I'm booked in F on CX472 (shorthaul HKG-TPE) through Avios points. Checking flightaware it's been served by three different types of aircraft in the past ten days: 777, 333, and once by a 350. From my understanding only the 777 has F, and only some configs of it. I have no idea how to determine config except by specifically looking at seat map for each flight (which seems tedious).
I'm aware equipment changes on shorthauls are common.
1) If an equipment change occurs, as someone statusless and in a low value fare, is there a chance I'll actually end up in economy (e.g. because fewer J seats on new plane)?
Very unlikely. You will be bottom of the F pile, but that's still only 6 passengers max
2) Do I have any recourse from Avios or CX if downgraded from F to J or Y? If it happened T-24, would CX offer to change flights to one with F considering there are so many daily flights?
You will be able to get a refund of the Avios difference between an F ticket and a J ticket, or you can change to a flight that has F if it is available
3) When do equipment swaps usually occur?
It varies, but in my experience it is usually either 2-3 months out as they fiddle with schedules, or on the day as incoming aircraft get delayed etc.
4) What's the best way to stay informed? By creating an EF flight alert or must I constantly re-search the flight's seat map?
Sorry for the questions; it feels like there's a lot of material to absorb. New to CX, flying 40k miles with them this year
