A group of Air Canada passengers have brought a class action suit today against the carrier, seeking $20 million in damages following an incident last January caused by a groggy pilot.

Fourteen passengers and two flight attendants were injured in the 13 January 2011 incident, in which the Air Canada Boeing 767-300 went into a steep dive while on a flight from Toronto to Zurich.

Air Canada had said right after the incident that it was the result of turbulence, but a report issued by the Transportation Safety Board of Canada on 16 April 2012 says the aircraft's first officer was fatigued after waking up from a 75min rest and was not feeling well.

While the first officer was waking up, the flight crew received a traffic alert and collision avoidance system target on the navigational display about a US Air Force Boeing C-17 coming from the opposite direction.

"The first officer initially mistook the planet Venus for an aircraft but the captain advised again that the target was at the 12 o'clock position and 1,000 feet below," says the report.

When the first officer saw the oncoming aircraft, he pushed forward on the control column after he interpreted the oncoming aircraft's position as being above and descending towards them, sending the 767 into a dive.

The captain then disconnected the autopilot and pulled back on the control column to regain altitude. The oncoming aircraft then passed beneath the 767.

"During the pitch excursion, the aircraft pitch changed from the cruise attitude of two degrees nose up, to six degrees nose down followed by a return to two degrees nose up. The vertical acceleration forces went to -0.5g to +2.0g in 5sec," says the report. "Computed airspeed increased 7kt then decreased 14kt before recovering to cruise speed with the aircraft's altitude decreasing to 34,600 feet increasing to 35,400 feet and finally recovering to 35,000 feet."

In the report, the board says that while the first officer reported for work feeling well-rested, he was not able to attain his usual 8h of sleep the previous night due to child care.

"It is likely that the first officer was suffering from high levels of sleep inertia," says the report.

The flight continued on to Zurich, where seven passengers were hospitalised.

In the law suit filed on behalf of the 95 passengers on board the flight, law firm Thomson Rogers says that the flight's passengers did not receive any explanation for the incident before the safety report was released.

Accusing Air Canada of covering up the incident, it adds: "In fact, Air Canada entered into purported settlements with passengers for modest compensation without explaining what they knew to be the true cause for the terrifying episode. The class action claim alleges that Air Canada covered up the true cause for the terrifying episode and claims punitive damages to punish their conduct."

Air Canada has 20 days from today to file a statement of defence in response to the suit if it plans to defend the proceeding.

Source: Air Transport Intelligence news