I'll be flying UA2045 BOS-PHL and UA2310 PHL-BOS tomorrow. Both flights are USAir operated. united.com does not allow me to checkin online for the outward leg.

1. Anyway to checkin online for these flights?
2. Anyway to checkin from the USAir site?

I am not a member of USAir's FFP, but only a member of UA MP.