Boeing 737-2A8 Advanced – VT-EFL

Incident Overview

Date: Friday 16 August 1991

Aircraft Type: Boeing 737-2A8 Advanced

Owner/operator: Indian Airlines

Registration Number: VT-EFL

Location: 38 km SW of Imphal Municipal Airport (IMF) – ÿ India

Phase of Flight: Approach

Status: Destroyed, written off

Casualties: Fatalities: 69 / Occupants: 69

Component Affected: Pilot-in-CommandPilot-in-Command

Investigating Agency: CoI IndiaCoI India

Category: Accident

On Indian Airlines flight 257, a scheduled flight to Imphal, the crew contacted the Imphal ATC at 12:34, cleared to descend to FL290 to 10,000 feet and instructed to report overhead the VOR for ILS runway 04. At 12:39, the crew reported 12 miles inbound at 10,000 feet, and then approached the VOR, still 14 miles out. The ATC then queried if the pilot could set course directly outbound for let-down. This was approved. Two minutes later, the flight reported approaching the VOR, still 14 miles out. The controller then queried ‘understand you are proceeding on a radial 217 for ILS’. The crew confirmed this. 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 commenced the procedure turn. The incident concluded with the airplane impacting Thangjing Hill, in inclement weather conditions with low clouds and occasional rain. The probable cause was a grave error by the Pilot-in-Command regarding adherence to operational flight plan and ILS let-down chart, resulting in a loss of time reference and misplacement in the hilly terrain.On Indian Airlines flight 257, a scheduled flight to Imphal, the crew contacted the Imphal ATC at 12:34, cleared to descend to FL290 to 10,000 feet and instructed to report overhead the VOR for ILS runway 04. At 12:39, the crew reported 12 miles inbound at 10,000 feet, and then approached the VOR, still 14 miles out. The ATC then queried if the pilot could set course directly outbound for let-down. This was approved. Two minutes later, the flight reported approaching the VOR, still 14 miles out. The controller then queried ‘understand you are proceeding on a radial 217 for ILS’. The crew confirmed this. 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 commenced the procedure turn. The incident concluded with the airplane impacting Thangjing Hill, in inclement weather conditions with low clouds and occasional rain. The probable cause was a grave error by the Pilot-in-Command regarding adherence to operational flight plan and ILS let-down chart, resulting in a loss of time reference and misplacement in the hilly terrain.

Description

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: “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”.

Primary Cause

Pilot-in-Command error regarding operational flight plan and ILS let-down chart, leading to a loss of time reference and misplacement.Pilot-in-Command error regarding operational flight plan and ILS let-down chart, leading to a loss of time reference and misplacement.

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