Casualties unknown

In-Flight Shudder and Structural Damage During Descent (N8640A)

Jacksonville, IL, US

On June 4, 1995, a Beech A35 (registration N8640A) was involved in an aviation accident near Jacksonville, IL. Investigators recorded the probable cause as: improper maintenance and inspection of the airplane's ruddervators. 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 experienced a violent shudder during descent; inspection revealed structural damage and unbalanced rudderovators with improper hardware.

Incident Overview

A pilot reported that while cruising at an en route altitude of 4,500 ft MSL, he encountered no turbulence. He initiated a descent by reducing power to 20 inches of manifold pressure and applying light forward pressure on the yoke. During the descent, the pilot felt a violent shudder and immediately released the pressure on the yoke, which caused the shudder to cease.

Post-Flight Inspection

Following the flight, inspection of the airplane revealed buckled and wrinkled skin, popped rivets, and bulkhead cracks. Examination of the rudderovators disclosed improper hardware installation, a loose bearing, and improperly installed elevator trim tabs.

Rudderovator Balance Testing

The rudderovators were tested for balance. The right rudderovator had a balance of 19.26 inch-pounds, which fell within the balance limits of 16.8 to 19.8 inch-pounds. The left rudderovator had a balance of 20.05 inch-pounds, which was outside the specified balance limits.

The source did not provide further details regarding the aircraft type, registration, operator, date, location, occupants, or injuries.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001207X03668. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.