Casualties unknown

2004-05-23: Piper PA-31-350 (N4105D) — Goodnews, AK

Goodnews, AK, US

On May 23, 2004, a Piper PA-31-350 (registration N4105D) was involved in an aviation accident near Goodnews, AK. Investigators recorded the probable cause as: The pilot's inadequate weather evaluation which resulted in an in-flight encounter with severe turbulence, and his exceedence of the design stress limits resulting in overstress of the wings. 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 1781061362Data APIEditorial standards

A twin-engine airplane encountered severe turbulence after departing a remote Bering Sea airport, resulting in wrinkling of upper wing surfaces and elevator.

Flight Details

The airline transport certificated pilot departed a remote airport located on the coast of the Bering Sea. The airport is situated near an area of low hills northwest of the field. The pilot reported that the wind conditions at departure were 070 degrees magnetic at 25 knots, with gusts to 30 knots.

Turbulence Encounter

After departure, the pilot initially climbed the airplane to about 1,200 feet. As the aircraft approached the area of low hills, the pilot descended to approximately 700 feet. At an indicated airspeed of about 185 knots, the airplane encountered severe turbulence lasting about 30 seconds. The pilot stated that during the turbulence, his radio headset was dislodged.

Post-Flight Inspection

Upon arrival at the destination, the pilot informed the director of maintenance that the airplane had encountered turbulence and appeared to have sustained damage to the wings. The director of maintenance subsequently inspected the aircraft and reported structural damage. Both upper wing surfaces exhibited wrinkling and rippling extending about 8 feet outboard from each engine nacelle. Additionally, the elevator displayed wrinkling that extended about 6 inches inboard from each of the outboard hinge attach points.

Weather Conditions

The closest official weather observation station is located about 32 nautical miles south of the accident site. An automated weather observation system (AWOS) at that station reported: wind 110 degrees (true) at 17 knots with gusts to 27 knots; visibility 7 statute miles; clouds and sky condition, 1,200 feet overcast.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20040604X00738. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.