The Philadelphia Eagles have signed Air Force 2nd Lt. Chad Hall to their 53-man roster, according to a report on the team’s website. He is expected to be active for the Eagles’ game with San Francisco, which will mark his regular-season NFL debut. The signing makes Hall, a 2008 graduate of the Air Force Academy, the first service academy grad to make a team’s active roster this season (Army grad Caleb Campbell is on Detroit’s practice squad). Hall has been on the Eagles practice squad since getting cut by the Eagles at the end of the preseason, and has reportedly shown continued progress…