Boston — A terrifying mid-air medical emergency unfolded on an Air Canada flight when the captain apparently suffered a seizure, causing the plane to swerve violently and prompting passengers — including children — to begin praying as the aircraft was diverted for an emergency landing.

The incident occurred Wednesday on PAL Airlines Flight 7664, operating on behalf of Air Canada. The twin-turboprop de Havilland Dash 8-400 departed Newark Liberty International Airport bound for Halifax, Nova Scotia, carrying 61 passengers.

Passenger Rodney McDonald described the horrifying moment the plane suddenly began swerving. “The moment the plane swerved, I knew something was wrong because it was not turbulence,” McDonald told ABC News. “It really felt like someone had jilted the controls and then it happened over and over again.”

McDonald, traveling with his wife and two sons, said the frightening experience immediately led to prayers aboard the plane. “Every thought goes through your mind, you start praying. My boys instantly started praying.”

Passengers and crew restrain pilot

A flight attendant quickly removed the incapacitated captain from the cockpit. McDonald and several other passengers rushed to assist, helping restrain the pilot — who appeared to be having a seizure — for approximately 40 minutes using seatbelts to secure his arms, legs, and chest.

“The pilot was out of control physically… it was clear that he was not in control of his faculties and needed to be restrained,” McDonald said. “It was a fairly strenuous 40 minutes.”

Meanwhile, the first officer took control of the aircraft. Air traffic control recordings captured the urgent message: “Pilot is incapacitated. Aircraft is being flown by the co-pilot.” The plane was diverted to Boston Logan International Airport, landing safely just before 2 p.m.

Emergency vehicles, including ambulances and fire trucks, swarmed the aircraft upon landing. The pilot was taken for medical treatment. No passengers were injured, and the flight later continued to Halifax after the aircraft was towed to a gate.

Air Canada confirmed that the captain experienced a medical issue and was removed from the flight deck per safety protocols. “The first officer took control of the aircraft and diverted the flight to Boston, where it landed safely,” the airline stated.

The pilot’s current condition has not been publicly released. The incident remains under investigation.