NTSB Factual Report

On March 6, 2009, about 1244 eastern standard time, an experimental, amateur-built Sonerai-II, N28MD, was substantially damaged when it impacted a tree during an off-airport emergency landing approximately 1 mile southwest of St. Mary's County Regional Airport (2W6), Leonardtown, Maryland. The certificated private pilot/owner sustained minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the personal local flight that departed about 1200. The flight was conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91.

In a written statement, the pilot/owner stated that he arrived at the airport about 1045, performed a preflight inspection, and started the engine. After warming the engine for a few minutes, he proceeded to perform an engine and flight control check. He noticed the airplane's sole engine-driven magneto was not operating; however, he felt confident that the electrical ignition system would be acceptable to remain in the traffic pattern for runway 29, in order to practice takeoffs and landings. While passing through about 400 feet above ground level, on his sixth takeoff, the engine started to lose power. The pilot then began manipulating the throttle to see if the engine would respond; however, this made no change. He then lowered the nose to maintain a safe glide speed and began preparing for an emergency off-airport landing. There was a tree located at the beginning of the open field. He attempted to adjust his flight path in order to avoid the tree; however, the airplane struck the tree near the wingtip.

The airplane came to rest in an open field approximately 4,300 feet beyond and 1,400 feet left of the extended centerline of the departure end of the runway.

The airplane was examined by an inspector from the Federal Aviation Administration (FAA). The FAA inspector found damage to the right wing tip, buckling of the skin on the right wing and fuselage, and the right wing root and wing spar were substantially damaged. Both propeller blades were splintered approximately 8 inches from the propeller hub. The airplane had been refueled on February 26, 2009; the fuel that remained on board was estimated at 8 gallons and was blue in color.

According to the pilot/owner, after the airplane had been recovered from the accident location, he removed the top cowling and noticed that an exhaust pipe from the No.2 cylinder had become disconnected. The location of the exhaust pipe was directly in front of the electrical wiring and one of the two coils that supplied power to the cylinders. The wiring was intact, but appeared "to have been hot," and the fuse for the electronic ignition system was found blown. After the fuse was replaced, the engine started and operated utilizing the electronic ignition.

A review of manufacturer guidance pertaining to the installation of the electronic ignition system revealed that it must be mounted on the accessory case located on the back of the engine. Also, the maximum permissible temperature that the coil should be exposed to is 190 degrees F.

According to photographs supplied by the pilot/owner, the coil was mounted on the firewall and in the immediately vicinity of the disconnected exhaust pipe.

According to the pilot/owner, the airplane's most recent conditional inspection was conducted on August 14, 2008. At the time of the accident, the airplane had 180 hours of total time in service. It was equipped with a Volkswagon/Great Plains VW 2180 engine. It had 193 total hours time in service and had been inspected 37 flight hours prior to the accident.

The pilot held a private pilot certificate with a rating for airplane single-engine land. His most recent FAA third-class medical was issued on April 24, 2008. The pilot reported to the FAA inspector on scene that he had 603 hours of total flight experience, 180 hours of total flight experience in the aircraft make and model, and 13 hours of flight experience in the 90 days prior to the accident.

The 1252 recorded weather at 2W6 included winds from 220 at 12 knots with wind gusts of 16 knots, 10 miles of visibility, clear skies, temperature 13 degrees C, dew point 2 degrees C, and an altimeter setting of 30.12 inches of mercury.

NTSB Probable Cause

The pilot's continued operation of the airplane with a known mechanical deficiency. Contributing to the accident was the improper installation of the electronic ignition system.