Incident Overview
Date: Thursday 13 July 1995
Aircraft Type: de Havilland Canada DHC-3 Otter
Owner/operator: Taquan Air Service
Registration Number: N472PM
Location: Ketchikan, AK –
ÿ United States of America
Phase of Flight: En route
Status: Substantial
Casualties: Fatalities: 0 / Occupants: 8
Component Affected: Elevator servo tabElevator servo tab
Investigating Agency: NTSBNTSB
Category: Accident
The pilot experienced a vibration during a climb adjustment, immediately transitioning to a landing due to a separation of the elevator servo tab. Examination revealed cracks on the trailing edge of the remaining servo tab, leading to the partial separation of the aircraft.The pilot experienced a vibration during a climb adjustment, immediately transitioning to a landing due to a separation of the elevator servo tab. Examination revealed cracks on the trailing edge of the remaining servo tab, leading to the partial separation of the aircraft.
Description
THE PILOT HAD JUST COMPLETED A CLIMBOUT AND WAS ADJUSTING THE TRIM FOR LEVEL FLIGHT, WHEN THE AIRPLANE BEGAN VIBRATING. HE LANDED IMMEDIATELY. EXAMINATION SHOWED THAT A PORTION OF THE ELEVATOR SERVO TAB HAD SEPARATED. EXAMINATION OF THE REMAINING SECTION OF THE SERVO TAB SHOWED THAT THERE WERE CRACKS IN THE TRAILING EDGE. THE DIRECTOR OF MAINTENANCE REPORTED THAT WHEN THE AIRCRAFT WAS PARKED, THE TAIL WAS ABOUT 10 TO 11 FEET ABOVE THE GROUND AND WOULD HAVE BEEN DIFFICULT TO INSPECT DURING PREFLIGHT. Probable Cause: THE CRACKS IN THE TRAILING EDGE OF THE ELEVATOR SERVO TAB, WHICH RESULTED IN ITS SUBSEQUENT FAILURE AND PARTIAL SEPARATION.
Primary Cause
Cracks in the trailing edge of the elevator servo tab.Cracks in the trailing edge of the elevator servo tab.Share on:
