1 fatality

1996-09-05: Cessna 340 (N128RP) — Michael A. O’Keefe — Wise River, United States of America

Wise River, United States of AmericaFlight

On September 5, 1996, a Cessna 340 (registration N128RP) operated by Michael A. O’Keefe was involved in an aviation accident near Wise River, United States of America in flight. One person was killed. Investigators recorded the probable cause as: The pilot's attempt to fly in adverse meteorological conditions which led a loss of aircraft control. Factors contributing to the accident include: the pilot's failure to obtain the most current information of the meteorological conditions prior to departure,… This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781206723Data APIEditorial standards

A pilot who received a weather briefing warning of turbulence and thundershowers departed without an update. About 35 minutes into the flight, he reported turbulence and then a dive. The aircraft impacted terrain in an inverted attitude and exploded. The probable cause was flight into adverse weather leading to loss of control.

Flight Briefing

The pilot received a full weather briefing from a Flight Service Station (FSS) on the morning of the accident. The briefer informed the pilot that moderate turbulence and icing were present along the intended route, and that isolated thundershowers were forecast. The briefer advised the pilot to call for an update just prior to departure.

Departure and Flight

The pilot departed approximately three hours after the briefing without contacting the FSS for an update. After a 15-minute delay, the pilot received an IFR clearance and proceeded on course.

Accident Sequence

About 35 minutes after departure, while cruising at 16,000 feet, the pilot reported, "in the clouds and the bumps are big time." Approximately three minutes later, the pilot radioed, "in a dive and I don't..." The airplane then impacted terrain in a nose-down, inverted attitude and exploded.

Meteorological Conditions

Analysis of recorded radar and meteorological data indicated that the airplane encountered a thunderstorm, strong updrafts, downdrafts, and turbulence.

Probable Cause and Contributing Factors

The probable cause was the pilot's attempt to fly in adverse meteorological conditions, which led to a loss of aircraft control. Contributing factors included the pilot's failure to obtain the most current meteorological information prior to departure, a thunderstorm, and turbulence.