Casualties unknown

2001-01-05: BELL 206B (G-OBAY) — Lake Windermere, Cumbria, GB

Lake Windermere, Cumbria, GB

On January 5, 2001, a BELL 206B (registration G-OBAY) was involved in an aviation accident near Lake Windermere, Cumbria, GB. Investigators recorded the probable cause as: The pilot assessed the cause of the accident as a loss of depth perception during a descent over a still dark lake surface in poor visibility and light conditions, with the need to adjust the external landing light adding to his distraction. This summary draws on records from the UK Air Accidents Investigation Branch (AAIB); 8 related events involving the same aircraft type or operator are linked below.

Sourcesthe UK Air Accidents Investigation Branch (AAIB)Primary reportUpdated 1785053200Data APIEditorial standards

A Bell 206B helicopter struck the surface of Lake Windermere during a descending turn for approach, after the pilot lost depth perception due to poor visibility and light conditions over the dark lake. The pilot exited the sinking helicopter and swam to shore, suffering mild hypothermia.

Accident Details

On 5 January 2001, at 0750 hours UTC, a Bell 206B helicopter, registration G-OBAY, operated by a private pilot on a flight from Chorley, Lancashire, struck the surface of Lake Windermere. The helicopter was powered by one Allison 250-C20 turboshaft engine. The pilot, aged 61, held an Airline Transport Pilot's Licence (Helicopters) with an Instructor's Rating and had accumulated 9,263 total flying hours, including 1,266 hours on type. He reported no injuries.

Flight and Weather

The flight was intended to collect the helicopter's owner from a private residence on the shore of Lake Windermere. Forecast conditions included calm winds, good visibility, no significant weather, a temperature of +2°C, and a dewpoint of +3°C. The pilot initially flew at 1,500 feet in clear conditions, descending to 1,000 feet within two miles of the landing site. The landing site was an open-ended walled garden on the east side of the lake shore, allowing only approaches from the east and departures to the west over the lake. The pilot was familiar with the site, having landed there two days prior.

Sequence of Events

The helicopter approached from the north heading west, requiring a descending left turn for an approach to the east. During the turn, the pilot reported that visibility deteriorated, and he lost all depth perception. Distracted by adjusting an external landing light, he failed to appreciate his rate of descent. As he turned onto finals, approximately 700 metres from the shore, the helicopter struck the water in a flat and level attitude. The pilot, wearing a four-point harness, exited the sinking helicopter via the left door. The water temperature was between +3°C and +5°C, and it took him about 45 minutes to swim to shore, suffering mild hypothermia. He was taken by ambulance to hospital, kept overnight for observation, and then released.

Damage

The helicopter sustained damage beyond economic repair.

Probable cause

The pilot assessed the cause of the accident as a loss of depth perception during a descent over a still dark lake surface in poor visibility and light conditions, with the need to adjust the external landing light adding to his distraction.