What happened
A ferry flight traveling from Raipur toward Calcutta-Dum Dum encountered deteriorating weather conditions during its descent. While descending to an altitude of approximately 1,830 meters, the crew received notification that visibility at the destination had decreased to 2 km. Due to changing wind components, air traffic control directed the aircraft to perform an approach to runway 01R, a runway lacking ILS capabilities.
As the aircraft progressed on final approach, it entered a low-pressure zone characterized by intense rainfall. Approximately 4 km from the airfield, the plane encountered heavy rain, and by the time it reached 900 meters from the runway threshold at an altitude of roughly 40 to 50 meters, visibility had dropped to zero. Although air traffic control alerted the crew to the minimums and the navigator suggested a go-around, the pilot continued the descent. The aircraft struck the ground 198 meters before the runway threshold and 20 meters left of the centerline. Following the impact, the plane slid into a swampy area. There were no fatalities among the seven crew members, though the aircraft was destroyed.
Findings
The investigation determined that the primary factor was the encounter with heavy rainfall which eliminated all visual references to the ground and runway. A critical contributing factor was the pilot's failure to execute a go-around despite warnings from both the navigator and air traffic control. Additionally, the crew's lack of familiarity with non-precision approach procedures for runway 01R contributed to the accident.