19990119000579A

Aircraft crashed under unknown circumstances. 4 fatal. (.19) on January 19, 1999, about 0445 hours pacific standard time, a Beech F35 bonanza, N336C, was destroyed when it collided with high terrain near Chino, California. The non-instrument rated private pilot and three passengers were fatally injured. The personal flight was conducted under 14 CFR part 91, and no flight plan was filed, nor were any air traffic control (ATC) services provided. The flight originated at the corona, California, airport, at an undetermined time and was en route to lake tahoe. The pilot and passengers were all off-duty firemen from the corona fire department, corona, and were headed for a snowboarding trip at south lake tahoe. None of the other passengers were rated pilots. Visual meteorological conditions prevailed at Chino airport at the time of the accident, which is 5 nautical miles from the departure point, and approximately 4 nautical miles from the accident site. The Chino airport aviation routine weather report (METAR), issued at 0453, indicated winds were calm and the sky condition was an 1,100 feet overcast. Preliminary recorded radar data for the area of the accident site was reviewed, covering a period from 0441:57 to 0444:56. According to the data, a target was tracked which initially headed west, turned north, and then made a 360 degree turn to the left. The initial recorded altitude of the target was 900 feet mean sea levels (MSL) and the last recorded altitude was 2,400 feet MSL. The last recorded position of the target was at latitude 33 degrees 54.48 minutes north, and longitude 117 degrees 39.58 minutes south. The main wreckage site was located in an area of rising terrain at an elevation of about 1,200 feet MSL (GPS) and at latitude 33 degrees 54 minutes north, longitude 117 degrees 39 minutes west. An initial impact site was identified on a small hill crest. Charring from the postimpact fire began at that point and spread downward and outward toward the main wreckage site. Red lens fragments, a light filament (that was stretched and distorted but continuous), and a lens cap were found immediately around the initial impact area. The left wing tip and portions of the left wing were located next to a ground scar that emanated at this point and was measured at 60 degrees to level. One propeller blade was also found near the ground scar. The propeller hub with one blade, a section of crankshaft still attached, and the right wing were located just over the hill crest, following a path on a 250-degree heading from the initial impact site. The terrain showed extensive fire damage. Plexiglass shards were found outside of the burn area that was clear, not distorted, and free of soot on both sides. Debris and loose items from the aircraft were scattered along the path. The main wreckage was located on a plateau about 180 feet from the initial impact point, and about (10) degrees downslope. The aircraft cabin area was consumed by fire and the exterior paint on the empennage was blistered and slightly discolored. The engine was found separated from the aircraft and was inverted on the left side of the empennage, slightly ahead of the left ruddervator. The flaps and the remainder of the left wing were located around the aircraft. Flight control continuity was established from the controls to the front cabin area, but could not be confirmed past that point due to the damage of the cabin. An examination of the aircraft and powerplant was conducted by the safety board in compton, California, on January 20, 1999. Both propeller blades exhibited chordwise scratching and were twisted toward the cambered side. The trailing edge of the separated blade found in the principal impact crater exhibited witness marks on the backside of the blade in the hub mounting area. The crankshaft and its separated piece exhibited a 45-degree fracture surface around their circumference. The dry vacuum pump separated from the mount and the internal rotor vanes of the pump were missing. The pump case showed rotational scoring on its back and side walls. The directional gyro and another gyro were disassembled and exhibited rotational scoring on the gyro and the case. The fuel manifold valve was disassembled and evidence of fuel was noted. Fuel screens for the manifold valve, fuel selector valve, and metering valve appeared clear and free of contamination. The examination of the aircraft revealed the landing gear was retracted and the flaps were in the full up position. The departure was planned for about 0430. No record was found that the pilot obtained a preflight weather briefing through an FAA or NWS source. Surrounding airports were reporting cloud coverage in the area of the accident site between 700 and 1,000 feet above ground level, with visibility's 3 miles or less. A terminal forecast for the area predicted visibility of 3 miles in mist, temporarily 1 mile in mist, between 0400 and 0600. An AIRMET was in effect for ceilings below 1,000 feet and visibility 3 miles in fog and mist for the departure area. The AIRMET noted occasional ceilings below 1,000 feet and visibility less than 3 miles in fog and precipitation for portions of the en route phase and at the destination. Mountain obscuration in clouds and precipitation was also forecasted. The departure airport was surrounded by hilly terrain with tops 1,000 to 3,000 feet above the airport elevation. Recorded radar data tracked the airplane from 500 feet AGL to the accident site at 1,112 feet MSL (about 600 feet above the airport). The airplane was climbing and completed one 360-degree turn, achieving 2,500 feet MSL. The turn continued in a much tighter radius and the airplane l ost 500 feet of altitude. The airplane completed one more turn as it continued to descend to impact ABOUT3 miles west of the airport. The most conservation weight and balance computation placed the airplane 241.2 pounds over maximum allowable gross weith with a CG location 2.57 inches aft o fthe rear limit. No discrepancies were found with the airplane or engine upon inspection. The pilot did not posses an instrument rating. (-23) on January 19, 1999, at 0446 PDT, a Beech BE-35-F35 bonanza, N3364C, was destroyed when it flew into a hillside in Chino Hills, CA. The point of impact occurred approximately 50 feet below the top of the hill. Private pilot and three passengers were fatally injured. The flight departed from corona airport in IMC conditions on a personal flight to lake tahoe, Nevada. Pilot did not have an instrument rating. Hours, make and model are unk nown because current logbooks were burned at accident sight.