Introduction
On May 30, 2010, at approximately 1500 mountain daylight time, a Cessna 172D, registration N2723U, operated by Adventure Leasing, sustained substantial damage after a partial loss of power during initial climb. The accident occurred at Las Cruces International Airport (LRU) in Las Cruces, New Mexico. Visual meteorological conditions prevailed at the time, and the personal flight was conducted under 14 CFR Part 91 without a flight plan.
Accident Sequence
According to the pilot’s report, the preflight inspection, engine run-up, and takeoff were normal. At an altitude of about 450 feet, the engine lost partial power. The pilot attempted to land in an area that had recently been used as a staging area for runway construction. The airplane touched down, went through a chain link fence, and came to rest against a sand berm and a mesquite tree. The pilot sustained serious injuries, while the two passengers were not injured.
Post-Accident Examination
FAA inspectors examined the airplane on June 1, 2010. The throttle and mixture controls were found full forward, and the flaps and flap handle were in the up position. Fuel samples taken contained very little water or contamination. This flight was the first operation since the aircraft’s annual inspection.
FAA inspectors also received reports of other partial power failures involving N2723U. Some of these failures were attributed to water in the fuel, while others remained unexplained. A review of the airplane’s maintenance records and applicable Airworthiness Directives revealed anomalies with the aircraft’s carburetor. The carburetor was retained by the FAA for further examination.
Engine Examination
On June 28, 2010, the engine was partially disassembled and inspected. The top spark plugs exhibited signs of a rich mixture setting, which the pilot confirmed he had selected while troubleshooting the power loss. The number 5 cylinder exhaust valve was found stuck open. A clear, unidentified liquid was present in the fuel line. Additionally, a significant amount of water was drained from the fuel system, primarily from the left tank. It was noted that the airplane had been parked outside during the winter and had been exposed to several rain storms. Maintenance personnel reported that a considerable amount of water had been drained from the right fuel tank during the most recent annual inspection.