N327PC

HISTORY OF FLIGHT

On April 25, 2003, about 1712 Pacific daylight time, a Cessna TR182, N327PC, collided with mountainous terrain while cruising in instrument meteorological conditions (IMC), on an instrument flight rules (IFR) flight plan. The airplane descended from 14,000 feet in mountain wave and icing conditions until it impacted upsloping 5,770-foot mean sea level (msl) terrain. The airplane was destroyed, and the instrument rated private pilot and passenger were fatally injured. The pilot co-owned and operated the airplane. The accident occurred about 1.5 miles south of Eagleville, California. The business flight was performed under the provisions of 14 CFR Part 91, and it originated from Scottsdale, Arizona, about 1214 mountain standard time (mst). The pilot's flight planned destination was the Lake County Airport, Lakeview, Oregon. The accident occurred about 53 nautical miles (nm) south-southeast of Lakeview after the pilot had been flying almost 5 hours.

While en route, the pilot had communicated with a series of Federal Aviation Administration (FAA) facilities. According to the FAA, at no time did he report experiencing any problems with his airplane. At 1241, the pilot received an IFR clearance to climb to 14,000 feet. The pilot acknowledged the clearance and climbed as directed, as evidenced by data transmitted from the airplane's Mode C (altitude reporting) transponder.

At 1532, the pilot advised the controller that he was unable to hold altitude, and he had descended to 13,000 feet. The controller informed the pilot that the minimum vectoring altitude was 13,300 feet. The pilot advised the controller that he would climb back to 14,000 as soon as possible. At 1539, the pilot reported he was back at 14,000 feet and asked if there were any reports of smoother air at either 16,000 or 18,000 feet. The controller cleared the pilot to maintain 16,000 feet.

The pilot reported level at 16,000 feet at 1541. He informed the controller that he had experienced light to moderate turbulence at 14,000 feet. Then, at 1603, the pilot advised the controller that he had descended below 15,000 feet but was climbing back to 16,000 feet. The controller instructed the pilot to maintain a block altitude of 15,000 to 16,000 feet. The pilot did not indicate that he was experiencing any problems. At 1651, the pilot requested a lower altitude. The controller instructed the pilot to maintain 14,000 feet.

At 1706, the pilot was still cruising at 14,000 feet, and he asked the controller whether he had "received any pilot reports for icing." The pilot also stated "I'm about to go in the soup here in a minute."

The controller responded "no reports in your area there's been reports north of Klamath Falls, and the Lake County altimeter two niner seven six." The pilot acknowledged the controller's information at 1706:51. There were no further transmissions recorded from the accident airplane pilot.

FAA recorded radar data indicates that about 1711:16, the airplane was cruising in a northerly direction near the centerline of Victor Airway 165, which has a minimum en route altitude of 14,000 feet msl, and a minimum obstruction clearance altitude of 11,900 feet msl. Without receiving an air traffic control clearance, the airplane descended and turned right.

By 1711:28, the airplane had descended to 13,800 feet. Recorded radar data indicates that 12 seconds later, at 1711:40, the airplane had descended to 13,200 feet. At this time, the airplane's position was 41 degrees 15.767 minutes north latitude by 120 degrees, 08.533 minutes west longitude. This was the airplane's last recorded position on radar. The airplane impacted terrain about 2 miles north of this location.

A witness, who resides near Eagleville, reported hearing the sound of a low flying airplane's engine about 1715. The noise abruptly terminated with the sound of a "boom." The witness additionally reported that she did not observe the airplane because the sleet was blowing nearly horizontally, and her visibility was reduced between 1.0 and 1.5 miles. About noon the following day, wreckage from the airplane was located approximately 1.0 mile west of where the witness had been located.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with airplane single engine land and instrument airplane ratings. The pilot received the instrument rating on September 20, 2001.

The pilot's flight record logbook indicated that as of April 22, 2003, his total flight time was approximately 600.1 hours. His total actual and simulated instrument flight time was about 39.8 and 37.8 hours, respectively.

The pilot's last flight review and instrument proficiency check were successfully completed on February 13, 2003. Both examinations were performed in the accident airplane. During the examinations the pilot logged 1.5 hours of simulated instrument flight time.

Since May 2001, all of the pilot's logged single engine flight time was acquired flying the accident airplane, and the pilot had logged about 167 hours in the airplane. The pilot's logbook indicated that between April 17 and 22, 2003, he had logged 6.3 hours of actual instrument flight time.

In pertinent part, the following notations were written in the pilot's flight record logbook:

Date Notation

(1) 9/25/2001 "First REAL IFR"

(2) 1/16/2001 "ICE in Valley..."

(3) 5/16/2002 "IFR into Decreasing weather"

(4) 4/21/2003 "IFR to Min GPS 34 Approach LOST GPS. MOD ICE"

(5) 4/22/2003 "IFR @ 15,000 NO ICE"

(6) 4/22/2003 "15,000 Auto Pilot Failed and came Back."

AIRCRAFT INFORMATION

Operating Limitations and equipment.

The airplane's engine was both turbocharged and carbureted. The maximum certificated operating altitude was 20,000 feet msl. The airplane was equipped with supplemental passenger and crew oxygen.

The airplane was not equipped with weather radar, anti-icing, or deicing equipment. Flight into known icing conditions was prohibited.

Maintenance Records.

The FAA reported that its review of the airplane's maintenance records revealed the airplane received its last annual inspection on January 17, 2003, at a total (airframe log) time of about 2,745 hours. The last maintenance performed on the airplane involved an oil change and landing light replacement, and it was accomplished on April 19, 2003, at a total time of 2,797 hours. Since accomplishment of the last annual inspection, no evidence of maintenance squawks or repairs was found relating to the flight control, pitot-static, or navigation systems.

METEOROLOGICAL INFORMATION

Weather Conditions, Surface and Constant Pressure Charts.

A staff meteorologist with the National Transportation Safety Board's Operational Factors Division performed a study of the forecast and observed meteorological conditions pertinent to the accident flight. The study findings are included in the docket for this accident report. In summary, the study indicated the following:

According to the Surface Analysis Chart produced by the National Weather Service (NWS), a low pressure center existed off the Oregon coast with an occluded front extending from the low pressure center southeastward into southwestern Oregon and into northern California. Another low pressure system was located in central Nevada, and it was associated with a stationary front that was oriented in a northeast to southwest direction. The accident site occurred ahead of the occluded front and northwest of the stationary front.

NWS radar summary charts depicted numerous echoes over Oregon and northern California, with scattered echoes over Nevada. Echoes in the range of very light to light intensity were identified west of the accident site and moving to the northeast at 20 to 23 knots. No echoes were identified over the accident site.

Constant pressure chart data depicted an upper level low pressure system off the Oregon coast with a trough of low pressure extending south off the northern California coast. The station models surrounding the accident site all indicated temperature-dew point spreads consistent with near saturated conditions at the 700 millibars level (about 10,000 feet). The station model for Reno, Nevada, indicated at the 500 millibars level (about 18,000 feet) a wind from the west-southwest at 90 knots, and a temperature of -18 degrees Celsius. The wind flow was depicted from the west-southwest about 50 knots over the accident site, with an approximately 40-knot horizontal wind shear per 100 miles. The advisory circular "Aviation Weather" (AC 00-45) identifies wind shears of 18 knots per 150 miles associated with moderate turbulence, and shears of 40 knots per 150 miles (similar to those found over the accident site) with severe turbulence.

Topography.

The accident site was located on the eastern upward slope of the Warner Mountain Range, which is oriented in a north-to-south direction. North-to-south oriented mountain ranges, especially those with steep slopes on the lee side like those found in the vicinity of the accident site, have been involved in previous accidents that were found related to mountain wave activity and downslope winds.

Upper Air Data.

The NWS's Reno Forecast Office assessed the atmospheric stability from soundings. In brief, at the accident airplane's reported cruising altitude of 14,000 feet, the wind was identified from 230 degrees at 57 knots. The temperature was identified as -17 degrees Celsius. The sounding had a lifted condensation level (LCL) or estimated base layer of the clouds and level of free convection (LFC) at 9,229 feet. The sounding had a relative humidity greater than 75 percent from this level to about 13,000 feet, which supports airframe icing from the freezing level (7,255 feet) to this level. This layer was identified as stable and supported rime type airframe icing. The sounding also in...