What happened
At approximately 2000 mountain daylight time, an Aeronca 65-CA was departing from a private grass airstrip near Fort Steele, British Columbia, for a local flight. The aircraft, operated by its owner, was carrying the pilot and a teenage passenger. During the takeoff roll to the north, the aircraft struggled to gain altitude, remaining low to the ground. As the plane approached a group of trees at the end of the runway, the pilot attempted a maneuver to avoid the obstacle. This maneuver involved a steep bank angle that caused the nose to drop, resulting in a rapid descent. The aircraft subsequently struck the roof of a house, with the engine and front cockpit penetrating the structure. The impact ruptured the fuel tank, though no fire occurred. The pilot and passenger sustained serious injuries, while residents in the backyard of the home escaped unharmed.
The investigation
Investigators examined the environmental and mechanical conditions present during the departure. The airfield, located at 3100 feet above sea level, was experiencing a high density altitude of approximately 5100 feet due to the temperature and atmospheric pressure. While winds at a nearby airport were reported from the south, conditions at the site were calm at the time of the accident, though southern winds had occurred earlier in the day.
Technical analysis focused on the performance of the 1941-built aircraft. Because the aircraft lacks a modern operating manual, investigators relied on known performance characteristics for this type. It was determined that at the calculated density altitude, the 65-horsepower engine would experience a roughly 23 per cent reduction in power to approximately 50 horsepower. The aircraft's gross takeoff weight was calculated at 1228 pounds, which was 22 pounds below its maximum limit. Maintenance records for the aircraft were found to be well-documented, with the most recent annual inspection completed in July 1998.
Findings
- The aircraft was operating in high density altitude conditions, which significantly degraded engine performance and overall flight capabilities.
- The addition of a second occupant increased the weight compared to the pilot's earlier, successful flight that same day.
- The pilot's attempt to maneuver around trees caused the aircraft to bank steeply, likely resulting in an aerodynamic stall at an altitude too low for recovery.