Opinion | Up, down & all around: IX1134’s last half hour7 min read . Updated: 14 Aug 2020, 07:55 AM IST
At 7:39pm, the flight was at 925 feet, flying at 325km/hour, and in good shape to land
At about 7.10pm, the altimeter shows that they are at just about 10,000 feet above sea level. It’s been about three-and-a-half hours since they took off.
Not that they have been at 10,000 feet all that while, not at all. At the start, they had climbed steadily — just the usual — reaching their cruising altitude of 35,000 feet within half an hour. They stayed there for nearly three hours, barrelling along at 800km/h and tracking a constant 124° — just east of south-east — all through. The descent began 15 minutes ago: a rapid 3,000 feet per minute for the first few minutes, then easing up to about 1,000fpm. While descending, they have also slowed significantly, to about 580km/h now. A few gentle banks to left and right, too, and now they are tracking a little closer to due east than 124°; in fact, at 105°, they are almost perfectly aligned with the runway that’s ahead.
What is this tracking measure, you ask? Superimpose a clock onto a compass, so that north coincides with 12 on the dial. That is, if you travel due north, you’re said to be tracking 0°. If you then turn 90° clockwise, you’ll end up facing east, looking at 3 on the dial: thus tracking 90° means heading directly east. 105°, then, is 15° further clockwise, or further to the south. That’s about the orientation of the runway. Naturally, if they want to land there the plane must fly in on that heading.
There’s no milestone marking 10,000 feet, of course. Nor is it likely that veteran pilots will notice the number on the altimeter. But think of it here as a reminder that the landing is not far away.
Actually, at that moment they are a little less than 20km out at sea, about 40km from the airport—but at 580km/h, those are not large distances. Indeed, a minute later they cross the coast, just north of the mouth of a river, and are now down to 9,000 feet. There’s an almost non-existent beach below, and a short stretch of coastal plain dotted with plenty of houses, then they cross the river itself. More houses on the other side, and from here, the flight path is a straight line more or less through the shallow valley of a stream that empties into the same river. The land below now rises into low hills, still with plenty of houses and structures, if not quite as dense as near the coast.
Two minutes pass and they have descended below 7,000 feet and are just 4km west of the runway. They have slowed even more and are now flying at about 480km/h. Only a few seconds later, the runway is a mere half kilometre ahead.
But they will not land. For they are at 6,000 feet, far too high to land when just half a kilometre from the runway. And 480km/h is far too fast as well. If you were on the ground and could see the plane above, you’d conclude that this is just an approach. In fact, if it flew directly overhead, you may even realize that they are not really aligned with the runway either. The 105° heading is right, but they are on a flight path that is parallel to and about 100m south of the runway. There’s a road of sorts there, but of course it’s no runway.
No, this flight is not landing.
Flying parallel to the runway and several thousand feet off the ground, the plane roars over the airport. About a fifth of the way along the runway’s 3km length, they bank left till, shortly before flying past the end of the runway, they are tracking 90°, due east. The plane is losing both height and speed steadily, an indication that they are indeed planning a landing. Only, they want to do it by approaching the other end — the eastern end—of the runway.
Three minutes that they fly due east. At 20km east of the airport, they have slowed to 400km/h and are down to about 3,300 feet. That’s when they bank right into a broad semicircle, some 4km in diameter. The huge turn takes a couple of minutes and when they come out of it, they are on a 285° heading, just north of due west— so in fact, they made slightly more than a semicircle. 285° means they are once again aligned with the runway, only this time from the east. They are also now flying at just 310km/h.
This time, they will land.
Five minutes pass. They have lost another 20km/h and well over a thousand feet in altitude. They are perfectly aligned with the runway as they soar in over its eastern end.
But wait — it’s clear already to anyone watching that they are too high to land. They should be much lower than 1,900 feet by now. The runway is some 350 feet above sea level, of course, but even with that reduction they are too high. They cannot safely lose the remaining 1,600 feet to the ground.
So about halfway down the runway, they take the split-second decision all pilots are trained for: abort the landing, climb and circle around to try again.
The time is 7:23pm. The two pilots take the decision and execute the manoeuvre to perfection.
The engines roar to give the plane speed and lift. Even before the plane passes the western end of the runway, it has accelerated to 330km/h. About a kilometre further on, now at 3,000 feet, they bank sharply left, tracking 230°—or nearly southwest — for a minute or so. Then they turn right. These two turns mark out one end of an enormous figure 8—an infinity symbol, more like it—that they will trace in the air over the next fifteen minutes.
The right turn leaves them tracking 300°, heading nearly northwest and now straight out to sea. Flying at 390km/h, they are climbing steadily, taking the next 7-8 minutes to get up to 7,175 feet. They are over 10km from the coast when they start banking left, readying to trace out the other end of the infinity symbol.
Again, there’s a semicircle to make in the air. When they start on it a couple of minutes and another 10 or so km out to sea later, this semicircle is about 8km in diameter. They descend as they make it, crossing their original flight path from some 25 minutes earlier. The semicircle ends at 7:33pm, when they find themselves at 4,650 feet and tracking 90° — due east, again. At 7:35pm, some 15km from the coast, they make the adjustment to align with the runway again, turning right till they are tracking about 109°. Not quite lined up — they have turned past the required heading — but there’s still time.
At 7:37pm, they cross the coast again, this time almost directly over the mouth of the river. This time, though, they are at 2,350 feet, almost 7,000 feet below where they were on their first approach. They are also flying at 350km/h, far slower than on that first approach. And they have turned and are tracking 101°—almost lined up with the runway.
In other words, they are in good shape to land.
At 7:38pm, they descend below 2,000 feet. Less than 10km to go to reach the airport.
At 7:39pm, they are at 925 feet, flying at 325km/h, still on a 101° heading. The runway is only 2km ahead. Still in good shape to land.
But that’s the final position the flight tracker site flightradar24.com records for Air India Express flight IX1134 on 7 August 2020, the Boeing 737 Vande Bharat flight from Dubai to Kozhikode.
Though we do know what happened to IX1134 a minute or so later. They touch down a little too far along the runway for safety. With a tailwind, rain and a wet surface, they cannot stop before the end of the runway. They roll through a buffer zone beyond the runway. They plunge over the edge and down the slope of the hill on which the runway is built. The aircraft finally comes to a halt on the ground some 35 feet below. It breaks into two. 18 people are killed.
That includes both pilots. The men who have tried so hard over the last half hour to bring their 184 passengers and 4 crew in safely.
All data in this column has been taken from a replay of IX1134 on 7 August on flightradar24.com
Once a computer scientist, Dilip D’Souza now lives in Mumbai and writes for his dinners. His Twitter handle is @DeathEndsFun