Accident Overview
On January 24, 2015, about 1744 Pacific standard time, a Cessna 150E, registration N4017U, was substantially damaged during a forced landing near Silver Springs Airport, Silver Springs, Nevada. The airplane was registered to Pier28 Inc., San Francisco, California, and operated by the private pilot under Title 14 Code of Federal Regulations Part 91. The pilot and his passenger sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The cross-country flight originated from San Carlos Airport, San Carlos, California, about 1351.
Pilot Narrative
The pilot reported that before the flight, the airplane was topped off with 100-low lead fuel, totaling 24 gallons. During the flight, he initially climbed to 11,500 feet mean sea level (msl) until encountering downdrafts southwest of the Squaw Valley VOR, then descended to about 9,800 feet msl before encountering updrafts. He noted that crossing Incline Village, they were at about 12,300 feet msl. Passing south of Virginia City, he initiated a descent by lowering the nose and reducing power. Shortly after, the engine lost power. He adjusted the mixture and throttle, and the engine regained power. About 10 to 15 minutes later, while continuing descent, both fuel gauges indicated about one-quarter tank, and the engine lost power again; attempts to restart failed. The airplane landed in an open field adjacent to the intended airport. During the landing roll, it struck the airport perimeter fence and came to rest upright.
The pilot stated that the cruise performance table from the pilot operating handbook (POH) estimates 4.4 gallons per hour (gph) at 10,000 feet and 4.2 gph at 12,500 feet at 2,500 rpm. Based on his experience flying the accident airplane for 426 hours over the past year and a half, he found actual fuel consumption to be about 6 gph in climb and 4 gph leaned at cruise. He estimated the POH allowance of 3.0 gallons for warm-up, taxi, takeoff, and climb to 10,000 feet matched his experience. He reported being airborne for about 1 hour before reaching cruise altitude, estimating 6 gallons burned in climb, leaving 16.5 gallons for about 4 hours endurance.
Fuel Examination
A Federal Aviation Administration (FAA) inspector examined the airplane the day after the accident. The right wing was structurally damaged. The inspector removed about 2 quarts of fuel from the left wing fuel tank and about 1 quart from the right wing fuel tank. No fuel was present in the airframe fuel strainer. The airplane sat unattended for more than 12 hours after the accident. Local law enforcement reported no evidence of fuel leaks observed.
Wreckage Examination
On June 1, 2015, the NTSB investigator-in-charge and an FAA inspector examined the recovered wreckage. The wings were removed for transport. All engine accessories remained attached. Throttle, mixture, and carburetor heat control continuity was established. No evidence of fuel leaks was found throughout the fuel system. An alternate fuel source was connected to the left wing fuel inlet line. The engine was primed and started normally, running at a maximum of 1,700 rpm for about 5 minutes due to propeller damage. A magneto check showed a maximum drop of about 50 rpm for both magnetos. The engine shut down normally using the mixture control. Fuel lines for both wings were intact and undamaged.
Aircraft Information
The 1965 Cessna 150E, serial number 15061411, is a two-seat, high-wing, fixed-gear airplane powered by a Continental Motors O-200-A engine rated at 100 horsepower, with a McCauley fixed-pitch propeller. It has two fuel tanks, each holding 13 gallons, of which 1.25 gallons per tank is unusable.
Fuel Consumption Calculations
Review of the 1965 Cessna 150 owner's manual showed that figure 5-3, Maximum Rate of Climb, indicates approximate fuel consumption of 3 gallons for climb from sea level to 10,000 feet, including warm-up and takeoff allowances, with mixture leaned above 5,000 feet. Figure 5-4, Cruise Performance with Lean Mixture, shows at 10,000 feet, 2,600 rpm burns about 4.8 gph, and 2,500 rpm burns 4.4 gph; at 12,500 feet, 2,600 rpm burns 4.5 gph, and 2,500 rpm burns 4.2 gph.
The NTSB investigator calculated that for the 3-hour 53-minute flight, using an estimated 3 gallons for takeoff and climb to 10,500 feet over about 35 minutes at a climb rate of 300 feet per minute, and 4.4 gph for the remaining 3 hours 18 minutes, total fuel used would have been about 17.5 gallons.