Introduction
On the day of the accident, the pilot arrived at the airstrip at approximately 0900 eastern standard time (EST) and prepared the ski-equipped de Havilland DHC–3 (Otter) aircraft, registration C-GOFF, serial number 65, for the morning flight. The aircraft was equipped with a turbine engine. Two passengers, together with supplies for an extended period—including a snowmobile and camping gear—were to be flown to a remote location. After loading the aircraft, the pilot waited for the weather to improve.
Accident Sequence
At approximately 1200 EST, the pilot and passengers boarded the aircraft and took off in an easterly direction. The aircraft became airborne near the departure end of the airstrip. Shortly after takeoff, the right wing struck a number of small bushes and the top of a birch tree. Subsequently, the aircraft descended and struck the frozen lake surface, which was approximately 70 feet below the airfield elevation, in a steep, nose-down, right-wing-low attitude. Upon coming to rest, the aircraft was inverted and partially submerged, with only the aft section of the fuselage remaining above the ice.
Injuries and Rescue
All occupants were wearing lap belts. The pilot and the front seat passenger received fatal injuries. The rear seat passenger survived the impact and evacuated the aircraft with some difficulty due to leg injuries. The following morning, about 22 hours after the accident, a local air operator that was searching for the missing aircraft located and rescued the surviving passenger.
Probable Cause
The investigation determined the following causes and contributing factors: 1. The pilot attempted to take off from an airstrip that was covered with approximately 18 inches of snow, and the aircraft did not accelerate to take-off speed because of the drag; the aircraft was forced into the air and was unable to climb out of ground effect and clear the obstacles. 2. The pilot did not abort the take-off when it became apparent that the aircraft was not accelerating normally and before the aircraft became airborne.
Findings as to risk included that unidirectional G switches, which are found on many types of ELTs, do not always activate the unit when impact forces are not aligned with the usual direction of flight. Other findings noted that the validity of the aircraft’s certificate of airworthiness was affected while it flew more flights than allowed by the ferry permit issued by Transport Canada, and that the rear passenger seat was found to be installed incorrectly, contrary to de Havilland Alert Service Bulletin A3/49, dated 19 July 1991.