Accident Description
The pilot of a single-engine airplane contacted Mizzu Approach Control approximately seven minutes after departing Columbia Municipal Airport (COU) in Columbia, Missouri, reporting a loss of power. Air traffic control (ATC) provided vectors back to COU. When asked if emergency equipment was needed, the pilot declined, stating that power had partially returned. Radar showed the aircraft in a right turn, nine miles northeast of COU at 4,000 feet mean sea level (msl). The pilot was unable to maintain 3,000 feet msl as requested by ATC, reporting a continued descent with the engine windmilling. Radar tracked the aircraft descending through 2,200 feet msl.
ATC inquired about the power loss; the pilot confirmed no power. ATC vectored the aircraft toward COU, stating it was six miles from the airport. The pilot expressed doubt about reaching the airport but then reported regaining power and attempting to climb. The pilot indicated ability to maintain 1,500 feet msl, and ATC instructed continued approach. No further radio contact was made. Radar showed the aircraft descending through 1,300 feet msl and lost contact at 900 feet msl, 4.8 miles northeast of COU. The aircraft was destroyed when it impacted into trees and a creek bed.
Weather at COU at the time included few clouds at 900 feet above ground level (agl), overcast ceiling at 1,600 feet agl, 10 miles visibility, and light rain.
Investigation Findings
Examination of the aircraft revealed the locking mechanism behind the key insertion point on the right fuel tank cap was missing, allowing light to be visible through it. An internal examination of the fuel filter and housing in the fuel injector servo found a large amount of reddish-brown flakes and powdered material, consistent with corroded metal. A solid piece of reddish-brown material approximately 1/4 inch long was retrieved from the filter housing. Corrosion was also present on plugs at both ends of the filter housing, the housing threads, the fuel filter, and the fuel filter spring. Rain had occurred the previous day. No other anomalies were discovered with the aircraft.