Idaho Falls Regional Airport
Aircraft Accident/Incident Report

Idaho Falls, Idaho 83401
Saturday, June 22, 2013 13:35 MDT

The rear passenger reported that shortly after departure, about 100-200 feet above ground level, the right engine surged. Two witnesses on the ground reported hearing several “pops” before the airplane banked sharply to the right. The airplane collided with the terrain shortly thereafter. The confined distribution of wreckage was consistent with a low-altitude aerodynamic stall. A witness, who fueled the accident airplane, noted that he did not see the pilot sump the airplane’s fuel tanks during the preflight. Fuel samples obtained after the accident from the fuel strainer assemblies tested positive for water contamination. During the postaccident engine examination, the fuel strainer assemblies were disassembled, and the filter elements, selector valve housing assemblies, and both fuel bowl assemblies exhibited water contamination, rust, and deposits. Visible sediment and rust were observed in several fuel system components on both engines. The airplane’s single-engine performance could not be calculated using the airplane’s performance charts because the airplane was over the maximum weight by 176.85 lbs. Further, the calculated density altitude was 6,108 feet. The surge and a possible power reduction to the right engine was likely due to the fuel contamination. Although the airplane was over its maximum weight and took off in a high density altitude—both of which would have affected the airplane’s performance—the pilot still failed to maintain adequate airspeed and control of the airplane. 

A loss of power to the right engine during the initial climb due to fuel contamination and the pilot's failure to maintain adequate airspeed and airplane control. Contributing to the accident was the pilot's inadequate preflight check of the airplane.