“They wouldn’t be able to install the kinds of capabilities you typically find on an Air Force One,” said Richard Aboulafia, managing director of AeroDynamic Advisory, describing a retrofit timeline of less than four years.

“In terms of encrypted communications, to electronic warfare, to back-up power systems — it wouldn’t have any of that in that time frame,” Aboulafia said. “Anybody on that jet would be advised to use burner phones and watch what they say.”

Nicholas Veronico, a former NASA contractor who worked on 747s and is an author of a book on Air Force One, agreed that a shorter timeframe would be problematic.

“If the conversion can be done within a year and President Trump is flying around the world in this new less-than-Air-Force-One Air Force One, then he’s flying in a compromised airplane. And we’re putting our president at risk,” Veronico said.