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Statuts:Enquête Officielle
Date:mercredi 27 octobre 1993
Heure:19:16
Type/Sous-type:Silhouette image of generic DHC6 model; specific model in this crash may look slightly different
de Havilland Canada DHC-6 Twin Otter 300
Compagnie:Widerøes Flyveselskap
Immatriculation: LN-BNM
Numéro de série: 408
Année de Fabrication: 1974
Heures de vol:40453
Moteurs: 2 Pratt & Whitney Canada PT6A-27
Equipage:victimes: 2 / à bord: 2
Passagers:victimes: 4 / à bord: 17
Total:victimes: 6 / à bord: 19
Dégats de l'appareil: Perte Totale
Conséquences: Written off (damaged beyond repair)
Lieu de l'accident:6 km (3.8 milles) ENE of Namsos Airport (OSY) (   Norvège)
Phase de vol: En approche (APR)
Nature:Transport de Passagers Nat.
Aéroport de départ:Trondheim-Værnes Airport (TRD/ENVA), Norvège
Aéroport de destination:Namsos Airport (OSY/ENNM), Norvège
Numéro de vol:WF744
Détails:
Widerøes Flyveselskap flight 744 was a domestic flight from Trondheim to Namsos and Rørvik in Norway.
The DHC-6 Twin Otter departed Trondheim at 18:37 with two pilots and 17 passengers on board. The captain was Pilot Flying.
The plane climbed to an altitude of 5000 ft and at 18:53 the flight contacted Namsos AFIS to obtain weather information.
The flight was approaching the Namsos NDB from the south and reported "Namsos beacon outbound" at 19:07. A teardrop pattern was flown in order to align with the approach track for runway 26.
The AFIS operator then gave a new update on the weather and said: "744, a heavy rainstorm, but the visibility seems to be good".
At 19:10:30 the plane approached the center line of the approach and the copilot said "Localizer alive".
At 19:14:01 the copilot said that they were at 2100 ft with 1100 ft as the next altitude. The descent was continued. The Namsos NDB was passed at 19:15:13. At that point the aircraft should have been at 2100 feet, but it had already desended below that altitude.
At 19:16:48 the plane hit a ridge about 6 km from the airport and crashed.

Probable Cause:

Significant findings (translated from Norwegian):
The Commission has considered the following findings as particularly important as these factors had a direct or indirect effect on the incident.
a) The circumstances of this aviation accident coincided with a "Controlled Flight Into Terrain". The investigation has shown that the aircraft could be operated normally and was apparently under the control of the crew during the approach;
b) The company had failed to implement a standardized concept of aircraft operation that the pilots fully respected and lived by;
c) The approach briefing was not not fully implemented in accordance with the rules. There were deficiencies in:
- "Call outs" during the approach
- Descent rate (ft/min) during "FAF inbound"
- Timing "outbound" from the IAF and the time from FAF to MAPt;
d) The crew did not execute the "base turn" at the scheduled time, with the consequence that the plane ended up about 14 NM from the airport;
e) The Pilot Flying ended the approach with reference to aircraft instruments and continued on a visual approach in the dark without visual reference to the underlying terrain. During this part of the approach the aircraft's position was not positively checked using any available navigational aids;
f) Both crew members had in all likelihood most of the attention out of the cockpit at the airport after the Pilot Not Flying announced that he had it in sight;
g) The crew was never aware of how close they were the underlying terrain;
h) The last part of the descent from about 500 ft indicated altitude to 392 ft can be caused by inattention to the fact that the plane may have been a little out of trim after the descent;
i) Crew Cooperation during the approach was not in accordance with with the CRM concept and seems to have ceased completely after the Pilot Not Flying called "field in sight";
j) Before the accident the company had not succeeded well enough with the introduction of standardization and internal control/quality assurance. This was essentially because the management had not placed enough emphasis on awareness and motivate employees;
k) The self-control system described in the airline operations manual and the parts of the quality system, was not incorporated in the organization and served as poor safety governing elements;
l) Neither the Norwegian CAA nor the company had defined what visual reference to terrain is, what sufficient visual references are and what the references must be in relation to a moving aircraft.

Accident investigation:
cover
Investigating agency: HSL Norway
Status: Investigation completed
Accident number: RAP.: 07/96
Download report: Final report
Language: 

Sources:
» ICAO Adrep Summary 4/94 (#268)
» Scramble 174


Photos

photo of DHC-6-Twin-Otter-300-LN-BNM
Seat map de Havilland Canada DHC-6 Twin Otter 300 LN-BNM
 

Plan
Ce plan montre l'aéroport de départ ainsi que la supposée destination du vol. La ligne fixe reliant les deux aéroports n'est pas le plan de vol exact.
La distance entre Trondheim-Værnes Airport et Namsos Airport est de 116 km (72 miles).
Accident location: Exact; as reported in the official accident report.

Les informations ci-dessus ne représentent pas l'opinion de la 'Flight Safety Foundation' ou de 'Aviation Safety Network' sur les causes de l'accident. Ces informations prélimimaires sont basées sur les faits tel qu'ils sont connus à ce jour.
languages: languages

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