A colleague has a family member who struggles with the stairs, and wouldn't be able to climb (injury). They've spotted a trip to Tasmania on Jetstar from Sydney, but are wondering if the planes have stairs or an air-bridge/jet-bridge.
The flights are JQ747 and JQ748, but I'd prefer a more generic way of finding out this information?
Flights JQ747/JQ748 are to/from Launceston Airport, which does not have aerobridges:
Due to airport operating restrictions, Launceston airport cannot provide aerobridges to board aircraft. All access onto the aircraft is via aircraft stairs or mechanical lifting equipment (Disabled Person Lift) operated by the airlines. airline staff will provide the assistance required to board the aircraft in an appropriate manner.
I would strongly advise you to contact the airline and notify them that you will likely need assistance, and arrive early for check in so you can ensure they're ready.
On the Sydney side, Jetstar flights typically do use aerobridges, but these are some bus-only gates as well. The airline will be able to advise you regarding this as well.
As for a generic way to find out, I suppose you could always look at the airport in the satellite view on Google Maps, but even if the airport has gates does not guarantee that your flight will use them. So, again, contacting the airline is by far your best bet.
There is no way to guarantee either. Aircraft parking assignments are planned in advance, but subject to change without prior notice due to various reasons, such as the previous flight using the gate being delayed.
You can decrease the risk of a bus gate (stairs) by choosing flights that come and go during the daytime, early evening, as they do their best to park turn around flights at the gate for more efficient loading and unloading. Flights that arrive late or depart very early may use aircraft that park overnight, which would be more likely to use a bus gate to keep jet bridges open for turn arounds.
But if the flight uses a bus gate or stairs, then all airlines and airports have means to board passengers with mobility issues, ranging from simply carrying a specially designed wheelchair up the stairs, to using a lift truck to move the passenger and wheelchair up to one of the service doors.
It is not the flight/plane themselves that could be the problem, but the airport.
If your friend's family member needs extra help to board the plane, then they should ask the airport/airline directly for assistance. (As soon as possible)
For example, I assume they will go to Launceston airport in Tasmania.
They have a "disability/accessibility plan" that supports different disability (wheelchairs and other )
https://www.launcestonairport.com.au/accessibility
I assume Sydney Airport has the same kind of assistance.
Either jet-bridges if boarding from the airport, or ramps (or elevators) if boarding from the tarmac.
As far as I am aware there is no generic way to discover this information. See the discussion at Ryanair Using Jetbridges, Where? about this topic where a Ryanair crewmember was unsure whether they use it at BUD or not as it was not his/her route and also someone pointed out sometimes it's just "depends" and that easyJet some places uses both.
Trying to address your need rather than answer your question directly:
I'd say that's the best you can do in your situation.
If the airport is small it may not have bridges and thus you know it will be stairs. Otherwise you can't know as it can be situational: "They don't have a gate for us, we are going to use stairs." It's happened to me twice at major (admittedly foreign) airports.
And since I wrote this I've had to use stairs twice at major US airports. Seattle has some "gates" that are always actually stairs.
