Fuel reserves insufficient during diversion in Sikorsky S61N Sea King incident

Casualties unknown • Airborne over Cornwall, GB

A passenger helicopter operating in Cornwall was forced to land at an unplanned location after a go-around due to deteriorating visibility and insufficient fuel for a planned diversion.

What happened

On 20 April 2004, a Sikorsky S61N Sea King, registration G-BFFJ, was performing a scheduled passenger flight from Penzance to the Scilly Isles. After completing the outbound leg, the crew prepared for the return journey to Penzance. At the time of departure from the Scilly Isles, the crew noted that weather conditions at Penzance had deteriorated, yet they chose to proceed with a fuel load that did not include sufficient reserves for a diversion.

During the approach to Penzance, the crew encountered poor in-flight visibility and initiated a go-around. They intended to divert to St Mawgan, where the weather was expected to be slightly better. However, while en route to the intended diversion airfield, the crew spotted a gap in the cloud cover over RAF Portreath. Due to the critical fuel state, they elected to land at the Portreath helipad. The aircraft landed with only 425 lbs of fuel remaining.

The investigation

The investigation examined the crew's decision-making regarding fuel planning and weather monitoring. It was established that at the time of the initial departure from Penzance, no official meteorological forecast was available for that airfield, requiring the crew to rely on unofficial reports and low-level forecasts. While the crew had the opportunity to uplift additional fuel during the turnaround at the Scilly Isles, they declined to do so to avoid delays to the flight schedule and the complexity of an engine shutdown.

Investigators found that the crew's decision to carry only the minimum VFR fuel was influenced by the excellent weather conditions observed earlier in the day. Although subsequent reports indicated deteriorating visibility, the crew believed the conditions would remain above approach minima for the short duration of the flight. Furthermore, the crew did not brief their go-around intentions because they initially believed the weather was sufficient to preclude the need for a missed approach.

Findings

  • The crew departed the Scilly Isles with a fuel load that was sufficient for the return to Penzance but lacked the necessary reserves for a diversion.
  • The decision not to refuel during the turnaround was driven by concerns regarding the flight schedule and the time required for refueling.
  • The crew's reliance on recent weather trends rather than the potential for further deterioration led to insufficient fuel planning.
  • The lack of an official, timely meteorological forecast for Penzance contributed to the crew's difficulty in assessing the required fuel load.

Probable cause

The crew operated with insufficient fuel reserves for a diversion because they relied on recent weather observations rather than accounting for the potential for further deterioration, compounded by a decision to prioritize schedule adherence over refueling during the turnaround.

Frequently asked questions

What happened in the 2004-04-20 Sikorsky S61N Sea King accident near Airborne over Cornwall, GB?

A passenger helicopter operating in Cornwall was forced to land at an unplanned location after a go-around due to deteriorating visibility and insufficient fuel for a planned diversion.

What aircraft was involved and where did it happen?

The accident on 2004-04-20 involved a Sikorsky S61N Sea King, registration G-BFFJ, at Airborne over Cornwall, GB.

What was the probable cause of the accident?

The crew operated with insufficient fuel reserves for a diversion because they relied on recent weather observations rather than accounting for the potential for further deterioration, compounded by a decision to prioritize schedule adherence over refueling during the turnaround.

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