What happened
The flight departed Belfast-Nutts Corner Airport at 1058 local time. The crew initiated an approach to Manchester-Ringway Airport from the northeast under marginal weather conditions. During the descent, while flying at an altitude of 1,350 feet in low visibility, the aircraft collided with a mountain slope in the Pennines range. The impact occurred approximately two miles east of Mossley, less than 50 feet below the summit of a peak that stands 1,400 feet high. The force of the collision destroyed the aircraft. All three crew members and 21 passengers were killed in the accident. Additionally, eight other passengers sustained serious injuries.
Findings
The official investigation identified several contributing factors to the tragedy. The primary cause was determined to be a navigation error combined with an incorrect approach procedure. Furthermore, the crew failed to accurately verify the aircraft's position before commencing the descent from a safe altitude.