PIA A320 Crash Karachi

[WillowRun 6-3]

Waiting for the CVR, FDR

In the category of clarifying, the video narrator's apparent ironic emphasis on the term "comfortable" provoked my earlier post - but not because I was suggesting the word itself was a possible problem or had led to a possible problem.
Instead - the way the narrator emphasized the word - with a kind of humorless or even bloodless irony - was provocative in that given how badly the approach had been handled up to that moment, the tale to be revealed by the recorders seems quite likely to deliver bigger shock value than what already has been noted in the thread and by the Blancolirio video(s). Even with awareness of facts assembled so far (from tracking websites and otherwise), on an approach so badly operated up to that moment, how the captain could have stated such a comfort level - I'm anticipating it will be shocking even more than realized already ....(was the point I had hoped to get at).

[Loose rivets]

Well before the end of the Raj there was a strong tendency to use old English sayings. This seems to have persisted while fading away in the UK during my lifetime.

The ATC guy was in a difficult situation. Having gone as far as he did, the next step would have been to tell the captain how to do his job. He of course has the right to do this in extreme situations, but then there's the delay due to an almost disabling feeling of disbelief.

The wheels being down for a first touch? I doubt that. The potential and kinetic energies were so great that the first tug on the stick would have seen them climbing sharply. Also the time to 4,500' feet down the runway from at least 1,500' would not have seen the gear stowed and doors safely back up.

[b1lanc]

Originally Posted by WillowRun 6-3

[SLF ... although having some knowledge of aviation law (and....lots of hours, of reading PPRuNe)]
The video from Blancolirio (Euclideanplane #1118) has the gent noting, with not very subtle emphasis, how the R/T included one of the crew saying they were "comfortable" with, or on, the approach profile on which they were proceeding.
Fairly sure that's a non-standard term, "comfortable".
If that's correct, is it a term that nonetheless has cropped up in R/T in previous accidents?
(I'm not speculating at all as to what could have led to usage of that term; it is greatly to be hoped the AAIB will report with compelling thoroughness and conformity to contemporary Annex 13 standards and, expected practices rather than those merely "recommended".)

You have to view the ATC transmissions in their entirety (thought limited as currently available).

You Tube

0.23 "We are comfortable. We can make it" That last sentence says more than the first. It's intent is to convince someone they can successfully put the kite on the ground. It's an attempt to reassure either ATC or the FO.
0:28 "We are comfortable now...." That says it all - despite prior transmission, crew wasn't really comfortable prior.
0:39 Then you get into the disagreement between ATC and crew that they were actually established on ILS 25L.

[GAPU]

Originally Posted by Loose rivets

The wheels being down for a first touch? I doubt that. The potential and kinetic energies were so great that the first tug on the stick would have seen them climbing sharply. Also the time to 4,500' feet down the runway from at least 1,500' would not have seen the gear stowed and doors safely back up.

A question for the experts please. Assuming the first touch was gear up and given the known high energy, what set of circumstances could lead to the subsequent 2 further touches? It looks like there was no tail strike or nose strike so that's three just on the engine cowls. I've read on here that if they initiated the GA on the first touch then the 2nd two would not have happened. So did they "bounce" along the runway losing energy before initiating the GA after the third touch? Is there any way that conflicting actions by the Captain and FO could explain the three touches?

[FullWings]

That’s an interesting one.

If you are sliding down the runway on the engines and attempt to get back in the air again, there would be considerable differences in the potential aerodynamic and other forces/couples compared with a normal rotation - how much AoA could you generate with the tail on the ground given the fuselage is much closer to the tarmac? It may only be possible to get back into the air if you are much faster than Vref? I doubt if this is a situation that receives much thought in the design of the aircraft or its certification. It’s certainly not in the training syllabus: “PIA 123 short finals for a gearless touch and go”...

[procede]

Originally Posted by GAPU

A question for the experts please. Assuming the first touch was gear up and given the known high energy, what set of circumstances could lead to the subsequent 2 further touches? It looks like there was no tail strike or nose strike so that's three just on the engine cowls. I've read on here that if they initiated the GA on the first touch then the 2nd two would not have happened. So did they "bounce" along the runway losing energy before initiating the GA after the third touch? Is there any way that conflicting actions by the Captain and FO could explain the three touches?

Your angle of attack basically decreases with the velocity squared and then there is the ground effect, which increase lift for a given angle of attack close to the ground. As you slow down, your angle of attack needs to increase to maintain horizontal flight.
My theory:
They were going so fast, that the pitch angle was close to zero at touchdown. When they scraped, they lost speed and as they climbed, the lift also decreased slightly out of ground effect. They did not pull the nose up enough to compensate for this, causing the aircraft to sink back.

The engines are in front of the gear, so pulling up should only be easier.

[DaveReidUK]

Originally Posted by FullWings

If you are sliding down the runway on the engines and attempt to get back in the air again, there would be considerable differences in the potential aerodynamic and other forces/couples compared with a normal rotation - how much AoA could you generate with the tail on the ground given the fuselage is much closer to the tarmac?

A quick back-of-the-envelope bit of geometry would suggest that about 5.5° of pitch attitude is achievable with the engines in contact with the runway, before the tail hits the deck.

[learner001]

At the assumed high (over)speed one would expect that the slightest pull force on the stick would have converted the flight path upwards.

It appears though, that for some reason there had not been a (sufficient) resultant pull force to create that sustained upward path initially.

I would not be surprised if we learn that counteracting stick inputs, with subsequent (multiple) alternating priority(ies) during the part, just prior and over the runway, may be presented on the FDR and the CVR…

(Just to keep the possibility open that the gear had been down already before touch down, these priority changes of controls could of course also have happened during circumstances where a possible unconscious ’trigger’ or ’reflex’ of either pilot occurred, resulting in inadvertently raising the gear prematurely…)

Remains another question: At what point was the autopilot kicked off?

[phiggsbroadband]

The engines are in front of the gear, so pulling up should only be easier.

Well we are now getting into the realm of what was the coefficient of friction of the carbon fibre engine cowls, against the runway, compared to the position of the C/G... Would that have produced a nose down pitching moment..? ( remember there was no nose-wheel to prevent a further pitch down.)

As an ex endurance event cyclist, I think that Dehydration, and Hunger Bonk will be part of the cause of this accident.

[22/04]

One thing that hasn't been raised is why the aircraft didn't make the turn requested by ATC on the approach - there may be a reason unknown to the aircraft - and presumably he was under a radar control service.

[aterpster]

Originally Posted by what next

If I read (and understood) everything correctly the controller did not offer them anything but instead instructed them to turn onto a specific heading away from the approach. To make them get rid of excess altitude and speed. So there should have been no captain's decision but compliance with that instruction. We really need that CVR transcript to understand what was going on.

If the Air Blue Flight 202 accident is precedence, which is a reasonable presumption, there won't be a CVR transcript:

https://www.caapakistan.com.pk/Uploa...ts/SIB-337.pdf

[homebuilt]

Originally Posted by 22/04

One thing that hasn't been raised is why the aircraft didn't make the turn requested by ATC on the approach - there may be a reason unknown to the aircraft - and presumably he was under a radar control service.

As far as I know according to the radio transmissions we have been able to read in the above posts, provided all exchange appears, the crew simply didn't want to follow ATC instructions. My opinion is this instruction from ATC for turning left heading 180° was an ultimate attempt to save the day because the controller watching his data obviously considered the flight beeing too high and too fast to safely land. It would be interresting to know how many controllers were manning the tower, just to wonder whether one of these guys could have been able to visually spot the gear-up aircraft, in order to shoot on his mike "PIA 8303 Go Around !!!" ...

[parkfell]

Originally Posted by 22/04

One thing that hasn't been raised is why the aircraft didn't make the turn requested by ATC on the approach - there may be a reason unknown to the aircraft - and presumably he was under a radar control service.

He was establishment on the ILS and was ‘comfortable’ and decided that a new heading was not necessary.
ATC accepted that, which was a reasonable thing to do even under ‘radar control’ as the pilot was ‘comfortable’, notwithstanding that the approach was grossly unstable and continued to be so.
The professional relationship between pilots and ATC is not always the easiest thing to explain. It does take time for the osmosis to work.

Had there been another valid reason (‘unknown to the aircraft’) then approach radar would have explained why a new vector was issued.

When I was at the College of ATC, Hurn many moons ago (No.54 course), I was told to start thinking of the relationship of a Boy Scout helping an ‘Old Dear’ across the road at a Zebra crossing.
Then gently absorb the legislation through osmosis with this in mind.

[Euclideanplane]

Originally Posted by aterpster

If the Air Blue Flight 202 accident is precedence, which is a reasonable presumption, there won't be a CVR transcript:

https://www.caapakistan.com.pk/Uploa...ts/SIB-337.pdf

Which is absolutely fine. In the Air Blue report there are observations taken from the CVR such as

During last 70 seconds from crash, despite calls from ATS and the EGPWS sounding 21 times as Terrain ahead including 15 times for pull up (extract of sound and alarms chronology is attached at Appendix-C), the Captain continued to take the aircraft on its fatal journey. The FO also informed the Captain 4 times about the terrain / Terrain Warning and asked him at least 3 times to pull up. But the Captain did not pull up, nor did he apply the TOGA (Take Off Go Around) thrust, contrary to the established SOPs.

Out of respect, you do not necessarily have to publish literally what went on in terms of prayers, calls for maternal assistance, and whatever else could have been uttered in a time of absolute despair. The summary of the factual pieces of communication or lack thereof, as in this extract, should be quite enough.

[aterpster]

I agree with you. Nonetheless, it is not a transcript. When that accident happened in 2010 I was able to get the information I needed from that report. But, we are used to the NTSB publishing a complete transcript.

[lomapaseo]

I'm not sure whether you actually want all the words, or the actual sounds traces..

It's typically considered adequate that the major parties to the investigation support a summary of the words and cite what they feel are important sounds in a written report. If you as a reader feel that you have something significant to offer in support of the investigation after reviewing the reports then you can petition on your own.

If on the other hand significant information is left out, you might hear about this from the parties themselves in their comments on the final report..

I'm not trying to be complete here,I'm just trying to understand what you really want. and why.

[ATC Watcher]

Originally Posted by homebuilt

A
. It would be interesting to know how many controllers were manning the tower, just to wonder whether one of these guys could have been able to visually spot the gear-up aircraft, in order to shoot on his mike "PIA 8303 Go Around !!!" ...

As I explained already at the beginning of this thread , TWR controllers cannot issue a Go around instruction for that reason, Once a PIC reports established on the ILS ,he is on his own , It is up to them to manage his approach .TWR Controllers should not interfere unless the runway is blocked or becomes not avail . In addition in many modern Towers you cannot monitor the approach anyway ( too far away )

[DaveReidUK]

Originally Posted by ATC Watcher

In addition in many modern Towers you cannot monitor the approach anyway ( too far away )

While a new tower at OPKC has been planned for several years, the current one (built in 1932) is atop the original terminal, not particularly high, and about 3/4 of the way down the runway from the 25 end (around 2.6 km from the 25L piano keys).

[parabatix]

'We are comfortable, we can make it'
Was there an 'Inshallah' there at the end?
May of course be quite usual but it grabbed my attention.

[zero/zero]

Originally Posted by phiggsbroadband

As an ex endurance event cyclist, I think that Dehydration, and Hunger Bonk will be part of the cause of this accident.

Why, do you have some special insight into what the crew ate and drank that day that nobody else does?? (they are not required to fast due to their occupation, although some obviously still do)

Plenty of people have crashed aircraft in a stupid way whilst fully fed and watered...