Ummmm.,
Funky me, It doesn't say Airforce one on the side of it. It says UNITED STATES OF AMERICA. And there are dozens of aircraft of all sizes that say that, including several 747s...
Airforce One is a PASSENGER, not an airplane, and if I read pprune later, I would be pretty embarrassed at having revealed my ignorance.
I suspect that the pratt who came on frequency is too embarrassed to admit it...
Cheers
Wino