Why Delta Flight 4819 Flipped After Landing, According to a Physicist

While investigators are still working to determine the cause of the crash of Delta Flight 4819, a physicist has offered an explanation for why it flipped over, saying, “The underlying physics is quite simple.”

On February 17, the Delta Air Lines jet crash-landed at Toronto Pearson International Airport, bursting into flames shortly after touching the runway and then flipping upside down. The plane’s right wing and tail were sheared off during the landing.

“Various forces acting on the airplane must remain in proper balance for the airplane to fly, and to land and take off smoothly,” Arun Bansil, a physics professor at Northeastern University, told Northeastern Global News.

The four forces that act on aircraft in flight are weight; lift, provided by the wings; thrust, provided by the engines; and drag, caused by air resistance.

Bansil added, “If the forces become unbalanced around any axis of the airplane, then the airplane will start rotating around that axis.”

Despite some injuries, all 76 passengers and four crew survived the crash-landing of the flight, which was inbound from Minneapolis-St. Paul International Airport.

According to reports, weather conditions at the time of the accident were challenging—with blowing snow and a gusting crosswind.

A crosswind is a term for horizontal winds that blow perpendicular to a given aircraft’s direction of travel. They can make both takeoffs and landings difficult.

Bansil said a sufficient crosswind could have caused Flight 4819’s rightward tilt as it came in for landing.

“A sudden gust of wind could cause the upward lift force on one wing to become much greater than that on the other wing and flip the airplane,” the physicist said. “One of the wings breaking and falling off would have a similar effect.”

“Hitting a snow or ice patch could tilt the plane and help flip it, although the runway was clear according to the news reports,” he added.

The crash is being investigated by the Canadian Transportation Safety Board, the U.S. National Transportation Safety Board and the Federal Aviation Administration.

Officials hope data from the craft’s black boxes, which have been recovered from the wreckage, will help reconstruct some of the events that led to the crash.

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