1 fatality

Descent into Terrain: VFR Flight Strikes Hill During Dusk Cross-Country (N257NW)

Novato-Gnoss Field, United States of AmericaFlight

On March 5, 1998, a Piper PA-31-350 Navajo Chieftain (registration N257NW) operated by Airpac Airlines was involved in an aviation accident near Novato-Gnoss Field, United States of America in flight. One person was killed. Investigators recorded the probable cause as: The pilot's failure to maintain adequate terrain clearance after initiating a descent over mountainous terrain at night and under marginal VFR conditions. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 2 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Source recordUpdated 2026-07-04Data APIEditorial standards

A VFR dusk cross-country flight collided with a hill at 1,500 feet after descending over mountainous terrain under marginal weather conditions. The pilot faced self-imposed schedule pressure to arrive for a final examination.

Accident Overview

A VFR cross-country flight conducted at dusk collided with the 1,500-foot level of a hill. Radar data indicated the aircraft was in a descent from 2,000 feet mean sea level (MSL) until radar contact was lost at approximately 1,500 feet MSL, with a final recorded ground speed of 194 knots.

Flight Details

The pilot had chosen a route approximately 5 miles west of the route routinely flown by company pilots. While crossing higher terrain, this route provided a more direct track to the destination. A company pilot flying a few minutes ahead of the accident flight reported that it was necessary to descend to between 1,200 and 1,500 feet MSL to maintain VFR conditions.

Weather Conditions

A low-pressure system approaching from the west had brought low stratus clouds, rain, and fog. At the time of the accident, a nearby weather reporting facility reported a broken ceiling at 1,300 feet, with visibility of 5 to 6 miles in light rain and mist.

Pilot's Schedule

On the evening of the accident, the pilot was scheduled to deliver a speech as her final examination for an evening college course. She had informed the instructor that she might be late, but was told the class could not be held past its scheduled dismissal time to accommodate her late arrival.

Probable cause

The pilot's failure to maintain adequate terrain clearance after initiating a descent over mountainous terrain at night and under marginal VFR conditions. The pilot's self-induced pressure to arrive at class with enough time remaining to take the final examination was a factor in the accident.

Frequently asked questions

What happened in the 5 Mar 1998 Piper PA-31-350 Navajo Chieftain accident near Novato-Gnoss Field, United States of America?

A VFR dusk cross-country flight collided with a hill at 1,500 feet after descending over mountainous terrain under marginal weather conditions. The pilot faced self-imposed schedule pressure to arrive for a final examination.

Were there any fatalities in the 5 Mar 1998 Piper PA-31-350 Navajo Chieftain accident?

The accident was fatal, resulting in 1 fatality.

What aircraft was involved and where did it happen?

The accident on 5 Mar 1998 involved a Piper PA-31-350 Navajo Chieftain, registration N257NW, operated by Airpac Airlines, at Novato-Gnoss Field, United States of America.

What was the probable cause of the accident?

The pilot's failure to maintain adequate terrain clearance after initiating a descent over mountainous terrain at night and under marginal VFR conditions. The pilot's self-induced pressure to arrive at class with enough time remaining to take the final examination was a factor in the accident.