The twin-engined AN-32, which is a tactical transport aircraft considered as the 'workhorse' of the Indian Air Force, got airborne from the IAF base at Tambaram at 0830 hours in the morning on July 22, 2016. It had a flight crew of six, and was carrying 23 passengers, all of them service personnel. The aircraft was on an official flight to Port Blair in the Andaman Islands. The total flying distance is 1,376km, and the aircraft was scheduled to reach its destination at 1120 hours.
About 300 km out from Tambaram, the aircraft did a steep descending left turn from 23000 feet. Then it disappeared from the radar—it probably went well below the radar cover. Media reports indicate that radar and radio contact with the aircraft were lost approximately 15 minutes after the takeoff. The aircraft did not reach the destination.
The aircraft has the ability to remain airborne for four hours. When no contact was reported from the destination airfield after this duration, 'overdue' action was initiated by the Air Force, and the aircraft is currently reported as missing. The entire flight route is over the Bay of Bengal with no land mass en route, and the Indian Navy has been pressed into service for the search. Currently, four ships and two maritime aircraft are involved in the search, which has been initiated from the destination.
What could have happened?
The first point that comes to mind is the ‘aircraft’ itself. It is a reliable aircraft which has been in service since the early 1980s. The aircraft has been operating in the most challenging environments with a very good flight safety record. While mechanical or system failures cannot be ruled out, the fact that the aircraft has two engines, and redundant systems, would enable a competent crew to handle the situation.
The second point is the ‘route’. From the flying point-of-view, this is not a very challenging route. The distance to the destination was well within the ‘range’ of the aircraft which is 2500km. However, there is a slight degree of difficulty involved. For any flight, the possibility of the destination not being available for landing is a planned contingency. This could be due to factors such as weather and runway blockage. In this route, the only available ‘diversionary airfield’ is the IAF airfield at Car Nicobar, which is 274km south of Port Blair. In case there is widespread bad weather, then both airfields could be affected. In such a contingency, the only options available to the pilot would be to turn back and land at any of the airfields on the Indian mainland. However, considering the total range of the aircraft, this decision would have to be taken well in advance. The fact that the destination was able to launch aircraft for the search indicates that the weather at the destination was not a problem.
The third point is ‘en route weather’. The satellite weather pictures available on the internet indicate that there was widespread clouding along the route. So, in all probability, the aircraft could have been in this cloud layer. The AN-32 has a fairly good onboard weather radar, and so, flying through these clouds should not have posed a problem for experienced aircrew. However, once again there is a catch. What if there was a failure of the onboard systems while the aircraft was in this thick cloud mass? The fact that the aircraft lost radio contact with the takeoff base after 15 minutes of flying could be indicative of a failure of the radio communications. If this was coupled with the failure of other electronic systems like the compass that indicates flight direction, it could have added to the problems facing the aircrew.
The last point to consider is ‘enemy action’. This appears most unlikely, and can be ruled out.
So, the most logical inference is that the problem could have been a combination of bad weather ‘en route’ coupled with failure of some onboard systems. At this point, we can only hope and pray that the crew were able to ‘ditch’ the aircraft in the sea, and the crew and passengers are safe.
The prognosis does not appear good.