This International Standard specifies the locations and types of aircraft ground service connections in order to optimize ground services, both fixed and mobile, for the following seven services: — 400 Hz electrical power; — preconditioned air for cabin conditioning; — pneumatic power for jet engine start; — potable water; — lavatory service (draining, flushing); — aircraft refuelling; — interphone (headset) connections. It focuses on these aircraft services because — these connections are those most frequently used during aircraft airport turnaround operations; — in terms of economic benefit, they have the greatest impact through improved efficiency. This International Standard applies to any new type of main line commercial transport category aircraft designed or built after its publication. In addition, it applies to any substantially modified new derivative aircraft type in the same category (derived from a previously existing type), insofar as technically and economically practical, if specified in the aircraft type specification established between customer airline(s) and manufacturer.