LAX98FA106

The airplane was on a VFR dusk cross-country flight when it collided with the 1,500-foot level of a hill. Radar data showed the aircraft in a descent from 2,000 feet until radar contact was lost about 1,500 feet msl, with a final ground speed of 194 knots. The route taken by the pilot was about 5 miles west of the route that the company pilots routinely flew, but while crossing higher terrain, it was a more direct route to the destination. A company pilot flying a few minutes ahead of the accident flight reported it was necessary to descend to between 1,200 and 1,500 feet msl in order to maintain VFR. A low-pressure system approaching the area from the west had resulted in low stratus, rain, and fog. At the time of the accident, a nearby weather reporting facility reported a 1,300-foot broken ceiling with 5- to 6-mile visibility in light rain and mist. On the evening of the accident, the pilot was scheduled to give a speech as her final examination in an evening college course. She had informed the instructor that she might be late, but had been told that he could not hold the class past its scheduled dismissal time to accommodate her late arrival.

History of flight

On March 5, 1998, about 1905 hours Pacific standard time, Airpac Flight 263, a Piper PA-31-350, N275NW, collided with trees and terrain near Novato, California. The aircraft was destroyed and the airline transport rated pilot, the sole occupant, received fatal injuries. The aircraft was being operated by Airpac Airlines, Inc., as a positioning flight under 14 CFR Part 91 when the accident occurred. The aircraft departed Santa Rosa, California, at 1848. Marginal visual meteorological conditions prevailed at the departure airport and no flight plan was filed.

The airplane was part of a flight of two company aircraft that departed the Sonoma County airport en route to the Oakland Metropolitan International airport. Airpac Flight 1961 was in the lead and Airpac Flight 263 was in trail, about 1 minute behind. The pilot of Flight 1961 stated that they were both navigating by a combination of dead reckoning and pilotage. They both had VOR navigation aids on their routes of flight that could be used to verify their positions and monitor progress.

During the flight, the pilot of Flight 1961 radioed the pilot of Flight 263 and asked about her progress. She reported that she was "still back here." Later, while he was about 20 miles north of the Oakland airport, he began to encounter instrument meteorological conditions. He called to advise the accident pilot, but this time he was not successful in establishing radio contact. Flight 1961 landed at the Oakland airport at 1920.

When Flight 263 did not arrive, the flight was reported overdue and a missing aircraft report was issued. At 0148 on March 6, a U.S. Coast Guard search and rescue helicopter, homing on an ELT signal, located the wreckage near the northern crest of a hill. The accident site was approximately 1,500-feet mean sea level (msl), about 40 miles north of San Francisco.

The pilot of Flight 1961 reported that the accident site was about 5 miles west of the route that Airpac pilots routinely flew between Santa Rosa and Oakland. While the westerly route is a more direct course to Oakland, it does, however, cross higher terrain. The pilot of Flight 1961 also reported that during the flight he found it necessary to descend between 1,200 and 1,500 feet msl in order to maintain VFR conditions.

Personnel information

The chief pilot reported that the pilot had flown between Santa Rosa and Oakland 2 to 3 times a week for the past 2 years. A review of her training records showed a Part 135 check dated September 19, 1997, and revealed that she had successfully passed a flight check in the aircraft and route flown as single pilot IFR. No training deficiencies or weaknesses were recorded in her file.

On the evening of the accident, she was scheduled to give a speech as her final examination in an evening college course. She had informed the instructor that she might be late, and had been told that he could not hold the class past its scheduled dismissal time to accommodate her late arrival.

Aircraft information

Both altimeters on the accident aircraft were set to 29.69 inHg. The current altimeter setting at 1850 at the departure airport was 29.78 inHg. Since each .01 equals 10 feet, an error of this magnitude and direction would cause the altimeter to indicate that the aircraft was 90 feet higher than it would be with the current setting.

The aircraft records reflected a current pitot-static system check.

The aircraft had last been refueled on the day of the accident. The fuel log shows that it was filled with 92.8 gallons of 100LL aviation fuel by truck No. 2 at the Hayward Jet Center, Hayward Air Terminal, Hayward, California. The operator estimated that 70 gallons were onboard at the time of the accident.

Meteorological information

The 2100 surface analysis chart showed a low pressure approaching the coast from the west. The 1904 Weather Surveillance Radar showed returns of 5 to 25 dBZ or video integrator processor (VIP) level 1 thunderstorm (weakest of 5 levels). At the time of the accident, Napa (APA) the nearest reporting station, reported a 1,300-foot broken ceiling with 5- to 6-mile visibility in light rain and mist.

Sun and moon illumination tables for the time and location of the accident reported nautical twilight with 58 percent moon illumination at an altitude of 69.3 degrees above the horizon.

Aids to navagation

The navigation radios, NAV 1 and 2, were set to 116.80 and 116.60. Oakland visual omni range tactical air navigation (VORTAC) is 116.80; however, 116.60 does not correlate to any very high frequency (VHF) navigational aid in the area. The omni bearing selector (OBS) settings were destroyed on both NAV radios.

The automatic direction finder (ADF) was set to 341 which is the frequency for the RORAY nondirectional beacon (NDB) locator middle marker (LMM). RORAY is associated with the OAK instrument lading system (ILS) 27R approach.

These NAVAIDS were reported to have been in service at the time of the accident. The aircraft maintenance records indicated that all navigation radios were serviceable.

Communications

The only radio communication reported from the accident pilot was in response to a request for an en route progress check from the pilot of Flight 1961.

The communication radios, COM 1 and 2, were set to the Sonoma County airport tower frequency and the company frequency, respectively.

The pilot had last used the Sonoma County tower frequency on her departure and the company frequency while en route. The aircraft maintenance records indicated that both communication radios were serviceable.

Wreckage and impact information

The accident site was located in an area of fully-grown oak trees. The geographic location was 38 degrees 9.19 minutes east latitude and 122 degrees 35.48 minutes west longitude, about the 1,500-foot level of Mount Burdell. The wreckage distribution was along a bearing of 144 degrees and extended about 300 feet from the initial point of impact to the main wreckage. A survey of the debris field revealed that all of the major flight control components were present at the accident site.

The trees on the northwest end of the accident site exhibited a series of broken limbs of up to 10 inches in diameter. The width of the initial swath through the trees was consistent with the tip-to-tip wingspan of the aircraft.

A section of the left wing was found to the left side of the swath near the initial impact point. The aileron was attached and the counterweight was in place. The wing had separated outboard of the fuel tank near the outboard flap hinge.

On the right side of the swath a section of the right wing was found, also near the initial impact point. The section was 3 feet in length measured inboard from the wingtip. A few feet beyond another section of the right wing with the right fuel tank and outboard engine nacelle were found.

The empennage was located about 50 feet beyond the initial impact point. Found nearby was one blade from the left propeller, two propeller hub springs, a "do not push" placard, and a section of burned wing tank with the fuel sender float still attached. Although the tank was sooted, the metal structure did not exhibit any evidence of heat distress.

The majority of the right horizontal stabilizer remained attached to empennage with the elevator and trim tab in place. The major portion vertical and rudder also remained attached and exhibited leading edge crushing. The upper section of the vertical and rudder had separated. A portion of the left horizontal and elevator remained attached to the empennage. The left horizontal had separated about 2 feet outboard of the tip. At the point of separation the spar was bent aft.

The next 5 feet of the left wing contained the left main landing gear assembly in the "up" position. Wing walk material partially covered the upper skin.

The cabin a