Accident
On October 23, 2010, about 1427 Pacific daylight time, a Piper PA-28-236, registration N228KK, experienced a partial loss of engine power during cruise flight. The aircraft was unable to sustain flight, and the pilot executed a forced landing in mountainous terrain approximately 4 miles east of Dorrington, California. The airplane, owned and operated by the pilot, sustained substantial damage. The instrument-rated private pilot received minor injuries.
Instrument meteorological conditions prevailed at the time of the personal flight, which was conducted under 14 Code of Federal Regulations Part 91. An instrument flight rules (IFR) flight plan was filed. The flight originated from Truckee, California, about 1330, and was en route to Borrego Valley Airport in Borrego Springs, California.
Pilot Report
The pilot reported to the National Transportation Safety Board investigator that he was cruising at 15,000 feet when the engine became rough and most power was lost. He notified Oakland Air Route Traffic Control Center of the emergency, and controllers tracked the descending flight path until the aircraft disappeared from radar around 1418. The pilot stated that he broke out of the clouds about 2,000 feet above the ground and observed a road and a clearing. During landing rollout, the airplane collided with trees, which severed the wings and bent the stabilator.
After landing, the pilot used his cell phone to contact the Federal Aviation Administration (FAA) and provided precise GPS coordinates from the crash site in the Stanislaus National Forest. He was rescued before sunset at an elevation of 5,400 feet mean sea level.
Weather and Conditions
The closest airport to the accident site was South Lake Tahoe Airport (TVL), about 44 miles away, with an elevation of 6,264 feet msl. At 1353, TVL reported an overcast ceiling at 2,900 feet agl and light rain, with temperature 8°C and dewpoint 5°C. The pilot reported climbing to about 15,000 feet msl approximately 10 minutes before the accident, cruising in actual instrument meteorological conditions. The outside air temperature was about -10°C. No ice was observed on the windshield or wings. The carburetor heat was off. The pilot stated that although the engine slowly lost manifold pressure, it never quit running, and he did not initially think to turn on the carburetor heat. Eventually, the engine lost so much power that flight could not be sustained.
Published icing probability charts indicate that at -10°C with 100 percent humidity, icing is likely when operating at cruise engine power.
Pilot's Opinion
In the pilot’s completed aircraft accident report, he opined that the cause of the loss of engine power was due to carburetor ice. He stated that had he used carburetor heat, the accident likely would have been avoided.