Casualties unknown

Aircraft Crashes After Encountering Icing Conditions During Flight (N8974M)

Ripon, CA, US

On January 10, 1989, a Beech 35-B33 (registration N8974M) operated by Richard Enterprises, Inc. was involved in an aviation accident near Ripon, CA. Investigators recorded the probable cause as: CONTINUED FLIGHT BY THE PILOT INTO KNOWN ICING CONDITIONS AND STRUCTURAL (WING) ICING, WHICH SUBSEQUENTLY RESULTED IN AN UNCONTROLLED STALL. A CONTRIBUTING FACTOR WAS THE ICING CONDITION. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A pilot received a weather briefing with freezing level and moderate icing precaution; after an amended route, the aircraft encountered ice, stalled, and crashed. The aircraft was not equipped for known icing.

Accident Overview

During a flight, an aircraft crashed after encountering icing conditions. The pilot had received a weather briefing prior to departure.

Weather Briefing

Before takeoff, the pilot obtained a weather briefing for the proposed route. The briefing included information about the freezing level, forecast at 5,000 feet, and a precaution for moderate icing conditions. The briefing did not include SIGMET Lima 1, which warned of moderate to severe icing conditions, but that SIGMET was not valid for the pilot's originally proposed route.

Flight and Incident

The pilot received clearance for an amended route of flight, which passed through the edge of the area defined by SIGMET Lima 1. Shortly after leveling at 11,000 feet, the pilot reported that the aircraft was in icing conditions and would not maintain altitude. While the air traffic control center controller coordinated with the terminal radar approach control for a lower altitude, the pilot reported that the aircraft was stalling. Shortly thereafter, the aircraft crashed in a right-wing-down, nose-low attitude and burned.

Aircraft Information

The aircraft was not equipped for flight in known icing conditions.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X27598. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.