PIA A-320 crash in Karachi

[SAS443 1,714]

 

49 minutes ago, threegreen said:

The reply above was probably not very clear on what I meant because of the way I used the 250 ft. I wasn't trying to indicate they were 250 ft higher or lower in itself, but rather that the difference in pressure altitude, even if just 250-ish ft, and its penalty on performance may play a role in just making it or not, especially if combined with one of the other factors (lower AOA for better gliding, for example).

Then I wholeheartedly agree. Little "disturbing" information here:

Imagine they were actually 250ft higher. Airbus A320 clean exhibits a glide number  of 17(?) meaning for every vertical unit lost, you gain 17 horisontally. So 250ft x 17 = 4250ft or 1295 meters will be travelled horisontally.

AvHerald reports crash site is approx. "1350 meters/0.74nm short of the runway threshold"

[OzWhitey 3,353]

On 5/23/2020 at 9:51 PM, Ray Proudfoot said:

Has any of this been made public? Unless it has I suggest you refrain from speculating as it's both disrespectful to those who have died and is pointing to the crew as being responsible which is uncalled for.

Leave discussion until the facts are known.

There’s a fair bit of public and semi-public information available now. PPRUNE is your best bet for links. We have ATC, physical evidence, witness reports and so on. The ATC recording is a good start for trying to understand this crash.

MTR’s summary is pretty spot-on given what is known as of today. 
 

[OzWhitey 3,353]

4 hours ago, Chock said:

Looks very much like if they'd just closed the throttles and accepted that they'd screwed up, they'd probably have had a - admittedly career-ending - survivable belly landing.

1. Should have gone around in the first place once they had an unstable high-energy approach.

2. Should have stayed on the ground once the sparks were flying.

3. Once airborne, should have headed straight ahead to the military airfield and landed there.

4. Once engines were out, should not have chosen the runway with the Model Colony apartments built most of the way up to the threshold.

Lots of opportunities for the pilots to salvage this one. The roads not taken...

[threexgreen 3,135]

1 hour ago, SAS443 said:

Then I wholeheartedly agree. Little "disturbing" information here:

Imagine they were actually 250ft higher. Airbus A320 clean exhibits a glide number  of 17(?) meaning for every vertical unit lost, you gain 17 horisontally. So 250ft x 17 = 4250ft or 1295 meters will be travelled horisontally.

AvHerald reports crash site is approx. "1350 meters/0.74nm short of the runway threshold"

This is a really good post, thanks. That's what I was assuming, that even slightly better conditions, whether weather-wise or in terms of handling the aircraft or both could possibly have made a huge difference. It's heartbreaking how close they were to at least avoiding the buildings.

Though it's a miracle still that only 4 people on the ground suffered injuries and even the buildings hit are reported to have suffered 'minor' damage, considering an aircraft crashed into the place. Same goes for the 2 passengers surviving and being able to give interviews just 2 days after. This could have easily been even worse.

[threexgreen 3,135]

50 minutes ago, OzWhitey said:

1. Should have gone around in the first place once they had an unstable high-energy approach.

2. Should have stayed on the ground once the sparks were flying.

3. Once airborne, should have headed straight ahead to the military airfield and landed there.

4. Once engines were out, should not have chosen the runway with the Model Colony apartments built most of the way up to the threshold.

Lots of opportunities for the pilots to salvage this one. The roads not taken...

Number 1, absolutely yes. But I can't even imagine the confusion going on on that flight deck onward from the point when you realize you just touched down on your engines. Perhaps they didn't even realize that. Then you have both engines quitting and from there it was probably a warning concert going on.

While we do have facts, a lot is still not known. The approach doesn't seem good at all, but I don't think it's fair or even possible to judge at this point.

[HighBypass 2,339]

One strange call from the radio I listened to on Juan Browne's video is ATC requesting the pilot to turn to 180, to which he replied they were already established on 25L. Would ATC not have seen that? Just curious.

I'm still amazed that the airliner managed to claw its way back into the air after scraping the runway like that. They're not fighter jets with power to weight ratios in excess of 1:1.. Even a MiG-29 no slouch in the power stakes didn't manage to take off. However I believe they shut down the engines soon after the jet contacted the runway. Not much of a fire streak..

https://www.youtube.com/watch?v=R_uSdxhYkUg

I don't believe this pilot shut the engines down until later and also ejected. He "appeared" to travel much further down that runway with the large trail of fire.

https://www.youtube.com/watch?v=SsO1Nu0JHwk

 

 

 

[OzWhitey 3,353]

46 minutes ago, HighBypass said:

One strange call from the radio I listened to on Juan Browne's video is ATC requesting the pilot to turn to 180, to which he replied they were already established on 25L. Would ATC not have seen that? Just curious.

I'm still amazed that the airliner managed to claw its way back into the air after scraping the runway like that. They're not fighter jets with power to weight ratios in excess of 1:1.. Even a MiG-29 no slouch in the power stakes didn't manage to take off. However I believe they shut down the engines soon after the jet contacted the runway. Not much of a fire streak..

https://www.youtube.com/watch?v=R_uSdxhYkUg

I don't believe this pilot shut the engines down until later and also ejected. He "appeared" to travel much further down that runway with the large trail of fire.

https://www.youtube.com/watch?v=SsO1Nu0JHwk

 

 

 

My take on the ATC is that they didn’t think the pilots should be attempting a landing given that they were way too high at 5nm out. Hence the attempt to vector the flight. Pilots were like “Nah bro, we’re good”...but then became distracted trying to pull together a landing that was never going to be a good idea (hence the flap overspeed warnings in the background of the ATC recording).

Deciding to land was a poor piece of airmanship, but it only became deadly serious once they forgot to lower the gear (there’s a small chance they put the gear up too early on the go around, which is not really any better).

Those two actions combined to create a truly life-threatening situation.

However, there were still multiple chances for them to make a decision that would allow everyone to walk away. From a human factors perspective, it is easy to understand why they made each of these subsequent calls, but the fact remains that they had plenty of chances to word not allowed victory from the jaws of defeat until right near the end, and they didn’t take them.

 

[HighBypass 2,339]

1 minute ago, OzWhitey said:

to word not allowed victory from the jaws of defeat

I never realised that the word meaning to "grab hurriedly at something" would be censored! 😎

Oh, and thank you for the rest of the informative post, Rob. I wasn't meaning to diminish the rest of your input!

[Chock 17,769]

52 minutes ago, OzWhitey said:

(hence the flap overspeed warnings in the background of the ATC recording).

As far as I'm aware that sound you can hear on the ATC recording is the landing gear overspeed warning chime. This is consistent with what we know about the situation, i.e. that they were too high and too hot, but instead of abandoning their approach, kind of went 'yeah, we can make it'.

So they stuck it in a dive, presumably hoping the gear and flaps would brake them on the descent. Unfortunately, what that warning chime means, is that you are over the speed at which the landing gear actually will deploy (over 250 knots), so it's not warning you about overstressing the gear because it is down (which I bet that's what they thought it meant), it's warning you that you are too fast and it's not gonna lower it at all. That's probably why they tried to touch down, thinking that the gear was actually down because the lever was down. 

If you think about it, this means it is quite likely the engine nacelles touched down at a speed near to 250 knots nearly halfway down the runway. At that speed, they probably would have blown or set fire to the tires anyway even if the gear had been down; that's faster than Concorde takes off at, and it has tires specially rated for its speed. If you've ever opened the engine cowling panel on an A320, you'll know they are not thick heavy metal, they'd have worn completely away in a second or two, exposing the bottom of the engine to friction damage and likely destroying the accessory drive mechanisms.

This would explain why they still had the airspeed necessary to get back into the air (I don't think that MiG 29 was doing 250 knots when its pilot raised the gear too early) and also probably why the gear came down after they had lifted off the runway because their speed bled off to less than 250 knots on the climb out with engines spooling down, and the gear handle would still have been down, which would then allow the gear to descend. Unfortunately, at that point they'd have been better off if the gear actually had not come down, from the point of view of wanting to be in a clean config to stretch the glide a bit more and actually really intentionally try a belly landing.

Edited May 25, 2020 by Chock

[n4gix 4,947]

Quote

Looks very much like if they'd just closed the throttles and accepted that they'd screwed up, they'd probably have had a - admittedly career-ending - survivable belly landing.

 

^^^ This! They shouldn't have missed hearing the nacelles dragging along the runway... :(

[HighBypass 2,339]

23 minutes ago, Chock said:

So they stuck it in a dive, presumably hoping the gear and flaps would brake them on the descent.

Did they not think of deploying the spoilers too or rather instead of the gear? That's what I do in the sim if I'm hot and high.. and above gear deployment speed .... oops 😵 Sorry if my humorous comment is too soon.

Regarding the speed theory Al: Yes, now you put it like that, IF the airspeed was that high, then scraping the nacelles may not drag the plane down - the speed decreases, but it still has enough to pull up and away from the runway.. for a little while.. Cheers for the explanation, sir!

[Chock 17,769]

13 minutes ago, HighBypass said:

Did they not think of deploying the spoilers too or rather instead of the gear? That's what I do in the sim if I'm hot and high.. and above gear deployment speed .... oops 😵 Sorry if my humorous comment is too soon.

Regarding the speed theory Al: Yes, now you put it like that, IF the airspeed was that high, then scraping the nacelles may not drag the plane down - the speed decreases, but it still has enough to pull up and away from the runway.. for a little while.. Cheers for the explanation, sir!

Just a guess, rather than an explanation, but a likely one. The issue with the MiG 29 is that the pilot is trying to be all hotshot and have the gear come up just as he pops off the runway, so he raises the gear right when the nose comes up and it starts flying, but at that point it is a bit like a hovercraft or an ekranoplan, i.e. it's flying in ground effect with smooth air bouncing up on the underside making it fly, but then the gear starts retracting forward, causing more drag and breaking up that smooth airflow which was making it look like it was flying properly, and next minute its a case of 'well, you see it was like this Comrade Major...'

I do actually have some bits of one of the MiG 29's ejector seat which collided at an airshow in the UK a few years ago (don't ask where I got them lol). I'll see if I can dig them out and photograph them for you; you'll be surprised how rough-looking the components are in comparison to western ejector seat components. Still, it didn't stop them from working pretty well. 

Edited May 25, 2020 by Chock

[mtr75 653]

6 hours ago, OzWhitey said:

1. Should have gone around in the first place once they had an unstable high-energy approach.

2. Should have stayed on the ground once the sparks were flying.

3. Once airborne, should have headed straight ahead to the military airfield and landed there.

4. Once engines were out, should not have chosen the runway with the Model Colony apartments built most of the way up to the threshold.

Lots of opportunities for the pilots to salvage this one. The roads not taken...

Yeah, this plane crash started ten minutes before and a few miles away from where it hit the ground. At 3,500 feet AGL 5 miles out its, “Tower, Pakistani International Air 8303, going around”. 

Though I will say, regarding point 4, I don’t think we know right now when the engines quit, but you’re always going to make your traffic pattern away from the parallel runway in that situation. And once they turned left it was goodnight Irene. 

[Chock 17,769]

1 minute ago, mtr75 said:

Yeah, this plane crash started ten minutes before and a few miles away from where it hit the ground. At 3,500 feet AGL 5 miles out its, “Tower, Pakistani International Air 8303, going around”. 

Yup, good landing starts with a good approach. Pretty much lesson one on how to land a plane.

[mtr75 653]

5 hours ago, threegreen said:

Number 1, absolutely yes. But I can't even imagine the confusion going on on that flight deck onward from the point when you realize you just touched down on your engines. Perhaps they didn't even realize that. Then you have both engines quitting and from there it was probably a warning concert going on.

While we do have facts, a lot is still not known. The approach doesn't seem good at all, but I don't think it's fair or even possible to judge at this point.

The approach was inexcusable. At 3,500 feet and 5 miles out, you have no chance of making the runway using a stabilized approach. I mean they got a flap overspeed warning on final. That’s just inconceivable. SOP for any 121 carrier is that if the approach is unstable, go around. It’s just automatic. And they knew for darn sure the gear wasn’t down when the engines hit the deck.