ISO 7718-1:2016 specifies minimum requirements for dimensions and unobstructed space around main deck passenger doors of future types of civil-passenger transport aircraft when they are intended to be compatible with the thousands of passenger boarding bridges and passenger transfer vehicles existing, or being planned, in airports worldwide. ISO 7718-1:2016 is not applicable to existing models of civil transport aircraft, or derivative models with entry into service up to year 2000 with the same fuselage, for which the aircraft-mating section of passenger boarding bridges or passenger transfer vehicles is expected to be compatible with ISO 16004. It is not the intent of this document to restrict in any way the basic design of any future types of civil-passenger transport aircraft. However, it aims at clarifying, for aircraft-design engineers, the design characteristics which would make it difficult or impossible for a new type of aircraft to adequately connect with existing airport passenger boarding bridges or passenger transfer vehicles. If basic aircraft-design requirements impose on a future model certain dimensional characteristics not complying with this document, note that: - either alternative methods of embarking/disembarking passengers will need to be implemented, such as integral aircraft stairs, etc.; - or existing passenger boarding bridges and/or passenger transfer vehicles in the airports where such a new type of aircraft is to operate will require some degree of modification/reworking; - or additional interface devices/equipment will be required in order to connect such a new type of aircraft with existing passenger boarding bridges and passenger transfer vehicles. Each case results in increased aircraft-handling constraints and operating cost.