Virgin pilot’s switch mix up led to in-flight upset that injured a crew member, says ATSB report

A Virgin pilot accidentally pulled the wrong switch on the flight deck sending a 737 into a roll that injured a crew member, the ATSB has found.

A Virgin Australia pilot inadvertently sent a flight attendant tumbling, when he tried to open the cockpit door of a Boeing 737 but instead put the aircraft into a roll on a Brisbane to Melbourne service.

The Australian Transport Safety Bureau investigated the incident over Ballina on September 6, 2023, finding the captain briefly looked away as he reached for the flight deck door switch.

As a result, instead of pulling the right switch, he activated the rudder trim control and held it for eight seconds, resulting in a 42 degree bank roll to the left.

The aircraft movement led to a flight attendant suffering a minor injury while trying to stabilise a food cart.

The ATSB investigation found both switches were positioned close to each other on the flight deck aisle stand panel between the two pilot seats.

The switches in question on the flight deck aisle stand panel on a Boeing 737. Picture: ATSB

ATSB chief commissioner Angus Mitchell said as the captain reached for the switch, he “looked up to the flight deck door and then inadvertently grasped and activated the rudder trim control instead”.

“Initially the autopilot countered the increasing left rudder trim’s resultant left yaw and induced the left roll, with an opposing and increasing right wing down aileron input,” said the ATSB report.

“However after about 5 seconds of full left rudder trim input, the autopilot reached the limit of its capacity to counteract it and the aircraft began to increasingly roll to the left.”

Attempts to stabilise the aircraft eventually identified the issue and the 737’s bank angle peaked at about 42 degrees to the left, triggering a bank angle alert.

One of the issues identified by the ATSB was the length of time which the flight door deck switch had to be held for, to allow a cabin crew member to enter the cockpit.

In response Virgin Australia made changes to its flight deck door entry procedures, to reduce the time needed for the door unlock switch to be held.

“The new procedure is designed to indicate that the crew member requesting entry is at the door and ready to enter, thereby limiting the time required for the door unlock switch to be held in the unlock position,” said the report.

“Other safety actions included a briefing on the event for flight crews, and changes to the non-technical skills program.”

The interior of a Virgin Australia Boeing 737. Picture: Supplied

Mr Mitchell said it was important such incidents were reported to the operator and the manufacturer, “as such occurrences may indicate a design error that needs correcting”.

“When selecting and activating any control or switch, it is critical flight crew ensure the intended control or switch is positively identified, and actually selected before being activated,” Mr Mitchell said.

There had been a number of similar incidents involving Boeing 737s overseas, the most serious of which involved an All Nippon Airways flight in 2011.

In that incident, the first officer went to open the cockpit door to the captain, but activated the wrong switch which resulted in the 737 dropping 6000 feet as the captain remained locked out.

A Virgin Australia spokeswoman said their team had worked closely with the ATSB to support the investigation and had made “procedural and training changes to prevent reoccurrence”.

“The safety of our guests and crew is our top priority,” said the spokeswoman.