aerobridge aeroplane air-industry airbridge airline airlines airplane airport airport terminal connect connecting enclosed extending extends gate jet bridge jetway moveable bridge passengers tarmac terminal terminal gate travel travelers traveling travellers travelling tunnel walkway jet-bridge moveable-bridge security staff stairs steps adjustable air jetty aircraft door angle board boarding bridge cab connected connection disconnect disconnected disembark disembarking extend extendable exterior gate attendant gateway height high interior loading bridge movable movable connector passenger boarding bridge passenger walkway portal retractable retractable tunnel retracted retracting safety slope sloping