Originally Posted by sftrvlr
If it has a US flight number, the miles are treated as if you flew US Airways. You will get EQMs, but they won't count towards the 500 milers.
This is actually the reverse of that - UA flight number on UA metal but purchased as a reverse CodeShare from USAir...Flight number when applied to Mileage Plus account should show up with the real UA flight number (since it would be UA metal) rather than a US flight number..