an operator for a period of three month.
Source: ICAO Annex 6