In order to make aircraft passengers comfortable, and in order to transport them between an airport terminal and an aircraft in such a way that they are protected from weather and other environmental influences, passenger loading bridges are used which can be telescopically extended and the height of which is adjustable. For instance, an apron drive bridge in present day use comprises a plurality of adjustable modules, including: a rotunda, a telescopic tunnel, a bubble section, a cab, and elevating columns with wheel carriage. Manual, semi-automated and automated bridge alignment systems are known for adjusting the position of the passenger loading bridge relative to an aircraft, for instance to compensate for different sized aircraft and to compensate for imprecise parking of an aircraft at an airport terminal, etc.several decades in developing ways of servicing plural doorways of a same aircraft, in order to reduce the length of time that is required to complete the boarding and deplaning operations for said aircraft. Although it is known to service more than one doorway in front of the wing of some types of large aircraft, for example using two separate apron drive bridges to service two different doorways, the actual time savings are nominal because some passengers must still traverse a long stretch of in-plane aisle in order to reach the nearer of the two different doorways.
Some types of aircraft include a rear door through which passengers can enter and leave the aircraft by means of steps that are lowered from the aircraft onto the apron or tarmac,