IMC, lack of weather briefing prove fatal

This May 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.

Aircraft: Piper Cherokee Six. Injuries: 2 Fatal. Location: Cruso, N.C. Aircraft damage: Destroyed.

What reportedly happened: The non-instrument-rated private pilot departed for the cross-country flight in the early morning hours before daylight. The pilot had logged approximately 616 hours, which included 66 hours at night. There was no record of the pilot receiving a preflight weather briefing from either a Flight Service Station or a computer service before the accident flight. According to radar data, about 30 minutes into the flight, the airplane changed its heading twice with accompanying rapid changes in altitude. Shortly thereafter the airplane began a rapid descent and hit steep mountainous terrain.

According to radar analysis of the flight conducted by a Safety Board meteorology specialist, the first-half of the flight took place under visual meteorological conditions but during the remainder of the flight the airplane most likely entered both a wave cloud and a layer of broken-overcast clouds that bordered the flight path. Strong northwesterly winds normal to mountain ridges existed in the area at the time of the accident. These winds would have caused the airplane to experience moderate to severe turbulence, and strong downdrafts due to either mechanical turbulence or mountain waves in the location where the final rapid descent occurred. There was no evidence of pre-mishap mechanical malfunction or failure observed during the examination of the engine or airframe.

Probable cause: The pilot’s inadequate preflight planning and inadvertent flight into instrument meteorological conditions with moderate to severe turbulence prevailing. Contributing to the accident were the instrument meteorological conditions and turbulence.

For more information: NTSB.gov