Well they have the 4 NEACAP E-4Bs as well. I wonder if the maintenance contract will cover them as well
because...
"The E-4B airframe has a usable life of 115K hours and 30K cycles, which would be reached in 2039; the maintenance limiting point would occur some time in the 2020s."
The first VC-25 is due to arrive in 2019. With a 30 year life I wonder what will replace the E-4B and then become the next replacement.