As government lawyers sort out the legal arrangement for accepting a luxury jet from the Qatari royal family, another crucial conversation is unfolding about modifying the plane so it’s safe for the American president.

Installing capabilities equivalent to the decades-old 747s now used as Air Force One would almost certainly consign the project to a similar fate as Boeing’s replacement initiative, which has been plagued by delays and cost overruns.

Air Force Secretary Troy Meink told lawmakers Thursday that those security modifications would cost less than $400 million but provided no details.

Satisfying Trump’s desire to use the new plane before the end of his term could require leaving out some of those precautions, however.

A White House official said Trump wants the Qatari jet ready as soon as possible while adhering to security standards. The official, who spoke on the condition of anonymity, did not provide details on equipment issues or the timeline.

Trump has survived two assassination attempts, and Iran allegedly also plottedto kill him, so he’s well aware of the danger he faces. However, he seems willing to take some chances with security, particularly when it comes to communications. For example, he likes to keep his personal phone handy despite the threat of hacks.

He boasted this week that the government got the jet “for free,” saying, “We need it as Air Force One until the other ones are done.”

Here’s a look at what it would take to make the Qatari plane into a presidential transport:

What makes a plane worthy of being Air Force One?

Air Force One is the call sign for any plane that’s carrying the president. The first aircraft to get the designation was a propeller-powered C-54 Skymaster, which ferried Franklin D. Roosevelt to the Yalta Conference in 1945. It featured a conference room with a bulletproof window.

Things are a lot more complicated these days. Boeing has spent years stripping down and rebuilding two 747s to replace the versions that have carried presidents for more than three decades. The project is slated to cost more than $5.3 billion and may not be finished before Trump leaves office.

A 2021 report made public through the Freedom of Information Act outlines the unclassified requirements for the replacement 747s under construction. At the top of the list — survivability and communications.

The government decided more than a decade ago that the new planes had to have four engines so they could remain airborne if one or two fail, said Deborah Lee James, who was Air Force secretary at the time. That creates a challenge because 747s are no longer manufactured, which could make spare parts harder to come by.

Air Force One also has to have the highest level of classified communications, anti-jamming capabilities and external protections against foreign surveillance, so the president can securely command military forces and nuclear weapons during a national emergency. It’s an extremely sensitive and complex system, including video, voice and data transmissions.

James said there are anti-missile measures and shielding against radiation or an electromagnetic pulse that could be caused by a nuclear blast.

“The point is, it remains in flight no matter what,” she said.

Will Trump want all the security bells and whistles?

If the Qatari plane is retrofitted to presidential standards, it could cost $1.5 billion and take years, according to a U.S. official who spoke on the condition of anonymity to provide details that aren’t publicly available.

Testifying before Congress this week, Meink discounted such estimates, arguing that some of the costs associated with retrofitting the Qatari plane would have been spent anyway as the Air Force moves to build the long-delayed new presidential planes, including buying aircraft for training and to have spares available if needed.

In response, Rep. Joe Courtney, D-Conn., said that based on the contract costs for the planes that the Air Force is building, it would cost about $1 billion to strip down the Qatar plane, install encrypted communications, harden its defenses and make other required upgrades.

James said simply redoing the wiring means “you’d have to break that whole thing wide open and almost start from scratch.”

Trump, as commander in chief, could waive some of these requirements. He could decide to skip shielding systems from an electromagnetic pulse, leaving his communications more vulnerable in case of a disaster but shaving time off the project.

After all, Boeing has already scaled back its original plans for the new 747s. Their range was trimmed by 1,200 nautical miles, and the ability to refuel while airborne was scrapped.

Paul Eckloff, a former leader of protection details at the Secret Service, expects the president would get the final say.

“The Secret Service’s job is to plan for and mitigate risk,” he said. “It can never eliminate it.”

If Trump does waive some requirements, James said that should be kept under wraps because “you don’t want to advertise to your potential adversaries what the vulnerabilities of this new aircraft might be.”

It’s unlikely that Trump will want to skimp on the plane’s appearance. He keeps a model of a new Air Force One in the Oval Office, complete with a darker color scheme that echoes his personal jet instead of the light blue design that’s been used for decades.

What happens next?

Trump toured the Qatari plane in February when it was parked at an airport near Mar-a-Lago, his Florida resort. Air Force chief of staff Gen. David Allvin was there, too.

The U.S. official said the jet needs maintenance but not more than what would be expected of a four-engine plane of its complexity.

Sen. Tammy Duckworth, an Illinois Democrat on the Senate Armed Services Committee, said it would be irresponsible to put the president and national security equipment aboard the Qatari plane “without knowing that the aircraft is fully capable of withstanding a nuclear attack.”

“It’s a waste of taxpayer dollars,” she said.

Meanwhile, Boeing’s project has been hampered by stress corrosion cracks on the planes and excessive noise in the cabins from the decompression system, among other issues that have delayed delivery, according to a Government Accountability Office report released last year.

Boeing referred questions to the Air Force, which said in a statement that it’s working with the aircraft manufacturer to find ways to accelerate the delivery of at least one of the 747s.

Even so, the aircraft will have to be tested and flown in real-world conditions to ensure no other issues.

James said it remains to be seen how Trump would handle any of those challenges.

“The normal course of business would say there could be delays in certifications,” she said. “But things seem to get waived these days when the president wants it.”