ISO 9667:2017 specifies dimensional and physical requirements of tow bar connections to tractor and aircraft (see Figure 1). It is applicable to any new type of commercial transport category aircraft tow bar designed or built after publication of ISO 9667:2017.
The purpose of ISO 9667:2017 is to standardize tow bar attachments to airplane and tractor according to the mass category of the towed aircraft, so that one tow bar head with different shear levels can be used for all aircraft that are within the same mass category and are manufactured in compliance with ISO 8267.