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3 fatalities

Mid-air collision over Dakar-Yoff Airport (6V-ADE)

Dakar-Yoff, SenegalLanding (descent or approach)

On December 9, 1993, a De Havilland DHC-6 Twin Otter (registration 6V-ADE) operated by Air Sénégal - SONATRA Société Nationale de Transports Aériens was involved in an aviation accident near Dakar-Yoff, Senegal during landing or approach. 3 people were killed. Investigators recorded the probable cause as: Both crews failed to respect their assigned altitudes, causing the aircraft to collide. At the time of the accident, the Twin Otter was about 100-300 feet too low and the NAMC was about 700-900 feet too high. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Source recordUpdated 2026-09-03Data APIEditorial standards

A Twin Otter and a NAMC YS-11A-117 collided near YF VOR after both crews deviated from assigned altitudes. The Twin Otter crashed into the sea, killing all three occupants.

Incident Overview and Aircraft Involved A mid-air collision occurred near YF VOR, a navigation aid associated with Dakar-Yoff Airport. The accident involved a Twin Otter and a NAMC YS-11A-117. The NAMC aircraft, registered C5-GAA, was operated by Gambia Airways on a scheduled flight from Dakar-Yoff Airport to Banjul. It carried 34 passengers and a crew of four. The Twin Otter had completed an uneventful flight from Saint Louis and was cleared to descend to Dakar-Yoff Airport. ## Flight Instructions and Collision The Twin Otter crew was instructed to maintain 3,000 feet over YF VOR. At the same time, the Gambia Airways NAMC YS-11A-117 departed Dakar-Yoff Airport. Its pilots were instructed to climb via radial 140 and maintain 2,000 feet while over YF VOR. When both aircraft reached the YF VOR, they collided. ## Aftermath and Casualties Following the collision, the NAMC YS-11A-117 crew returned to Dakar and landed safely despite the left wing being partially torn off. The Twin Otter entered an uncontrolled descent and crashed in the sea a few kilometers offshore. All three occupants of the Twin Otter were killed.

Probable cause

Both crews failed to respect their assigned altitudes, causing the aircraft to collide. At the time of the accident, the Twin Otter was about 100-300 feet too low and the NAMC was about 700-900 feet too high.
Midair collision

Related events

Same operator

Frequently asked questions

What happened in the 9 Dec 1993 De Havilland DHC-6 Twin Otter accident near Dakar-Yoff, Senegal?

A Twin Otter and a NAMC YS-11A-117 collided near YF VOR after both crews deviated from assigned altitudes. The Twin Otter crashed into the sea, killing all three occupants.

Were there any fatalities in the 9 Dec 1993 De Havilland DHC-6 Twin Otter accident?

The accident was fatal, resulting in 3 fatalities.

What aircraft was involved and where did it happen?

The accident on 9 Dec 1993 involved a De Havilland DHC-6 Twin Otter, registration 6V-ADE, operated by Air Sénégal - SONATRA Société Nationale de Transports Aériens, at Dakar-Yoff, Senegal.

What was the probable cause of the accident?

Both crews failed to respect their assigned altitudes, causing the aircraft to collide. At the time of the accident, the Twin Otter was about 100-300 feet too low and the NAMC was about 700-900 feet too high.

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