Jet bridge
[2] Depending on building design, sill heights, fueling positions, and operational requirements, a jet bridge may be fixed or movable, swinging radially, or extending in length.[4] The first operational "Aero-Gangplank", as it was dubbed by inventor Lockheed Air Terminal, was installed by United at Chicago's O'Hare Airport in 1958.The cabin, at the end of the loading bridge, may be raised or lowered, extended or retracted, and may pivot, to accommodate aircraft of different sizes.As such, jet bridges provide enhanced access to aircraft for passengers with many types of disabilities and mobility impairments, as they may board and disembark without climbing stairs or using a specialized wheelchair lift.Thus, airports use mobile staircases to facilitate disembarking at hardstands (remote parking positions) and have buses transporting passengers to terminals.If the bridge is not retracted fully before departure, it may contact protruding parts of the taxiing aircraft (e.g., a pitot tube), requiring repair and delays.Several incidents of jet bridges collapsing include Sydney,[7][8] Hong Kong, Seattle, Los Angeles,[9] Baltimore,[10] and Islamabad.[11] Airports frequently charge increased fees for using loading bridges on stands as opposed to mobile stairs, therefore low-cost airlines such as Ryanair have avoided using these wherever possible.There are some jetways (such as several older bridges on the north terminal at Edmonton International Airport) that sit directly on the ground, as opposed to supports.