NTSB Factual Report

On February 6, 1994, at 1526 Pacific standard time, a homebuilt experimental Lampman Kitfox IV airplane, N92NL, collided with mountainous terrain about 5 miles west of the Banning, California, airport. Visual meteorological conditions prevailed at the time and no flight plan was filed for the operation. The aircraft was destroyed in the accident sequence. The private pilot and a pilot-rated passenger sustained fatal injuries. The flight originated from the Banning airport on the day of the mishap at 1500 hours as a local area personal flight.

According to the aircraft owner, the pilot had performed maintenance on the landing gear prior to the accident flight. The pilot had the owner's permission to fly the aircraft.

A ground witness was standing on top of the upper wall of a canyon-like gully about 1/2 mile from the crash site. The witness stated that he observed the aircraft fly over at an altitude which was about 50 feet above the level of his head. The aircraft was then over the center axis line of the gully proceeding in an upslope direction. The witness said the aircraft seemed to be maintaining about 300 feet above the floor of the gully and, when the aircraft passed over, the engine was running in a normal manner.

The witness then returned to what he was doing and a few minutes later observed the aircraft on the ground on the side of the gully. The witness stated that he immediately made his way over to the accident site and found the pilot still conscious. The witness reported that there was a heavy odor of fuel in the immediate vicinity to the point that he became nauseous. The witness said he helped extricate the pilot from the wreckage and the pilot told him "the engine cut out on me." The pilot subsequently expired after admission to a hospital.

Federal Aviation Administration (FAA) inspectors from the Riverside, California, Flight Standards District Office examined the aircraft on the accident site. The inspectors reported that the site is in a bowl-shaped gully or canyon with a diameter of about 400 yards. The inspectors said the aircraft appeared to have impacted the rocky ground in a near-vertical descent attitude between two large boulders. The aircraft was found at the accident site in a vertical nose-down attitude wedged between the boulders.

According to the inspectors report, control system continuity was established from the cockpit controls to the elevator and ailerons. Impact damage precluded a continuity determination for the rudder control cables. All three wooden propeller blades were observed to have fractured at about the midspan points of each blade, with the outboard portions fragmented into longitudinal splinters.

After recovery of the aircraft from the site, a detailed examination was conducted of the airframe and engine.

Complete continuity was established for the control, fuel, and ignition systems. The fuel shutoff valve was found in a 3/4 on position during internal examination of the unit. Fuel was found in the lines leading to both carburetors.

The Rotax 582UL engine, serial No. 4015281, was examined in detail with technical assistance from the manufacturer. The engine crankshaft was rotated, with cylinder compression and valve wheel continuity established. The Power Takeoff (PTO) cylinder spark plugs were found sooted. The Magneto (MAG) cylinder spark plugs exhibited normal operating signatures. Internal examination of the cylinders revealed no unusual conditions. Both pistons were found moderately carbonized with the rings free to move.

The choke arm jam nuts on the carburetors were found loose. The PTO carburetor choke jam nut was found backed all the way up the shaft while the MAG side carburetor choke jam nut was one turn loose on the shaft. According to the manufacturers representative, the choke arm jam nut locations would result in an overly rich mixture condition with the choke in the on position.

The MAG cylinder carburetor float needle valve setting was found at the richest position. The main jet size was noted to be 170 (normal size is 165). The carburetor bowl was disassembled and one of the two floats was found disengaged from the valve arm.

The PTO cylinder carburetor float needle valve setting was found at the richest position. The man jet size was noted to be 170 (normal size is 165). Both floats in the carburetor bowl were found engaged on the valve arm.

The fuel pump was disassembled. The diaphragms were found intact and the internal valves functional. Fuel was found in the unit. The pilot sustained fatal injuries in the accident and an autopsy was conducted by the Riverside County Coroner's office. The attesting pathologists reported that the cause of death was attributed to multiple traumatic injury. Samples were obtained for toxicological analysis with negative results for alcohol and all screened drug substances.

NTSB Probable Cause

1) THE PILOT'S DECISION TO FLY IN MOUNTAINOUS TERRAIN AT A LOW LEVEL, AND 2) HIS FAILURE TO MAINTAIN ADEQUATE AIRSPEED WHILE MANEUVERING TO REVERSE DIRECTION IN A BOX CANYON, WHICH RESULTED IN AN INADVERTENT STALL SPIN.