NTSB Identification: SEA02LA116.
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Accident occurred Friday, June 21, 2002 in Yakima, WA
Probable Cause Approval Date: 05/30/2003
Aircraft: Beech G35, registration: N4647D
Injuries: 2 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot reported that he experienced light to moderate turbulence approximately 10 minutes prior to the accident while cruising at an airspeed of about 150 mph. The pilot initiated a 1,000 foot per minute descent about 15 nautical miles northwest of the airport, and stated that his indicated airspeed was between 170 and 180 mph. During the descent, the pilot stated that the aircraft began to shake violently. The pilot applied equal pressure to the rudder pedals, pulled out the throttle, pitched up the nose to slow down, and the shaking stopped. The pilot continued the descent for landing without further incident. During the inspection of the airframe, wrinkles, creases and compression signatures were found in the skin to both the left and right sides of the empennage from fuselage stations (FS) 233.5 to FS 272 were noted. The airframe skin pulled away from five rivets located on the bottom of the empennage, along the left side, and forward of FS 256.9. The skin from left to right side pulled away from all of the empennage bottom rivets at FS 256.9. The skin pulled away from six of the rivets along the right side, and forward of FS 256.9. The two longitudinal running rivet rows on the bottom had the skin pulled away from seven rivets on the left side and six rivets on the right side. All applicable AD's had been complied with at the time. No AD speed restrictions were in effect for this model aircraft. Normal operating range for this model aircraft is between 66 - 175 mph.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

Empennage flutter which resulted in structural damage during descent for landing. Turbulence was a factor.

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