Investigation Summary
The accident occurred during the last scheduled flight before the Easter holiday. Værøy Airport was notorious for difficult wind conditions due to its location immediately north of a steep mountain ridge. On the day of the accident, the crew landed at Værøy despite reports of a moderate gale. While parked, a peak wind gust of 57 knots was recorded, which exceeded the Twin Otter's maximum limit of 50 knots for ground operations. Despite this, the crew elected to taxi and take off. During the climb, the captain deviated from standard procedures by choosing a 320° heading and maintaining 10° of flaps to combat the conditions. Approximately 55 seconds into the flight, the aircraft entered an area of severe turbulence. The rapidly shifting aerodynamic loads caused an overload failure of the tailplane or rudder. The Cockpit Voice Recorder captured a rattling sound followed by the sound of unsynchronized propellers before power was lost. The main wreckage was located on April 15, 2,300 meters from the airport at a depth of approximately 10 meters. The aircraft struck the water in a steep, nose-down, left-banked attitude. The impact was high-energy, leaving 80% of the wreckage fragmented within a 300 by 400 meter area, which significantly complicated recovery efforts.
Final Conclusions
The Accident Investigation Board Norway (AIBN) concluded that the primary cause was the aircraft encountering wind conditions that exceeded its structural design criteria, leading to a fracture in the tail surface/elevator. Contributing factors included the crew's decision to operate in weather conditions that exceeded established safety limits for both the aircraft type and the specific airport. A second inquiry in 1994-1995 re-examined potential fatigue in an elevator control rod but ultimately reaffirmed that extreme wind-induced stress was the definitive cause of the structural failure.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Empennage (Tail Section)
The tailplane and rudder suffered a structural overload failure due to extreme turbulence, rendering the aircraft uncontrollable.
Elevator Transfer Mechanism
A specific end piece in the elevator control system was scrutinized for fatigue during a 1994 re-investigation, though it was not found to be the primary cause.
Interesting Facts
- 01The aircraft was operating in winds gusting to 57 knots, exceeding the 50-knot limit for ground operations.
- 02The airport had a self-imposed wind limit of 20 knots for departures from the south, which was exceeded during the accident flight.
- 03The captain's body was never recovered from the crash site.
- 04Værøy Airport was permanently closed to fixed-wing aircraft following the accident and replaced by a heliport.
- 05The aircraft was under control for the first 55 seconds of the 63-second flight.
Safety Actions & Advisories
Airport Closure
Værøy Airport was permanently closed to fixed-wing commercial traffic due to the inherent danger of mountain-induced wind shear.
Fleet Inspection
Following reports of potential fatigue, Widerøe grounded its Twin Otter fleet to inspect elevator transfer mechanism end pieces; 86 parts were replaced globally as a precaution.
Known Controversies & Unanswered Questions
Fatigue vs. Overload Dispute
Reference ↗In 1994, an English engineer alleged the crash was caused by fatigue in an elevator component rather than weather. The AIBN reopened the case but concluded the fatigue was not the primary cause, though the manufacturer subsequently changed subcontractors for the part.