History of Flight
On 22 July 2024, an AW189 search and rescue helicopter (registration G-FSAR) operated from the Falkland Islands under contract to the Ministry of Defence. The aircraft was tasked to assist a fishing vessel in distress approximately 190 nm east of Stanley Airfield. After a rotors-running refuel at Stanley to maximum capacity, the helicopter departed at 1629 hrs and routed to the vessel's position. The crew faced challenging conditions: night, severe weather, estimated 8 m wave height, and wind at 270° gusting 50 kt.
Upon arrival, the vessel was listing 50° to starboard with its front end submerged. The crew conducted an overhead check but deemed a winch rescue from the vessel unduly hazardous due to excessive deck movement. They then attempted to rescue personnel from a life raft. The winchman was deployed but was submerged by a large wave, causing neck and shoulder pain; he was recovered. With limited fuel, the crew decided another life raft attempt was not feasible.
As they prepared to depart, a person was spotted floating face-up near the aircraft. The winchman was lowered and attempted to secure the casualty with two rescue strops, but due to the casualty's oversized, fuel-contaminated suit and severe conditions, only one strop could be positioned. As the casualty was lifted clear of the water, his left arm slipped out of the strop. The winchman maintained the strop with physical force and brought the casualty to the aircraft door, but difficulties with the casualty's low position and greater-than-normal weight caused him to slip out of the strop and fall back into the sea. Time on scene had been exceeded by two minutes, and the crew departed for Stanley.
The return flight was challenging, with heavy rain and low temperatures requiring anti-ice system activation, increasing fuel consumption. The winchman's helmet communications failed due to water ingress, and his neck and shoulder symptoms worsened. Upon arrival at Stanley, the crew consulted with the Air Commander and decided to return to base. A second rescue attempt was planned for the following morning but was prevented by adverse weather, including freezing rain, low cloud, and high winds.
Recorded Information
The aircraft was fitted with a cockpit voice recorder (CVR) with a 2-hour recording duration. Due to the long transit, the incident period was overwritten. Information was recovered from onboard CCTV and the aircraft's sensor system.
Aircraft Information
The AW189 on this contract was equipped with a Limited Ice Protection System (LIPS), which requires a 500 ft deep layer of positive air temperature for natural de-icing. Flight in freezing rain, freezing drizzle, or supercooled liquid droplets is prohibited. LIPS does not affect fuel consumption, but engine anti-icing, which increases fuel burn, is required when LIPS is active.
Aircraft Performance
The commander calculated the aircraft's radius of action (ROA) using maximum usable fuel of 2,000 kg, including 180 kg reserve and 153 kg for 20 minutes on scene. Fuel burn figures were taken from the operator's operations manual. A 10% contingency was added. With a pessimistic groundspeed estimate (40 kt tailwind outbound, 45 kt headwind inbound), the ROA was calculated at 186 nm. Actual fuel load achieved was 1,970 kg, reducing ROA to 183 nm. The distance to the vessel was 189 nm.
Meteorology
Post-event review by the Met Office indicated a forecast low-level weather chart available to the crew. The following morning, a frontal system brought freezing rain, a freezing level at sea level, and full cloud cover from surface to above FL100, preventing a second rescue attempt. Wind and swell conditions remained severe.