Aviation Accident Summaries

Aviation Accident Summary WPR15LA090

Silver Springs, NV, USA

Aircraft #1

N4017U

CESSNA 150E

Analysis

The pilot reported that, before takeoff for the cross-country flight, the airplane had been topped off with fuel and had a total of 24 gallons onboard. During the descent for landing, the engine lost power. The pilot adjusted the mixture and throttle controls, and the engine regained power. About 10 to 15 minutes later, while continuing the descent, he noted that both fuel gauges indicated about one-quarter of a tank of fuel. Shortly after, the engine again lost power. The pilot's attempts to restart the engine were unsuccessful. The airplane was unable to reach the runway, and the pilot landed the airplane in an open field adjacent to the airport. During the landing roll, the airplane struck the airport perimeter fence and came to rest upright. Immediately following the accident, no evidence of any fuel leaks was observed. The airplane was left unattended until the following day, at which time, about 2 quarts of fuel was removed from the left wing fuel tank, and about 1 quart of fuel was removed from the right wing fuel tank. No fuel was present within the airframe fuel strainer. Performance calculations indicated that, if proper leaning procedures were used, the flight would have required about 17.5 gallons of fuel and that about 5 gallons of usable fuel should have been remaining after the airplane reached its destination. The investigation was unable to determine why so little fuel remained in the airplane after the accident. After the airplane was recovered, an alternate fuel source was plumbed to the left wing inlet line. The engine successfully started; due to damage sustained to the propeller, the engine was run at a reduced power setting, and it ran for 5 minutes. The reason for the loss of engine power could not be determined.

Factual Information

On January 24, 2015, about 1744 Pacific standard time, a Cessna 150E, N4017U, was substantially damaged during a forced landing near the Silver Springs Airport, Silver Springs, Nevada. The airplane was registered to Pier28 Inc., San Francisco, California, and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot and his passenger sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight. The cross-country flight originated from San Carlos Airport, San Carlos, California, about 1351.In a written statement to the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that prior to the flight; the airplane had been topped off with 100-low led fuel, totaling 24 gallons. During the cross-country flight, he initially climbed to an altitude of 11,500 feet mean sea level (msl), until encountering downdrafts southwest of the Squaw Valley VOR. The pilot stated that the airplane descended to an altitude of about 9,800 feet msl, before encountering a series of updrafts. He added that as they crossed Incline Village, they were at an altitude of about 12,300 feet msl. The pilot further reported that as they passed south of Virginia City, he initiated a descent by lowering the nose and reducing power. A short time later, the engine lost power. The pilot stated that he adjusted the mixture and throttle, and the engine regained power. About 10 to 15 minutes later, while continuing a descent to his intended destination, the pilot noted that both fuel gauges indicated about one-quarter of a tank of fuel, when the engine lost power a second time, and the pilot was unsuccessful at restarting the engine. Subsequently, the airplane landed in an open field adjacent to the intended destination airport. During the landing roll, the airplane 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 a power setting of 2,500 rpm. He added that after having flown 426 hours in the accident airplane over the past year and a half, he found that the true performance numbers to be approximately 6 gph in the climb, and 4 gph leaned at cruise. The pilot further stated that the POH estimates a consumption of 3.0 gallons of fuel, including allowances for warm-up, taxi, take-off, and climb to 10,000 feet, which matched his experience of 6 gph and 1/2 hour to climb to 10,000 feet. The pilot reported that he was airborne for about 1 hour before reaching his intended cruise altitude, and estimating that they had burned 6 gallons of fuel during the climb, and had 16.5 gallons of fuel remaining, or about 4 hours of endurance. Examination of the airplane by a Federal Aviation Administration (FAA) inspector the day following the accident revealed that the right wing was structurally damaged. The inspector stated that he removed about 2 quarts of fuel from the left wing fuel tank, and about 1 quart of fuel from the right wing fuel tank. No fuel was present within the airframe fuel strainer. The airplane was recovered to a secure location for further examination. In addition, prior to the inspector's arrival, the airplane sat unattended for more than 12 hours following the accident. Local law enforcement reported that following the accident, no evidence of any fuel leaks was observed. Examination of the recovered wreckage was conducted on June 1, 2015, by the NTSB IIC and an FAA inspector. The wings were removed from the airframe to facilitate wreckage transport. All engine accessories remained attached to their respective mounts. Throttle, mixture, and carburetor heat control continuity was established from the cockpit controls to the engine. No evidence of fuel leaks was observed throughout the fuel system. An alternate fuel source was plumbed to the left wing fuel inlet line. The engine was primed using the engine primer, and started normally. Due to the damage sustained to the propeller, the engine was run at a maximum revolution per minute (rpm) of 1,700 for about 5 minutes. A magneto check was performed with a maximum drop in rpm of about 50 for both magnetos. The engine was shut down normally using the mixture control. The fuel lines for both the left and right wing were intact and undamaged. No evidence of any fuel leaks were observed throughout the fuel system. The airplane, manufactured in 1965, was a two-seat, high-wing, fixed-gear airplane, serial number (S/N) 15061411, and was powered by a Continental Motors O-200-A engine, rated at 100 horsepower. The airplane was also equipped with a McCauley fixed pitch propeller. Additionally, the airplane was equipped with two fuel tanks, which hold 13 gallons per tank, of which, 1.25 gallons is unusable for each tank. Review of the 1965 Cessna 150 owner's manual revealed that figure 5-3, Maximum Rate of Climb data, for a climb from sea level to 10,000 feet, approximate fuel consumption would be 3 gallons. The chart states in part "…mixture leaned to smooth operation above 5,000 feet. Fuel used includes warm-up and takeoff allowances." In addition, figure 5-4, Cruise Performance, With Lean Mixture, shows for an altitude of 10,000 feet, 2,600 rpm, an approximate fuel burn would be 4.8 gallons an hour, or 2,500 rpm, 4.4 gallons an hour. For an altitude of 12,500 feet, 2,600 rpm, an approximate fuel burn would be 4.5 gallons an hour, or 2,500 rpm, 4.2 gallons an hour. The IIC calculated that for the 3 hour 53 minute flight, using an estimated 3 gallons for takeoff and climb to 10,500 feet, spanning about 35 minutes, at an estimated climb rate of about 300 feet per minute, and 4.4 gallons of fuel burn per hour for the remaining 3 hours and 18 minutes of the flight, a total of about 17.5 gallons of fuel would have been used.

Probable Cause and Findings

The loss of engine power for reasons that could not be determined during a postaccident examination of the airplane.

 

Source: NTSB Aviation Accident Database

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