Bloomberg: "The first new Air Force One isn’t expected to be delivered until 2018, when it will be tested before entering service in fiscal 2023."
5 years of testing? Seems a little excessive considering it only has a planned 30 year lifespan.
Partly because they don't need it until 2023 (or maybe won't pay for it), but the 747-8 is selling badly, so the prod line might close ~2016.