Accident Overview
On April 8, 2011, at approximately 1130 Pacific daylight time, a Bartholomew Lancair 320 experimental amateur-built airplane, registration N320BB, sustained substantial damage during a forced landing after a loss of engine power. The accident occurred near Temple Bar Airport in Temple Bar, Arizona. The commercial pilot, who was the sole occupant, received minor injuries. The flight was operating under Part 91 as a personal cross-country trip. Visual meteorological conditions prevailed, and no flight plan was filed. The flight had originated in Las Vegas, Nevada, about 20 minutes prior.
Flight Details
According to the pilot, the airplane was in cruise flight at 5,500 feet mean sea level (msl) when haze was observed ahead, prompting a descent to 3,500 feet msl. At approximately 4,000 feet msl, the pilot noticed the engine slowly winding back. He cycled the throttle and propeller, but engine power was not restored. The fuel boost pump was turned on with no change. The pilot did not apply carburetor heat. When about 300 to 400 feet above ground level, the engine reached near idle. During the forced landing, the airplane struck an embankment, causing the landing gear to collapse, damage to the right wing and bottom of the fuselage, and separation of the rudder from the vertical stabilizer.
Weather Conditions
Regional weather included a low pressure system over southern Utah with a cold front extending north-south across Arizona into Mexico, located just east of the accident site. Departure weather from North Las Vegas Airport at 1053 reported wind from 170 degrees at 15 knots gusting to 25 knots, visibility 10 miles, clear skies, temperature 52°F, dew point 18°F. As the flight proceeded east, cloud cover increased and lowered, with increasing moisture and relative humidity. At 1124, Kingman, Arizona (50 nautical miles from the site) reported wind 240 degrees at 14 knots, visibility 6 miles, clouds at 900 feet agl, overcast at 1,600 feet, temperature 37°F, dew point 36°F, light rain and mist. By 1205, conditions deteriorated to light snow and overcast at 900 feet. A Remote Automated Weather Station 11 nautical miles from the site reported temperature 32°F and dew point 30°F at accident time. According to a carburetor icing chart, these conditions placed the airplane in serious carburetor icing conditions at cruise power.
Postaccident Examination
A Federal Aviation Administration inspector examined the engine after the accident. No deficiencies were found that would have precluded normal engine operation. A detailed report of the examination is available in the public docket for this investigation.