Background
The aircraft was operating a ferry flight from Raipur to Calcutta-Dum Dum. En route, the crew was informed that weather conditions at Calcutta had worsened, with visibility limited to 2 kilometers.
Flight
While descending to an altitude of 1,830 meters, the wind component changed, and the crew was vectored for an approach to runway 01R, which was not equipped with an instrument landing system (ILS). On final approach, at a distance of 4 kilometers from the airfield, the airplane entered a low pressure area with heavy rainfall. At a distance of 900 meters from the runway threshold and an altitude of 40 to 50 meters, visibility dropped to zero due to torrential rains.
Accident
Air traffic control informed the crew about the minimums, and the navigator advised the captain to initiate a go-around maneuver. However, the captain continued the descent and passed below the glide path. The aircraft struck the ground 198 meters short of the runway threshold and 20 meters to the left of the centerline. It slid for several yards and came to rest in a swampy area.
Rescue
All seven crew members were rescued. The aircraft sustained damage beyond repair.
Probable Cause
According to official findings, the airplane entered an area of heavy rainfall, reducing visibility to zero. In a very short time, the crew lost visual contact with the runway and all visual references with the ground, causing the aircraft to pass below the glide path and strike the ground. For unknown reasons, the captain failed to initiate a go-around maneuver and ignored warnings from ATC and the crew. A contributing factor was that the crew was not aware of the non-precision approach procedures for runway 01R.