N900RA

HISTORY OF FLIGHT

On November 21, 2001, at 1126 Pacific standard time (PST), an Aero Commander 500S, N900RA, collided with terrain near Eagleville, California. Commander Northwest Limited was operating the airplane under the provisions of 14 CFR Part 91. The airline transport pilot licensed pilot, a commercial rated pilot passenger, and three passengers sustained fatal injuries; the airplane was destroyed. The personal cross-country flight departed Reno, Nevada, at 1037, en route to Wenatchee, Washington. Visual meteorological conditions prevailed at the nearest reporting station, which was 24 miles away. An instrument flight rules (IFR) flight plan had been filed. The approximate global positioning system (GPS) coordinates of the primary wreckage were 41 degrees 17.69 minutes north latitude and 120 degrees 11.936 minutes west longitude.

According to Federal Aviation Administration (FAA) records, the pilot called the Reno Automated Flight Service Station at 0941. The records show that the pilot filed an IFR flight plan, then asked for the winds aloft forecast. The specialist provided the winds aloft information. The pilot did not request any additional weather briefing information for the flight. No other record was found that the pilot obtained additional weather forecast information from any official source associated with the FAA or the National Weather Service. At the time of the pilot's call to the Reno AFSS, several AIRMET weather advisories had been issued hours prior detailing warnings for turbulence along the route of flight. The advisories warned of occasional moderate turbulence below 18,000 feet in moderately strong westerly winds especially in the vicinity of mountainous terrain. Clear Air Turbulence (CAT) between 18,000 and 40,000 feet was forecast over the area of the accident site due to jet stream wind shear and mountain wave activity. Complete details of the weather forecasts and conditions can be found in the Meteorological Information Section of this report.

A transcript of recorded radio transmission indicated that the pilot informed clearance delivery that he would depart under visual flight rules (VFR) and pickup his IFR clearance en route. At 1044, the pilot requested his IFR clearance from Reno Departure Control. Departure control cleared him to his destination via radar vectors Lakeview (LKV) VORTAC (very high frequency omni-directional radio range, tactical air navigation) as filed. They then cleared him via the V165 airway as filed, and the pilot acknowledged the clearance.

At 1051, the pilot checked in with Oakland Air Route Traffic Control Center (ARTCC) climbing through 12,000 feet to 14,000 feet. The controller instructed the pilot to fly a heading of 350 degrees to intercept V165.

At 1054, the pilot asked if he could maintain 12,500 feet. The controller advised him that the minimum IFR altitude on V165 was 14,000 feet, and the pilot cancelled his IFR flight. The controller said that he could provide flight following, but would lose radar contact in 20 miles. At 1059, the controller advised the pilot that he had lost radar contact, and instructed the pilot to squawk VFR and approved a frequency change; the pilot acknowledged the transmission.

Recorded radar data depicted a target operating along V165 at a mode C reported altitude of 10,500 feet. Between 1112 and 1126, the data indicated a series of up and down oscillations of 100 to 200 feet, which increased in frequency as the target approached the Warner Mountain Range. At 1124:58, the target made a slight change in course to the northwest and began descending.

The last target occurred at 1126:22, at 41 degrees 17 minutes 09 seconds north latitude and 120 degrees 11 minutes 41 seconds west longitude. This was about 1/2 mile east of Eagle Peak (elevation 9,920 feet). Rescuers discovered the wreckage near the crest of Eagle Peak on November 23. A team recovered the wreckage on July 23, 2002.

PERSONNEL INFORMATION

A review of FAA airman records revealed that the pilot held an airline transport pilot certificate with an airplane multiengine land rating. He held a commercial pilot certificate with ratings for single engine land, single engine sea, and glider aero tow. He held a certified flight instructor certificate with ratings for airplane single engine and multiengine land, instrument airplane, and glider. The operator estimated that the pilot's total flight time was 20,000 hours.

The pilot held a ground instructor certificate with ratings for advanced and instrument. He held an airframe and powerplant mechanic certificate.

The pilot held a second-class medical certificate issued on February 23, 2001. It had the limitations that the pilot must wear corrective lenses and possess glasses for near and interim vision.

AIRCRAFT INFORMATION

The airplane was an Aero Commander 500S, serial number 3070. The operator reported a total airframe time of 8,101 hours. The last annual inspection occurred on September 30, 2001.

The airplane had a Textron Lycoming IO-540-E1B5 engine, serial number L-8632-48, installed on the left side. Time since overhaul on the engine at the annual inspection was 1,197 hours.

The airplane had a Textron Lycoming IO-540-E1B5 engine, serial number L-6421-48, installed on the right side. Time since overhaul on the engine at the annual inspection was 1,197 hours.

METEOROLOGICAL INFORMATION

A National Transporation Safety Board staff meteorologist prepared a factual report, and a summary of the report follows. All directions are referenced to true north and distances are in nautical miles. Heights are above mean sea level (msl) unless otherwise noted. Visibility is in statute miles and fractions of statute miles. The IIC converted all time to PST.

The report included a topographical map, which showed the accident site on the eastern slope of the Warner Mountain Range.

Surface Observations

Alturas (KAAT), California, which was the nearest reporting station, was 24 miles west-northwest of the accident site at an elevation of 4,374 feet. It had an Automated Surface Observation System (ASOS). An aviation routine weather report (METAR) for Alturus was issued at 1055. It stated: auto; skies 3,400 feet overcast; visibility 10 miles; winds from 190 degrees at 12 knots; temperature 8 degrees Celsius (C); dew point 4 degrees C; altimeter 29.90 inches of mercury. The remarks section noted that the thunderstorm sensor was inoperative.

A METAR for Alturus at 1155 stated: auto; skies 3,400 feet overcast; visibility 10 miles in light rain; winds from 220 degrees at 6 knots; temperature 7 degrees Celsius (C); dew point 5 degrees C; altimeter 29.88 inches of mercury. The remarks section noted less than 0.01 inch of precipitation since the last observation, and that the thunderstorm sensor was inoperative.

Surface Analysis Chart

The National Weather Service (NWS) Surface Analysis Chart issued for 1000 on November 21, 2001, depicted a low pressure system over Idaho with a dissipating cold front to the south of the accident site. This system turned into a warm front and connected with an occluded frontal system with a low pressure system with a central pressure of 988 millibars (mb) off the Pacific coast. Across central and northern California, two high pressure systems with central pressures of 1019 mb and 1020 mb were on either side of the dissipating cold front, with one high pressure system located immediately to the south-southwest of the accident site. The isobars depicted an increasing gradient off the Pacific Northwest coast, but no significant pressure gradient over northern California at the surface.

Weather Depiction Chart

The NWS Weather Depiction Chart issued for 1100 depicted the dissipating cold front to the south of the accident site. It depicted a large area, which included the accident site, of marginal visual flight rule (MVFR) conditions over central and northern California, and southern Oregon. Station models in northern California closest to the accident site depicted the MVFR conditions with continuous light to moderate rain with overcast ceilings from 1,600 to 3,000 feet. Two isolated areas of IFR conditions were also depicted across western and central California, to the west and south of the accident site.

Radar Summary Chart

The NWS Radar Summary Chart for 1115 depicted a large area of echoes over central and northern California, western Nevada, Oregon, and western Washington. It depicted echo intensity in the vicinity of the accident site as very light to light rain, with echo tops to the west ranging from 22,000 to 24,000 feet. One of the closest radar sites used in northern California, however, was not available. The closest cell motion was over Oregon and indicated movement to the east-southeast at 51 knots.

Constant Pressure Charts

The NWS constant pressure charts for 700 mb depicted a low pressure system off the Washington and Oregon coast with an associated trough of low pressure extending eastward and southward from the low. A high pressure system was also depicted further to the south of the low in the Pacific Ocean approximately 28 degrees north latitude and 132 degrees west longitude. Between these two systems, the compressed contour lines over northern California and Oregon indicated a steep pressure gradient, with the strongest gradients off the Pacific Northwest coast. The orientation of the contour lines indicated westerly winds over Oregon, northern California, and Nevada. The zero degree isotherm was out of phase with the contour lines and was to the west of the accident site. The 700 mb best approximated the conditions of the last known altitude of the accident airplane at 10,500 feet, and indicated a westerly wind with temperatures below freezing.

The station model for Reno on the 700 mb chart indicated a height of 3,032 meters (9,948 feet), with a west-southwest wind at 40 knots, a temperature of -1 de...