Narrative:The Twin Otter descended below minima during a localizer approach without glide path and struck the ground.
|Date:||Wednesday 27 October 1993|
de Havilland Canada DHC-6 Twin Otter 300
|C/n / msn:|| 408|
|First flight:|| 1974|
|Total airframe hrs:||40453|
|Engines:|| 2 Pratt & Whitney Canada PT6A-27|
|Crew:||Fatalities: 2 / Occupants: 2|
|Passengers:||Fatalities: 4 / Occupants: 17|
|Total:||Fatalities: 6 / Occupants: 19 |
|Airplane damage:|| Damaged beyond repair|
|Location:||6 km (3.8 mls) ENE of Namsos Airport (OSY) ( Norway)
|Phase:|| Approach (APR)|
|Nature:||Domestic Scheduled Passenger|
|Departure airport:||Trondheim-Værnes Airport (TRD/ENVA), Norway|
|Destination airport:||Namsos Airport (OSY/ENNM), Norway|
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.
» ICAO Adrep Summary 4/94 (#268)
» Scramble 174
Official accident investigation report
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 Trondheim-Værnes Airport to Namsos Airport as the crow flies is 116 km (72 miles).