This part of ISO 8267 specifies the interface requirements for tow bar attachment fittings on the nose gear (when towing operations are performed from the nose gear) in conventional tricycle type landing gears of commercial civil transport passenger and freight aircraft. Its purpose is to achieve tow bar attachment fittings interface standardization by aircraft mass category (which determines tow bar forces) in order to ensure that a single type of tow bar with a standard connection can be used for all aircraft types within or near that mass category, so as to assist operators and airport handling companies in reducing the number of different tow bar types used.