Lufthansa and United both offer FRA-IAD service; transferring UR points to United (whose miles can also be used to book Lufthansa flights) will likely be your best bet. Check availability at United.com before transferring points though; transfer is instant and you can do so during the booking process if you find flights you want. Economy flights are 30k UR points/United miles each way.
Last edited by bodiddely; May 1, 2016 at 6:43 pm