OROVILLE, CA, USA
N2161G
Piper PA-28-181
After 4 hours of flight, the engine lost power and the pilot made a forced landing onto a road. The airplane struck a sign and veered off the road into rocks, which collapsed the nose gear. The pilot flew for 1-hour periods on the right tank, the left tank, and then the right tank again. He reselected the left tank and noted the right tank was on the empty mark. About 25 minutes later the engine lost power. The pilot maintained 1,000 feet for the first part of the flight, climbed to 6,500 feet, then descended to 4,500 feet for the remainder of the flight. He cruised at 2,500 rpm throughout the flight and leaned to 100 degrees rich of peak EGT (exhaust gas temperature). The performance section of the POH stated that the cruise power setting and cruise fuel flow should be selected using the Lycoming Operator's Manual (LOM). This manual was not in the airplane and he did not reference one during his preflight planning. He had never used this manual in his training or checkout in this type of airplane. The operating conditions section of the LOM stated that performance cruise (75 percent rated) was 2,450 rpm, 135 hp (horsepower), with a fuel consumption of 10.5 gph (gallons per hour). Above 75 percent, it said to maintain full rich position of the mixture control. Using the sea level and altitude performance chart at standard temperatures, Lycoming engineers determined the power generated under the conditions the pilot stated he encountered. For the portion of the flight at 1,000 feet, the airplane was generating 165 hp, and consuming fuel at the rate of 13.49 gph. At 6,500 feet, 134 hp was generated using 10.95 gph. At 4,500 feet, 144 hp was generated using 11.77 gph. The retriever drained 18 ounces of blue fuel from the wing fuel tanks and 3 ounces from the sediment bowl. An inspection of the airplane revealed the vents were clear, fuel flowed through the fuel system without leaks, and the spark plugs were clean.
HISTORY OF FLIGHT On September 4, 1998, about 1920 hours Pacific daylight time, a Piper PA-28-181, N2161G, sustained substantial damage during a forced landing on a road 3 nautical miles south of the airport at Oroville, California. The forced landing was precipitated by a loss of engine power during cruise. The private pilot and two passengers were not injured. Aviation West of Long Beach, California, operated the airplane under the provisions of 14 CFR Part 91. The personal cross-country flight departed Santa Paula, California, at 1552, en route to Chico, California. Visual meteorological conditions prevailed and no flight plan had been filed. The pilot stated he was flying from Long Beach to Redmond, Oregon, for a fly-in at a kit plane manufacturer. The day before he departed, he asked that the airplane be filled with fuel, rather than to the tab markers as was normally done. The Pilot's Operating Handbook (POH) indicated fuel capacity was 24 gallons per tank when full and 17 gallons when filled to the tabs. A review of the operator's records revealed the airplane completed a 1.4-hour flight 4 days earlier and was serviced with 14 gallons of fuel. Fuel receipts showed an additional 12.2 gallons were dispensed the day before the accident flight. The pilot stated he planned for 3.5 hours en route to Chico where he would stop for fuel. Departure from Long Beach was delayed until 1332 due to inclement weather. The pilot headed east past Corona, California, then flew toward Lancaster, California. Due to mountain obscuration, he said he could not proceed as planned and landed at Santa Paula. He said he personally filled the tanks to full capacity. The receipt indicated he dispensed 20.59 gallons. After departing Santa Paula, the pilot maintained an altitude of 1,000 feet msl (mean sea level) until past Santa Barbara, California. At Gaviota VOR he climbed to 6,500 msl. He maintained that altitude until Paso Robles, California, where he descended to 4,500 feet. When his global positioning system indicated he was 18 nautical miles from Chico, he commenced a gradual descent. He maintained a power setting of 2,500 rpm in cruise flight. He leaned the mixture to 100 degrees rich of peak exhaust gas temperature (EGT). He stated that from takeoff at 1552, until 1650, he operated from the right fuel tank. Then he selected the left tank. At 1750, he switched to the right tank again. He noted the left fuel quantity gauge was slightly above the half tank mark. He switched back to the left tank at 1850. He observed that the right tank fuel quantity indicator was bobbing just above empty. About 1915, the engine rpm lowered. The pilot turned the electric boost pump on and switched to the right tank. He observed the left tank was indicating empty. The fuel pressure came up and engine power was restored for approximately 1 minute before the engine again lost power. The pilot landed on a road with no traffic. The left wing tip contacted a road reflector. The airplane veered off the road, through a barbed wire fence, onto a rocky slope, and the nose gear collapsed. A document supplied by the operator noted the time on the hour meter prior to departure from Long Beach was 2737.1; it was 2742.1 after the accident. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed the pilot held a private pilot certificate with an airplane single engine land rating. A review of the pilot's logbook revealed 163.4 hours were accumulated between September 1978 and March 1985. No flights were logged from then until August 1996. Total pilot time when the accident occurred was 230 hours. The first flight logged in a PA 28-181 was on May 22, 1982. On May 27, 1982, an entry by a flight instructor stated check out complete. Between August 1996 and December 1996, seven instructional flights in a PA 28-181 were entered. The pilot held a second-class medical certificate dated October 31, 1996. AIRCRAFT INFORMATION The airplane was a Piper PA 28-181 Archer, serial number 28-7990193. An inspection of the airplane's logbooks revealed an annual inspection dated February 8, 1998. This entry noted the airframe total time was 3,481 hours at a tachometer reading of 1,800. The engine was a Textron Lycoming O 360-A4M, serial number L-25805-36A. The normal procedures section of the POH stated that use of the mixture control in cruise flight reduced fuel consumption, especially at higher altitudes. It stated the mixture should be leaned during cruise above 5,000 feet altitude, and at pilot's discretion at lower altitudes when 75 percent power or less was being used. It further stated that should any doubt about how much power was being used; the mixture should be in the full rich position below 5,000 feet. It was recommended "that one tank be used for one hour after takeoff, then the other tank used for two hours; then return to the first tank, which will have one and one half hours of fuel remaining if the tanks were full at takeoff. The second tank will contain approximately one half hour of fuel." The performance section of the POH stated that the cruise power setting and cruise fuel flow should be selected using the Lycoming Operator's Manual (LOM). The pilot stated this manual was not in the airplane and he did not reference one during his preflight planning. He also stated he had never used this manual in his training or checkout in this type of airplane. The operating conditions section of the LOM stated that performance cruise (75 percent rated power) was 2,450 rpm, 135 hp (horsepower), with a fuel consumption of 10.5 gph (gallons per hour). Above 75 percent, it stated to maintain the full rich position of the mixture control. Another chart in the LOM demonstrates the effect of fuel/air ratio on cylinder head temperature, power, and specific fuel consumption at constant rpm and manifold pressure in cruise range operation. Based on this chart and the pilot's statement that he leaned the mixture, Lycoming engineers determined a value of 0.48 for the brake specific fuel consumption (BSFC). Using the sea level and altitude performance chart at standard temperatures, Lycoming engineers determined the power generated under the conditions the pilot stated he encountered. The engineers used these values and the formula "HP times BSFC" to determine fuel flow in pounds per hour. Dividing the result by a fuel weight of 5.87 pounds per gallon yielded the fuel consumption in gallons per hour. For the portion of the flight at 1,000 feet, the airplane was generating 165 hp and consuming fuel at the rate of 13.49 gph. At 6,500 feet, 134 hp was generated using 10.95 gph. At 4,500 feet, 144 hp was generated using 11.77 gph. The retriever drained 18 ounces of blue fuel from the wing fuel tanks and 3 ounces from the sediment bowl. The retriever removed the wings during recovery. TESTS AND RESEARCH A Safety Board investigator examined the wreckage in September 1998, at Plain Parts in Sacramento, California. No stains were evident on the top of the wing or near the filler cap, and none were observed on the bottom of the wing by the fuel drain or tank vent. The carburetor sustained some damage; however, the mixture control could be moved from stop to stop. The retriever connected a supply of aviation gasoline to the inlet line of the electric fuel pump. He applied electrical power and turned the electric boost pump on. System pressure went into the green arc and no fuel leaks were observed. The retriever connected a fuel supply to the primer line and activated the primer, with no leaks observed. The spark plugs were not discolored or sooty. All bottom plugs and the top plug from cylinder number two were moist. The bottom inch of cylinder number two's rocker cover was damp. The outboard section of cylinder number two's intake pipe exhibited a deep blue stain that varied in width from 0.25 to 0.75 inch, and was tacky to the touch. No other stains were evident in the engine compartment or on the engine cowling.
the pilot's inaccurate preflight and in-flight fuel consumption calculations, which resulted in fuel exhaustion. The pilot's failure to obtain the proper engine power setting charts to use in fuel consumption calculations was also causal.
Source: NTSB Aviation Accident Database
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