What happened
On June 16, 2024, a Tecnam P2006T, registration N968GV, was involved in an accident near Larkspur, Colorado, during a multi-engine instructional flight. The flight involved a flight instructor and a commercial pilot receiving instruction.
After completing several landings at Centennial Airport, the crew climbed to 10,800 feet MSL to practice one-engine-inoperative (OEI) procedures. During the training, the crew intentionally shut down the left engine. Although they successfully restarted the engine on a second attempt, the flight instructor later noticed the aircraft required increased right rudder to maintain control, and the left engine's RPM and coolant temperature began to decrease.
As the crew diverted toward Perry Park Airport, the instructor secured the left engine and feathered the propeller. The aircraft subsequently lost altitude rapidly and became difficult to control. Realizing they could not reach the airport, the instructor prepared for a forced landing on Interstate 25. Just before impacting the southbound lanes of the highway, the pilot pitched up and banked left to avoid oncoming vehicles. The aircraft struck a road sign with the left wing and came to rest inverted in a marshy area.
The accident resulted in 2 serious injuries and 0 fatalities.
The investigation
Post-accident examination of the N968GV revealed that the left propeller lever was in a retarded position but was not fully feathered. The lever and the pedestal upper cover had sustained damage. Both engines were found to be functional during test runs, with no mechanical failures identified that would have prevented normal operation.
Investigators noted that the carburetor heat levers were positioned to the OFF position. A review of the FAA's Carburetor Icing Probability Chart indicated that the atmospheric conditions during the flight were conducive to the formation of serious icing at glide power settings.