Originally Posted by RobOnLI

If Y=0 then you won't be able to SDC. Business class availability means nothing when trying to SDC (unless you are booked/purchased business class). So you need to hope that UA upgrades a bunch of people and releases Y inventory at the same time. Technically you need "H" class to do this but my understanding is that many UA agents will just look at the "Y" bucket and give you a seat if inventory exists.



sbm12 covered most of your questions. With regards to #1 CO.com will offer you standby options at check-in that are within 24 hours and that have G class available. CO.com does not currently offer any SDC options to UA flights. Technically you can only switch from CO to UA at the airport up to 3 hours before your scheduled flight.

Just wondering why you would want to SDC from EWR-HNL unless you don't want that long of a non-stop. Trying for an upgrade on the continental US portion? Adding a stop in LAX or SFO practically adds no miles to the flights and last minute upgrades to either of those airports are basically nil.

-RM