Originally Posted by
crazycrab955
No Y->J Star Alliance upgrades are made available on the A380 or 77W (save for a very rare system glitch), so your chances are essentially nil.
In general, the only way to upgrade Y->J on the A380 or 77W is to use KrisFlyer miles to do so.
I was doing research on this recently, and what seems to be the case is that you CAN upgrade from economy into business on the A380 or 77W, you just have to make sure to buy an economy class ticket in the right fare class: Y/B.
A couple of issues with that, though:
The first is that Y/B-class tickets on the A380/77W seem to be almost impossible to come by via the SQ website, even when you try to book a Flexi fare (which will usually be in E-class). This means you'll need to find a travel agent to issue you a ticket in Y/B.
Then you get to the second, more serious impediment, which is what I discovered when I tried to get a travel agent to see how much a Y/B-class ticket cost. The Y/B fare is even more expensive than a C/D-class fare, so you'd be spending less money booking yourself straight into business class, rather than using Star Alliance miles to upgrade.
On the other hand, even discounted business class tickets (i.e. D) are eligible for Star Alliance upgrade awards, so it might make more sense to use Star Alliance miles for those.