PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rumours & News (https://www.pprune.org/rumours-news-13/)
-   -   PIA A320 Crash Karachi (https://www.pprune.org/rumours-news/632693-pia-a320-crash-karachi.html)

Airbubba 22nd May 2020 18:26


Originally Posted by DaveReidUK (Post 10790106)
While not conclusive, the Mode S altitude readouts referred to in previous posts would support the proposition that the aircraft descended to 0' AAL during the GA.

And they also seem to indicate that there was never weight on wheels sensed on the first approach since the Mode S uncorrected altitude did not go to zero as it did on previous landings with AP-BLD.

slfie 22nd May 2020 18:32


Originally Posted by Airbubba (Post 10790100)
Here's a detail from one of Hamza Omer's widely published pictures of the aircraft, presumably after the first approach. There does appear to be damage from nacelle scrapes and the RAT is indeed deployed.

Thanks, that pic explains the earlier comment about damage to the lip of the left nacelle - looks like it's actually just the normal bits underneath the fuselage in the background.

asdf1234 22nd May 2020 18:38


Originally Posted by bobjones (Post 10790141)
There are salt flats just south of downwind runway 25

And the PAF runway the other side of the main drag going into town. This might have been their best option but of course if their engines were still burning when they turned downwind they would have no need for this option.

Geoff Hunt 22nd May 2020 18:55


Originally Posted by blessing786 (Post 10789657)
Maybe leaked by some insiders since its Pakistan.

It would add to injury to assault, if PIA did release the manifesto without officially informing passengers and staff affected by the crash.

Sads time indeed....

Yep. It's Pakistan. What is 'an official notice to the families?' Pakistan authorities ask.

JumpJumpJump 22nd May 2020 19:15

Surprised that nobody has asked how current they were. Hours in las 90, 30 and 7 days could be surprisingly low in the current climate

Busbert 22nd May 2020 19:32


Originally Posted by Fursty Ferret (Post 10790143)
You can't miss it on an Airbus, there's an additional ECAM master warning for gear not down.

You can hear the Master Warning CRC on the atc recording of the initial approach. My reading is the GEAR NOT DOWN warning was activated (LG lever in UP with aircraft below x (2500?) feet).

squidie 22nd May 2020 19:38

Potentially gear issues on first landing, RAT may give that away at the moment. I think the possibility that there was some terrain contact with the engines slightly followed by a go around. But unsure on the final approach that resulted in the crash. By looking at the CCTV clips both engines are out as the crew are attempting to max out the lift with the high AoA.

Could have had a genuine fault with the gear followed by a depletion of fuel on the go around...

blue up 22nd May 2020 19:48

Are the oil cooler lines right at the very bottom of the cowling on the CFM56-b5 series? Wondered if they were in the firing line during a pod strike.

Iron Duck 22nd May 2020 20:13

Why did no-one notice?
 
From what I can see from the videos and stills, the U/C, flaps & slats are retracted in the still shot of the scraped nacelles, but the U/C is down in every video clear enough to see. The videos are not clear enough to ascertain the flap & slat position. In every image the engines are trailing white vapour. So, I'm not surprised they stopped, possibly from oil starvation. In the video of the aircraft descending into the buildings, it's quite clear that the first plume of smoke is wrapped around a fireball, so I think it unlikely that overall fuel starvation is the cause.

The interesting bit in all this is how the engines came to be damaged, and how it seems no-one noticed at the time, because it looks as if they must have been damaged a good 5 minutes before the aircraft crashed. How is it, then, that this aircraft came to bang its engines on the ground without anyone noticing, and with no remarks about it on the radio?

ZAGORFLY 22nd May 2020 20:14


Originally Posted by PoppaJo (Post 10789731)
I’m not sure if that video showing the port side is the real deal. Seems like a normal approach to me. If it is the video, then glide speed is good and I assume they simply landed short. Gear is down.

only if we have a photo showing the RAT we know that it was a double engine out. from the photos i have seen of the wreck it looks that the fan was not rotating under power.

giggitygiggity 22nd May 2020 20:18


Originally Posted by squidie (Post 10790191)
Potentially gear issues on first landing, RAT may give that away at the moment. I think the possibility that there was some terrain contact with the engines slightly followed by a go around. But unsure on the final approach that resulted in the crash. By looking at the CCTV clips both engines are out as the crew are attempting to max out the lift with the high AoA.

Could have had a genuine fault with the gear followed by a depletion of fuel on the go around...

The RAT most likely fell out automatically when the gearboxes were destroyed as they're on the bottom of the engines. Both IDGs would have probably failed leading to RAT deployment. The final pitch angle was more likely just a natural reaction to them going down with no hope of climbing away from the city, the plane looks stalled so that doesn't suggest they're flying alpha max and sadly, probably just a sign of them wrenching back on the stick


Originally Posted by ZAGORFLY (Post 10790216)
only if we have a photo showing the RAT we know that it was a double engine out. from the photos i have seen of the wreck it looks that the fan was not rotating under power.

To split hairs, an extended RAT doesn't necessarily mean the engines have necessarily both failed, only that the AC busses aren't powered. This photo to me clearly shows the RAT as extended.

https://cimg3.ibsrv.net/gimg/pprune....1609143754.jpg

pattern_is_full 22nd May 2020 20:26

On the one hand, I am firm believer in "never say never." There have been too many aviation accidents where observers say "No pilot (or crew, or aircraft) would ever do that!" - only to be proven wrong when the final report comes out. Pilots and planes sometimes do the craziest things.

I do have doubts that a crew would attempt to complete a 550nm flight if they had bounced the engines on the tarmac on take-off, but you just never know.

I do have doubts the impact mushroom cloud would have been that large (see end of final glide video) if the fuel tanks were empty, but you just never know.

For the moment I lean to the theory of - ground contact during gear-up touchdown (intentional or not) - followed by mechanical engine failure due to ground contact (G forces, inner inlet shrouds dislodged, fan strikes, oil loss, etc.) - followed by attempt to stretch glide at alpha-floor (which rarely works, but if the alternative is hitting a 5-story concrete building head-on....?).

Will stay tuned for further information.

Airbubba 22nd May 2020 20:43


Originally Posted by giggitygiggity (Post 10790219)
To split hairs, an extended RAT doesn't necessarily mean the engines have necessarily both failed, only that the AC busses aren't powered. This photo to me clearly shows the RAT as extended.

And, probably not a player in this case unless some checklist calls for it but the RAT can be deployed manually using a guarded switch on many aircraft including apparently the A320. I know it works even with the battery switch off on some Boeings after a colleague with SR-71 stickers all over his flight kit demoed it one day on the ramp while trying turn on the battery to start the APU.

zoomee 22nd May 2020 20:54


Originally Posted by Feathers McGraw (Post 10789787)
Could the dirty lower nacelles be due to oil leaks, maybe over the whole flight? I know it's both engines but maybe there was some sort of systematic maintenance error.

If the oil loss is total then both engines could run down due to lack of lubrication.

Assuming the engine is a CFM 56 (a guess but maybe representative) there are U Tube videos showing how to rebuild the oil pump. Pump, manifolds and lines are mounted on the bottom of the fan ring...pretty much exactly where you see the black soot (maybe dirty oil?) trail start from in the pictures. If it touched the ground at all I would expect some of those lines got crunched.

BrooksPA-28 22nd May 2020 21:01

Questions about this video
 

Originally Posted by skadi (Post 10790037)

There is some reason to question the validity of this video. The photos of the plane (showing the rat deployed) show the gear up. The video shows the gear down. The ATC transmission mentions a belly landing. This also implies a gear up configuration. Finally it appears to me that the shape of the buildings that the plane passes behind, are distorted by the plane's passage. This could be an artifact of the video compression. It would be interesting if someone could identify the building and surrounding area, then match that to the crash location.

eagle21 22nd May 2020 21:02

It is clear that the controller did not think that they would make the first approach just based on their energy 3500ft at 5NM. It will be interesting to find out what the rate of descent was in the last minute of the first approach. If there were over speed (flaps) warnings masking a Landing gear not down ECAM and a high rate of descent with a low thrust setting by the the time the GPWS gives you the TOO LOW GEAR there may only be a few seconds to react. Imagine high workload from a high energy approach, the low thrust setting, late go around decision and into the flare mode and not enough back stick pressure (big pull required low down) and ground contact quite possible. The rest would be consistent with a double engine failure from the damage.


giggitygiggity 22nd May 2020 21:02


Originally Posted by Airbubba (Post 10790232)
And, probably not a player in this case unless some checklist calls for it but the RAT can be deployed manually using a guarded switch on many aircraft including apparently the A320. I know it works even with the battery switch off on some Boeings after a colleague with SR-71 stickers all over his flight kit demoed it one day on the ramp while trying turn on the battery to start the APU.

I apprecieate that, from memory, even the dual AC loss asks you to press the button just incase it doesn't automatically pop out. I can't remember but dunno on the A320 if it works with the batts off? Seems sensible as they can't rule out that some idiot could have turned them off for some reason. Never flown a boeing, is it not guarded?

Stillapilot 22nd May 2020 21:06

This is a possible scenario:

LGCIU 1 fault, GPWS off as per ECAM to prevent spurious 'TOO LOW GEAR' flight continues, LGCIU 2 Fails on final, high workload, gear missed, no GPWS call outs due to being selected off earlier. Aircraft flares, crew notice abnormal attitude etc. Baulk landing, nacelles contact runway. Damage is done to IDG's, both fail on go around, aircraft loses AC1+2 RAT extends, further (currently unknown) damage done to engines on contact with runway results in dual engine failure.
It's an idea based upon the current information


Airbubba 22nd May 2020 21:07


Originally Posted by offa (Post 10790194)
Nacelle scrape could have been from an early retraction on take-off with aircraft settling and causing additional damage or suspected damage to gear, The initial approach could have been inspection flypast before the fatal approach?


Originally Posted by pattern_is_full (Post 10790223)
I do have doubts that a crew would attempt to complete a 550nm flight if they had bounced the engines on the tarmac on take-off, but you just never know.

I listened to the 0800Z recording of their departure out of Lahore on LiveATC.net No mention is made any damage or anomaly.

Seems hard to imagine a gear up pass going all the way down to touchdown in a 'modern' airliner.

Still, some odd things happen in South Asia.

Remember the Air India crew that was low on fuel after forgetting to raise the gear on takeoff?

https://www.pprune.org/rumours-news/...oisy-here.html


Airbubba 22nd May 2020 21:14


Originally Posted by giggitygiggity (Post 10790250)
Never flown a boeing, is it not guarded?

It is guarded and it's not near the battery switch. But it is also on the overhead and uses a similar square switchlight.


All times are GMT. The time now is 23:34.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.