Investigation Summary
The flight was operating a domestic route from Mumbai to Ahmedabad and was delayed by 20 minutes due to a late passenger. As the aircraft approached Ahmedabad, visibility was deteriorating due to haze, dropping from 6 km to 2 km. The airport's Instrument Landing System (ILS) was partially degraded, with the glide path out of service, necessitating a non-precision localizer-DME approach. Cockpit Voice Recorder (CVR) data revealed that the crew became fixated on gaining visual contact with the runway. They failed to make mandatory altitude call-outs and maintained a speed of 160 knots, which was higher than the prescribed approach speed. The aircraft descended through the 500-foot MDA without the crew reporting the runway in sight, eventually impacting terrain in a paddy field near Chiloda Kotarpur village.
Final Conclusions
The official cause was attributed to pilot error resulting from non-adherence to established procedures under poor visibility conditions. The crew failed to monitor the altimeter and descended below the minimum safe altitude while attempting to locate the runway visually. Weather was cited as a significant contributing factor, as the haze obscured the ground and the lack of approach lights and a functional glide path increased the crew's workload and reliance on visual cues.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
Localizer-DME
A non-precision approach system providing lateral guidance and distance information, used here because the ILS glide path was unavailable.
VASI
Visual Approach Slope Indicator lights, which were functional but likely obscured by the 2 km haze.
Altimeter
The primary instrument for monitoring altitude, which the investigation found the pilots neglected during the final descent.
Interesting Facts
- 01The accident was the deadliest in the history of Indian Airlines at the time.
- 02The aircraft had accumulated 42,750 flight hours and 47,520 landings since its delivery in 1970.
- 03The airport's glide path was out of service, and approach lights were absent, as noted in several NOTAMs.
- 04Only two passengers survived the crash, both with serious injuries.
- 05The aircraft was destroyed by a post-impact fire in a paddy field.
Safety Actions & Advisories
Enhanced Approach Monitoring
The investigation emphasized the mandatory requirement for pilots to maintain instrument monitoring until the runway is clearly visible at the Minimum Descent Altitude.
Infrastructure Improvements
Recommendations were made to ensure critical landing aids, such as ILS glide paths and approach lighting systems, are maintained and operational at major airports.