Air Canada B763 over Atlantic on Jan 14th 2011, control inputs cause 16 injuries

Last Update: April 16, 2012 / 15:44:21 GMT/Zulu time

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Photo of Air Canada G-VSXY, Boeing 767-300 — Air Canada G-VSXY, Boeing 767-300 (Photo credit: markyharky / Flickr / License: CC by)

Incident Facts

Date of incident
Jan 14, 2011

Airline
Air Canada

Aircraft Registration
G-VSXY

Aircraft Type
Boeing 767-300

ICAO Type Designator
B763

The Canadian TSB released their final report concluding the probable causes of the accident were: Findings as to causes and contributing factors - The interrupted sleep obtained by the first officer prior to the flight increased the likelihood that rest would be needed during the overnight eastbound flight. - The first officer slept for approximately 75 minutes which likely placed the first officer into slowÂ–wave sleep and induced longer and more severe sleep inertia. - The first officer was experiencing a circadian low due to the time of day and fatigue due to interrupted sleep which increased the propensity for sleep and subsequently worsened the sleep inertia. - By identifying the oncoming aircraft, the captain engaged the first officer (FO) before the effects of sleep inertia had worn off. - Under the effects of sleep inertia, the first officer perceived the oncoming aircraft to be on a collision course and pushed forward on the control column. - The frequency of training and depth of the training material on fatigue risk management to which the flight crew were exposed were such that the risks associated with fatigue were not adequately understood and procedures for conducting controlled rest were not followed by the flight crew. - Although the seatbelt sign was on and an announcement about potential turbulence was made, several passengers were injured during the event because they were not wearing their seatbelt. Findings as to risk - North AmericanÂ–based pilots flying eastbound at night towards Europe are at increased risk of fatigueÂ–related performance decrements. - The use of multiple safety occurrence reporting systems may result in some safety issues not being properly identified and analyzed. - Some passengers may not be aware of the inherent risks in not wearing a seatbelt at all times when seated. Other finding - As the aircraft cockpit voice recorder (CVR) was only capable of recording for 2 hours, the event was overwritten. About 3 hours into the flight the first officer (12,000 hours total, 2,000 hours on type) expressed the need to a controlled rest, the captain (14,800 hours total, 400 hours in command on type) agreed, the purser was not informed about the controlled rest however. 38 minutes later the captain turned the fasten seat belt sign on in anticipation of forecast turbulence ahead. Cabin crew followed up with an according announcement and made a visual check of the passengers. Most of the passengers were asleep, many of the passengers were lying down across the three center seats. Another 37 minutes later the captain made his required position report to Shanwick Oceanic Control Center, this transmission woke the first officer up, he reported he was not feeling well although he had just rested for 75 minutes. At that time another aircraft was enroute in opposite direction at FL340 and appeared on the Boeing's TCAS display. The captain adjusted his navigation display while the first officer attempted to acquire visual contact with the traffic but mistook planet Venus for the aircraft until the captain pointed out the aircraft was at 12 o'clock and 1000 feet below. Both aircraft flashed their landing lights, the first officer acquired visual contact with the other traffic but interpreted its position as being above and descending towards them. He reacted to the perceived impending collision by pushing the yoke forward. The captain, who was monitoring the navigation display at that time to monitor the other traffic, noticed the control column move and the altitude to decrease, therefore disconnected the autopilot and pulled the control column to regain assigned altitude. The aircraft crossed at that point, there was no TCAS traffic or resolution advisory. The flight data recorder showed that the altitude decreased to FL346 and increased to FL354 with vertical accelerations between -0.5G and +2.0G in 5 seconds. None of the passengers in business class had been injured, in economy class however a number of passengers had contacted cabin fixtures and armrests causing injuries. Two medical professionals identified themselves and provided first aid. The cockpit crew established radio contact with medical services and dispatch, the various injuries were assessed, a decision was reached that it was acceptable to continue the flight to Zurich. 14 passengers and two flight attendant had received injuries, all injuries were of soft tissue variety, a few were lacerations. 7 people were taken to hospital after landing in Zurich. The Canadian TSB analysed that the first officer was fit for the flight despite some sleep interruptions for child care in the days prior to the flight. The sleep interruptions, especially in the 24 hours prior to the flight, likely increased the risk the first officer would feel fatigue however. During the controlled rest the first officer fell completely asleep showing his level of fatigue. The captain permitted the first officer to rest beyond 40 minutes maximum, that are set to prevent the body to enter the slow-wave sleep. The 75 minutes rest increased the probability of entering slow-wave sleep, interruption from which would increase likelihood of sleep inertia. Given the first officers comment to feel unwell after waking up it was likely the first officer was suffering from high levels of sleep inertia. The CTSB continued the analysis: The FO was not in a state to effectively assimilate the information from both the instruments and from outside the aircraft or effectively provide an appropriate response. Despite having been trained to interpret TCAS targets and react to them, the FO was drawn to rely on immediate perceptual information. Under the effects of sleep inertia, the FO was likely confused and disoriented and perceived the aircraft on an imminent collision course. Consequently, the FO pushed forward on the control column to avoid the collision. The FO quickly realized the error because the traffic appeared to be moving down in the visual field, which did not make sense.By that time, the captain had reversed the control movement to return the aircraft to the previous altitude. Air Canada took four safety actions as result of the occurrence: - reminders to the crew to followed standard operating procedures to permit controlled rests be performed safely, especially notify cabin crew of the rest and to arrange a call from cabin crew after 45 minutes - remind flight crew of the benfits of strategical lateral offsets by 1-2nm at all times unless the aircraft is being placed on a less desireable track - collect data on the Toronto-Zurich route to understand the alertness levels of flight crew - a reminder to cabin crew that cabin crew are an important part of the standard operating procedures for controlled rest emphasizing the flight deck briefing that is required and the call to the flight deck after 45 minutes have elapsed