CEN10FA465

The total loss of engine power due to fuel starvation as a result of accumulated debris in the fuel system from an undetermined source. Also causal was the inadequate annual maintenance inspection that did not include inspection of the firewall fuel strainer and the fuel inlet screen.

The pilot reported that he was crossing Lake Michigan at 10,000 feet above mean sea level when the engine lost power. He was near the mid-point (about 24 miles from the shoreline) of the lake with a 40-knot headwind, so he turned around to return to shore. He attempted to restart the engine but was unsuccessful. The pilot ditched the airplane about 5 miles from shore and it quickly sank. Postaccident inspection of the airplane revealed that the firewall fuel strainer gasket did not provide a complete seal between the fuel screen and the fuel strainer's upper body. A portion of the gasket was positioned over the exit port, which created a gap. This allowed debris in the fuel to migrate to the engine's fuel inlet filter screen in the fuel metering assembly. The inspection of the fuel inlet filter screen revealed that it was partially obstructed with debris. The orifice of the fuel inlet passage contained the same debris that obstructed the flow of fuel through the orifice to the fuel screen. The airplane had undergone an annual maintenance inspection about 7.5 hours prior to the accident. The mechanic, who had an inspection authorization, reported that he did not inspect the gasket on the firewall fuel strainer, nor did he remove and inspect the fuel inlet filter screen as required by the manufacturer's service manual. The debris was composed of materials similar to wood chips, sawdust, paint, varnish, cloth, glass fibers, metal shavings, sand, and soil. The source of the contaminants was not determined. The postaccident inspection revealed no other preexisting airframe anomalies. The engine was run on a test stand and the engine produced the rated horsepower. The airplane's owner's manual indicated that the glide distance for an airplane at 10,000 feet above the water's surface was 15 miles.

HISTORY OF FLIGHT On July 23, 2010, at 1017 eastern daylight time (edt), a Cessna U206F, 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 the Gratiot Community Airport (AMN), Alma, Michigan, at 0850 and was en route to Rochester International Airport (RST), Rochester, Minnesota. The single-engine airplane was over Lake Michigan at 10,000 feet above mean sea level (msl) when the engine lost power. The pilot reversed course but was unable to reach the shore, and he 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 at the time of the accident. An instrument flight rules (IFR) flight plan was activated. On July 23, 2010, about 0659, the pilot rated passenger called the Princeton Automated Flight Service Station to obtain a weather brief and to file an IFR flight plan. The briefer informed him that there was an airmen's meteorological information (AIRMET) for IFR conditions for the entire route of flight that was valid until about 1100 - 1400. There was a Convective significant meteorological information (SIGMET) to the south that paralleled the route of flight. The briefer reported that the winds aloft were from 260 degrees at 41 knots at 9,000 feet, and 270 degrees at 35 knots at 12,000 feet. The pilot rated passenger filed the flight plan and identified the flight as a "lifeguard" flight. The pilot reported that the purpose of the flight was to take one of the passengers to the Mayo Clinic in Rochester, Minnesota, for medical treatments. The flight was a personal flight and was not associated with a charity organization. The patient and his wife were seated in the aft seats, seats 5 and 6. The patient's doctor was sitting in the middle row on the left in seat 3. The pilot was in the left front seat and the pilot rated passenger was in the right front seat, seat 2. The fuel tanks were filled to capacity the night before the flight. The pilot reported that after climbing to 10,000 feet msl, he leaned the fuel mixture to approximately 14 gallons per hour (gph). The pilot reported that all of the instrument readings were within normal limits as they crossed the shore near Ludington, Michigan. The head winds were about 40 knots "directly on the nose." Near mid-point over the lake (about 24 statute miles from the shoreline), the engine began to misfire and lose power, with the fuel flow dropping to about 11 gph. The pilot attempted to regain power by pushing in the mixture control to full rich but without effect. About 1005, the pilot contacted the Minneapolis Air Route Traffic Control Center (ARTCC) and reported that the airplane was losing power. He reversed course toward the Michigan shoreline. The fuel flow dropped to about 8 gph. The pilot switched fuel tanks and adjusted the mixture control in and out to try to regain power. He attempted to prime the engine but that had no effect. He reported that he turned on the high boost pump and got a short burst of power for about 30 - 45 seconds, but then the engine "failed completely." The airplane descended through a cloud layer. About 1012, the airplane was about 12 miles from Ludington and about 2,300 feet above mean sea level (msl) and the airplane was still in the clouds. The surface weather at Ludington indicated that the cloud bases were at 1,800 feet msl. The pilot reported that they had a few minutes before water impact after breaking out of the clouds, so he had everyone don and inflate their life vests. Before impact, the pilot unlatched the pilot's door on the left side of the airplane, and he had the front door of the rear cargo door unlatched. The pilot reported that he did not lower the flaps since the cargo doors would not open if the flaps were extended. The pilot reported that when he ditched the airplane, either the tail or the landing gear hit the water as he pulled up to go over a swell. The airplane pitched forward, flipped over on its back, and began to fill with water. The pilot unbuckled his seat belt and shoulder harness, fell a short distance, pushed the door open, and got out. He reported that the airplane was sinking rapidly. He saw the right seat passenger and the doctor in the water. A wave hit the pilot and when he resurfaced "everything was gone." He kept yelling but got no response. He eventually started to swim toward the shoreline. About 30 minutes later a US Coast Guard helicopter flew over him but they did not spot him. A few minutes later a fishing boat spotted him and rescued him from the water. He was transferred to a Coast Guard vessel and was taken to shore. Using side scanning sonar, the Michigan State Police Dive Team located the airplane in about 173 feet of water on July 30. The dive team recovered all the bodies, with the last body being recovered on the morning of August 1, 2010. The airplane was found resting on its main landing gear on the sandy lake bottom. The airframe and engine were separated by the water impact. Both were raised to the surface by a local commercial recovery service on August 1, 2010. The airframe and engine were taken to a local facility where the National Transportation Safety Board (NTSB) conducted its on-site investigation. PERSONNEL INFORMATION The 66-year-old pilot held a private pilot certificate with a single-engine land and airplane instrument ratings. He reported that he had 2,660 total flight hours with 1,200 hours in a Cessna 206. He had logged 25 hours of flight time in the last 90 days, and 7 hours in the last 30 days. He held a third-class medical certificate that was issued in November 2008. The pilot reported that he had flown similar "lifeguard" flights in the airplane with the pilot rated passenger in the past. He reported that the pilot rated passenger performed copilot duties when he flew with him. The pilot rated passenger also owned an airplane. When they flew in the pilot rated passenger's airplane, the accident pilot would perform copilot duties. The 70-year-old pilot rated passenger held a private pilot certificate with a single-engine land and airplane instrument ratings. He held a third-class medical certificate that was issued on November 17, 2009. He had 2,150 hours of total flight time at the time of his medical examination. AIRCRAFT INFORMATION The airplane was a single-engine Cessna U206F, serial number U-206-01734, manufactured in 1972. It was designed to seat six and it had a maximum gross weight of 3,600 pounds. The airplane was equipped with a pilot (left) side door and a clamshell rear door serving the back two rows of seats. The accident airplane had its middle, right seat (Seat 4) removed. The engine was a 300-horsepower Continental IO-520-F3B, serial number 280171R. Annual Inspections The airplane's maintenance logbooks indicated that four different inspection authorization (IA) mechanics had conducted the required annual maintenance inspections on the airplane within the last ten years. The logbooks indicated that the same IA mechanic had performed the last three annual maintenance inspections. On September 27, 2007, the IA mechanic performed his first annual maintenance inspection of the airplane. The total airframe time was 3,893.4 hours. His second annual inspection of the airplane was conducted on October 1, 2008, and the airplane had a total time of 3,908.1 hours. The last annual maintenance inspection was conducted on November 5, 2009, and it had a total time of 3,938.0 hours. At the time of the accident, the airplane had flown 7.5 hours since the last inspection and had a total time of 3,945.5 hours. FAA inspectors interviewed the IA mechanic c