I have to admit I can't see why an airbridge makes the process any quicker than mobile steps, let alone two airbridges. It can be quite time consuming to get the airbridge aligned correctly, and the slope from terminal to the end of the airbridge can be quite alarming when used on a 737.
You’re right it doesn't make it quicker.
You can turn an aircraft faster with 2 sets of steps.
However for weather reasons stated already (Passenger Comfort) and also Staffing reasons Air Bridges are far better.
To supervise a disembarking A330 without a bridge usually requires 4 staff. Dispatcher, staff under the wing to prevent passengers walking under it. Staff member on the service road to prevent the passengers getting run over by service vehicles.
The Air Bridge also acts to prevent passengers from leaving FOD (Foreign Object Debris) on the ramp, Turning their mobiles on and lighting up cigarettes when they walk off into the fresh air.
Some passengers are completely thick. Bowser metres from them and they are smoking.
Passengers also have this amazing ability to slip, fall and walk as close to any object usually dangerous on a ramp.
Air Bridge allows Dispatcher to know the passengers are safe.
Bottom line Air Bridge saves on staffing costs.
Airbridges for Ryanair ha They'll be doing away with stairs altogether shortly to save on costs and just having some extension ladders to use instead to board and deboard
Ryanair, even when air bridges are an option on stand will not use them for the reason it slows down the boarding process. It would be very difficult to board and disembark a 737-800, which carries 189 passengers within 25 minutes block to block.
Hard enough with the stairs.
Hope this helps.
Jonathan