Aviation Accident Summaries

Aviation Accident Summary WPR10LA123

Pahrump, NV, USA

Aircraft #1

N8959B

CESSNA 172

Analysis

The pilot reported that about 10-15 minutes after departure he heard three loud "pops" and the engine rpm dropped to about 1200. The pilot attempted to restart the engine by adjusting the fuel selector, mixture, and throttle, but was unsuccessful. The pilot initiated a forced landing to desert terrain. As the airplane touched down, the nose landing gear sunk into the ground and the airplane nosed over and came to rest inverted. A postaccident examination of the engine by a Federal Aviation Administration inspector revealed that the carburetor float valve was improperly installed, which restricted fuel flow to the engine. According to a Continental Motors representative, the carburetor overhaul requirements were the same as specified for the engine; 10 to 12 years since placed in service or last overhauled, whichever comes first. A review of the aircraft logbooks revealed no entries pertaining to the maintenance or overhaul of the carburetor.

Factual Information

On January 30, 2010, about 0945 Pacific standard time, a Cessna 172U, N8959B, experienced a loss of engine power during cruise flight and the pilot made a forced landing in the vicinity of a landing strip in the desert near Pahrump, Nevada. Chapter 163 Flying Club operated the personal cross-country flight under the provisions of Title 14 Code of Federal Regulation Part 91. The certified private pilot and one passenger were not injured. The airplane sustained structural damage to the tail section. Visual meteorological conditions prevailed for the flight that departed the Shoshone Airport (L61), Shoshone, California, at 0930. The flight was destined for North Las Vegas Airport (VGT), Las Vegas, Nevada, and no flight plan had been filed. In a written statement, the pilot reported that about 10-15 minutes after departure he heard three loud "pops" and the engine rpm dropped to about 1200 rpm. The pilot attempted to restart the engine by adjusting the fuel selector, mixture, and throttle, but was unsuccessful. The pilot initiated a forced landing to desert terrain. As the airplane touched down, the nose landing gear sunk into the soft ground, and the airplane nosed over and came to rest inverted. During a post accident examination of the engine by a Federal Aviation Administration (FAA) inspector, the carburetor was removed from the engine and disassembled. The fuel inlet screen was removed. The FAA inspector reported that fine sand and pebbles consistent with an impact with the ground were observed. The FAA inspector further reported that carburetor bowl was removed and the float valve was found to be improperly installed. A review of the airplane's maintenance logbooks revealed that the airplane's most recent inspection, an annual inspection, occurred on February 27, 2009. The most recent engine overhaul occurred in February 2004. Maintenance conducted on the carburetor or fuel system was not mentioned in the logbook entries. A representative from Continental Motors reported that the time between overhaul for a carburetor is the same as specified by the engine manufacturer; 10 to 12 years since placed in service or overhaul, whichever comes first.

Probable Cause and Findings

Fuel starvation as a result of the improper installation of the carburetor float valve by unknown personnel.

 

Source: NTSB Aviation Accident Database

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