LAX05FA132

About 1 hour into the flight the airplane entered an uncontrolled descent and broke up in flight. The pilot, who did not possess an instrument flight rating, had received a standard weather briefing from a flight service station prior to departure. The briefer advised the pilot that a cold front existed perpendicular to the airplane's route of flight that produced multiple cloud layers to 30,000 feet, overcast conditions, rain, nimbostratus clouds, moderate turbulence, and moderate icing conditions along the frontal boundary. The airplane's radar track depicted the airplane cruising at 13,400 feet mean sea level (msl) on a steady southeasterly course. Analysis of the weather conditions showed that the flight encountered instrument meteorological conditions and ice as it approached the frontal boundary. Weather radar imagery depicted an encounter with the western edge of two bands of radar echoes, which could be associated with strong up- or downdrafts that could result in an upset to the airplane. If the autopilot system were engaged it would have masked the trim and heading changes that usually accompanies ice accumulation, and upon disengagement of the autopilot system, the airplane would be in an unbalanced flight condition. Recorded radar data showed that the last radar return in line with the southeasterly course occurred at 0901:54, with a mode C reported altitude of 13,400 feet msl. The next three radar returns occurred between 0901:59 and 0902:14, and depicted the track in a right-hand turn and a descent to 12,400 feet msl, which was the last identified altitude. This change in altitude corresponded to a 3,000- to 4,000-feet-per-minute rate of descent. Numerous primary targets in patterns indicative of an in-flight breakup were identified in the same vicinity from 0902:14 to 0903:08. Examination of the wreckage revealed permanent set deformation of the structural elements of the wings and horizontal stabilizers that was indicative of positive aerodynamic loading beyond the structures yield point. All fractures were overload in character. The wreckage was widely scattered over a distance in excess of 1,600 yards.

1.1 History of flight

On April 7, 2005, at 0903 Pacific daylight time, a Cessna T210L, N8126L, broke up in flight and impacted terrain near Tranquility, California. The airplane was operated by the private pilot under the provisions of 14 CFR Part 91. The pilot and two passengers were fatally injured; the airplane was destroyed. Instrument meteorological conditions prevailed, and a flight plan had not been filed. The flight originated at Healdsburg Municipal Airport, Healdsburg, California, about 0800, with an intended destination of Scottsdale, Arizona.

The pilot and two passengers were traveling to Scottsdale, on a weekend golf trip, where they were to meet up with other members of their party. The pilot received a weather briefing from Oakland Automated Flight Service at 0554. The airplane departed Healdsburg sometime before 0800. The initial radar track was picked up over the San Pablo Bay in the San Francisco area at 0801:30, at 11,600 feet mean sea level (msl). The track continued on a southeasterly course until over Crows Landing, California, where it made a deviation to the south. After the track passed over the San Luis Reservoir it turned left to regain its original southeasterly course. The track ended at 0902:21 in the vicinity of Tranquility. Radar data revealed that the altitude encoding transponder (mode C) reported a change of altitude of 1,000 feet from 12,400 to 13,400 feet msl between the times of 0848 and 0853. The final track segment depicted the airplane level at 13,400 feet msl and traveling in a southeasterly direction when it turned abruptly to the right. The last radar return was recorded at 0902:14, at a position of 36 degrees 37.22 minutes north latitude by 120 degrees 24.12 minutes west longitude, at an altitude of 12,400 feet msl. No record of radio communication between the pilot and air traffic control (ATC) was located by the Federal Aviation Administration (FAA) for the time period surrounding the accident.

1.5 Personnel information

A review of FAA airman records from Oklahoma City, Oklahoma, revealed that the pilot held a private pilot certificate with a single engine land rating that was issued on June 3, 1992. The pilot did not hold an instrument rating. The pilot held a third-class medical certificate that was issued on January 1, 2005. No restrictions or limitations were listed on the medical.

The pilot's flight logbook was recovered from the airplane wreckage. Examination of the logbook revealed that the pilot had accumulated 576.2 hours of single engine flight time. His last recorded flight occurred on March 16, 2005, and consisted of an insurance check ride in a PA-32. The entry made prior to that was dated November 18, 2004, where the pilot recorded a 2.8-hour flight in the accident airplane. The endorsement page of the logbook contained one entry, a flight review signed by a certified flight instructor (CFI) on September 14, 2003.

1.6 Aircraft information

The airplane was a Cessna T210L, serial number 21060613, single engine, high wing, 6-place airplane. A review of the airplane's logbooks revealed a total airframe time of 3,415.2 hours at the last inspection. An inspection in accordance with the scope and detail of Appendix D of 14 CFR Part 43 (annual/100-hour inspection) was completed on September 24, 2004.

The airplane was powered by a Teledyne Continental TSIO-520-H4 factory remanufactured engine, serial number 217474-R. An examination of the engine logbook revealed that the engine had been installed into the airplane on August 8, 2003. The engine was inspected in accordance with an annual inspection on September 24, 2004, at a total time since maintenance overhaul (TSMO) of 33.6 hours.

The airplane had a factory installed Nav-O-Matic 400A autopilot, which provides altitude hold, heading hold, and VOR tracking. There were no autopilot discrepancies noted in the maintenance records.

The airframe and power plant (A&P) mechanic who performed the annual inspection stated that the airplane's crew oxygen system had not been inspected during the annual and was not in service.

A fuel receipt with the pilot's name on it was obtained from Healdsburg Aviation, Inc. The date and time on the receipt was April 7, 2007, at 06:56:51. The receipt recorded the total amount of fuel purchased was 58.094 gallons.

The airplane's pilot operating handbook states in the limitation section that flight into known icing conditions is prohibited.

1.7 Meteorological information

1.7.1 Surface Analysis Chart

The southwest section of the National Weather Service (NWS) Surface Analysis Chart for 0800 depicted a high-pressure system with a central pressure of 1027-millibar (mb) over Colorado. To the north, a low-pressure system with a central pressure of 1001-millibars (mb) was located over the Oregon and Nevada border with a cold front extending from the low south to southwestward into Nevada, central and southern California, and into the Pacific Ocean. The accident site was located in the cold air mass behind the position of the surface cold front.

The station models behind the cold front, over central and southern California, indicated broken to overcast sky conditions.

1.7.2 Surface Observations

The area surrounding the accident site was documented utilizing official NWS meteorological aerodrome reports (METARs) and specials (SPECI). The reports are in standard format, provided in plain language. The variation for wind at Fresno is 15 degrees east, and cloud heights are reported above ground level (agl).

Madera Municipal Airport (KMAE), Madera, California

Madera weather observation at 0853, automated, wind from 300 degrees at 8 knots; visibility 10 miles in light rain; ceiling broken at 3,500 feet, broken at 4,100 feet, overcast at 9,500 feet; temperature 12 degrees Celsius (C); dew point 9 degrees C; altimeter 30.02 inHg. Remarks: automated observation system, rain began at 0849; sea level pressure 1016.3-mb; hourly precipitation less than 0.01-inch (trace); temperature 11.7 degrees C; dew point 8.9 degrees C; thunderstorm sensor not operating.

Lemoore Naval Air Station/Reeves Field (KNLC), Lemoore, California

Lemoore Naval Air Station (KNLC) special weather observation at 0845, wind from 330 degrees at 10 knots; visibility 7 miles in light rain; a few clouds at 6,000 feet; ceiling broken at 14,000 feet, overcast at 20,000 feet; temperature 13 degrees C; dew point 7 degrees C; altimeter 30.00 inHg. Remarks: sea level pressure 1016.0-mb.

Lemoore Naval Air Station (KNLC) weather observation at 0855, wind from 330 degrees at 13 knots; visibility 7 miles in light rain; ceiling broken at 5,000 feet, broken at 14,000 feet, overcast at 20,000 feet; temperature 12 degrees C; dew point 9 degrees C; altimeter 30.01 inHg. Remarks: sea level pressure 1016.2-mb; hourly precipitation less than 0.01-inch (trace); temperature 12.2 degrees C; dew point 8.9 degrees C.

Fresno Yosemite International Airport (KFAT), Fresno, California

Fresno weather observation at 0856, wind from 300 degrees true at 10 knots; wind 280 variable 350 degrees; visibility unrestricted at 10 statute miles; scattered clouds at 8,000 feet; ceiling broken at 14,000 feet, overcast at 18,000 feet; temperature 13 degrees C; dew point temperature 7 degrees C; altimeter 30.01 inHg. Remarks: automated observation system, sea level pressure 1015.9-mb; temperature 13.3 degrees C; dew point 7.2 degrees C.

Merced Municipal Airport/Macready Field (KMCE), Merced, California

Merced Municipal Airport special weather observation at 0830, automated, wind from 330 degrees at 8 knots; visibility 3 miles in light rain and mist; a few clouds at 600 feet; ceiling broken at 2,200 feet, overcast at 3,400 feet; temperature 11 degrees C; dew point 9 degrees C; altimeter 30.02 inHg. Remarks: automated observation system, hourly precipitation 0.06-inch; thunderstorm sensor