Accident Overview
On March 19, 2011, about 1115 Pacific daylight time, a Cessna TU 206G, registration N6169Z, sustained substantial damage to the forward portion of the fuselage and empennage during a forced landing. The aircraft was being used for a local instructional flight under 14 Code of Federal Regulations Part 91, operated by the Civil Air Patrol. Visual meteorological conditions prevailed, and a company visual flight rules flight plan had been activated. The flight originated from and was returning to Pierce County Airport – Thun Field (PLU) in Puyallup, Washington.
Flight and Event Details
The certified flight instructor and commercial pilot receiving instruction sustained minor injuries. According to a representative from the operator, the pilots performed the pre-landing checklist while on the left midfield downwind for runway 34. They switched the fuel selector to the right tank position and activated the auxiliary fuel boost pump. Shortly after, while turning from base leg to final at 900 feet mean sea level, the airplane began to sink. Full engine throttle was applied, but the engine did not power up. The airplane subsequently collided with up-sloping terrain approximately 400 feet short of the approach end of the runway. The nose landing gear collapsed, and the airplane nosed over.
Aircraft and Engine Information
The Cessna TU 206G was equipped with a Continental TSIO-520-CCM engine, which is turbocharged, fuel injected, and paired with a constant speed propeller. The fuel system includes a 2-stage electric auxiliary fuel boost pump, placarded “emergency” and “start,” used for engine starts and emergencies. The manufacturer’s approved checklist specifies that during descent and before landing, the auxiliary fuel pump switch should be set to OFF. A representative from the engine manufacturer reported that operating the auxiliary fuel boost pump at a low engine power setting would flood the engine and result in a loss of engine power.
Postaccident Examination
Postaccident examination of the airframe and engine revealed no preaccident mechanical malfunctions or failures that would have precluded engine operations. An engine examination report is contained in the public docket for this case file.