Flight Sequence
The Seair Seaplanes Ltd. deHavilland DHC-2 MK 1 (registration C-GTMC) was departing Lyall Harbour, Saturna Island, for Vancouver International Airport. After an unsuccessful downwind takeoff attempt, the pilot took off into the wind. At approximately 1603 Pacific Standard Time, the aircraft became airborne but remained below surrounding terrain. It turned left, descended, and collided with the water. The cabin submerged before responders arrived.
Occupants
Eight persons were on board. The pilot and one adult passenger survived and suffered serious injuries. No emergency locator transmitter signal was heard.
Weather Conditions
The 1600 weather report for Victoria reported wind 160° true at 13 knots. In Lyall Harbour, wind was estimated from the southeast at 18 knots gusting 26. These conditions are conducive to mechanical turbulence and mountain waves due to the lee of high terrain.
Aircraft Information
The DHC-2 MK 1 (serial number 1171) was manufactured in 1957. Modifications included a gross weight increase (Viking Air STC SA92-63) and battery relocation (FAA STC SA397NW). The stall warning hot circuit was connected via a 5-amp fuse, and additional lights were added to the same circuit. The stall warning horn had been filled with silicone sealant to reduce noise, which was undocumented. The flaps were set in the landing configuration for takeoff; nothing in the flight manual prohibited this.
Weight and Balance
The pilot calculated takeoff weight at 5050 pounds with CG at the aft limit. Actual weight was 5204 pounds, 296 pounds below maximum, but CG was 0.87 inches aft of the aft limit.
Pilot Information
The pilot held a commercial license, had about 2800 total flight hours (2350 on DHC-2), and had received underwater egress training six weeks prior. Fatigue was not a factor.
Stall Warning
During the takeoff and upset, the stall warning horn and light were not detected. The stall warning system circuit modifications may have affected its operation.
Accident Sequence Details
After takeoff, the pilot set climb power. The aircraft climbed slowly, drifting toward the northern ridge. The pilot turned left (downwind) to leave the harbour. During the turn, the left wing dropped and the nose pitched down. Maximum power was applied, but the aircraft descended rapidly. Just before impact, the aircraft recovered to wings-level and slight nose-up, but the descent rate remained high. Upon water contact, floats collapsed upward into the wings and propeller. The pilot's seat failed and he was unrestrained.