Originally Posted by
garykung
In theory - yes.
In practice - based on inventory and the miles you have.
I have tried many times to do WT+ to J using my Asia Miles over the last 5 years or so for HKG/LHR and SIN/LHR but have never been able to get the upgrades. Strangely enough I have been op-upped once LHR-SIN, and my wife has experienced it twice, all within the last months.