Accident de Havilland Canada DHC-6 Twin Otter 300 LN-BNS,

ASN Wikibase Occurrence # 326057

Date:	Thursday 12 April 1990
Time:	14:44
Type:	de Havilland Canada DHC-6 Twin Otter 300
Owner/operator:	Widerøes Flyveselskap
Registration:	LN-BNS
MSN:	536
Year of manufacture:	1977
Total airframe hrs:	27304 hours
Cycles:	58709 flights
Engine model:	Pratt & Whitney Canada PT6A-27
Fatalities:	Fatalities: 5 / Occupants: 5
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	1,8 km W off Værøy-Stolport Airport (VRY) - Norway
Phase:	Initial climb
Nature:	Passenger - Scheduled
Departure airport:	Værøy-Stolport Airport (VRY/ENVY)
Destination airport:	Bodø Airport (BOO/ENBO)
Investigating agency:	HSL
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
A de Havilland Canada DHC-6 Twin Otter 300 passenger plane, registered LN-BNS, was destroyed in a loss of control accident off Værøy, Norway. All three passengers and two crew members were killed.
Widerøes flight WF839 arrived at Værøy-Stolport Airport (VRY) at 14:30 in gusty conditions. Three passengers deplaned, two came on board. After the airplane was fueled, it taxied out for the last leg to Bodø Airport (BOO). The following wind conditions were radioed to the crew: "wind variable middle direction 250 at 21 max 57". The crew asked for confirmation that the wind was gusting to 57 knots, which was confirmed. The wind force of 57 kts was 7 knots over the allowed to operate the aircraft on the ground. The crew taxied to runway 25 and were given a new wind measurement for the west end of the airfield with variable orientation (varied within 210°-290°) and gusts of 34 knots. This wind speed was 14 kts over the company limit for departures.
The pilot in command commenced takeoff and reported rolling at 14:42. After takeoff the airplane turned to the west and climbed over sea. It entered an area of severe turbulence/wind shear and the crew had difficulty to control the airplane. The forces imposed on the airframe exceeded the design strength leading to an overload failure of the tail surface or elevator, or both.
The plane hit the sea in a left banking attitude, nose down and at a high vertical speed.

CAUSE: "The cause of the accident was that the plane during departure came into the wind that exceeded the aircraft's design criteria. Thus there was a break in the horizontal stabilizer / elevator which meant that the plane could no longer be controlled."

Accident investigation: