Reagan

So, we arrive in Washington. Good flight. Sarah read a book and I watched TV. Nice feature.

The airbridges at the JetBlue terminal in Reagan airport are interesting. They are fixed bridges, but not like ours.

Think about our gate 26, where Asia X parks.

That bridge is “L-shaped”. There are two parts to the bridge:

• The fixed structure, from the terminal to the adjustable structure.
• The adjustable structure sits at right angles to the fixed structure, and connects to the aircraft. It is height adjustable to the aircraft being used.

The floor of the adjustable structure slopes from the aircraft to the fixed structure. As a result, the adjustable structure needs to be quite long to allow height adjustment between short and tall aircraft, without making the floor climb too steep.

The shortcoming with gate 26 is that the flexible structure is too short to be able to adjust between tall and short aircraft. We cannot park an A320 or a B737 on this gate because the floor would need to rake up severely to reach the door. Passengers would struggle to walk up the incline safely.

Compare this with gate 19. Forget for the moment that this is a “drivable” bridge. Not so much an “L-shape”, only the head turns to the aircraft. As a result, there is no fixed structure. As the head raises to meet the aircraft door, the entire tunnel to the terminal follows it up, angling higher and higher. Because this section of the structure is much longer, the incline is gentle, allowing any aircraft size to park here.

Now lets look at the bridges at Reagan. The terminal is round, with solid brick piers that come out from the terminal at regular intervals. These are the full height of the terminal, the width of a normal airbridge, and probably 10-15m long.

Imagine an empty matchbox. Push the box open half an inch. Now sit the box on it’s side (on the striking surface). This box is the bridge structure, and the slot we have opened is where we mount the bridgehead. It slides up and down this slot to meet the aircraft.

Finally, there is a floating floor, like gate 19, which is fixed at the terminal end, as well as at the bridgehead. The floor floats inside the brick structure, only attached at the two ends.

Want a small aircraft to park there? Lower the bridgehead in its channel, and the floor follows it down.

Want a larger aircraft? Raise the bridgehead up in its channel, and the floor will follow it up, increasing the incline of the floor.

The maintenance and probably installation costs must be considerably cheaper than the drivable tin box we are used to.