History of Flight
On July 23, 2010, at 1017 eastern daylight time, a Cessna U206F, registration N82531, sustained substantial damage when it was ditched in Lake Michigan about 5 miles west of Ludington, Michigan, after a loss of engine power. The airplane was owned and operated by the pilot as a personal flight under 14 Code of Federal Regulations Part 91. It departed Gratiot Community Airport, Alma, Michigan, at 0850 and was en route to Rochester International Airport, Minnesota. The single-engine airplane was over Lake Michigan at 10,000 feet above mean sea level when the engine lost power. The pilot reversed course but was unable to reach the shore, and ditched the airplane. The pilot survived and was rescued by a fishing boat about 38 minutes later. The pilot-rated passenger and three other passengers did not survive. Visual meteorological conditions prevailed; an instrument flight rules flight plan was activated.
The pilot reported that after climbing to 10,000 feet, he leaned the fuel mixture to approximately 14 gallons per hour. All instrument readings were normal as they crossed the shore near Ludington. Near mid-point over the lake, the engine began to misfire and lose power, with fuel flow dropping. The pilot attempted to regain power by adjusting mixture and switching tanks, but the engine failed completely. During the descent, the pilot had everyone don life vests. The pilot unlatched doors before impact. During ditching, the airplane pitched forward, flipped over, and filled with water. The pilot escaped and was rescued.
Aircraft Information
The airplane was a single-engine Cessna U206F, serial number U-206-01734, manufactured in 1972, designed to seat six. It was equipped with a pilot side door and clamshell rear cargo door. The engine was a 300-horsepower Continental IO-520-F3B. The airplane had flown 7.5 hours since its last annual inspection, with a total time of 3,945.5 hours. The inspection revealed that the IA mechanic did not remove the fuel strainer screen during the last annual inspection and did not check the fuel metering inlet screen.
Meteorological Information
At 0955, the surface weather at Ludington was: wind 290 degrees at 6 knots gusting to 17 knots; visibility 10 miles; ceiling 1,800 feet overcast; temperature 24°C; dew point 22°C; altimeter 29.81 inches. At 1016, the observation was: wind 270 degrees at 7 knots; visibility 10 miles; ceiling 1,600 feet overcast; temperature 24°C; dew point 22°C; altimeter 29.82 inches.
Wreckage and Impact Information
Postaccident inspection revealed that the fuselage was intact; the empennage was partially separated with extensive wrinkling. The engine was separated from the fuselage. The flaps were found down about 30 degrees. About 60 gallons of fuel remained in the wing tanks, with the first five gallons drained appearing to be a mixture of fuel and water. The firewall fuel strainer gasket did not provide a complete seal; a portion was positioned over the exit port. The engine's fuel inlet filter screen was partially obstructed by debris, and the fuel inlet passage orifice contained similar debris blocking most of the opening.
The debris from the fuel inlet screen was sent to the NTSB Materials Laboratory for examination. The engine was tested and produced rated horsepower without anomalies.
Survival Aspects
The pilot used life vests from the pilot-rated passenger's airplane. During the descent, passengers donned their life vests. The pilot heard some vests inflate. During recovery, the patient and his wife were found in the airplane; the patient still had his vest on, but the wife's vest had come off and was found deflated. The pilot-rated passenger and doctor were found on the lake bottom; the doctor had his vest on but deflated; the pilot-rated passenger was not wearing a vest. Life vests were manufactured in the 1980s; CO2 cartridges were expended. Tests showed the vests inflated properly with new cartridges.
Tests and Research
The engine was run on a test stand and operated normally, producing rated horsepower. The NTSB Materials Laboratory examined debris from the fuel inlet screen, finding cellulosic material, amber flakes, metallic shavings, paint flakes, granular particulates, and fibers.
Probable Cause
No probable cause was stated in the source.