NTSB Factual Report

HISTORY OF FLIGHT

On June 12, 2011, about 0630 mountain standard time, an experimental amateur-built Murphy Moose, N189SB, was substantially damaged by fire following a forced off-airport landing about 11 miles east of Aguila, Arizona. The owner-pilot was not injured. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan had been filed for the flight.

The pilot based the airplane at Phoenix Deer Valley Airport (DVT), Phoenix, Arizona, and departed DVT about 0600 to practice landings and takeoffs on unprepared airstrips about 45 miles to the northwest. Shortly before 0630, when the airplane was circling at an altitude of about 1,400 feet above ground level, the engine started to lose power. The pilot increased the throttle setting, which temporarily seemed to help, but then the engine began to surge, and the pilot smelled fuel. He checked for evidence of fuel in the cockpit, found none, and then turned the airplane to head for Wickenburg Municipal Airport (E25), Wickenburg, Arizona, which was about 9 miles away. The engine continued to lose power, and the airplane began to lose altitude, so the pilot decided to conduct a precautionary landing on a nearby highway. While on a left base leg for the landing on the highway, the engine quit. Since he did not believe that he could reach the highway, the pilot opted to land on the desert terrain. The touchdown and rollout were uneventful; the airplane was undamaged, and the pilot was uninjured. After the pilot secured the airplane, he exited and noticed fuel dripping from the engine compartment. A fire erupted in the engine compartment, and the pilot was unable to limit or extinguish the fire.

PERSONNEL INFORMATION

According to the pilot, he held a private pilot certificate with a single-engine land rating. He reported a total flight experience of 2,000 hours, including 405 hours in the accident airplane make and model. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued in January 2011, and his most recent flight review was completed in February 2010.

AIRCRAFT INFORMATION

According to FAA information, the airplane was manufactured by the pilot in 2006. The airplane was constructed in the Phoenix, Arizona, area, while construction and airworthiness were approved by an FAA designated airworthiness representative who was located in New Mexico.

According to the pilot, the airplane was equipped with modified automobile engine, which was a fuel-injected Chevrolet Corvette LS6 engine that utilized a "high pressure" fuel system. The pilot stated that all fuel lines forward of the firewall were fire-sleeved.

FAA-provided information documented a similar event in September 2006, involving the same pilot and the same airplane. In that event, the pilot was taxiing at DVT when a fire erupted in the engine compartment. The cause of that event was attributed to a fuel line that became disconnected, which then sprayed fuel onto the hot engine. Subsequent to that event, the pilot repaired the airplane.

METEOROLOGICAL INFORMATION

Automated weather observations from several airports to the southeast of the accident site included winds from the northwest at speeds of about 5 knots; visibility 10 miles; clear skies; and temperatures above 23 degrees C.

WRECKAGE AND IMPACT INFORMATION

The accident site was located about 9 miles west-southwest of E25. The site was about 1/4 mile south of US Highway 60, between mileposts 96 and 97. The site elevation was about 2,188 feet above mean sea level. The distance from touchdown to the airplane stopping point was determined to be about 630 feet. The airplane remained upright and was initially undamaged, but was subsequently damaged by the fire. Personnel from Air Transport, an aircraft recovery organization located in Phoenix, photo-documented the scene and recovered the airplane on the day of the accident.

The majority of the airplane was consumed by the fire, and some remaining components, particularly the engine, were extensively fire-damaged. The fuselage forward of the empennage was almost fully consumed; the empennage and outboard wing sections remained. The pilot reported that the airplane had recently completed a scheduled inspection, and therefore, the maintenance records were in the airplane during the accident flight. Those records were consumed by fire.

An inspector from the FAA Scottsdale Flight Standards District Office visited the accident site and the recovery facility on June 16, 2011. An NTSB investigator examined the fuel system on August 8, 2011, at the recovery facility.

The engine and cabin area of the airplane were examined, and displayed extensive thermal damage. Various non-aviation fittings were noted throughout the engine installation. The oil and coolant system lines utilized multiple sections of cast-iron or galvanized steel fittings and line segments, typical of those used for home plumbing installations.

The intake manifold, valve covers, and throttle body were completely consumed by the fire. The fuel control lines and rods were partially consumed; they remained attached and safetied by cotter keys. The cylinder fuel distribution lines (downstream of the throttle body) remained, but all fittings had been consumed by the fire.

A fuel line was located in the aft engine area, and was traced to the upper engine deck. The line was of the braided type, and its partially-consumed fittings remained attached at both ends. Fragments of material similar in appearance to fire sleeve were noted wrapped around the line, and no breaches were noted to any of the braid material.

The electrically-driven twin fuel pumps were found near the lower firewall. All fuel lines into and out of the pumps had been thermally consumed. The B-nut fittings to the pumps were relatively secure, but could be rotated about 1/8 of a turn tighter. The fuel selector valve was found within the remnants of the cabin area. All fuel lines into and out of the valve had been thermally consumed; the B-nut fittings were tight and could not be rotated.

The majority of the fuel control system had been consumed by the fire, with only two fuel injector nozzles and the fuel injector rail identifiable. The rail appeared mechanically intact, with no cracks or breaches. All remaining identifiable fuel lines and B-nut fittings were examined, and all appeared to be secure.

NTSB Probable Cause

A fire that originated from a fuel leak at an undetermined location in the engine compartment. Contributing to the accident was the builder's use of non-aviation hardware for engine fluid fittings and lines.