Status: | Accident investigation report completed and information captured |
Date: | Friday 16 August 1991 |
Time: | 12:46 |
Type: |  Boeing 737-2A8 Advanced |
Operator: | Indian Airlines |
Registration: | VT-EFL |
MSN: | 21497/504 |
First flight: | 1977-11-17 (13 years 9 months) |
Total airframe hrs: | 29729 |
Cycles: | 33574 |
Engines: | 2 Pratt & Whitney JT8D-17A |
Crew: | Fatalities: 6 / Occupants: 6 |
Passengers: | Fatalities: 63 / Occupants: 63 |
Total: | Fatalities: 69 / Occupants: 69 |
Aircraft damage: | Destroyed |
Aircraft fate: | Written off (damaged beyond repair) |
Location: | 38 km (23.8 mls) SW of Imphal Municipal Airport (IMF) ( India)
|
Phase: | Approach (APR) |
Nature: | Domestic Scheduled Passenger |
Departure airport: | Calcutta-Netaji Subhas Chandra Airport (CCU/VECC), India |
Destination airport: | Imphal Municipal Airport (IMF/VEIM), India |
Flightnumber: | IC257 |
Narrative:Indian Airlines flight 257 departed Calcutta at 11:54 on a scheduled 60-minute flight to Imphal, India.
The crew contacted Imphal at 12:34. The flight was cleared to descent to from FL290 to 10,000 feet and asked to report overhead the VOR for ILS runway 04.
At 12:39 the crew reported 12 miles inbound at 10,000 feet. The pilot then asked the air traffic controller as to whether they could set course directly outbound for let down. This was approved. Two minutes later the flight reported approaching overhead the VOR, although it was still 14 miles out. The controller then queried: "understand you are proceeding on a radial 217 for ILS". This was confirmed by the crew.
At 12:42 Imphal ATC cleared the flight to proceed outbound for an ILS approach to runway 04 descending to 5,000 feet. At 12:44 the flight reported commencing the procedure turn. This was the last contact with the flight.
The airplane impacted Thangjing Hill, in inclement weather conditions with low clouds and occasional rain.
Probable Cause:
PROBABLE CAUSE: "The accident occurred by reason of a grave error on the part of the Pilot-in-Command in not adhering to the operational flight plan and ILS let down chart and not realizing that his early descent to 10,000 feet and turning right for outbound leg without reporting overhead VOR would result in loss of time
reference and as such misplace him in the hilly terrain. The Pilot-in-Command's action may have been influenced by his extreme familiarity with the terrain".
Classification:
Non-adherence to procedures
Controlled Flight Into Terrain (CFIT) - Mountain
Sources:
» Civil aviation aircraft accident summary for the year 1991 (DGAC India)
Photos
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Calcutta-Netaji Subhas Chandra Airport to Imphal Municipal Airport as the crow flies is 599 km (374 miles).
Accident location: Exact; deduced from official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.