LAX07LA075

The engine experienced a partial loss of power and the airplane collided with a dirt berm during the precautionary landing. While the pilot was sightseeing over a relative's construction site, about 1,500 feet mean sea level (msl), the airplane's engine surged and experienced a partial loss of power. According to the pilot, he opted to perform an off-airport landing in an open field below. The airplane touched down on the dirt field and collided with a dirt berm located at the end of the field. There was no evidence of premishap mechanical malfunctions observed during the examination of the engine and airframe. Although the atmospheric conditions were conducive to the formation of serious carburetor ice at cruise power, the airplane's manufacturer conducted testing indicating that the outside air would be sufficiently heated as it passed through the intake system to preclude the formation of carburetor ice.

History of flight

On January 26, 2007, about 1145 Pacific standard time, a JIHLAVAN KP-5 light sport aircraft (LSA), N215KP, experienced a partial loss of engine power and collided with a dirt berm during the precautionary landing in Moorpark, California. The airplane sustained substantial damage during the accident sequence. The pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The commercial pilot, the sole occupant, sustained minor injuries. The local personal flight departed Santa Paula Airport, Santa Paula, California, about 1100. Visual meteorological conditions prevailed, and a flight plan had not been filed.

The pilot reported that after departing Santa Paula he planned on maneuvering the airplane around a construction site that a family member owned. While maneuvering about 1,500 feet mean sea level (msl), the airplane's engine surged and experienced a partial loss of power. The pilot opted to perform an off-airport landing in an open field below. The airplane touched down on the field, which was comprised mostly of loose dirt. The brakes were somewhat ineffective due to the loose terrain, and the airplane collided with a dirt berm located at the end of the field.

Several construction workers witnessed the accident and submitted written accounts of their observations. One witness reported that the airplane briefly touched down on the flat dirt and departed. The airplane then flew back and touched down again, crashing into a slope during the landing. Another witness stated that the airplane was circling above his location. The airplane landed and collided with a ditch.

Airplane information

The National Transportation Safety Board investigator-in-charge (IIC) reviewed files on the accident airplane maintained by the Federal Aviation Administration. The JIHLAVAN KP-5, single engine airplane, serial number 5111129K, was manufactured in 2005. It was issued an airworthiness certificate in the light sport category on October 27, 2005. Despite numerous attempts, no engine logbooks were located. According to the pilot, the airframe and engine had accumulated 98.2 flight hours prior to the accident.

The airplane had a Rotax 912ULS engine (tractor-configuration), serial number 5645163. The engine's intake air was drawn from inside the cowling (adjacent to the lower firewall) and routed through an air filter. The intake air was then directed into a sole airbox that fed both carburetors.

The engine was outfitted with two Bing "Constant Compression" carburetors. These variable venturi carburetors were not equipped with butterfly valves; rather, they utilized moving slides to regulate airflow. This configuration enabled the venturi area to change with the throttle setting.

The airplane did not have carburetor heat, nor did it have an alternate air source.

Meteorological information

A routine aviation weather report (METAR) for Camarillo, California (located about 12 miles southwest of the accident site), was issued at 1155. It stated: skies clear; visibility 10 miles; winds from 230 degrees at 5 knots; temperature 62 degrees Fahrenheit; dew point 46 degrees Fahrenheit; and an altimeter of 30.03 inHg.

The temperatures were applied to an industry Carburetor Icing Probability Chart revealing that the recorded temperatures were within the "serious icing at glide power" portion of the chart.

Tests and research

Following recovery, the Safety Board IIC examined the airplane at the maintenance facilities of Ray's Aviation, Santa Paula, on February 16, 2007.

The airplane was separated into three major components for the purpose of recovery. The wreckage consisted of the left and right wing, and main airframe (with the engine attached at the mounts). Recovery personnel detached both wings from their respective inboard roots, leaving the filler necks exposed from the inboard fuel tank.

The Safety Board IIC established control continuity from the control rod ends at the wing sections (disconnected by recovery personnel) to the flap and aileron control surfaces. Continuity was additionally established from the rod ends at the inboard wing sections to the cockpit control stick. Continuity was established from the cockpit controls to the rudder and elevator control surfaces. Both wings contained numerous dimples of damaged skin. The left wing was gouged where the rib was damaged about 11 feet 2 inches outboard; the puncture stretched about 3 inches aft.

The engine remained intact with the cowling secured. The engine had incurred visible external damage consisting of an upward crushing to the muffler and connected exhaust stacks, as well as the water cooler. A teardown examination was preformed during which, all cylinders, pistons, and accessories were removed and inspected.

Continuity was established for both the throttle and choke control cables and manipulation of the controls both forward and aft moved the cables from stop to stop.

The spark plugs were secure at each position with their respective spark plug leads attached. The plugs were removed, examined, and photographed. The spark plug electrodes remained mechanically undamaged, and were gray with a yellow coloration in the center. The top spark plugs, attached to their respective leads, were positioned adjacent to the crankcase while the engine was cranked with the master switch activated. Spark was obtained from each spark plug.

The crankshaft was rotated by turning a propeller blade still affixed to the spinner assembly; it was free and easy to rotate in both directions. Compression was observed in all four cylinders, with air felt to egress through the top spark plug bores during rotation. The complete valve train was observed to operate in proper order, with lift action observed at each rocker assembly. Clean, uncontaminated oil was observed at all four rockerbox areas. Mechanical continuity was established throughout the rotating group and valve train during the rotation of the crankshaft.

All cylinders were removed, revealing no evidence of foreign object ingestion or detonation. All valves were intact and the internal cylinder domes and piston crowns exhibited similar combustion deposits and coloration. The camshaft was observed to rotate freely and the visible lobes were egg-shaped with no evidence of corrosion or pitting.

The internal ducts of the exhaust displayed deposits of white powder. The oil filter was removed and cut open; there was no evidence of residue or contamination inside.

The fuel selector was selected in the "off" position, which the pilot indicated he had selected after the accident. The fuel selector was removed and examined. It appeared to function normally by allowing air pressure to pass the switch unit when in the "on" position and closing air from passing when in the "off" position. Air pressure was routed from both the right and left fuel selector lines (where they attached to the fuel selector). The air was felt egressing the respective filler neck in the fuel tank located in the inboard wing.

The electrically driven fuel pump, located just aft of the fuel selector, was removed and rigged to an electrical source. It produced suction at its inlet when electrical power was applied. Removal of the fuel filter inside the pump revealed that is had trace amounts of debris in the tip, which had the consistency of dirt. The engine driven fuel pump was removed and engaged by applying a downward force, which resulted in the unit rapidly ejecting fluid that was consistent in odor with automobile gasoline.

Removal of both the right and left Bing carburetors revealed that the bowls were full with a fluid consistent in appearance and odor to that of automobile gasoline. The floats were intact and buoyant. The diaphragms on top of the bowl units were pliable and the springs were intact.

There was no evidence of premishap me