Boarding stairs

They can occasionally be pushed by hand, but usually they are pulled by tractors[4] or are self-propelled, being permanently mounted on a specialized vehicle, a pseudo-van[clarification needed], with an electric or gasoline engine, which transports the stairs around the airport and places them attached to the side of the aeroplane door.

Optional features may include canopies, heating, supplemental lighting and a red carpet for VIP passengers; most models have a handrail for added safety.

[8] This method of boarding the plane, although it is the most comfortable for the passenger, consumes more resources of the airport, which, consequently, charges the airlines.

In order to save costs, some low-cost airlines often forgo this upgrade and use the classic boarding stairs.

Depending on building design, sill heights, fueling positions, and operational requirements, a jet bridge may be fixed or movable, swinging radially, and/or extending in length.