Investigation Summary
Flight 530 was a scheduled service from London to Oslo. Because British European Airways (BEA) intended to use Vickers Vikings on the route, they utilized Gardermoen instead of the more central Fornebu airport due to runway length requirements. During the approach in heavy cloud cover, the crew requested permission to land using the low frequency radio range system. The aircraft passed the radio range station located 8km north of the airport but subsequently struck the Mistberget mountain. The investigation revealed that the aircraft's radio range equipment was missing a marker beacon receiver due to a parts shortage, forcing the pilots to manually calculate their distance from the beacon. Additionally, the crew had set their equipment to 'compass' instead of 'antenna', which widened the navigation beam from four degrees to twenty degrees, significantly reducing precision. The aircraft was at 620 meters when it should have been at a minimum altitude of 1,000 meters according to the route instruction book.
Final Conclusions
The investigation commission, led by Major Halle and published in January 1947, concluded the cause was improper airmanship. This was attributed to insufficient training in radio range navigation combined with shortcomings in the aircraft's equipment. The pilots initiated the let-down procedure too early, leading to a collision with terrain while the aircraft was otherwise fully functional.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Radio Range Navigation
A low-frequency navigation system used to guide aircraft along specific paths. The investigation found the crew had insufficient training in this system.
Marker Beacon Receiver
A component that provides a visual or aural signal when passing over a specific point; this aircraft lacked the receiver, forcing manual distance calculations.
Interesting Facts
- 01The aircraft was a Douglas C-47A Skytrain built in 1944.
- 02The flight carried 15 people: 5 crew members and 10 passengers.
- 03Three crew members (Captain, First Officer, and Radio Operator) were killed; two crew members (including the steward) and all 10 passengers survived.
- 04The aircraft's radio range equipment lacked a marker beacon receiver due to a lack of parts.
- 05The crew had incorrectly set their navigation equipment to 'compass' instead of 'antenna', widening the beam width from 4 to 20 degrees.
- 06Weather conditions included 10/10 cloud cover with a base at 3,000 meters (9,800 feet).
Safety Actions & Advisories
Radio Range Training Standards
The investigation highlighted the necessity for improved pilot training in low-frequency radio range navigation, particularly for operations in mountainous terrain under instrument meteorological conditions.
Equipment Maintenance and Completeness
The accident underscored the risks of operating scheduled services with missing navigational components, such as marker beacon receivers, which increased pilot workload by requiring manual distance calculations.