Accident Overview
On a scheduled flight from Terrace, British Columbia, to Sandspit in the Queen Charlotte Islands, an MD Helicopters 369D (registration C-FLDW, serial number 280258D) departed at 0747 Pacific daylight time. The helicopter proceeded southwest along the Skeena River but failed to arrive at Sandspit within the flight-planned times, prompting a search. Department of National Defence search and rescue teams located debris on the western and northern shores of Porcher Inlet, approximately 22 nautical miles south of Prince Rupert. The debris was positively identified as belonging to the missing helicopter. Oil and bubbles observed on the water surface indicated the likely position of the airframe and engine in water exceeding 500 feet in depth. The pilot, the only person on board, was not found despite searches of the water surface and surrounding land areas. Several boats remained in the inlet overnight to watch for signs of fire or flares, but none were observed. The helicopter wreckage was later recovered for examination.
Flight Details
The pilot had been operating out of Terrace for four years and was familiar with the route to Sandspit and shake-block operations in the Queen Charlotte Islands. The usual route followed the Skeena River southwest, then south to Bonilla Island light station, and direct to Sandspit Airport. A flight plan filed with the Terrace Flight Service Station indicated the route, time, and that the pilot planned to cross to Sandspit at 1000 feet, weather permitting. The flight plan stated the helicopter had two hours of fuel on board (a full fuel load) at departure. The pilot had completed three days of off-duty rest before this scheduled trip.
Weather Conditions
Reported weather at locations en route included:
- Terrace Airport at 0747: ceiling 500 feet broken, visibility ½ statute mile in light drizzle and fog.
- Prince Rupert Airport at 0800: calm wind, visibility 1 1/8 sm in light drizzle, ceiling zero; improving to 2 sm visibility and 100 feet overcast by 0817.
- Bonilla Island light station at 0730: ceiling 400 feet overcast; at 0800: overcast, visibility 2 sm in light drizzle and fog, northeast wind 2 knots.
- Sandspit Airport at 1000: wind 270° at 9 knots, visibility 20 sm, few clouds at 3000 and 4500 feet.
Departure from Terrace required a special visual flight rules (SVFR) clearance due to low visibility; the pilot received this clearance along with latest Terrace weather. Once clear of the control zone, the pilot required ½ sm visibility and clearance from cloud. The Prince Rupert weather was below VFR minima but improved to about 1½ sm by the time the flight reached the area. The pilot's planned route avoided the Prince Rupert control zone. No radio communication occurred between the Prince Rupert Flight Service Station and the pilot.
Pilot and Aircraft Information
The helicopter was certificated for visual flight only. Transport Canada authorized low-visibility operations down to ½ sm, provided the pilot had 500 hours pilot-in-command time, completed a pilot decision-making course, and received low-visibility training as per the company operations manual. The pilot met all conditions. The aircraft was equipped with a VHF transceiver (aviation band) and a VHF/FM transceiver (marine band). The VHF unit was working at departure, but no further communications were reported. The FM transceiver could receive marine weather broadcasts, but none of its preset channels covered the intended route. Investigators found no record of the pilot obtaining a formal weather briefing before takeoff.
Flight Progress and Wreckage Examination
Based on sightings and time-distance calculations, the helicopter traveled at an average speed of about 70 knots. The flight manual listed best-range speed as 116–119 knots for the conditions; the reduced speed is consistent with a typical response to degraded visibility. Operating at lower speed increases fuel consumption and reduces reserves.
Radar data was unavailable; the NAV CANADA radar at Sandspit cannot monitor flights below 1800 feet in the Prince Rupert area. The Canadian Coast Guard has no ground-based marine radar in the north coast region.
Glassy water conditions were possible near the occurrence site: wind was calm at Prince Rupert, and Bonilla Island reported a northeast wind of 2 knots with rippled seas. Porcher Inlet, sheltered by terrain, was likely under the same air mass, increasing the potential for glassy water.
The main fuselage was recovered from about 530 feet of water, including the passenger compartment, engine, transmission, drive shaft components, main-rotor hub, collective and cyclic linkages, and one main-rotor blade. The instrument panel, equipment, and personal effects were also found. Major components like the tail-rotor section were identified but not recovered.
Examination showed the forward fuselage and cockpit were destroyed, preventing inspection of pilot controls. Fracture surfaces were contaminated by salt-water corrosion. Drive shafts connecting the engine to the main transmission and the transmission to the tail rotor were broken in torsional overload, consistent with a sudden stoppage while powered. The skid gear was torn off rearward; a crush line indicated the helicopter tipped forward and left after water contact. The cockpit was destroyed back to the bulkhead. The recovered main-rotor blade was attached to the hub and bent in overload; all five blades broke in overload at the hub.
Instrument panel inspection revealed the transponder was set to code 1200 (normal VFR) and the altimeter subscale to the Prince Rupert setting of 30.31 inches of mercury. The three lights for transponder panel backlighting showed overheating; the bulb nearest the power switch had melted and fused to the plastic switch, likely occurring during the last flight. Two of four bulbs associated with the tail-rotor chip light were illuminated at impact. The approved rotorcraft flight manual cautions that a chip detector light indicates possible internal deterioration of the tail rotor transmission and advises landing as soon as possible.
Probable Cause
No probable cause was explicitly stated in the source.