This may have been asked before, but I could not find an answer.

Tomorrow, in about 12 hours I have a flight ATL-IAD-CDG-OSL. All segments except CDG-OSL is UA, which is SK codeshare. Flight bought on UA.com

Would I be able to do a sdc to ATL-EWR-OSL all on UA metal? I do not have to explain the benefit of this. There is space available in both cabins (I am currently in P fare). There is P fare available as well.

Thanks.

David