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Pakistan plane crash: Jet carrying 107 people crashes into houses near airport

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  • #31
    Originally posted by xspeedy View Post
    The clip of the plane descending at high AoA looks as though its going too fast to be stalling, it looks like they have enough speed to glide and I wonder why is the nose up?

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    • #32
      Oh my god, this is frigging unbelievable. How did the engines contact the ground 5000 ft down the runway and how did they kept them dragging them for 2000 ft?????

      I think if you want to intentionally do that, you can't.

      On May 23rd 2020 Karachi Airport reported based on CAA inspection report that the runway inspection revealed scrape marks of the left engine start 4500 feet down the runway, the right engine scrape marks begin 5500 feet down the runway. About 6000-7000 feet past the runway threshold the scrape marks end.
      http://avherald.com/h?article=4d7a6e9a&opt=0

      --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
      --- Defend what you say with arguments, not by imposing your credentials ---

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      • #33
        Originally posted by Jingogunner View Post

        The clip of the plane descending at high AoA looks as though its going too fast to be stalling, it looks like they have enough speed to glide and I wonder why is the nose up?
        Why are you saying too fast? In my view they are gliding at minimum speed / maximum AoA. The slower you fly, they higher the AoA needed to sustain flight. Of course all that goes to trash if you stall, so they were not stalled but slightly before stall. Possibly, this is the feat of the flight control computers limiting the AoA to alpha max and blocking the pilots intent to pitch even higher up trying to extend a glide beyond the laws of physics. Somehow similar to the 1st A320 crash, the Air France one in that air show.

        --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
        --- Defend what you say with arguments, not by imposing your credentials ---

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        • #34
          Originally posted by Evan View Post

          They do look kind of shredded on the bottom (could be the low resolution). If this was from ground contact, this is just insane.

          Maybe a gear collapse and they got airborne again?
          The marks under the engines show burning fuel had been blown back in the slipstream. There are no marks on the belly of the plane. Therefore, the engines had not been scraped along the ground before the go around, as some have suggested.



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          • #35
            Originally posted by Jingogunner View Post
            The marks under the engines show burning fuel had been blown back in the slipstream. There are no marks on the belly of the plane. Therefore, the engines had not been scraped along the ground before the go around, as some have suggested.
            Where is the facepalm emoji when you need it most?

            --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
            --- Defend what you say with arguments, not by imposing your credentials ---

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            • #36
              Originally posted by Gabriel View Post
              Oh my god, this is frigging unbelievable. How did the engines contact the ground 5000 ft down the runway and how did they kept them dragging them for 2000 ft?????

              I think if you want to intentionally do that, you can't.
              This can't be happening. It's like a bad made-for-TV movie. They must have still been flying around 1G and just skimming along the runway, without gear compression there would be no ground spoiler activation, but still, that would cause friction and loss of airspeed and you would expect the plane to sink down on the engines. Perhaps with thrust spooling up the friction was overcome...

              One thought: if they did, in fact, forget to lower the main gear before the first landing attempt, it may have been the result of some CRC warning confusion. There is a CRC aural warning for L/G GEAR NOT DOWNLOCKED and there is a CRC warning for L/G GEAR NOT DOWN. Since they were possibly getting an L/G GEAR NOT DOWNLOCKED warning on ECAM for a problem with the nose gear, and were ostensibly working that problem when they passed through 750 AGL, they may have mistaken the L/G GEAR NOT DOWN warning for the L/G GEAR NOT DOWNLOCKED warning and merely ignored it. Of course, a quick ECAM check would have shown them the situation, but... high workload, non-stellar pilots on a bad day...

              Another thought: If they used the gravity extension crank and failed to reset it before landing (this assumes there was no apparent green system issue), the main gear could have collapsed on landing. But then the gear doors would still have been open and the damage would be pretty obvious in those pictures. So nevermind.

              So either they intentionally attempted a belly landing (without notifying ATC of their intention or holding first to exhaust any possibly of getting the gear down) or they botched the go-around and pulled the gear up too soon. I can't see any other way into this situation. They were 1700ft high passing the FAF, so possibly the sink rate was too high to arrest during a late go-around, but why would they pull in the gear before establishing positive climb? I'm still wondering why you would pull in the gear at all if you are having gear extension issues.

              At this point, knowing very little, it looks like we might be seeing an absurd new echelon of pilot error.

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              • #37
                Another thought: If you were intentionally executing a gear-up landing on an 11,000+ ft runway and you touched down with almost 7000ft of runway in front of you and settled on both engines with almost 6000ft left, why would you think to accelerate and get airborne again? Who does touch and goes without wheels?

                It can't be that.

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                • #38
                  I have confirmation that there was only 1 go-around.

                  We may want to revisit the Emirates 777 scenario. They came in an unstabilized approach (from 3500 ft @ 5 miles, the approach almost had no choice but to be unstablized at least until very low), they attempted to land but something went wrong (a bad bounce, they touched down too long, etc...) so they went around but somehow they forgot to add thrust (which had been already retarded at 20 ft). They pitched up and initially gained altitude and retracted the gear, but they lost speed and started to sink. They added thrust but not in time to avoid runway contact but they also didn't hit as hard as Emirates did and managed to accelerate dragging the engines (they already had TOGA thrust since before the ground contact) and climbed out.

                  That is at least a way how you can have the plane contacting the ground gear up as far as 5000 ft down the runway (after a first "touch and go" in a more reasonable touchdown zone followed by a failed subsequent go around with the airplane settling back on the runway).

                  --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                  --- Defend what you say with arguments, not by imposing your credentials ---

                  Comment


                  • #39
                    Originally posted by Gabriel View Post
                    I have confirmation that there was only 1 go-around.

                    We may want to revisit the Emirates 777 scenario. They came in an unstabilized approach (from 3500 ft @ 5 miles, the approach almost had no choice but to be unstablized at least until very low), they attempted to land but something went wrong (a bad bounce, they touched down too long, etc...) so they went around but somehow they forgot to add thrust (which had been already retarded at 20 ft). They pitched up and initially gained altitude and retracted the gear, but they lost speed and started to sink. They added thrust but not in time to avoid runway contact but they also didn't hit as hard as Emirates did and managed to accelerate dragging the engines (they already had TOGA thrust since before the ground contact) and climbed out.

                    That is at least a way how you can have the plane contacting the ground gear up as far as 5000 ft down the runway (after a first "touch and go" in a more reasonable touchdown zone followed by a failed subsequent go around with the airplane settling back on the runway).
                    I mostly concur with this theory, except it leaves out reports of initial problems with the nose gear. I suspect those reports are incorrect. If they did have a gear issue, I doubt they would have come straight in. I think the gear issue might have occurred after the go around, or maybe there was no gear issue at all. The misinformation coming from these 'official' sources in places like Pakistan and Iran seem to be worth even less than Trump's medical advice. In the process of losing both engines, they probably lost the powered gear extension and either hadn't gotten to the alternate extension when those photos were taken or it was jammed due to poor maintenance (there is precedent for this and an emergency AD was issued).

                    But I can't believe they 'settled back on the runway' and they got it up again. I think they may have skimmed it, but without much weight.

                    Comment


                    • #40
                      Hi Gabe.

                      scontent - sfw atc # 5?

                      I like to add another source. First of all, I do not assume that wikipedia knows everything, or everything better than investigators from the NTSB. But if there is a en dot wiki, that's always my first source. Here it is.

                      https://en.wikipedia.org/wiki/Pakist...es_Flight_8303

                      date of the incident: May 22nd 2020
                      a/c type: Airbus A320
                      .. in the air since: 2004
                      departure: OPLA Intl airport (Lahore)
                      arrival: OPKC Jinnah Intl airport (Karachi)

                      So, from Pakistan to Pakistan, a domestic flight with 99 souls on board that Airbus A320.

                      Injured and fatalities: 2 injured and 97 dead souls on board.
                      Survivors: 2 .

                      Development of the fatal crash.
                      The pilot had made an aborted landing attempt before he encountered a technical issue.
                      taken from the en wiki, May 24th 2020.
                      So, I like to second what you said, Gabe.
                      One go around.
                      Twelve seconds later, he issued a mayday alert,which was the final communication between the control room and the aircraft.
                      again from the source '[...] Flight # 8303', see above.

                      I looked it up, this is a distance of not much more than 551.5 nautical miles. So, piece of cake for an A320.

                      Assumed that you take enough fuel with you.

                      I'm here in this forum long enough so that I'm able to remember cases where the responsible Flight Captain tried to fly a distance of.. what was that.. 1,900 nautical miles?
                      But that was an a/c type which was only able to fly 1,750 nautical miles nonstop, as a maximum.
                      Chapecoense. November 28th 2016.

                      I assume that there was enough fuel in this Airbus A320. Who would try to save fuel in an A320 during a really short 552 nmi flight?
                      There are really men who know more about an A320, but I'd order 50% of the max FOB (fuel on board), and up we go.

                      So, what really happened?

                      PS: I just wondered how the threadstarter counted 107 souls. According to en dot wiki,
                      99 souls on board, 97 dead on board
                      plus
                      8 injured (or dead) on the ground.
                      I don't know the exact numbers, but that would make sense, 97 on board + 8 on the ground = 105.

                      Then there really is the question, another 8 dead on the ground, which does not happen so much often, dead persons on the ground,
                      was that avoidable?

                      I always assume, that in almost all cases, fatalities on the ground are avoidable. But I really have a shining prototype.
                      Flight Captain Chesley Sullenberger III .
                      He chose the river to avoid fatalities on the ground.
                      That's what airlines are good for, amongst others,
                      The Gold Member in the 747 club, 50 years since the first LH 747.
                      And constantly advanced, 744 and 748 /w upper and lower EICAS.
                      Aviation enthusiast, since more than 35 years with home airport EDDL.

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                      • #41
                        So it is confirmed that both engines scraped along the runway... and quite a long way towards the end of the runway,........
                        Indicates a botched go-around with gear being retracted too early?
                        The damage to the undersides of the engines would have ripped out oil and fuel lines... and doomed the engines.

                        Also problems with the initial approach - they were way too high and fast.. initiated a rapid decent to capture the glideslope.. a theory is that they deployed the landing gear early to help slow down.. as they were too fast the landing gear does not deploy due to the protections inbuilt.. but the gear handle stays down.. maybe missed before landing... although it seems incredible that they would have silenced all the alarms that must have been blaring in the cockpit. and ignored all the warnings on the EICAS.

                        Other factors in the mix... first flight for some months due to lockdown and pilots fasting due to Ramadan...

                        The CVR should reveal what was actually going on in the cockpit... incredible that they did not mention scraping the engines on the runway to the Tower or nobody at the airport saw what happened

                        Comment


                        • #42
                          Originally posted by flyingphilnewson View Post
                          So it is confirmed that both engines scraped along the runway... and quite a long way towards the end of the runway,........
                          Indicates a botched go-around with gear being retracted too early?
                          The damage to the undersides of the engines would have ripped out oil and fuel lines... and doomed the engines.

                          Also problems with the initial approach - they were way too high and fast.. initiated a rapid decent to capture the glideslope.. a theory is that they deployed the landing gear early to help slow down.. as they were too fast the landing gear does not deploy due to the protections inbuilt.. but the gear handle stays down.. maybe missed before landing... although it seems incredible that they would have silenced all the alarms that must have been blaring in the cockpit. and ignored all the warnings on the EICAS.

                          Other factors in the mix... first flight for some months due to lockdown and pilots fasting due to Ramadan...

                          The CVR should reveal what was actually going on in the cockpit... incredible that they did not mention scraping the engines on the runway to the Tower or nobody at the airport saw what happened
                          Interesting. I don't know what happens if you try to lower the gear above 260kts and leave the lever down. The safety valve prevents hydraulics from operating above 260kts, but, once below 260kts, will the valve open and the gear deploy by itself or does that require recycling the lever?

                          Also, what is the associated ECAM warning? AFAIK, there is no L/G OVERSPEED warning. Would you get the L/G GEAR NOT DOWNLOCKED warning? Would you get the red arrow on the indicator? Or would you just get nothing? If you were clueless on the 260kt protection feature, how would you recognise the problem?

                          In my FCOM there is no mention of the 260kt requirement in the L/G GEAR NOT DOWNLOCKED QRH procedure. It just instructs you to recycle the gear and, if that fails, use the gravity extension. In this scenario, if the pilots tried recycling the gear above 260kts it would be unsuccessful and then they might lower the gear manually at an unsafe speed.

                          Know your airplane is, I guess, the lesson there.

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                          • #43
                            Our team from Plane Spotters Pakistan compiled the chain of events into an article that contains a comprehensive information file about what we know over 72 hours after the accident. This file is based on official documents, eye-witness accounts and known facts of the flight.

                            Do give it a read
                            https://www.magazine.jetliners.co/?p=666

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                            • #44
                              Originally posted by Evan View Post

                              Know your airplane is, I guess, the lesson there.
                              You feeling OK?

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                              • #45
                                Originally posted by ATLcrew View Post

                                You feeling OK?
                                Just looking for answers. Do you have any?

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