Introduction
On July 8, 2013, about 2320 Pacific daylight time, a Cessna 182H, registration N2062X, experienced a loss of engine power and subsequently landed on a road near Hesperia, California. The airplane was operated by the pilot under 14 CFR Part 91. The commercial pilot and a passenger received minor injuries, and the airplane sustained substantial damage. The cross-country personal flight had departed Apple Valley Airport, Apple Valley, California, about 2300, with a planned destination of French Valley Airport in Murrieta/Temecula, California. Night visual meteorological conditions prevailed, and no flight plan was filed.
Flight History
According to the pilot, after departure to the south, he leveled the airplane for cruise at 7,500 feet mean sea level. While approaching Lake Arrowhead, California, he began to lean the fuel mixture and the engine lost all power. He reduced to best glide speed and cycled the fuel selector valve from the "both" to "right" and then "left" positions, with no change in power. He set the mixture control to full rich, and realizing he could not glide over the adjacent ridgeline to reach the Los Angeles Basin, initiated a shallow left turn. During troubleshooting, he discovered that cycling the throttle control forward and aft produced intermittent bursts of partial power.
The airplane descended toward unlit desert terrain. Shortly, the landing lights illuminated a boulder field, and the GPS system issued terrain warnings. Unable to see surrounding terrain, the pilot maneuvered toward Hesperia Airport using GPS while continuing to "pump" the throttle. As the airplane came within about 2 miles of the airport, the right main landing gear struck a house chimney. The airplane continued another 1/4 mile, and the pilot spotted a flashing stop light, aiming for it aware of a newly constructed 4-lane road. The airplane landed in the center of the road and rotated to the right as the damaged right main gear contacted the ground. It slid along the shoulder and down an embankment, coming to rest against a power distribution pole. Both wings and the lower cabin structure sustained substantial damage.
Examination Findings
Post-accident examination by the NTSB investigator and an FAA inspector revealed the engine was undamaged. The gascolator was full of clear blue fuel; all fuel lines from the gascolator to the carburetor inlet were intact with tight fittings. Removal of the carburetor drain plug allowed fuel to flow from the bowl. The engine mixture control inner cable remained attached to the mixture control arm, but the outer spiral sleeve had detached from its clamp on the carburetor body. Movement of the mixture control in the cabin resulted in unpredictable movement of the arm. The cable and clamp were coated in oily residue and black debris, and the spiral sleeve showed polishing and flattening in the area bound by the clamp. Rotating the throttle lever produced squirts of fuel from the accelerator pump discharge tube. The carburetor was disassembled and examined; no anomalies that would preclude normal operation were found.
The airplane was equipped with a JPI EDM-700 Engine Monitor that recorded exhaust gas and cylinder head temperatures, oil temperature, fuel flow, and fuel used at 6-second intervals. Data showed that about 8 minutes after engine start, EGT and CHT for all six cylinders rose to about 1,300°F and 330°F, respectively, with a fuel flow of 21 gallons per hour. These values remained constant for another 8 minutes. Over the next 90 seconds, fuel flow gradually decreased to 3 gallons per hour, with a temporary rise then drop in EGT to 375°F and CHT decline to 180°F. For the next 2 minutes, fuel flow increased to 6 gallons per hour, and EGT began a gradual recovery to pre-anomaly levels. Over the next 7 minutes, EGT began to rapidly fluctuate across cylinders between 1,100°F and 1,375°F, while CHT remained constant at about 275°F. Thirty seconds later, EGT dropped to 750°F, and the recording ended.
The carburetor was a Precision/Marvel Schebler MA-4-5 series with an accelerator pump connected to the throttle linkage. The pump's fuel was supplied from the main fuel bowl via a check valve, operating independently of the mixture control position. Repetitive throttle movement forced a small amount of fuel to flow continuously through the discharge tube and into the carburetor throat.
Maintenance records indicated the last event was an owner/operator assisted annual inspection on March 11, 2013, about 30 flight hours prior to the accident. Entries included lubrication of the carburetor mixture cable, tightening of mixture cable attach points at panel and carburetor, and inspection of all controls for security and travel. No entries indicated replacement of the cable or clamp since the engine was installed 1,021.08 flight hours earlier in August 2001.