Cathay Pacific Asia Miles - J itin but one leg S? What is S?

My upcoming trip on AA/CX is BOS-LAX-HKG-SIN and back on AA and CX.

All legs show in J, however shows one of the legs (HKG-SIN) in S... What is S? (no mention of it in cx.com)

I phoned AA EXP desk and they said that the leg in question is "on request"...

S class is a heavily discounted Economy subclass on CX (non-mileage-earning even on AsiaMiles). HKG-SIN does tend to be fuller in J than in Y these days with all the bankers shuttling up and down, but I'm very surprised in full-fare J isn't available. If you share the flight details we may be able to help more.

but I'm very surprised in ful-fare J isn't available.

That's right, full fare J is nearly always avail on SIN flight... Unless you book the flight in extreme short time or holidays like Xmas :confused:

Did you book it on AA.com? That engine, for some odd reason, loves to stick certain flights into S, even if the booking code stipulates otherwise.

For example, if you did a dummy booking for economy LAX-HKG-LAX.. the fare basis is generally an H fare.. but some/all segments will book into S, some into H. I booked once and immediately phoned web services to make sure everything was in the proper H inventory.