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Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

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Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#221

Post by jimktrains2 »

lolc wrote: post #139
TheOtherHobbes wrote: post #134

Earlier quoted context omitted.

Because most pilots can fly professionally enough not to hit it.

There are failures modes a pilot has no chance of resolving.

There are worse places to take off/land. Midway (MDW) has very little distance from the runway to houses and highway. Princess Juliana International Airport on Sint Maarten (SXM) has very little distance from the end of the runway to the ocean. Gibraltar International Airport (GIB) is also basically on the water.

Overrunning the runway is often considered avoidable from my limited understanding. Planes are flight worthy under _a lot_ of issues. Even single engine failure or engine fire after V1 (the speed at which you can't abort/reject takeoff without overrunning the runway) isn't cause to abort/reject takeoff.

With landing, the plane needs to touch down early enough and at the correct speed to stay on the runway.

Overrunning the runway is never considered a "good" thing. Rejected takeoffs that shouldn't have been and bad landings are often causes of death. They're expected to not happen.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#222

Post by manigandham »

oe wrote: post #130
nitinreddy88 wrote: post #96

Earlier quoted context omitted.

What caused them to retun in half way? Report says Trichy airport informed pilot about posssible damage to plane. Pilot ignored it saying everything is green. What happened in 4hrs to divert back to Mumbai is still mystery. Will be interesting to see full report

Is it possible that Dubai refused to let them land with a flyable but potentially pretty broken plane?

It would be the opposite, every major airport will be open for a plane in trouble.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#223

Post by avip »

danaliv wrote: post #180
rhn_mk1 wrote: post #152

I hate articles introducing three-letter-mysteries and leaving the readers in confusion. To add insult to injury, none of the comments seem to acknowledge that the topic is impentrable. What is the mysterious ILS that was hit? Even after reading the Wikipedia article, I only have a vague idea - seems to be a radar system, both on ground and in the air. Did the plane hit a radar tower?

Others have noted that ILS stands for Instrument Landing System. It’s a system used for landing airplanes when you can’t see the runway, typically getting you down to 200 feet, but with special training and equipment you can get down to 100 or even zero (autoland). ILS is the world standard for getting airplanes onto runways in bad weather. The ground portion of an ILS consists of two antenna arrays, one at the end o…

Another one of these comments that make this forum always a joy to read. Thanks for the detailed walkthrough.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#224

Post by avar »

azernik wrote: post #195
throw2016 wrote: post #188

Earlier quoted context omitted.

The accidents rates by country paints a completely different picture. [1] This wikipedia list of glaring pilot incompetence leading to fatalities doesn't seem to show any bias for specific regions. [2] When using anecdotal data one just can't make sweeping judgements and conclusions data does not support, that takes discussion into the region of prejudice and bigotry. This anecdotal one person usually 'an insider' fi…

That first link is pretty inapplicable - the numbers it shows are total fatalities and total accidents since 1945, not scaled for population of the country, not scaled for the quantity of air travel (in a time range where, especially early on where air travel was least safe, there were vast regional differences in wealth and frequency of flying), and over a long enough period that it doesn't really reflect the curren…

These numbers seem correct, but I don't see how they add up to "extreme [pilot] incompetence" mentioned upthread. The countries that do worse are poorer, and therefore consistently fly older airframes with worse maintenance schedules, and regulations aren't as strict.

For all we know Africa has the best pilots in the world but the crappiest airframes, or fantastic pilots and awesome airframes but their maintenance is atrocious.

I'm not saying I find that especially plausible, but until these numbers are at the very least adjusted for hull loss rates by region of operator per million departures per age of airframe we're comparing apples to oranges.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#225

Post by oe »

manigandham wrote: post #222
oe wrote: post #130

Earlier quoted context omitted.

Is it possible that Dubai refused to let them land with a flyable but potentially pretty broken plane?

It would be the opposite, every major airport will be open for a plane in trouble.

Sure. I just thought that they weren't in as much trouble that they needed to land immediately, but could have caused some trouble after landing.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#226

Post by JshWright »

danaliv wrote: post #180
rhn_mk1 wrote: post #152

I hate articles introducing three-letter-mysteries and leaving the readers in confusion. To add insult to injury, none of the comments seem to acknowledge that the topic is impentrable. What is the mysterious ILS that was hit? Even after reading the Wikipedia article, I only have a vague idea - seems to be a radar system, both on ground and in the air. Did the plane hit a radar tower?

Others have noted that ILS stands for Instrument Landing System. It’s a system used for landing airplanes when you can’t see the runway, typically getting you down to 200 feet, but with special training and equipment you can get down to 100 or even zero (autoland). ILS is the world standard for getting airplanes onto runways in bad weather. The ground portion of an ILS consists of two antenna arrays, one at the end o…

There are lots of great YouTube videos explaining how these work with some visualizations.

Here's a good one: https://youtu.be/FeELh0kMSIA

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#227

Post by usrusr »

nitinreddy88 wrote: post #98

Its mystery how plane survived such a huge impact Airport perimeter damage: https://mobile.twitter.com/ANI/status/1050582092688629760

The landing gear is built to withstand hitting a concrete runway with a 737, whereas a thin brick wall can be brought down with just a hammer. It's like rock-paper-scissors: wheels beat wall, ILS antenna beats fuselage skin.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#228

Post by prolikewh0a »

kijin wrote: post #147
mbell wrote: post #97

Unless I'm misinterpreting the satellite image its ~150m from the end of the runway to that wall[0] and it also looks a bit downhill from the runway to the wall[1]. I don't see how this could happen without the pilots noticing; they would have been skimming the ground well past the end of the runway. [0] https://www.google.com/maps/place/Tiruchirapalli+Internation... [1] https://twitter.com/shukla_tarun/status/105058…

Perhaps they were slightly airborne, like 0.5m above the ground, but ground-based instruments recorded the plane as still being "on the ground" (i.e. same altitude as the runway) because of the downhill slope? If they really were on the ground, the pilots would have continued to feel the vibration of the wheels against the ground, a very clear indication that they aren't flying. I'm even more surprised that the plane…

Measurements from those instruments would be from the aircraft itself as these are ADS-B transmissions from the aircraft.

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#229

Post by [deleted] »

IronSoul wrote: post #100

Pilot did not follow the climbing trajectory, too low and hit the boundary wall. Nothing surprising in India where everyone follows his/her rules, if such thing called rules exist. Looks like pilot was flying as if he is driving on Indian road, a dent or a tear here and there is not a problem, as long as engine is running. Finally, Indian sky has become a reflection of Indian roads, what a shame!

[deleted]

Re: Air India Express 737 Hits ILS, Damages Wall on Departure, Flies for 4 Hours

#230

Post by solids »

murukesh_s wrote: post #102
IronSoul wrote: post #100

Pilot did not follow the climbing trajectory, too low and hit the boundary wall. Nothing surprising in India where everyone follows his/her rules, if such thing called rules exist. Looks like pilot was flying as if he is driving on Indian road, a dent or a tear here and there is not a problem, as long as engine is running. Finally, Indian sky has become a reflection of Indian roads, what a shame!

I think it's not appropriate to generalize. How many such incidents happen?

Just look at the numbers.

Indian aviation doesn't kill more thousands due to the great work that Airbus (mostly) has done to keep poor airmanship killing people.

But at the end of the day, look at incidents in India and it's clear: perhaps revert to trains. Yes, they have a poor record too, but proportional to numbers of journeys/passengers to death or accident, minor compared to Indian air carriers.

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