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

ASN Wikibase Occurrence # 325144

Date:	Wednesday 27 October 1993
Time:	19:16
Type:	de Havilland Canada DHC-6 Twin Otter 300
Owner/operator:	Widerøes Flyveselskap
Registration:	LN-BNM
MSN:	408
Year of manufacture:	1974
Total airframe hrs:	40453 hours
Engine model:	Pratt & Whitney Canada PT6A-27
Fatalities:	Fatalities: 6 / Occupants: 19
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	6 km ENE of Namsos Airport (OSY) - Norway
Phase:	Approach
Nature:	Passenger - Scheduled
Departure airport:	Trondheim-Værnes Airport (TRD/ENVA)
Destination airport:	Namsos Airport (OSY/ENNM)
Investigating agency:	HSL
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
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 descended below that altitude.
At 19:16:48 the plane hit a ridge about 6 km from the airport and crashed.

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: