Inadvertent descent of Cougar Helicopters Sikorsky S-92A highlights importance of maintaining hands-on flying proficiency when flying automated aircraft
Gatineau, Quebec, 12 September 2013 – The Transportation Safety Board of Canada (TSB) today released its investigation report (A11H0001) into an incident where a Sikorsky S-92A operated by Cougar Helicopters Inc. inadvertently descended and came within seconds of striking the water in July 2011.
"The aviation industry is increasingly relying on cockpit automation in its day-to-day operations," said Daryl Collins, the Investigator-in-Charge.
"Despite the many benefits of cockpit automation in aviation, it is vital that flight crews maintain their hands-on visual and instrument flying proficiency so that they have the experience and confidence to deal with unusual situations."
In this incident, the flight departed an oil platform for St. John's International Airport, Newfoundland and Labrador with 2 crew members and 5 passengers aboard. During the departure, the captain made a large, rapid aft control input just prior to activating the go-around mode, causing the helicopter to enter a nose-high, decelerating pitch attitude in cloud. As the helicopter's airspeed decreased below the minimum control speed, a rapid descent occurred. The captain, subtly incapacitated, possibly due to spatial disorientation, did not take action to recover from the descent in a timely manner. The first officer, lacking confidence in his abilities to recover from the inadvertent descent, did not take control of the helicopter, as required by the company's standard operating procedures. When the helicopter exited the bottom of the clouds at 200 feet above the water, the flight crew saw the water below and the captain increased collective pitch, which increases the amount of lift produced by the main rotor system, and the descent was arrested 38 feet above the water. There were no injuries or damage to the aircraft.
The investigation found numerous operational, procedural and training issues that contributed to this occurrence. Flight crews, for example, did not routinely practice unusual attitude recoveries, nor were they trained to recognize and respond to subtle incapacitation. This could reduce pilots' confidence to take control in these situations and increase the risk of an accident.
Since the incident, Cougar Helicopters improved its unusual attitude training and now requires pilots to fly a minimum of 2 manually flown instrument approaches every 90 days. It has also clarified its standard operating procedures related to unusual attitude recovery, subtle incapacitation, and autopilot usage.
The TSB is an independent agency that investigates marine, pipeline, railway and aviation transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.
For more information, contact:
Transportation Safety Board of Canada
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