Accident Overview
On May 19, 2012, at approximately 0730 Pacific daylight time, an Experimental Light Sport Jackson Top Dog rigid-wing weight-shift aircraft, registration N214AB, impacted terrain about 10 miles southwest of Apple Valley, California. The student pilot, sole occupant, sustained serious injuries, and the aircraft, owned and operated by the pilot, suffered substantial damage. The local flight operated under 14 CFR Part 91 in visual meteorological conditions after departing from an open field near the pilot's home. No flight plan was filed.
Pilot's Account
According to the student pilot, who reported 750 hours in this make and model, he had just taken off and climbed to nearly 150 feet above ground level when engine rpm began to decrease. Shortly after, the engine experienced a complete loss of power. Immediately after the power loss, the pilot turned toward a nearby road in an attempt to land. During the turn, the aircraft descended into terrain at a rate resulting in substantial damage to both the wing and the pilot's seating structure.
Examination Findings
The aircraft was recovered to the owner's home, where a Federal Aviation Administration Inspector from the Riverside Flight Standards District Office directed and oversaw an examination of the airframe and engine. Initial inspection revealed that the Rotax 582 engine had no impact damage and its three-bladed propeller remained attached. The engine lacked an oil injection system, requiring oil to be pre-mixed with fuel. Both carburetors were disassembled; their piston slides and diffusers functioned properly with no internal contamination. Air filters were an acceptable brand (K&N) but not the correct style or part number for the engine, and lacked the required oil additive for proper air filtration. Fuel filters, correctly mounted, contained paper elements not approved by Rotax; the PTO-side filter was clean, while the MAG-side filter showed only minimal debris insufficient to interrupt fuel flow. The fuel pump was the proper type and tested functional on another engine. Spark plugs were the correct type but gapped at 0.22 inch, exceeding Rotax's recommended 0.16-0.20 inch. Plugs appeared black with heavy soot and oil deposits. Spark plug connectors, leads, ignition module, coolant system, rotary valve lubrication system, pistons, cylinder walls, and exhaust system were in good condition with no anomalies or leaks.
The examination disclosed three anomalies, each with potential to contribute to an engine stoppage, according to a Rotech Flight Safety representative:
1. Both carburetor sockets (rubber induction connections) exhibited poor condition with multiple cracks around their circumference. Rotax Service Information SI-04-1987 indicates air leakage through such cracks could contribute to an engine stoppage and requires scheduled inspections. 2. Spark plug condition suggested the High Altitude Corrector (H.A.C.) kit was incorrectly calibrated. Rotax Service Information 2 S 89-E mandates at least annual H.A.C. checks and adjustments; failure may cause an overly rich mixture leading to spark plug fouling and potential engine stoppage. 3. The fuel pump was mounted incorrectly, with its oil drain hole facing the engine instead of downward. Section 15 of the Rotax Installation Manual states an incorrect position may prevent proper oil condensate drainage, possibly causing the pump to hydraulic and stop working.
No other significant anomalies were found by the time of examination completion.