Narrative:A de Havilland DHC-3T Turbine Otter airplane, experienced an anomalous in-flight vibration and uncommanded nose-down pitch during cruise flight in the vicinity of Homer, Alaska. The airplane sustained substantial damage to the right elevator. The flight departed Seldovia, Alaska, about 0900, en route to Anchorage, Alaska.
According to the pilot, during cruise flight, the airplane vibrated and subsequently pitched nose-down. The pilot applied corrections and continued the flight to the destination. After landing, the pilot and a mechanic examined the airplane and found that the skin on the right elevator servo tab was separated from the hinge, and spar structures inside the right elevator were cracked.
This same aircraft, N3125N, was involved in an accident on 4 June 2015, when during cruise flight, while applying back pressure to the control yoke, a vibration was felt. The pilot immediately reduced power and executed a precautionary landing. After landing it was found that the skin on the right elevator servo tab was fractured and separated from the hinge, and spar structures inside the right elevator were cracked.
Probable Cause:
PROBABLE CAUSE: "The flutter failure of the right elevator servo tab due to the improper fabrication of the servo tab and maintenance personnels subsequent failure to detect anomalies with the servo tab."
Accident investigation:
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Investigating agency: | NTSB  |
Status: | Investigation completed |
Duration: | 2 years and 8 months | Download report: | Final report
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Classification:
Elevator issue
Normal landing
Sources:
» NTSB
Photos
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Sedona Airport, AZ to Anchorage-Ted Stevens International Airport, AK as the crow flies is 3950 km (2468 miles).
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.