An accident that could have been easily averted

It will be used as an example of what pilots and ATCs should be mindful of

Based on conversations with the aviation expert of Nepal - Hemant Arjyal

Frankly, I was unsure whether to do this piece. Following Monday’s crash of the US-Bangla aircraft at TIA, my mind had been oscillating, perhaps like the mind of the ill-fated plane’s pilots as they struggled to decide whether to land from the north (‘20’) or from the south (‘02’). We are still not sure how this accident, which could have been easily avoided, ended up being so tragic.

This crash has aroused not only deep sympathy but also immense curiosity. And not just here but the world over. This was particularly because of the availability of live communication audio between the air traffic controller (ATC) and the aircraft. One can listen to it over and over again. It is just a headphone away for anyone. For novices though, understanding the ATC jargon could be problematic.

Without going into the details of the accident per se, I want to approach it from a different angle. While it may be natural for someone at the US-Bangla to blame Kathmandu ATC for the accident, many on our side will disagree. But the blame game does not help anyone, nor does it enhance aviation safety. A rational and impartial analysis is vital. I have thus taken the liberty to extract comments on aviation forums following the crash. Needless to say, those comments come without any trace of regional bias. I save my dui-paise for the end.

As the accident was avoidable, many wondered if the ATC transcript was in fact real. They found it unbelievable, even mind-blowing. Most people on the forums wondered how the pilots got the runway number, the flight number and the wind direction all wrong. But all agreed that there was utter confusion both in the flight deck and in the tower.

Confirmation, Compass, confusion

One comment was particularly perceptive as it suggested the crash was a result of the mind processing what it expects to hear rather than what is being actually said, or what you would call confirmation bias. When you get wind from a ‘220’ direction and are flying into and with a ‘02/20’ runway, you are naturally better off landing from 02 than from 20 because of the unfavourable tailwind (a headwind is generally more preferable for take-offs and landings).
The fact that ‘02’ is a compass heading (of 20 degrees) raises the potential for confusion: wind from 220, a 02/20 runway—it’s a lot of 2s and 20s. The problem is compounded if you are not a native English speaker as you process the language less instinctively.

This commentator further said that as people find themselves in stressful situations—like landing an airline with a tailwind in an airport in a foreign country with very high terrains around—their reasoning faculties shut down and they go with their instinctive judgement. The less experienced someone is at a task, the higher this tendency is. It can even reach a point where people disregard information that clearly indicates something is wrong.

If both the pilots make the same cognitive error, there is nobody there to question it. The commentator rightly points out that this is the kind of cognitive stress or cockpit resource management (CRM) concern that is a nightmare for beginners.

Likewise, another extremely sharp comment hit the nail on the head, “Oh, my goodness just tell them to go around, this cannot be real! ATC gave them what they wanted and thought it will fix it. ATCs were aware that the pilots were confused.”

This, more or less, summarises everything that happened. Listening to the audio, the captain sounds very calm, and can be heard clearly reading back the ATCs’ instructions. The ATCs, on the other hand, sounded agitated and unsure. But this is not to suggest that the ATCs were primarily responsible for the crash: it was the captain’s prerogative to make a missed approach and try a stabilized approach later.
Domino effect
It was the captain who initiated the domino effect by swinging between ‘02’ and ‘20’, not just once but right up to the end. The confused ATC gave him the option to land at any end of his choosing. Disoriented as the captain was, how come he didn’t see obstructive landmarks as he passed over at a very low altitude—and still thought he could land?

They say a sure way for a pilot to get disoriented quickly is to attempt too late a turn at low altitudes while also trying to manage the radios and other critical flight phase items. This was what happened with the US-Bangla flight.

As we notice in the audio, our ATC seems to first shoot and then re-think and go for quick change, creating more confusion. This has been the hallmark of our ATCs for long. And this is not the first time I have said so. An ATC has to be a patient listener cum speaker. But most of our ATCs seem to lack this basic skill. Agreed, it is hard to do away with your native accent, but you can surely speak slowly and intelligibly to make sure the person at the other end understands what you’re saying. It saves a lot of time and unnecessary hassles.

This accident will go down in history as the most unfortunate accident that could have been avoided with the available tools and procedures. I am sure it will be used as an example of what pilots and ATCs should avoid. It could be instructive for airports the world over with a ‘02/20’ orientation that are otherwise operating quite normally.

Photo : Ashok Dulal, AMN