LAX98LA284 · 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.

Verbatim NTSB analysis and probable cause from the NTSB dataset