5 questions answered about the unresponsive plane that flew over D.C.

Updated June 6, 2023 at 2:41 PM ET

Flares, a "head-butt" maneuver and missiles at the ready: Those are some of the military's options when a wayward aircraft raises alarms in U.S. airspace. All those options were in play on Sunday afternoon, when an unresponsive Cessna jet flew over Washington, D.C., and crashed in Virginia.

For officials in charge of Washington's sensitive airspace, "their need to react is going to be much more significant than if the same event occurred over the central United States," former Federal Aviation Administration official Michael J. McCormick tells NPR.

McCormick should know: He helped design and implement the protocols for the airspace around the U.S. capital. He is now an assistant professor and program coordinator at Embry-Riddle Aeronautical University.

Air traffic control lost contact with the Cessna "during its ascent" — just 15 minutes after taking off — the National Transportation Safety Board said Tuesday in a message to NPR. The plane was flying from Elizabethton, Tenn., to Long Island MacArthur Airport in New York.

As the jet set off military and defense alarms, it also triggered a series of questions from residents, many of whom heard and even felt a sonic boom after F-16 fighter jets were ordered to intercept the plane.

"Six F-16s from three different air bases" were launched, according to John Kirby, White House National Security Council spokesperson. "They had to turn on the speed to get to him, which is why people here in the District area heard a sonic boom," he said on Monday.

The emergency ended in tragedy: The pilot and three passengers died on the plane that went down more than a mile from the Blue Ridge Parkway, the Virginia State Police told NPR via email.

Emergency crews found wreckage of the Cessna business jet "in a wilderness area" west of Wintergreen, Va., according to Wintergreen Fire and Rescue. The NTSB says its investigators reached the scene Tuesday morning, after hiking through rough wooded terrain.

"The wreckage is highly fragmented," the agency said. "Investigators are expected to be on scene for three to four days," it said, adding that the wreckage will be taken to a secure facility in Delaware for analysis.

What went wrong aboard the Cessna aircraft?

Air traffic controllers' final attempt to contact the plane happened at 1:28 p.m. local time, when the craft was around 31,000 feet, the NTSB said. The jet climbed to 34,000 feet and remained around the altitude until 3:23 p.m., when it began to descend. Nine minutes later, the Cesssna crashed.

As McCormick says, "It's very unfortunate, and from what's available in open press, I can see that it was a tremendous loss of life, of almost an entire family."

The Cessna Citation business jet was registered to Florida-based Encore Motors of Melbourne Inc. The New York Times reported that the head of the company, John Rumpel, said his daughter, 2-year-old granddaughter, her nanny and the pilot were on the plane. Rumpel told the Times they were returning to their New York home after visiting his house in North Carolina.

Immediately after he heard about the unresponsive plane, McCormick says, he believed a lack of air pressure inside the plane was likely to blame.

If a plane rapidly loses air pressure at around 35,000 feet, anyone inside would have mere seconds to put on an oxygen mask before losing what is known as "useful consciousness." The change would be more gradual if the craft lost pressure over a longer period.

"Everything I've read about it since then supports that," McCormick says, adding that he believes the aircraft lost pressure on its northbound journey.

"We have had corporate aircraft that have lost pressurization and everybody on board loses consciousness. And the aircraft then starts to fly on its own until it exhausts the fuel, then it crashes."

Such circumstances have been linked to high-profile tragedies, from the 1999 crash that killed golfer Payne Stewart to the 2005 crash of a Helios Airways airliner, in which 121 people died.

Why did the plane turn back to the south?

One detail among many that interests McCormick is the plane's flight path. The jet had flown to New York as planned — and then turned back south, only to crash. One explanation is that the plane's crew lost consciousness before reaching Long Island.

"It must have been programmed in the autopilot flight control system for the next leg of flight to be from New York back to Tennessee or down to the southwest," he says.

In most cases where an air crew is incapacitated, McCormick says, "the aircraft will just continue heading on its current heading and flight path, until fuel exhaustion takes place."

Because the jet flew through Washington's airspace at a high altitude of around 34,000 feet, it wasn't deemed a direct threat to the capital.

"If the aircraft had sped up and started to descend toward Washington, then it would actually change that calculus," McCormick says.

What happens when a plane isn't responsive?

An air traffic controller unable to make contact with an aircraft immediately informs their supervisor, who then begins an open call to the Domestic Event Network, a communication line encompassing all air traffic control facilities.

"There are protocols in place at all the air traffic control facilities across the United States, after the events of Sept. 11, 2001," says McCormick — who was a manager at New York Air Traffic Control when terrorists struck on that date in 2001.

The system also includes national defense and homeland defense agencies, quickly elevating information to higher levels. At that point, senior officials can make decisions about possible military intervention, including scrambling fighter jets, as happened Sunday.

"Once they get a visual acquisition on the aircraft, they do what they call a head-butt procedure," McCormick says, "where they will fly close to the aircraft and they get a visual on it, then try to get the aircraft to see them. The next step would be they would shoot flares."

A "head-butt" might sound dramatic, but it's not like what you've probably seen in movies, where a fighter gets alarmingly close to another plane — possibly inverted. In the real world, two fighters are normally sent on an intercept, McCormick says: One jet takes a position behind the wayward aircraft while the other jet flies toward it from the forward direction.

"They want to visually be in the line of sight of the people in the cockpit, is what it's really all about," he says. If anyone in the cockpit is alert and conscious, the thinking goes, seeing a military aircraft approach would help them realize something has gone wrong.

What are the military's options?

After trying to get an aircraft's attention, a decision would then need to be made about possibly shooting it down, based on the assessed threat level.

"In this instance they did not," McCormick says. "They were able to visually acquire the aircraft, they were able to actually see inside the cockpit and see that the air crew appears to be non-responsive, to make a determination that aircraft is not a threat. And they chose not to shoot it down."

In such cases, he says, military craft simply fly along with the aircraft until it runs out of fuel, "and they will watch and make sure the aircraft hits the ground in an area that minimizes risk to people on the ground."

"It could fly out over water, or it could fly over remote areas, which in this case it did. So the military did not have to make that tough decision whether to shoot the aircraft down or not."

How serious was the security alert?

The plane set off alarms because of the many sensitive potential targets in the D.C. region, but McCormick says the unresponsive jet would have caused a stir in any part of the U.S.

"Wherever it occurred, they still would have scrambled military aircraft to intercept and to get a visual on the aircraft in question, so they can make an assessment on a possible threat," he says.

By flying through the National Capital Region airspace, the plane triggered even more alerts.

"There is a significant level of defense capability around Washington," McCormick says. Potential responses range from anti-aircraft missiles and fighter jets to helicopters — and officials who control those assets would have been placed on an elevated security level on Sunday.

"There is something called the National Capital Region Coordination Center, in an undisclosed location in which the FAA, Homeland Security agencies and the military are all co-located," McCormick says. "And they are constantly monitoring the airspace in and around the area," he added.

But, he adds, the threat level was not deemed high or direct enough to evacuate President Biden, who was playing golf at Joint Base Andrews around when the military dispatched fighters.

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