Casualties unknown

Vibration Prompts Immediate Landing After Elevator Servo Tab Separation (N472PM)

Ketchikan, AK, US

On July 14, 1995, a DE Havilland DHC-3 (registration N472PM) was involved in an aviation accident near Ketchikan, AK. Investigators recorded the probable cause as: THE CRACKS IN THE TRAILING EDGE OF THE ELEVATOR SERVO TAB, WHICH RESULTED IN ITS SUBSEQUENT FAILURE AND PARTIAL SEPARATION. 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

During climbout, a pilot encountered vibration while adjusting trim for level flight, prompting an immediate landing. Inspection revealed a separated portion of the elevator servo tab and cracks in the remaining section.

Incident Overview

The pilot of the aircraft had just completed a climbout and was adjusting the trim for level flight when the airplane began vibrating. Reacting promptly, the pilot landed the aircraft immediately.

Post-Inspection Findings

A subsequent examination revealed that a portion of the elevator servo tab had separated from the aircraft. Further inspection of the remaining section of the servo tab showed that there were cracks present in its trailing edge.

Maintenance Observations

The director of maintenance reported that when the aircraft was parked, the tail was approximately 10 to 11 feet above the ground. This height, according to the director, would have made it difficult to inspect the tail area during a preflight check.

No other anomalies were reported during the examination.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001207X03836. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.