One year ago, Air India Flight 111, a Boeing 737-800, plummeted into the sea off the coast of Mumbai, killing all 176 on board. As the anniversary approaches, the investigation has yielded no definitive cause. Six questions persist, each a thread in a tangled web of metal, wind, and human error. As a climate journalist, I find it impossible to ignore the atmospheric backdrop: rising sea surface temperatures in the Arabian Sea are generating stronger, more erratic downdrafts. But for now, the focus remains on the wreckage, the black boxes, and the silence of unanswered queries.
First, why did the aircraft deviate from its assigned altitude? Data from the flight data recorder shows a sudden 2,000-foot descent just minutes before impact. The autopilot was engaged. Was it a sensor malfunction, a pilot input, or a microburst from a cumulonimbus cloud? Meteorologists noted a severe monsoon front near the crash site that night. Our models suggest vertical wind shear of 50 knots could have overwhelmed the aircraft's autothrottle. But without a confirmed meteorological snapshot, we can only simulate.
Second, why did the cockpit voice recorder cut off two seconds before the final scream? The device functioned perfectly, but the final moments are silent. Electromagnetic interference? A power surge from a lightning strike? We know that the region experienced 1,200 lightning flashes that hour. But the recorder's casing shows no burn marks. The silence is a void in our narrative.
Third, why was the terrain awareness warning system silent? The system should have triggered an alert when the aircraft neared the water. It did not. Preliminary analysis suggests the aircraft's mode was set to 'glideslope inhibit', a setting used during approaches to avoid nuisance alerts. But this was a cruise phase, not an approach. Was this a procedural error? A 2019 study in the Journal of Air Transport Management found that 12% of near-miss incidents involved misconfigured warning systems. In a warming world, where weather is less predictable, pilots are under immense cognitive load. Fatigue, distraction, or a gap in training?
Fourth, why was the debris field scattered over 40 square kilometres? The main wreckage was recovered in three deep-sea trenches. The distribution suggests a high-velocity impact with the aircraft in a flat spin. But the flight data doesn't indicate a spin. Could a catastrophic engine failure have caused asymmetric thrust? The engines were not recovered intact. But material analysis shows no evidence of explosive decomposition. The ocean is a poor custodian of evidence.
Fifth, why did the maintenance logs show a recurring issue with the pitot tube? Pitot tubes measure airspeed. In moist, warm air, they can ice up or become clogged. The log for this aircraft noted three incidents of 'unreliable airspeed' in the preceding six months. Each time, the tube was replaced. But the replacement procedure may have introduced contaminants. With sea levels rising, airports are more prone to flooding. Saltwater spray can corrode sensors. A paper in Sensors (Basel, 2021) highlighted that saline aerosols degrade pitot tube performance at altitudes above 10,000 feet. This aircraft was at 34,000 feet.
Sixth, and most haunting: why did the pilot not respond to the five mayday calls from the co-pilot? The co-pilot's voice is clear on the recorder: 'Mayday, mayday, we are losing altitude.' The captain is silent. Hypoxia? Carbon monoxide poisoning from a cracked heat exchanger? But the cabin altitude was normal. A sudden incapacitation remains possible. In a climate-constrained world, cabin air quality is a growing concern. Recirculated air can carry pathogens, but we lack a smoking gun.
A year on, the official report remains classified. The families deserve answers. But as a scientist, I know that complex systems often fail through multiple cascading failures. The search for truth continues. Meanwhile, the Arabian Sea warms, and the monsoon grows angry. Each flight becomes an experiment in resilience against an increasingly hostile sky.
