History of the Flight
At approximately 1950 eastern daylight saving time, a Cessna 421C (registration C-GVPB) operated by les Ailes de Charlevoix inc. departed from runway 15 of Charlevoix Airport, Quebec, for a visual flight rules charter flight to Trois-Rivières, Quebec. On board were one pilot and five passengers. Shortly after takeoff, witnesses on the ground observed greyish smoke emanating from the left engine. The aircraft then entered a steep left turn followed by a descent. After briefly continuing on a new heading, it yawed, entered an uncontrolled roll, nosed down, and crashed. The impact and subsequent fire destroyed the aircraft.
Injuries and Damage
All six occupants sustained fatal injuries in the crash. The aircraft was destroyed by impact forces and the post-crash fire. No other damage occurred on the ground.
Aircraft and Crew Information
The aircraft was a 1978 Cessna 421C powered by two Teledyne Continental GTSIO-520-L engines. The pilot held a commercial pilot licence and had accumulated 5,261 total flying hours, with 1,215 hours on the Cessna 421 type. His proficiency certificate had been renewed in early June 1994. The aircraft's weight and balance were within prescribed limits; the estimated takeoff weight was 7,450 pounds, below the maximum of 7,560 pounds.
Meteorological Conditions
Weather at Charlevoix Airport around the time of the accident was not directly observed, but the last regular observation at 1600 EDT reported broken clouds at 2,000 and 10,000 feet, a temperature of 17°C, and winds from the southeast at 9 knots. At Quebec City Airport (80 nautical miles southwest), conditions at 2000 EDT included broken clouds at 2,500 feet and light winds.
Wreckage and Impact
The aircraft crashed on a heading of 090° magnetic, with a descent angle of 60° and left bank of 44°. The fuselage came to rest 118 feet from the initial impact point on a heading of 230° magnetic. The left wing separated at the initial impact. The landing gear was down and locked, flaps were retracted, and trim tab positions were consistent with a takeoff configuration except for the elevator trim tab, which was found separated and at a 20° tab-down position—but this could not be confirmed as its pre-impact setting.
Engine and Systems Analysis
Greyish smoke from an engine is typically caused by a major oil leak burning on hot exhaust components. In the Cessna 421, oil lines are internal except those in the supercharging system. If a supercharger oil line ruptures, oil could spray on exhaust stacks, producing smoke, and the supercharger would cease to function. On teardown, the left engine showed no pre-impact anomalies that would have prevented normal operation, but the left supercharger was not turning at impact, and the left propeller was found feathered—indicating that engine was not producing power. The right engine appeared normal. The aircraft's left turn was consistent with asymmetrical thrust from a power loss on the left side. The pilot did not maintain airspeed above the minimum control speed (VMC).
Probable Cause
It is probable that a loss of oil pressure in the left engine caused a loss of power just after take-off. The pilot was unable to maintain the minimum control speed (VMC) of the aircraft.