United 737 airplane on runway
Credit: Robert Alexander/Getty Images

A United flight from Newark to Bogota, Colombia, diverted to Washington, D.C. on Sunday after both autopilot systems onboard the aircraft failed, even though the pilots had control of the aircraft.

About an hour into the flight, pilots made an emergency diversion to Dulles Airport, according to Flight Aware.

Cabin crew stopped service and announced that the flight was diverting to Washington. The captain later told passengers that although crew was still in command of the aircraft, both autopilot systems had failed and “protocol required them to divert,” AeroInside reported.

The plane burned fuel before landing but still came in overweight, and an emergency crew inspected the plane before it made its way to the gate. Passengers had to wait for a replacement aircraft, and arrived in Bogota about three and a half hours after schedule.

Autopilot failures are not entirely uncommon, which is why most commercial aircraft come equipped with a backup system. In the event of failure, pilots can activate the second system. Although it’s a common adage that “airplanes fly themselves” these days, pilots are trained to perform all the same procedures as the autopilot and both human and machine must be present to ensure a safe flight.

Between the captain, co-pilot and two autopilots there are multiple layers of protection built into the cockpit.

United did not immediately respond to a request for comment.