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Passenger Boarding Bridges are now, more typically, mobile units which use an articulating mount to fasten them to the terminal at one end and are supported on powered wheels at the other end with the bridge between built as an extendable tube. Although relatively rare, there are PBBs of this type still in use. A retractable gantry would then be extended from the platform to allow passengers access to the aircraft. The aircraft would follow the ground marshaller or the stand entry guidance and stop with the aircraft door abeam the platform. In its earliest and most basic configuration, a Passenger Boarding Bridge consisted of a fixed platform, which may or may not have been height adjustable, connected to the terminal building by an enclosed bridge. The use of Passenger Boarding Bridges mitigates most of the risks associated with the requirement to allow passengers to access the ramp. Ensuring passenger safety on the ramp is manpower intensive and becomes increasingly more difficult as passenger numbers or the volume of aircraft and consequent Ground Handling traffic increase. Passengers may also be taken to a remote parking stand by bus but the final segment of their journey to the aircraft is still on foot from the bus to the aircraft.
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At smaller airports and those with low traffic volume, passengers will often leave the terminal and walk outdoors across the apron to board the aircraft via mobile boarding stairs or, in some cases, airstairs if the aircraft is so equipped. Moving passengers from the terminal to an aircraft, and from the aircraft back to the terminal, efficiently, expeditiously and safely is a major objective of efficient airport operations. Passenger Boarding Bridges can be found in many configurations and may be fixed or movable depending upon the installation.
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The PBB allows passengers to board and disembark an aircraft without the requirement to go outside or to be exposed to the elements.
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A Passenger Boarding Bridge (PBB) (also known as an air bridge, jet bridge, jetway, and sky bridge as well as by other terms) is an enclosed, elevated passageway which extends from an airport terminal gate to an airplane.
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