On May 27, 2002, approximately 2230 Pacific daylight time, a Cessna 182P single-engine airplane, N52404, was destroyed when it impacted mountainous terrain while maneuvering near Pleasanton, California. The airplane was registered to and operated by the pilot. The non-instrument rated private pilot, sole occupant of the airplane, sustained fatal injuries. Night instrument meteorological conditions prevailed, and no flight plan was filed for the 14 CFR Part 91 personal cross-country flight. The flight originated at the Nevada Country Air Park Airport, Grass Valley, California, at 2125, and was destined for the San Carlos Airport, San Carlos, California.

It was reported to the National Transportation Safety Board investigator-in-charge (NTSB IIC) by a friend of the pilot, whom the pilot had flown from San Carlos to Grass Valley earlier in the evening, that prior to departing on the return trip to San Carlos the pilot added 15 gallons of fuel to both the left and right wing tanks of the airplane. The friend of the pilot also reported that during the flight to Grass Valley, the pilot could hear air traffic control when they transmitted to him, but observed that at times air traffic control could not hear the pilot when he attempted to reply. The pilot's friend also stated that prior to his departure from Grass Valley the pilot did not receive a weather briefing.

According to the pilot's brother, who was interviewed by the NTSB IIC, the pilot would frequently fly down the eastern side of the Diablo Mountain range until he was clear of the restricted airspace," then cut across the range and head west directly toward San Carlos." The pilot's brother further stated that this was a regular route the pilot flew and that he was very familiar with the area and the mountainous terrain. He also stated that when he flew with him, his brother "frequently had a hard time holding his altitude."

The pilot contacted Sacramento Terminal Radar Approach Control (TRACON) at 2128 and requested flight following to San Carlos at an altitude of 4,500 feet mean sea level. The controller queried the pilot as to his position, and the pilot replied, "Just left, uh, Nevada County." The controller then gave the pilot a transponder code. At 2204 the pilot was instructed to contact Travis Approach Control, which he did. At 2218 the controller instructed the pilot to remain on his current transponder code and to contact Bay Approach. At 2219 the pilot contacted Bay Approach, informing the controller that he was VFR (visual flight rules) to San Carlos, flying over Mount Diablo (elevation 3,849 feet mean sea level) at 4,500 feet mean sea level. The controller instructed the pilot to cross the east bay shoreline at or above 2,000 feet mean sea level and to remain clear of the Class B airspace. At 2228 the controller radioed that he had lost contact with the aircraft, radar services were terminated and that the pilot should change radio frequencies and transponder codes. There was no reply from the pilot. The controller then asked an airline crew flying through the area to try contacting N52404. All attempts to contact N52404 were unsuccessful.

Radar data showed the aircraft at an altitude of 4,400 feet mean sea level at 2219:33. The aircraft then climbed slightly, after which it began a descent. At 2223:38 the aircraft's altitude was reported at 2,300 feet mean sea level and radar contact was lost. At 2225:10 the aircraft reappeared on radar at 2,200 feet mean sea level. The aircraft continued descending and reached an altitude of 2,000 feet mean sea level at 2226:01. The aircraft's radar track followed a 195-degree heading and the aircraft maintained an altitude of 2,000 feet mean sea level.

At 2227:43, the last radar contact showed N52404 was level at 2,000 feet mean sea level on a heading of 174 degrees 1.1 nautical miles north of the accident site. At 2228, radar contact with N52404 was lost, and all subsequent attempts by the controller to contact the pilot were unsuccessful.

The aircraft wreckage was located at 1127 on May 28, at the 1,680-foot level of a 1,930-foot Diablo Mountain Range ridge line, 14.9 nautical miles from the Oakland VOR on the 094-degree radial.


At the time of the accident the pilot held a private pilot certificate with a rating for single-engine land aircraft. A relative reported that the pilot had accumulated approximately 500 hours of total flight time.

The pilot held an expired class III medical certificate dated April 25, 2000. A limitation indicated that the holder must have available glasses for near vision.


The Area Forecast, which covered California, was issued at 1945 on May 27, valid until 0800 on May 28. The forecast for the coastal stations north of Salinas, California, located 64 nautical miles south-southwest of the accident site indicated scattered to broken clouds at 1,500 feet above ground level, broken clouds from 8,000 feet to 10,000 feet above ground level, with isolated light rain showers. By 2200 conditions were forecast to become overcast clouds at 1,000 to 1,500 feet above ground level, layered clouds to 15,000 feet above ground level, with isolated light rain showers and occasional visibility between 3 and 5 statute miles with mist.

Airmet Sierra, for IFR (instrument flight rules) and mountain obscuration was issued at 1845 on May 27, valid until 0100 on May 28, covering the accident area. The Airmet specified mountains occasionally obscured by clouds, with conditions continuing beyond 0100 on May 28.

Terminal Aerodrome Forecasts (TAF) for Oakland (OAK, located 14.9 nautical miles west of the accident site) and San Jose (SJC, located 15 nautical miles south of the accident site) were issued at 1631 on May 27, and were valid from 1700 on May 27 to 1700 on May 28.

The OAK TAF indicated temporary conditions from 2100 May 27 to 0100 May 28 to be visibility 4 statute miles, light drizzle and mist, and overcast clouds at 900 feet above ground level.

The SJC TAF indicated from 2200 on May 27 visibility would be greater than 6 statute miles, scattered clouds at 3,500 feet above ground level, and broken clouds at 6,000 feet above ground level.

At 2153, the weather observation facility at OAK reported wind 270 degrees at 7 knots, visibility 10 statute miles, overcast clouds at 700 feet, temperature 14 degrees C, dew point 14 degrees C, and an altimeter setting of 30.03 inches of Mercury.

At 2253, the weather facility at OAK reported wind 280 degrees at 8 knots, visibility 10 statute miles, overcast clouds at 700 feet, temperature 14 degrees C, dew point 13 degrees C, and an altimeter setting of 30.05 inches of Mercury.

At 2154, the weather observation facility at Hayward Municipal Airport (HWD), Hayward, California, (located 10 nautical miles west-southwest of the accident site) reported wind 300 degrees at 7 knots, visibility 10 statute miles, overcast clouds at 900 feet, temperature 14 degrees C, dew point 12 degrees C, and an altimeter of 30.03 inches of Mercury.

At 2254, the HWD weather reporting facility indicated wind 300 degrees at 6 knots, visibility 10 statute miles, overcast clouds at 700 feet, temperature 14 degrees C, dew point 12 degrees C, and an altimeter of 30.03 inches of Mercury.

At 2153, the weather observation facility located at the Livermore Municipal Airport (LVK), Livermore, California, (located 6 nautical miles northwest of the accident site) reported wind 270 degrees at 5 knots, visibility 10 statute miles, sky clear, temperature 13 degrees C, dew point 12 degrees C, and an altimeter of 30.02 inches of Mercury.

At 2253, the weather facility at LVK reported wind 260 degrees at 7 knots, visibility 10 statute miles, broken clouds at 900 feet, broken clouds at 11,000 feet, temperature 13 degrees C, dew point 12 degrees C, and an altimeter of 30.02 inches of Mercury.


Examination of the accident site revealed that the wreckage distribution path of 100 feet was along an initial measured magnetic heading of 140 degrees, and that the subsequent and final distribution path was along a magnetic heading of 190 degrees. The main wreckage came to rest in a mountainous area of extensive tree canopy approximately 20 to 30 feet high on a variable slope of 60 degrees. The aircraft was located at an elevation of 1,680 feet above sea level at latitude North 37 degrees 38.12 minutes and longitude West 121 degrees 55.87 minutes. There were numerous breaks observed in the trees near the accident site. These breaks were in a line generally parallel to the ridge line.

Initial impact with trees was evidenced by a four-foot section of the outboard end of the right wing found wrapped around a tree approximately 20 feet above the ground. Located forty feet further along the distribution path and in a 15 to 20 foot high tree, was a five-foot section of the left wing. The tail section was found on the ground downhill, approximately 10 feet from the left wing piece. The remainder of the aircraft was found 60 feet from the left wing section along the aircraft's direction of flight.

With the exception of the portions of the aircraft located away from the main wreckage site, the aircraft was consumed by fire. The only identifiable parts of the fuselage at the main wreckage area, other than the engine and the firewall, were the landing gear box area and various pieces of sheet metal from the tail section. The two cabin doors, with the locking pins extended, were recovered from the site.

It was determined that all of the flight control surfaces remained attached to some section of the structure. Flight control cable separation was either the result of being cut by the recovery team or was broomstrawed in appearance. The rudder cables were broomstrawed just forward of the rudder horn and both elevator cables were broomstrawed in appearance. One left aileron cable had been pulled out of the aileron bellcrank. The left elevator had separated from the elevator horn, while the right elevator had remained attached. Flight control continuity was partially confirmed.

The left fuel bladder tank, located in the portion of the wing found in the tree, was breached. The post-impact fire consumed the remainder of the fuel system aft of the firewall, including the fuel selector. The fuel strainer filter was clear. The fuel strainer bowl exhibited some corrosion in the bottom of the bowl. No fuel was found in either strainer.


An autopsy on the pilot was conducted by the Alameda County Coroner's Bureau, Oakland, California, on May 29, 2002. According to the autopsy report, the pilot's cause of death was attributed to extensive blunt trauma.

The FAA Civil Aeromedical Institute (CAMI), Oklahoma City, Oklahoma, conducted toxicology testing on the pilot. According to the postmortem toxicology report, results were negative for carbon monoxide and cyanide. Ethanol was not detected in the heart or muscle tissue. No drugs were detected in the liver samples.


On May 31, the engine was examined by a representative of Teledyne Continental Motors under the supervision of the NTSB IIC at the facilities of Plain Parts, Pleasant Grove, California. Prior to the examination the following external impact damage was noted: there was cooling baffle deformation due to impact damage; the oil sump was crushed upwards; the vacuum pump had been broken off of the left accessory pad; the left magneto had been broken off of the crankcase and had impact damage to its capacitor; the rear of the engine had light discoloration from fire; both exhaust manifolds exhibited ductile deformation in an upward direction.

All top spark plugs were visually inspected and the electrodes exhibit normal operating signatures. All six pistons exhibited combustion deposits on their domes.

The engine crankshaft was rotated by hand. All six cylinders produced compression and normal valve actuation was observed. During the rotation of the crankshaft the right magneto produced spark. The left magneto shaft, rotated by hand, failed to produce spark. The associated capacitor of the magneto had been damaged due to impact forces.

The oil filter was removed, opened, and inspected visually. Oil was present in the filter and no solids were present.

Mechanical continuity of the engine was established by observing the rotating components at the accessory section of the engine.

During the removal of the propeller from the crankshaft it was observed that four of the six mounting studs had been stripped out of the propeller hub. The blade retaining rings of both blades had been dislodged from their respective grooves. Approximately 1 1/2 inches of the tip of blade #1 had been broken off. The remainder of the blade exhibited "S" bending. The tip of blade #2 had been bent forward.


The airplane was released to the owner's representative on June 24, 2002.

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