# How is an aircraft aligned at a jet bridge?

I see these jet bridges (or aerobridges) at nearly every new airport I go to. How are aircraft aligned with these bridges, particularly the A380 which has doors on both decks?

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 ..."

• "I wonder what would happen if I pressed that ..." - the reason why there should't be allowed red buttons on control panels other than the terminate-stop-panic one – Mindwin Jun 5 '15 at 17:11
• @Mindwin Or the one that announces how many times it's been pressed. – user253751 Jun 6 '15 at 6:05
• There are two red buttons one of which is 'stop' and the other appears to be 'stop I'm on fire' (or some other cause of smoke) – Pete Kirkham Jun 6 '15 at 22:44
• Auto-leveller.. that is what maintains the constant height relative of the jet bridge to the aircraft. There's usually a roller which folds out and contacts the aircraft fuselage. As the aircraft moves down (pax leaving the rear and coming forward) the roller will move and this will tell the bridge to lower. – Anilv Jul 10 '18 at 2:03

The Aircraft aligns with the gate through ground markings, radar sensors and eventually ground operators signals.

After the aircraft stops the jet bridge is aligned with the aircraft's door by an operator that commands the various bridge actuators (wheels, extension, rotation).

Image source

The bridge can move to an extent but the aircraft is driven up to a designated spot that is marked on the ground. Here is a video of it all happening.

This can be also accomplished with someone on the ground directing

• you cannot be directly connected with the ground crew while the aircraft is autonomously moving (and pushbacks are not used for gate alignment) – Federico Jun 5 '15 at 13:28
• My apologies I will amend the answer – Dave Jun 5 '15 at 13:29
• So after the jumbo jet is parked, does this guy goes back to his game of ping pong? – Farhan Jun 5 '15 at 14:01
• @Federico Actually, a pushback tug CAN pull the aircraft into the gate, although this is used only when necessary -- usually in cases of extremely tight wingtip clearance where very precise steering is required. When this is done, the aircraft is stopped on a mark, the engines are shut down, and then the ground crew hooks up the towbar and establishes communication in the same manner as used for pushing back. The pilots then release brakes, & the aircraft is pulled in to the gate. Something similar can also be done if the aircraft is stopped & shut down too far off the mark -- not often. – Ralph J Jun 6 '15 at 17:37
• I've been on a plane where they've used a tug due to snow. I think it was Stockholm. "We're just waiting for a tug to pull us up to the gate" comes over the PA. After some movement, and a halt, a further announcement: "we're just waiting for a larger tug..." – Roger Lipscombe Jun 7 '15 at 19:01

They align themselves with the stand guidance system

Azimuth Guidance for Nose-In Stand (AGNIS) is a passive system which uses a system similar to PAPI lights to display red and green lights to indicate whether the plane is too far left or right.

An active system is for example the Honeywell Advanced Visual Docking Guidance. A camera detect the airplane and changes the sign to guide the pilot to the correct place.

(image source wikipedia)

After the plane is aligned to the gate the jet bridge is maneuvered up to the plane's door.

• this is the alignment to the gate, not to the "jet bridges" – Federico Jun 5 '15 at 13:35
• being aligned to the gate is required for the jet bridges to reach the plane. – ratchet freak Jun 5 '15 at 13:38
• I agree, but aligning to the gate does not imply being aligned to the bridges. and the questio is "how the aircraft aligns to the bridges" not "to the gate" – Federico Jun 5 '15 at 14:48
• Federico, I can't understsnd your comments. Parking "at the gate" (alingng left/right, and distance wise as in the photo above with the yellow markings) IS INDEED, PRECISELY parking so as to align with the jetway. Ratchet - am I right? (Or is the "gate" something else?! many yards back, or??) Sure, the OP needs to additionally understand that the jetway moves on wheels. – Fattie Jun 8 '15 at 8:04