DFW07LA172

The 1,058 hour private pilot observed a gradual loss of engine power. Unable to restore full engine power, the pilot attempted to fly to the nearest airfield. While en route, the engine experience a total loss of engine power. The nose landing gear dug into soft ground during the landing roll and the airplane nosed-over coming to rest in the inverted position. The engine was examined and ran 3 times by a representative of the engine manufacturer. The carburetor was also shipped to the manufacturer for examination and bench flow. Both examinations were conducted under government oversight. The reason for the total loss of engine power could not be determined.

On August 11, 2007, at 1305 central daylight time, a single-engine Cessna 172C airplane, N1835Y, sustained substantial damage during a forced landing following a loss of engine power near Pascagoula, Mississippi. The private pilot and his passenger were not injured. The airplane was owned and operated by the pilot. Visual meteorological conditions prevailed for the personal flight conducted under 14 Code of Federal Regulations Part 91. The flight departed as a round-robin flight from the Ocean Springs Airport (5R2), near Ocean Springs, Mississippi.

According to a telephone interview with the pilot, the airplane's engine began to experience a gradual loss of engine power during cruise flight. After unsuccessfully restoring power, the 1,058-hour private pilot elected to perform a precautionary landing at the Trent Lott Airport (KPQL) near Pascagoula, Mississippi. While enroute to KPQL, the engine power continued to decay, leading to a total loss of engine power. The pilot added the only suitable area for the forced landing was an area of reclaimed land. After the aircraft touched down, the nose wheel "got trapped in loose soil" causing the aircraft to nose-over and come to rest in the inverted position. While inverted, the pilot was able to free his passenger and egress through the right side cabin door.

A Federal Aviation Administration (FAA) inspector performed the on-scene examination of the wreckage. According to the inspector, the airplane sustained structural damage during the forced landing. No obvious mechanical defects were noted.

On August 21, 2007, a representative from Teledyne Continental Motors (TCM) conducted an engine inspection under the supervision of the responding FAA inspector. According to the TCM representative, after giving the engine a clear water rinse to remove sand intrusion, the engine operated normally for two engine runs. On the third engine run, the TCM representative "noted that the carburetor mixture control shaft appeared to [be] loose, allowing excessive circumferential play on the mixture control shaft." The TCM representative concluded that until the carburetor mixture control shaft was moved, "the engine accelerated normally without any hesitation, stumbling or interruption in power and demonstrated the ability to produce rated horsepower." The carburetor was secured and shipped to Precision Airmotive Corporation for further analysis.

On September 6, 2007 a technical representative from Precision Airmotive Corporation conducted a carburetor inspection under the supervision of the NTSB. Flow testing indicated that the carburetor was operating "rich" with tested levels of 10 pounds per hour flow over the full throttle setting and 3.3 pounds per hour flow over the near idle setting. This exceeded the limits of +/- 4.0 for the full throttle limit and +/- 0.5 at the near idle limit. The mixture control rotation was noted as "OK." The representative stated in a telephone interview that he did not find any discrepancies that would have resulted in a loss of engine power as described by the pilot.

Twelve minutes prior to the accident, an automated weather reporting station located approximately 7 nautical miles to the northwest of the accident site reported winds calm, visibility 10 statute miles, skies clear, temperature 96 degrees Fahrenheit, dew point 76 degrees Fahrenheit, and a barometric pressure of 29.91 inches of Mercury.