LAX05FA023 · Cessna 182Q

While traversing a mountain range between two valleys, the aircraft collided with mountainous terrain after a likely encounter with clouds, moderate turbulence, and up and down drafts in the 500- to 1,000-foot-per-minute range. Examination of the wreckage and the accident site showed that the airplane collided with mountainous terrain while in a wings level cruise flight attitude. The autopilot switch was found in the ON position. The noninstrument rated private pilot departed in VFR conditions with three passengers for a 134-mile trip to celebrate one passenger's birthday at a fly-in restaurant destination. There were no records of the pilot having received weather briefings from any Federal Aviation Administration (FAA) facilities. Recorded radar data showed that instead of flying a direct route the airplane meandered towards a mountain top VOR navigational aid and eventually was about 18 miles off a direct course between the departure and destination airports. About 30 minutes into the flight, the airplane had reversed course and was headed back towards the open desert departure area when radar contact was lost. A moderate north-south surface pressure gradient produced strong, gusty northerly low-level winds over the higher elevations of the mountain range. Observations from satellite imagery indicated that mostly clear skies were present from the departure airport until the accident airplane reached the vicinity of the accident area. A weather satellite visible image showed that cloud cover from the northwest did cover the accident site around the estimated time of the accident though there were clear areas south and west of the VOR. Cloud bases reported around the VOR ranged from on the surface to less than 1,000 feet agl, with tops generally 8,000-10,000 feet mean sea level (msl) in the area. No in-flight advisories (SIGMET or AIRMET) were valid for the accident location when the accident airplane departed. However, AIRMET TANGO was updated at 1335, to include a forecast of occasional moderate turbulence below 12,000 feet over coastal mountain areas. According to pilot reports from very near the accident area around the time of the crash, moderate turbulence and up and down drafts were being experienced from 500 feet to 1,200 feet per minute. There are two small lakes in the vicinity of the VOR. Overflying one lake on the accident flight's last radar observed heading would take the airplane over low terrain on a route back toward the departure airport, whereas overflying the second lake on the last observed heading would take the airplane toward mountainous terrain that rises to 5,430 feet msl within 2 miles, and is the location of the accident site.

Verbatim NTSB analysis and probable cause from the NTSB dataset