My record, although in LBB with AA, was 56 of 60 hours. I spent 2 nights in a row babysitting airplane mechanics. It was great though because we didn't have to escort them on the ramp, just be there to let them in so I got paid to sleep. It was a very bizzare feeling though when I walked landside. I'd been on ramp the whole time so I'd been outside plenty but it felt so freeing to go landside to take my 4 hour nap in my car between shifts.