NTSB Factual Report

On May 19, 2012, about 0730 Pacific daylight time, an Experimental Light Sport Jackson Top Dog rigid-wing weight-shift aircraft, N214AB, impacted the terrain about 10 miles southwest of Apple Valley, California. The student pilot, who was the sole occupant, received serious injuries, and the aircraft, which was owned and operated by the student pilot, sustained substantial damage. The local 14 Code of Federal Regulations Part 91 flight, which had just taken off from an open field near the student pilot's home, was being operated in visual meteorological conditions. No flight plan had been filed.

According to the student pilot, who reported having 750 hours in this make and model aircraft, he had just taken off, and had climbed to almost 150 feet above ground level when the engine rpm began to decrease. Soon thereafter the engine experienced a complete loss of power. Almost immediately after the loss of power, the pilot turned toward a nearby road in order to try to land there. During that turn the aircraft descended into the terrain at a rate that resulted in the substantial damage to both the wing and the structure within which the pilot was seated.

The aircraft was recovered to the home of the owner, where the airframe and engine underwent an examination directed and overseen by a Federal Aviation Administration Inspector from the Riverside Flight Standards District Office. The initial part of the inspection revealed that the Rotax 582 engine had not suffered any impact damage, and that its three-bladed propeller was still attached. Further examination determined that the engine did not have an oil injection system, which therefore required the oil to be pre-mixed with the fuel. Both carburetors were disassembled, and the piston slide on each functioned properly. No anomalies were noted with the piston slides or the diffusers. There was no evidence of internal contamination in either carburetor. The air filters on both carburetors were of an acceptable brand (K&N), but were not the correct style or part number for this engine. The filter elements were without the special oil additive required for proper filtering of air. The fuel filters, which were mounted correctly, were examined, and although their elements were of material not approved by Rotax (paper), the PTO-side filter was clean, and the MAG-side filter showed only a small amount of filtered debris in insufficient amount to interrupt fuel flow. The fuel pump was the proper type, and was later tested on another engine where it functioned properly. The spark plugs were determined to be the proper type, but were gapped at 0.22 inch, instead of the 0.16 to 0.20 inch recommended by Rotax. The spark plugs appeared black, with heavy amounts of soot and heavy oil deposits. The spark plug connectors and leads were of the correct type, were connected correctly, and appeared to be in good condition. The ignition module was in good condition and of the proper type. The coolant system, which still contained coolant, was in overall good condition, was connected properly, and had no leaks. The rotary valve lubrication system, which still had oil in its reservoir, was in overall good condition, with no anomalies or leaks found in its system. The pistons and cylinder walls showed no evidence of oil starvation, seizure marks, or thermal distress. The exhaust system was in good condition, with no indication of unapproved modifications.

Although the examination did not disclose a condition that would have automatically led to the loss of engine power, the following three anomalies were discovered. According to a representative of Rotech Flight Safety, each of these anomalies had the potential to contribute to an engine stoppage.

1.Both the MAG-side and the PTO-side carburetor sockets (rubber carburetor-to-engine induction connections) were found to be in poor condition, with multiple cracks around their entire circumference. According to Rotax Service Information SI-04-1987, leakage of air through such cracks could contribute to an engine stoppage, and therefore Rotax requires that they be inspected on a scheduled basis, to include prior to each flight.

2.Based on the condition of the spark plugs, it appeared that the High Altitude Corrector (H.A.C.) kit that had been installed on the engine had not been correctly calibrated. Rotax Service Information 2 S 89-E requires that the H.A.C. be checked, and if necessary adjusted, at least once each flying season. Failure to do so can lead to an overly rich fuel-to-air mixture, which may lead to the fouling of the spark plugs, and contribute to an engine stoppage.

3.The fuel pump was mounted in an incorrect position, with the oil drain hole facing the engine, instead of toward the bottom of the fuel pump. Section 15 of the Rotax Installation Manual (fuel systems) states that an incorrect installation position may result in the oil condensate not draining properly, possibly causing “the fuel pump to hydraulic and stop working,” resulting in engine stoppage.

At the time of the completion of the examination, no other significant anomaly had been found.

NTSB Probable Cause

A loss of engine power during the initial climb for reasons that could not be determined because the anomalies revealed during the postaccident examination would not have necessarily precluded normal operation. Contributing to the accident was the inadequate maintenance, which failed to detect existing anomalies in engine-related systems.