A program official at Wright-Patterson has said the White House has urgently asked for the jets because of reliability concerns as the planes age, among other concerns.
Richard Aboulafia, a senior aviation analyst with the Virginia-based Teal Group, said in an email the tweet was "complete nonsense. But making program management and military requirements decisions via tweet is just very wrong."
In an interview, he said the president-elect's position on the Air Force One replacement was "very concerning."
"This is not from the standpoint of the contract, but just from deeper lack of understanding for what the president does," he said. "It's very important for the president to travel, visit other places in the country, and other countries and be able to manage national emergencies while he travels. You can't do that without Air Force One.
"Now the alternative is he thinks a 50-year-old Air Force One will do the job," Aboulafia said. "Hopefully, nobody can be that completely misinformed."
A message seeking comment was sent to Trump spokespersons this morning.
Todd Harrison, director of the aerospace project at the Center for Strategic and International Studies in Washington, D.C., said it's a tradition for an outgoing president to request a new Air Force One "so that it would not be seen as being for personal benefit." President George H.W. Bush's administration OK'd the purchase of the current fleet, he noted.
"If Trump cancels the program now, it could be another eight years before a new replacement program is started, so that aircraft would be pushing 40 years old by then," Harrison wrote.
The production of the iconic Boeing 747 jumbo jet could come to an end "so it's not clear that the Air Force would be able to buy a commercial derivative plane like the 747 from a U.S. company in the future."
Neither Boeing nor the Air Force has released the latest figures on the program.
Aboulafia said the more than $4 billion Trump cited was "about right over 10 years."
"It's incredibly expensive to be able to manage a country and fight a war from the air, and build two planes that can do that," he said. But he rejected the claim the costs were "out of control."
Loren B. Thompson, a senior defense analyst at the Virginia-based Lexington Institute and a defense industry consultant, said in an email the president-elect "probably overstates" the cost of the two new jets.
"Boeing thinks the program will cost less, but it is hard to say precisely how much because the Air Force hasn't finalized the requirements for the program.
"This is a plane that might need to remain airborne for days during a nuclear war," Thompson wrote. "It must be able to carry out functions no other plane in the world would need to accomplish."
The jet's cost is driven by its mission with self-protection measures such as shielding against electromagnetic pulse in a nuclear explosion and specialized communication gear to command a nuclear strike "which is why it is so much more expensive than the planes Trump is used to buying," Harrison wrote.
The National Museum of the U.S. Air Force hopes to land one of the current Air Force Ones when the plane was expected to be retired in the next decade to add to its collection of 10 presidential aircraft.