In its recently released final report, the UK’s Air Accidents Investigation Branch (AAIB) cited the crew’s ineffective monitoring of the flight instruments and poor crew resource management in the fatal ditching of a CHC Scotia-operated Airbus AS332 L2 Super Puma near Sumburgh Airport in August 2013. Four of the 16 passengers died in the crash.
According to the AAIB, the helicopter’s decreasing airspeed went unnoticed by the pilots until the helicopter was in a critically low-energy state. The captain’s attempt to recover was unsuccessful and the helicopter struck the surface of the sea approximately 1.7 nm west of the airport, the report said. The helicopter rapidly filled with water and rolled inverted, but was kept afloat by the deployed flotation bags.
Each pilot also had a different understanding of how the approach was to be flown, adding to the lack of crew coordination. Further, the first officer tended to defer to the captain’s decisions and neither adhered to standard phraseology.
The operator’s standard operating procedures at the time did not optimize the helicopter’s automated systems. Thus, the non-precision approach was flown with the autopilot in three-axes with V/S mode, requiring the captain—the pilot flying—to control the airspeed with the collective pitch lever. The AAIB suggests this should have been accomplished by engaging IAS mode on the cyclic pitch axis and adjusting the vertical speed with the collective pitch lever, which crews have since been instructed to do.