Originally Posted by Muckus
You can transfer mile for mile into US Airways from AMEX
No, you cannot (see
https://www.flyertalk.com/forum/showthread.php?t=477998 and numerous, numerous other threads).
For the most part, AmEx MR transfers to traditional airlines are 1:1 and MR Options transfers 2:1. The two *A airlines still participating for mileage transfers are ANA and Air Canada.