Aviation Accident Summaries

Aviation Accident Summary LAX99FA160

GORMAN, CA, USA

Aircraft #1

N3403J

Cessna 150G

Analysis

The accident site is in a mountain valley between the departure and destination airports. A ground witness observed the aircraft flying about 400 feet above ground level, in and out of the cloud bases beneath an overcast ceiling, up the valley toward higher terrain. A resident who lives directly above the accident site reported that the mountainside where the aircraft wreckage was later located was obscured in clouds at the time of the accident. No preimpact mechanical malfunctions were found during examination of the wreckage.

Factual Information

HISTORY OF FLIGHT On April 22, 1999, about 1230 hours Pacific daylight time, a Cessna 150G, N3403J, was destroyed when it impacted a mountain near Gorman, California. The private pilot, who was not instrument rated, was fatally injured. Instrument meteorological conditions prevailed in the area of the accident site for the personal flight and no flight plan was filed. The flight was operated in accordance with 14 CFR Part 91 by the owner and departed from Meadows Field, Bakersfield, California, at 1136. There were no witnesses to the accident and the estimated accident time is based upon the departure time from Bakersfield and the elapsed time on the engine tachometer. The pilot's logbook, found with the wreckage, contained an entry dated April 22, 1999, which stated [Gas] "18.74 gals @ 279.3 eng. hrs @ BFL." At the accident scene the engine tachometer read 280.2 hours. According to the Federal Aviation Administration (FAA) Western Pacific Region Air Traffic Quality Assurance Office, the pilot was cleared for takeoff at Bakersfield at 1136. Radar service was terminated by Bakersfield Approach (Departure) Control at 1156, when the aircraft was approximately over the intersection of the 5 and 99 freeways in the southern San Joaquin Valley. The controller recalled that the mode C altitude report was about 3,500 feet msl when radar service was terminated. Bakersfield Approach Control radar data is not recorded and a review of Los Angeles Center recorded radar data failed to show the aircraft. The wreckage was discovered by pilots of an U.S. Customs Service helicopter that was southbound through the area at 1650. The pilot reported that the weather in the area was "improving rapidly" and that he had a 1,500- to 2,000-foot ceiling over Gorman with unrestricted visibility so he decided to fly directly southbound over Gorman VORTAC. As he approached the VORTAC one of his passengers observed the aircraft wreckage on the hillside below. The Customs pilot landed his helicopter and determined that it was a recent accident. The surface winds were about 20 knots. He also reported that he had flown northbound through the area that morning about 1000, and the conditions were so low that he opted to climb through a hole in the clouds and fly VFR on top. The owner of the property lives in a home atop the mountain about 250 feet above where the accident occurred and is employed as a corporate pilot. He was at home on the day of the accident and reported that the mountain was "zero-zero" in clouds all day until about 1600, when conditions started to improve. Earlier in the day his wife drove down the mountain to interstate highway 5 below and reported that conditions were foggy all the way down into the town of Gorman, which is about 500 feet lower. Winds were blowing 20 to 40 knots from the north. He did not hear the plane crash and learned about the accident when a U.S. Customs Service pilot came to his house about 1700 and told him there was a crashed plane on the mountainside below. A California Highway Patrol officer, who is also a commercial licensed pilot, was driving northbound on highway 5 about 3 miles north of the accident location at noon. He estimated that there was a ragged ceiling at 300 to 600 feet (agl) in the area. He observed a Cessna 150 or 172 come out of the clouds at low altitude going the opposite direction (southbound) over the freeway at low altitude. The aircraft had its landing light on and the first thing he saw as the aircraft came out of the clouds was the light, and then the image of the aircraft. He was immediately concerned because he knows of wires crossing the valley at nearly that height, and also because he knew that the terrain rises to the south and the pilot was going to either have to descend further or re-enter the clouds. When he heard later that day that a plane had crashed, he went to the scene. He believes that the plane at the accident site is the one he saw earlier. He examined the landing light bulb filament, and, based on his CHP training, believes it was on at impact. The pilot's wife told the Safety Board investigator that she had flown "many, many times in white out conditions" with her husband and that it was his practice to "drop down" to stay out of the clouds. METEOROLOGICAL INFORMATION The nearest weather reporting point is at Sandberg, California, which is 100 degrees (magnetic) and 8.5 miles from the accident site in a mountain location approximately the same elevation. At 1222, the Sandberg automated weather observation was: Visibility 4 miles in mist with broken cloud layers at 300 and 600 feet and an overcast cloud layer at 1,400 feet (elevations are in feet above ground level, agl). The temperature and dew point were 7 degrees Celsius, and the altimeter setting was 29.73. In remarks it was noted that the ceiling was variable between 100 and 500 feet. WRECKAGE AND IMPACT INFORMATION The accident location is on an east facing 40-degree mountain slope in a valley oriented north to south. Covered with natural grasses, typically 1-foot tall, the slope rises to the west to a crest about 250 feet above the accident site. The property owner's home is located on this crest directly above the accident site. There are no other homes in the area. Opposite the accident site on the east side of the valley is another slope similar in height to the accident location. To the south about 1/4 mile the valley closes off and rises approximately 300 feet to the site of the Gorman VORTAC navigational aide. The north end of the valley opens to the Grapevine Pass, which leads to the southern San Joaquin Valley and the town of Bakersfield. The accident site is at latitude 34 degrees 48.56 minutes north and longitude 118 degrees 51.90 minutes west (GPS). The elevation at the site is approximately 4,600 feet msl. All of the aircraft was present at the accident site except the nosewheel assembly, which was not located. There was no fire. There was a debris field oriented from the northeast uphill to the southwest. At the northeast end there was an area of disturbed dirt approximately 4 feet wide, 6 feet long and 1 foot deep. Emanating from the hole were two lateral marks on the surface oriented north-south, which were approximately equal to the span and thickness of the wings. At the northwest end were wingtip fairing fragments and small pieces of green glass, and at the southeast end were wingtip fairing fragments and small fragments of red glass. Uphill 30 feet on a bearing of approximately 210 degrees from the area of disturbed dirt was the majority of the wreckage. The fuselage and left wing were inverted and pointing back to the northeast. The aft fuselage and empennage was separated but remained attached by control cables and was upright. The nose and cockpit area were extensively damaged and the leading edge of the left wing was compressed aft to the mid-chord point. The right wing remained attached to the cabin ceiling structure; however, it was lying with the top surface up and with the leading edge oriented uphill to the southwest. The leading edge of the right wing was compressed outboard of the wing strut attachment aft to approximately the main wing spar. Over the next 30 feet uphill to the southwest was a debris field of light Plexiglas and plastic parts and cockpit contents. The emergency locator transmitter (ELT) mount was installed at the fuselage station where the aft fuselage separated, and the ELT was ejected from its mount and antenna and came to rest about 15 feet upslope of the fuselage wreckage. The wreckage was further examined on April 24, 1999 at Aircraft Recovery Services in Compton, California. Flight control continuity was established, as was engine control continuity. The directional gyro instrument was disassembled and the gyro rotor did not exhibit any circumferential scrape marks. The instrument vacuum pump, an oil lubricated (wet) type, was broken from the its mount on the nose of the engine; however, the interior components of the pump were undamaged. The altimeter read 7,400 feet (msl). When shaken, loose parts were heard inside the altimeter case. The case was opened and the sector gear shaft was found loose within the case and the sector gear was unsupported and loose from the gear train mechanism. One blade of the propeller was bent back approximately 135 degrees over its span and the other blade was bent back about 30 degrees. Both blades exhibited torsional twisting and chordwise scratches on the camber of the blades. The propeller flange was broken circumferentially from the crankshaft but remained loosely in place. The engine was mechanically continuous and there was compression and valve action in all cylinders when the engine was rotated by hand. The magnetos were timed at 26 degrees before top dead center and both magnetos sparked at all four posts when rotated by hand. The spark plug wires were sheared at several locations and both P-lead wires were broken. The top spark plugs were removed and the electrodes were clean and light gray in appearance. The inlet air filter was obstructed by dirt. The carburetor was separated from the engine at the carburetor base and the fuel supply line was separated at the fuel sump attachment. The air path was clear and there was a trace of fluid in the carburetor that smelled similar to aviation fuel. The fuel sump contained no fuel and the filter screen was clear. The oil filter was opened and it and the engine oil screen were clear. The right-hand muffler was collapsed and the left-hand muffler was damaged with the internal baffles broken. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed by the Los Angeles (California) County Department of Coroner, case number 99 02861. A toxicological analysis was performed by the FAA Civil Aeromedical Laboratory in Oklahoma City, Oklahoma, case number 9900071001. ADDITIONAL INFORMATION The aircraft wreckage was released to Mr. Rob Cheek, adjuster for Universal Loss Management Co, Los Angeles, on April 28, 1999.

Probable Cause and Findings

The pilot's intentional flight into adverse weather conditions beneath a low ceiling in mountainous terrain.

 

Source: NTSB Aviation Accident Database

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