Aviation Accident Summaries

Aviation Accident Summary LAX97FA225

MORENO VALLEY, CA, USA

Aircraft #1

N7373K

Cessna R172K

Analysis

There is no record of the pilot having received a weather briefing before takeoff. Radar data showed the aircraft following a highway toward higher terrain at approximately the altitude of the cloud bases. At the end of the radar data the aircraft climbed until radar contact was lost near the accident site in mountainous/hilly terrain. Witnesses at the accident site reported that the aircraft flew 300 to 400 feet over their position and was barely visible in the base of the clouds. The engine was 'straining' and then they heard the plane crash. Rescue personnel said that at the time of their arrival the visibility at the site was about 50 feet in fog.

Factual Information

HISTORY OF FLIGHT On June 28, 1997, at 0722 hours Pacific daylight time, a Cessna R172K, N7373K, impacted mountainous terrain in cruise flight near Moreno Valley, California. The aircraft was destroyed and the commercial pilot and one passenger were fatally injured. Instrument meteorological conditions prevailed at the accident site. The personal flight departed Long Beach, California, about 0656 destined for Aha Quin, California. According to the pilot's wife, the pilot and passenger were flying to Aha Quin to have the annual inspection performed on the aircraft. The pilot took tools and planned to do some of the work himself. There was no further record of any communication with the aircraft after departure from Long Beach. There was no record that the pilot received a weather briefing and no flight plan was filed. Personnel at Southern California TRACON replayed recorded radar data from the time of the accident and were able to identify a VFR (1200) transponder equipped aircraft with which radar contact was lost at the time of the accident. A plot of this aircraft's flight path in the 10 minutes before the accident is attached and shows the aircraft following the route 91 (Riverside) freeway northeast-bound at 1,600 to 1,800 feet msl. At 0721:40 the aircraft begins a climb from 1,800 feet until radar contact is lost near the accident site at 0722:03 when the aircraft had reached 2,200 feet. Stratus clouds existed over coastal areas Southern California inland to the coastal slopes of mountains and passes. Bases of the overcast clouds were about 2,000 feet msl. The NTSB investigator drove to the accident site via the eastbound 91 (Riverside) freeway, departing Corona about 0830 and arriving at the accident site about 0930. The weather along the route consisted of low stratus clouds and visibility of about 1 mile. The stratus clouds were dissipating at the accident site at the time of the investigator's arrival. Two witnesses who were riding mountain bikes near the accident location reported hearing the aircraft and seeing it briefly as it flew over their position before hearing the crash. The witnesses were in the valley about 1/4 - 1/2 mile west of the accident site where, they estimated, the elevation is about 300 - 400 feet lower. They estimated they were about 75 feet below the "fog level". They heard the plane approach from the south or southwest but could not see it because of the clouds. As it got closer, they finally saw it descend from the base of the clouds in a right turn to an easterly heading after which it climbed up into the clouds and disappeared. They saw the belly (underside)of the aircraft as it turned. Shortly thereafter they heard it crash. They reported that the engine sounded like it was "straining" . The weather at March Air Force Base, 6 miles southeast of the accident site at 0724 was a broken ceiling at 900 feet and visibility of 1.5 statute miles. Riverside County sheriff's deputies and fire department personnel reported that the visibility was restricted in fog to approximately 50 feet at the accident site on their arrival. According to these deputies, the weather east of the accident site was clear and visibility unrestricted and the weather west of the accident site was overcast clouds, low visibility, and mountains obscured in clouds. PERSONNEL INFORMATION According to the pilot's logbook, he had flown about 49 hours in the previous year, of which 3.5 hours were actual IFR and 1.1 hours was simulated IFR. In the 6-month period before the accident, the pilot had flown 10.2 hours, which included an instrument competency check, on February 9, 1997. During the competency check the 1.1 hours of simulated instrument flight were flown including four instrument approaches. A friend of the pilot, who is a private pilot, said that as far as he knows the pilot's only flying was in his own airplane. He believes that the pilot maintained instrument proficiency and sometimes flew in actual IFR conditions. He couldn't understand why the pilot didn't file IFR to VFR conditions on top on the day of the accident. According to the aircraft logbook, the accident aircraft had flown 48 hours in the year before the accident. AIRCRAFT INFORMATION A friend of the pilot, who also holds a pilot certificate, said that he doubts there were any mechanical or equipment discrepancies with the aircraft that prevented the pilot from filing IFR to VFR on top. The friend said that they regularly talked about their airplanes and that had anything been wrong, the pilot would have mentioned it in the course of conversation. WRECKAGE AND IMPACT INFORMATION The aircraft impacted a rock outcropping on the west face of a mountain slope at latitude 33 degrees 59.02 minutes, and longitude 117 degrees 17.57 minutes west (GPS). The elevation is approximately 2,100 feet msl. On the rock face, about 20 feet above the base, was a shattered area of rock with black oil, the engine starter motor and small engine debris. Horizontally, approximately 15 feet left and right of the shattered area, was a 1- to 2-foot-high area or white paint debris and small scars on the rock face. The rock outcropping is essentially flat and vertical in the area. Below the base of the outcropping the mountain side slopes downward on approximately a 45-degree slope to the west. The wreckage was found at the base of the outcropping, below the impact marks, oriented approximately 085 degrees. A 4-foot diameter boulder was dislodged from the rock face and rolled about 300 feet down the mountain slope. The entire aircraft was present at the accident site except one propeller blade, which was not recovered. There was no fire, although fire department personnel who responded to the scene reported a strong fuel smell when they arrived. The cabin ceiling structure with wings attached was folded back over the tail cone and the fuselage lower skin beneath the cabin was folded over facing upwards and toward the rock face. The engine and the fractured propeller hub, with one blade attached, were found near the empennage; however, the propeller nose dome was found approximately 40 feet northwest of the main wreckage, and the engine oil cooler was found approximately 50 feet west. The remainder of the debris field was within 50 feet of the main wreckage. The aircraft was destroyed back to the mid-chord of the wing. The fuel tank in the right wing had burst and exhibited the impression of the wing spar and the rock face. The aft cabin was substantially damaged and there were compression wrinkles in the tail cone. The instrument panel was destroyed and the leading edge of both wings was crushed back to the mid-chord point. The propeller hub was shattered with deep rock gouges and the attached propeller blade had a gouge in the leading edge near the base. The propeller shaft was sheared at the engine case with 45-degree fracture surfaces on the shaft. The engine was approximately 15 feet southwest of the airframe wreckage. There were deep rock gouges in the nose case of the engine and the engine mounts were broken at their attachment to the case. The cylinder heads of the front cylinders (number 5 and 6) were broken off, and those for the middle cylinders were broken in the rocker box area. All accessories and appliances, except the fuel injection flow divider on the top of the engine, were broken off the engine. The exhaust pipes were separated as was most of the intake manifold. The throttle valve in the fuel injection body was found off the engine with the valve trapped approximately 80 degrees open. The engine driven vacuum pump was located with the shear coupling intact. The rear (bench) seat was not installed. The flight control cables were continuous aft of the baggage compartment to the empennage control surfaces. The emergency locator beacon switch was in the "off" position and had not been moved by emergency personnel. According to the aircraft delivery documents, the aircraft was equipped with a Cessna 300A autopilot. A roll servo in the right wing was found with the roll pin sheared on the output gear. The output shaft of the servo turned with resistance. A flight case bearing the pilot's name was found in the wreckage. Inside was a Jeppesen chart binder. Only visual navigation charts were found open in the wreckage. TESTS AND RESEARCH An autopsy was performed on the pilot by the Riverside County Coroner. Toxicological tests were performed on the pilot by the FAA Civil Aeromedical Institute in Oklahoma City, Oklahoma. Detected was Diphenhydramine, an antihistamine, and ephedrine and pseudoephedrine, two decongestants. The aircraft wreckage was released to Mr. Steven Lora, Claims Manager, USAIG, on July 21, 1997.

Probable Cause and Findings

The pilot's continued VFR flight into instrument meteorological conditions, and his attempt to climb through a low stratus cloud layer while in mountainous/hilly terrain. The pilot's failure to obtain a weather briefing, the weather, and the terrain were factors.

 

Source: NTSB Aviation Accident Database

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