On 9 December 2012 the pilot of a Robinson R22 helicopter took off from a fishing camp at the mouth of the Normandy River in Queensland on a private flight.
The pilot was flying north along the coastline at about 600 ft above the ground when he saw an object in the water about 100 m from the coast. The pilot turned the helicopter towards the object and descended to take a closer look.
As the pilot approached the object the helicopter’s tail rotor hit the water which caused the helicopter to rotate to the right before the pilot lost control. The pilot closed the throttle, and the helicopter settled into the water, before rolling over to the right. Unharmed, the pilot escaped via the passenger door and swam to shore before walking back to the fishing camp he left earlier.
Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates.
The pilot reported that the wind was about 20 knots with a high smoke haze and flat light conditions. Flat light is an optical illusion also known as ‘sector or partial white out’ that causes pilots to lose their depth-of-field and contrast in vision. Flat light conditions are usually accompanied by overcast skies inhibiting good visual clues. These conditions can occur anywhere in the world, primarily in snow covered areas but can also occur in dust, sand, mud flats or over water. Flat light can completely obscure features of the terrain, creating an inability to distinguish distances and closure rates. It can give pilots the illusion of ascending or descending when actually flying level.
The dangers of flying helicopters over water have long been recognised. In July 1985 Robinson Helicopter Company issued Safety Notice SN-19 about the hazards of flight over water, making special reference to the potential for pilots’ loss of depth perception over water. The safety notice recommended maintaining a height of 500 ft AGL and avoiding manoeuvres over water below 200 ft AGL.
Read the report: Loss of control involving a Robinson R22, VH-HTD, Princess Charlotte Bay, Queensland, on 9 December 2012