Modern aircraft are designed and built according to strict standards which are laid down by national and international authorities to conform with International Civil Aviation Organisation (ICAO) Annex 8 (Airworthiness). In Europe, aircraft design must conform to European Aviation Safety Agency (EASA) standards.Aircraft manufacturers publish full details of aircraft performance in the Aeroplane Flight Manual (AFM), together with the approved aircraft operating technique necessary to achieve AFM performance. Aircraft must be able to operate safely throughout their flight regime in such a way that a safe outcome will result from specified malfunctions (e.g. power unit failure), occurring at any point throughout the flight range.
The maximum aircraft mass at take-off must is the maximum mass calculated for the aircraft type, the runway elevation, length, slope and braking action, and the prevailing weather conditions such that the aircraft can:Maintain specified minimum rates of climb after take-off with full power and with one power unit inoperative;If a power unit failure is detected during the take-off run, either:abandon the take-off and stop within the runway length; or,continue the take-off, clearing all obstacles during the climb-out path by a specified margin.Continue the flight with one engine inoperative, either returning to the departure airfield, the destination, or a specified alternate airfield clearing all terrain en-route by specified margins.Land safely at the departure airfield, the destination or the specified alternate airfield.The correct operating technique requires the aircraft to be flown at specified configurations, power settings and speeds corresponding to the actual aircraft mass throughout the take-off, initial climb, approach and landing.