67-056
1972-JUL-11 · Grytøya, Norway

Royal Norwegian Air Force — Flight 67-056

A Royal Norwegian Air Force DHC-6 Twin Otter crashed into Lille Tussen Mountain on Grytøya Island during a military transport mission. The flight was scheduled from Bardufoss to Bodø, with an intended intermediate stop at Stokmarknes-Skagen Airport. The aircraft struck the mountain approximately 20 metres below the 800-metre summit while operating in poor weather conditions. Investigation revealed that the pilot had a blood alcohol concentration between 1.0 and 1.5 permille and had received insufficient rest following a party the previous night. Despite being advised at departure to bypass the stop at Skagen due to weather and fly directly to Bodø, the pilot elected to proceed with the original flight plan, subsequently drifting north of the intended track into high terrain.

Aircraft
de Havilland Canada DHC-6 Twin Otter 100
Registration
67-056
Phase
Cause
Souls on Board
17
Fatalities
17
Origin → Dest
Bardufoss Airport (BDU) → Stokmarknes-Skagen Airport (SKN)
Report

Investigation Summary

The flight was scheduled as a transport mission from Bardufoss (BDU) to Bodø (BOO) with an intermediate stop at Stokmarknes-Skagen (SKN). Before departure, weather briefings indicated poor conditions at Skagen, and the pilot was advised to bypass the stop and fly directly to Bodø. The pilot disregarded this advice and departed for Skagen at 15:18. While en route on this leg, the aircraft drifted north of its intended south-westerly course. At 15:43, the Twin Otter impacted the eastern face of Lille Tussen Mountain on Grytøya Island. The crash site was located near the summit at an elevation of approximately 780 metres. All 17 people on board, including 14 passengers and 3 crew members, were killed instantly. Post-mortem analysis confirmed the pilot was significantly intoxicated, which likely impaired his navigation and decision-making during the encounter with adverse weather and mountainous terrain. Following decades of public pressure and claims of potential technical failure or sabotage, a formal reinvestigation process was initiated in the late 1990s. The Accident Investigation Board Norway (AIBN) released its final reinvestigation report in 2005, which upheld the original findings, concluding that the primary cause was pilot error due to alcohol impairment and navigation mistakes.

Final Conclusions

The accident was caused by Controlled Flight Into Terrain (CFIT) resulting from pilot impairment and poor operational decision-making. Contributing factors included the pilot's high blood alcohol level (1-1.5 permille), lack of sleep, and the decision to attempt a landing at Skagen despite official advice regarding deteriorating weather conditions.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Engines
Pratt & Whitney Canada PT6A-20

Systems & Failure Modes

i

Pratt & Whitney Canada PT6A-20

The turboprop engines powering the DHC-6 Twin Otter; no mechanical failure was cited in the accident narrative.

Interesting Facts

  • 01The pilot's blood alcohol concentration was measured at 1-1.5 permille.
  • 02The aircraft struck the mountain at an altitude of approximately 780 metres.
  • 03The pilot had attended a party the night before the flight and had insufficient rest.
  • 04The aircraft was 15 km NNW of Harstad at the time of the impact.
  • 05The flight was a military transport operation.
  • 06Manufacturer Serial Number (MSN): 56.
  • 07The aircraft was manufactured in 1967.

Safety Actions & Advisories

AIBN Reinvestigation

Following decades of public controversy and claims of technical failure or sabotage, the Accident Investigation Board Norway (AIBN) conducted a formal reinvestigation. The final report, released in 2005, utilized modern forensic review to confirm the original findings of pilot impairment and navigational error, effectively closing the case on alternative theories.

Location

Grytøya, Norway · 68.9744, 16.4011

ACCIDENT SITE · Coordinates taken from the entered by an editor.

Case File History

  1. CorrectionUpdated safety actions.
  2. New evidenceUpdated findings.
  3. CorrectionUpdated investigation summary.
  4. CorrectionUpdated investigation summary.

Related Cases

Case ID · rnoaf-dhc6-1972Last updated · Filed

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