Man who threatened to stab passenger on Frontier flight, forcing emergency landing, sentenced to prison

A man from Ohio has been sentenced to 30 months in prison after he drew a weapon on a plane and threatened to stab a fellow passenger.

William Liebisch, 43, of Cincinnati, was sentenced Thursday after interfering with the official duties of a flight crew following his actions on Nov. 11, 2022, when he carried a box cutter onto a Frontier Airlines flight and told a fellow passenger that he wanted to stab someone on the plane, according to the U.S. Attorney’s Office for the Northern District of Georgia.

“The flying public deserves to travel in peace without fear that a fellow passenger will create a violent disturbance,” U.S. Attorney Ryan K. Buchanan said in a statement. “Liebisch’s conduct created panic among the flight crew and his fellow travelers. His prosecution and sentence hopefully provide a message of deterrence to others.”

Following the prison sentence, Liebisch will have three years of supervised release. He initially pleaded guilty on Dec. 14, 2023.

FRONTIER AIRLINES FLIGHT DIVERTED TO ATLANTA AFTER PASSENGER FOUND IN POSSESSION OF BOX CUTTER

In Nov. 2022, Liebisch arrived at the Cincinnati airport with a ticket for Frontier Airlines flight 1761, which was scheduled to travel from Cincinnati to Tampa. Following his disruption, however, the pilot was forced to make an emergency landing in Atlanta.

“Safety is paramount to everyone aboard commercial aircraft, including flight crew at their workplace,” said Joseph Harris, Special Agent-in-Charge, Department of Transportation Office of Inspector General, Southern Region. “As illustrated by today’s sentencing, we will continue working diligently with our law enforcement and prosecutorial partners to hold accountable unruly passengers who disrupt airline operations.”

Liebisch was initially allowed to pass through the TSA security checkpoint with the box cutter still in his possession after officials removed the blade, believing it to be disabled, the attorney’s office said. Once onboard the flight, Liebisch inserted a spare blade that was stored in the handle of the box cutter.

TSA TO CONDUCT TRAININGS AFTER MAN ALLEGEDLY THREATENS PASSENGERS ON FLIGHT WITH BOX CUTTER

A passenger saw Liebisch with the box cutter and overheard that he intended to stab someone. The passenger informed another passenger, who then reported to flight attendants.

This information was passed on to the captain and the other flight attendants. The captain then made the decision to make an emergency landing at the nearest airport, which was Hartsfield-Jackson Atlanta International Airport.

“We would like to thank the passengers who took action to prevent the violence Liebisch threatened in the air.  No one should face harm while flying,” said FBI Atlanta Special Agent in Charge Keri Farley. “The FBI and our law enforcement partners will do everything we can to prevent violence, intimidation, and threats of violence that endanger passenger and flight crew safety on commercial flights.”

A U.S. Navy veteran and another former member of the military aboard the plane helped subdue the suspect before the situation escalated further, FOX 5 Atlanta reported.

Upon exiting the plane, Liebisch attempted to stab one of the flight attendants and the Atlanta Police Department ultimately arrested him, the outlet reported.

This case was investigated by the Federal Bureau of Investigation and the Department of Transportation.