ERA10LA301

The pilot descended to 1,000 feet mean sea level and attempted to increase the engine power. The engine did not respond and the pilot realized that the airplane would not be able to make it to the closest airport. He elected to perform a forced landing on a road. An automobile pulled out on the road and the pilot had to extend the airplane's glide. The airplane collided with mangrove trees and came to rest off the side of the road. A postaccident examination of the airframe, flight controls, and engine assembly revealed no evidence of a mechanical malfunction. The airplane was configured with one magneto installed on the left side of the engine and an experimental electronic ignition system installed on the right side. An electronic module was installed on the magneto pad and connected to two high-tension spark coils mounted on top of the engine, which fired the upper spark plugs. There were two wires from the module to each coil supplying the trigger voltage signal to fire the spark plugs. One of the wires to the right coil, firing cylinder Nos. 1 and 3, was not connected. A wiring harness connected the module to the airframe electrical system and the spark coils. The harness was connected to the module with a "D" plug, which was held in place with two screws. The plug was found disconnected from the module and hanging loose. This likely resulted in the complete loss of power to the right ignition system, causing a partial loss of engine power as reported by the pilot. Review of the airplane logbooks revealed the airplane had flown 25.7 hours since the last condition inspection. The airframe and powerplant mechanic who performed that inspection stated that he did not check the "D" plug during that condition inspection.

On June 7, 2010, at 1310 eastern daylight time, an experimental amateur-built Hood Tango 2, N76HT, experienced at partial loss of engine power while descending in the vicinity of New Port Richie, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The personal flight was conducted in accordance with Title 14 Code of Federal Regulations Part 91. The pilot made a forced landing to a highway and the airplane collided with mangrove trees receiving substantial damage. The pilot was not injured. The flight originated from Williston Municipal Airport (X60) Williston, Florida, at 1234. The pilot was receiving flight following from Federal Aviation Administration (FAA) Tampa approach. The pilot stated he was at 2,600 feet mean sea level (msl) and informed the controller he would like to descend to 1,000 feet msl. The controller advised the pilot of towers along his route of flight and the pilot reported he had the towers in sight. The pilot initiated a descent by decreasing power. He subsequently increased power and the engine did not respond to the power change. The pilot informed the controller of the problem, and the controller provided distance and direction to the nearest airport. The pilot observed a road to his left and informed the controller he could not make the airport and would land on the road. The engine power continued to decrease and the pilot initiated a forced landing to the road. A car pulled out on the road and the pilot had to extend the airplane's glide. The airplane collided with mangroves bushes and came to a complete stop off the side of the road. Review of the aircraft logbooks revealed the last condition inspection was conducted on April 9, 2010. The Hobbs meter at the time of the inspection was 242.3 hours. The airplane has flown 25.7 hours since the condition inspection. Examination of the airplane revealed the propeller assembly remained attached to the propeller crankshaft propeller flange. The propeller spinner was damaged. The engine cowling remained attached and was not damaged. The engine assembly remained attached to the engine mounts and firewall and was not damaged. The nose landing gear was collapsed and remained attached to the engine mount. The forward cabin area remained intact. The Hobbs meter on the airplane indicated 267.0 hours. The throttle was three-fourths forward. The propeller and mixture were full forward, and the fuel selector was in the off position. Continuity of the flight controls was confirmed from the control sticks aft to all flight control surfaces, except for the right wing, where the flight control cables failed consistent with overload. There was no deformation to the left or right cabin seats and the left restraint system was in use at the time of the accident. The right seat restraint system was secured. The right wing was fragmented from the wing root extending outboard to the wing tip. The upper and lower wing surfaces were missing. The wing spar remainedattached to the airframe. The right flap and right aileron were separated from their attachment points. The right fuel tank was destroyed and the right main fuel cap was not located. No fuel staining was observed on the fragments of the wing or the right side of the fuselage. The right main landing gear was collapsed and remained attached to the wing. The aft fuselage and empennage were not damaged except for the tail cone located beneath the stabilator and rudder assembly. The vertical stabilizer remained intact and was not damaged. The rudder assembly remained attached to all attach points and was not damaged. The horizontal stabilator and trim assembly remained attached and were not damaged. The left wing remained attached to the airframe. The leading edge of the wing tip was shattered. The upper and lower wing surfaces were not damaged. The left aileron was attached to its attachment points. The left flap was attached to its attachment points and was in the retracted position. The fuel cap was missing. The left wing had been submersed in water and it could not be determined how much fuel had been in the left main fuel tank. There was no staining on the wing or the left side of the fuselage or empennage. The left main landing gear remained attached to the wing. Examination of the engine assembly was conducted on June 10, 2010.The engine cowling was removed and an examination of the engine revealed there was no evidence of a mechanical malfunction. One magneto was installed on the left side of the engine and an experimental electronic ignition system was installed on the right side of the engine. An electronic module with rotating components was installed on the magneto pad, connected to two high tension spark coils mounted on top of the engine. These coils fire the upper spark plugs. There are two wires from the module to each coil supplying the trigger voltage signal to fire the plugs. One of these wires to the right coil, firing cylinder Nos. 1 and 3, had been pulled from a crimp connector. A wiring harness connects the module to the airframe electrical system and the spark coils. The harness is connected to the module with a "D" plug, held in place with two screws, similar to a computer cable connection. The plug was found disconnected from the module and hanging loose. This would cause a complete loss of power to the right hand ignition system, causing a partial loss of engine power as reported by the pilot. The airframe and power plant mechanic stated he did not check the "D" plug during the airplane's most recent annual condition inspection.