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What Happens When a Pilot Multitasks?

Multitasking is bad everywhere

Photo by Thomas Bormans on Unsplash

Thai Airways 311

“No, that’s wrong,” said the pilot as the warning chimed, “Terrain, Terrain, Pull up” in the cockpit. But the warning was accurate, and seconds later, Thai airways 311 slammed into a mountain 11,000 ft above the ground.

Any air crash has a chain of events leading up to the crash. The pilot of Thai airways 311 was so sure about where his plane was that he ignored other cues telling him otherwise about the aircraft’s position.

Bangkok to Kathmandu

Thai Airways 311 was a flight from Bangkok to Kathmandu airport: Kathmandu airport is nestled in the Himalayas. Beautiful, soaring mountains surround the airport.

Many passengers fly to Kathmandu to view this picturesque place, but the mountains also pose a challenge to flights landing at the airport.

To the south of the airport lie 8,000 ft mountains, while to the north, mountains tower up to 20,000 ft.

Most aeroplanes prefer landing at Runway 02 from the south because of the relatively lower peaks compared to the North of the airport.

Having said that, landing from the south is still demanding. Aeroplanes approaching Kathmandu have to make a steep descent while keeping their aeroplane away from peaks.

Thai Air 311 had an experienced crew: The pilot was skilled, and the First officer was well trained.


They were flying into the airport from South to runway 02 on July 31, 1992. But the aeroplane never made it to the airport.

The search for the aeroplane began south of the airport because the aeroplane was coming from that direction. But the search crew couldn’t find any debris. The investigators were becoming edgy: where did the plane go?

The crash site in North

They got the answer when a local villager informed them about the aeroplane wreckage north of the airport-27 miles from the airport. It was befuddling; the plane shouldn’t have been there.

The crash site was a remote & hostile terrain. The aeroplane had crashed into a vertical rock standing 11,000 ft above the ground.

One of the investigators said, “the site was an absolute disaster. Looking at the wreckage, you couldn’t think it belonged to an Airbus A310. You couldn’t even tell the aeroplane had two engines.”

The investigators had to trek for 5 hours to reach the crash site, and the terrain was brutal; an investigator lost his life while trekking to the site.

This was the first time I heard an investigator die while investigating the crash.

C.V.R and F.D.R

The investigators recovered the (C.V.R )Cockpit Voice Recorder; the Flight Data Recorder (F.D.R) was a fortuitous discovery.

While C.V.R lets investigators know what was being spoken in the cockpit, the F.D.R gives information about various flight parameters — direction, altitude, speed, engine performance

When the investigators heard the C.V.R, everything was normal; the crew was preparing to land at Kathmandu airport.

What did the C.V.R reveal?

Trouble began when the A.T.C informed them that Runway 02 was unavailable due to poor visibility and rain.

If they wanted to land, they could use runway 20 from the North, but North had mountains as high as 20,000 ft.

The captain would have to circle the airport and land from the North.

Circling an island or flat terrain is much easier than circling a landscape bordered by mountains.

The captain asked the F.O, “how much fuel did they have? Please calculate the fuel required for Calcutta.” He wanted to divert to Calcutta airport. The F.O answered flippantly, “We have enough fuel to get back to Bangkok.”

The reply browned off the pilot. The pilot asked, “How much fuel have we got? Is it 15, 32, or 42?”

The F.O realised that captain wanted exact figures and started calculating, but they again heard from the A.T.C that runway 02 was opened as conditions had improved.

However, while configuring the aeroplane for landing, the pilot noticed that the flaps wouldn’t extend to the configured setting. But unfortunately or fortunately, the flaps problem was resolved, and the aeroplane continued towards Kathmandu.

Photo by Raimond Klavins on Unsplash

Pilots had to start their approach again

The pilot continued his approach to Kathmandu airport. But the flap problem, the runway closing and re-opening meant the pilots lost time.

They had to begin the descent at a particular point: An early descent would mean crashing into an 8,000 ft mountain, and a late descent would mean overshooting the runway or unsafe landing.

The pilot realised they were too high and too close for a straight-in approach; they decided to turn to the ROMEO waypoint to start their approach again.

Waypoints are geographical coordinates in the sky that help the plane to navigate.

The pilot requested the A.T.C to allow him to fly back to ROMEO, but the A.T.C didn’t respond.

The aeroplane was heading North where mountains as high as 20,000 ft stood.

The pilot realised that they were heading towards the mountains, started turning the aircraft right by turning the heading knob incrementally. And in the middle of the turn, the A.T.C asked them to descend to 11,500 ft.

And the Kathmandu airport didn’t have a radar, so the Air traffic controller (A.T.C) relied on the pilots to give them the aeroplane location relative to the airport. Meanwhile, the A.T.C warned the pilot to avoid turning left as there was traffic.

So the pilot was climbing, turning, and then descending, communicating to the A.T.C, all at the same time. Every time he turned the knob right, he had to take his eyes off the instrument that would tell him which direction he was turning and how much of the turn was left.

And the aeroplane instrument didn’t have cardinal points marked (N,S,E,W). The pilot was confused and lost his situational awareness; the mental picture he had in his head regarding the aeroplane was different from what was going on.

He had turned the aeroplane 360, back on the collision course with the mountains, but he didn’t realise it.

Missed opportunity

The pilots did have the opportunity to catch their mistakes, but the pilot was confident.


When the A.T.C had asked the pilots to report their location, the pilot said 5DME from the airport. This was strange because it had been more than 5 minutes since the pilots had turned around.

If they had been flying south, the distance should have been 20–25 DME. The A.T.C asked the pilots again, and this time the pilot, with an irritated but assertive voice, said, “5DME, 05 DME,” and the inexperienced air traffic controller became reluctant to ask further questions.

The A.T.C was like,“ the pilot looks like a person who knows what he is doing. So, I better not bug him.”

First Officer

The first officer did notice the pilot’s mistake and asked a mitigated question, “are we flying north, huh?” the captain didn’t respond. And a few seconds later, the cockpit had the alarms going off, “Terrain, Terrain, pull up, pull up.”

But the captain believed it was a false warning. The mental picture pilot had about the aircraft was completely different from where the aircraft really was.

He was lost in the mountains; He was situationally unaware of where the aircraft was, and he was unaware that he was situationally unaware.


Whether flying an aircraft or doing a quotidian task, multitasking is never a good idea. The human brain sucks at multitasking. One may think they can work on several projects concurrently and save time, but often the quality of the work deteriorates, or something goes wrong, and the person has to start work all over again.

So avoid multitasking and deal with one task at a time.



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