How is an aircraft aligned at a jet bridge?
How are aircraft aligned with these bridges


They are not (but read on)

Aircraft are aligned to a point on the concrete, not to the jetbridge(s).

It is the jetbridge itself that carries out the final alignment to the aircraft door.

Jetbridges are actually motor vehicles with wheels, tyres, motors and (often) steering. It just happens that their rear end is tethered and their bodies articulate and/or telescope to accomodate the motion at the "front" end..

You drive one using a set of controls at the end furthest from the terminal building

-jet bridge controls

- driving a jet bridge

I believe some also have what is effectively variable height suspension like old Citroens (except I imagine it is hydraulic or jack-screw).

The aircraft is driven to the terminal so the nose wheel follows a  guide line and stops at a marking appropriate for the aircraft type. Then the jet bridge is driven up to the aircraft door.

As the aircraft is gradually burdened with self-loading freight and sinks on it's suspension, the jetbridge metaphorically bends its knees so that the SLF don't trip up or fall into the aircraft. That is, the jetbridge maintains alignment, the aircraft is pretty passive in the job of alignment.



I have to admit I didn't notice these jetbridge controls for many years as I was usually either busy rushing to my seat or busy rushing to the baggage reclaim. One time there was a delay at the aircraft door that was long enough for my bored gaze to alight on the controls and for the thought to briefly wander across my mind - "I wonder what would happen if I pressed that ..."