Sep 3: mailed application for second passport
Sep 11: received letter saying they needed my original passport to process a second passport by mail
Oct 7: mailed original passport with tracking, would have mailed it sooner but needed it for a trip
Oct 16: passport arrived in Sterling, VA, interesting note that the tracking fell off on Oct 9, I called the NPC and they mentioned it was held in a security inspection
Oct 17: approved, shipped that evening from Arkansas
Oct 19: USPS shipping said it arrived, but it didn't
Oct 21: second passport actually arrived
Very surprised on the quick turnaround. Basically a week to tell me I needed to submit my original passport. Then once it cleared the security inspection, a single day for approval.