I was made to understand that he was using AF1 for the flight, which is a four engine 747-8 aircraft.
The one you are talking about is AF2 which is an AF C-32 used by the VP and other dignitaries. In my reading I found the C-32 was equipped with the same configured dual performance Pratt & Whitney F117-PW-100 turbofan engines. If one was taken out, it could fly with a little work from the pilots and could land. Very seldom does the president use the C-32 as the 747-8 AF1 is predominately bigger and has a greater range.
rwood
The AF1 designation is reserved ONLY for the actual plane that POTUS is flying on, so if it is a 747, then that is AF1. If it is a 757, then the 757 is AF1. That is how the article refers correctly to the 757 plane...as AF1.
There is NO specific 747 AF1. We are just so used to seeing POTUS using a 747 in that role. I admit that it seems strange to see a 757 referred to as AF1!