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777 Crash and Fire at SFO

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  • #91
    Last ATC exchange was final clearance to land 28L 40 seconds before impact. No indication of problem in pilot's voice or message.

    BA38 (777 at LHR) also had similar ATC clearance exchange 32 seconds before impact with no indication of problem. The BA 777 managed to get a mayday out 10 seconds before impact and retract some flap to extend the glide.

    Witnesses report plane wobbled on approach. Could be interpreted either as aerodynamic stall, control problems or controlled change of direction (cleared for 28L but might have been lined up for 28R?)
    Other witness said that the plane flipped over on its back, so goes to show how unreliable witnesses are.

    Passenger said that the plane 'flipped up and down' before impact. Passengers on BA38 didn't feel anything out of the ordinary before impact.

    Looking at new photos, could be the right main gear that struck sea wall first explaining the debris field right of centre line. Also, the ground marks only start 80-120 feet from the aircraft suggesting that the aircraft was somehow airborne as it left the runway. A twitter pic shows one wing high and the fuselage at a high angle. This may have looked something like a cartwheel but it certainly wasn't sliding on the ground all the way from original gear or tail impact.

    There is also interesting damage to the leading edge of the vertical stab. Could it be possible that the gear sheared off and struck the vertical stab leading to the disintegration of the rear empennage? Not sure. But looking at the fuselage section still attached to the vertical stab, the front edge looks like a failure under tensile load supporting the theory that the vertical stab was pulled back. With a tail strike, that section of fuselage would show compressive failure, i.e. buckling. Similarly, the end of the main fuselage just above the pressure bulkhead does not show compression or buckled edges at the top.
    Nor do the ground marks show the classic signs of a tailstrike.

    One might also expect to see buckling of the top fuselage just aft of the main wings in a tailstrike severe enough to rip the tail off.

    Either way, he was way low on the GS. But I may have to retract the low airspeed theory.

    Best guess is:
    - Low on GS with right wing low
    - Right main gear strikes sea wall
    - Gear flips up and hits vertical stab
    - Rear empennage breaks off/apart
    - Aircraft starts to yaw right raising left wing
    - Rapid deceleration
    - Aircraft pancakes down and slides short distance to final position

    Superb aircraft design holds together saving a lot of lives!

    Main question is why he was low on GS.

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    • #92
      Passenger witness says he heard the engines rev up, so puts doubt on the fuel starvation theory.

      Comment


      • #93
        Originally posted by akerosid View Post
        Only the second 777 ever to be written off; hopefully still non-fatal, though reported that many taken to hospital.

        LN 553. Crashed on landing at San Francisco International Airport, July 6, 2013.. HL7742. Boeing 777-28E(ER). JetPhotos.com is the biggest database of aviation photographs with over 5 million screened photos online!


        LN 553, first flight Feb 2006.
        Well I wonder what rock did I just crawl out from under? What, where, and when was there another 777 loss / crash? I cannot remember any other 777 crashes. Was there heavy loss of life?

        Thanks for any help on this.

        Rick.

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        • #94
          Just read this article: http://ca.news.yahoo.com/airport-lan...053403798.html. In this case, what type of visual approach light system does SFO have, and would this have been the main guide for a pilot landing at SFO yesterday?

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          • #95
            BA 38 at Heathrow. Yesterday's crash was the first 777 crash that ended with loss of life.

            Doug

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            • #96
              The type's second hull-loss occurred on July 29, 2011, when an EgyptAir 777-200ER registered as SU-GBP suffered a cockpit fire while parked at the gate at Cairo International Airport.[201] The plane was successfully evacuated with no injuries,[201] and airport fire teams extinguished the fire.[202] The aircraft sustained structural, heat, and smoke damage, and was written off.[201][202] Investigators focused on a possible electrical fault with a supply hose in the cockpit crew oxygen system.[201]

              Also a ground worker killed during a re-fuelling fire in denver in 2011. Not really attributed to the 777 type though.

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              • #97
                Originally posted by Gabriel View Post
                I am guessing that it's:
                Geographic crooordinates - - ground track (direction) - grounspeed - airspeed - altitude - vertical speed.

                Typical approach speed can be in the order of 150kts. Typical stall speed would be in the order of 110kts.
                Its actually this.

                MST Latitude Longitude Course Direction KTS MPH feet Rate Location/Type


                The airspeed at 300ft was 123Knots and at 100ft it was 109knots. Just for comparison, I looked at the past 20 flights of Asiana214 and the lowest airspeed at touchdown was around 125 knots.
                Last edited by saupatel; 2013-07-07, 15:29.

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                • #98
                  Nice work, Saupatel !!!

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                  • #99
                    Looking at the pics on AV Herald.... Why or what is the extra dark area of pavement that has been added between the Google Earth pic and the start of the runway as it exists now ? Could that have fooled the pilot into thinking the runway started there ?

                    Comment


                    • Originally posted by TheKiecker View Post
                      Looking at the pics on AV Herald.... Why or what is the extra dark area of pavement that has been added between the Google Earth pic and the start of the runway as it exists now ? Could that have fooled the pilot into thinking the runway started there ?
                      It looks like the runway threshold has been displaced.

                      You can see the white arrow where the centerline would be.
                      This is the displaced threshold zone. You can start the take-off from that zone, you can also use to complete the stop on a landing or rejected take-off from the opposite runway.
                      But you are not allowed to land in that zone. When landing, the runway officially starts after the last arrow (in this case there is only one) and after white line that crosses 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 ---

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                      • Originally posted by Dispatch Dog View Post
                        .............
                        One might also expect to see buckling of the top fuselage just aft of the main wings in a tailstrike severe enough to rip the tail off.
                        ...............
                        There is fuselage buckling both aft and fwd of the wings. Fortunate that the fuselage held together at these high load points.

                        Comment


                        • Originally posted by Dispatch Dog View Post
                          There is also interesting damage to the leading edge of the vertical stab. Could it be possible that the gear sheared off and struck the vertical stab leading to the disintegration of the rear empennage? Not sure. But looking at the fuselage section still attached to the vertical stab, the front edge looks like a failure under tensile load supporting the theory that the vertical stab was pulled back.
                          I very much doubt that the main landing gear hitting fin has the ability (read power) to rip all the tailcone behind the pressure bulkhead. This zone is stronger than one might think, since it must bear the loads of the control surfaces in extreme conditions.

                          I would also expect that the empenage (tali cone + horizontal and vertical surfaces) would be mainly intact.

                          What we have instead is:
                          - Everything behind the rear bulkhead gone.
                          - The fin still firmly attached to the upper zone of the tail cone.
                          - Each horizontal stabilizer mainly intact on the runway, but separated from the tailcone.
                          - No news about the bottom of the tailcone.

                          It looks more plausible to me that the bottom of the tailcone struck the seawall and got ripped. The structure holding the horizontal stabilizer falied and the upper part of the tailcone was pulled back (with the fin and all).

                          --- 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


                          • Originally posted by Highkeas View Post
                            There is fuselage buckling both aft and fwd of the wings. Fortunate that the fuselage held together at these high load points.
                            Kris Sanchez ‏@KrisNBC 28m
                            #SFOCrash SF General chief of surgery says some patients have paralyzing spine fractures, severe road rash as if dragged .

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                            • Gonna pile on with an earlier Deadstick post.

                              You are a top of the line pilot...you fly long haul routes, that means 2 landings/month (and highly automated ones at that!).

                              You fly all-night red eyes which means royaly screwed up sleep rythims.

                              You are cruising into SFO after being locked in a god-forsaken cockpit for 13 hours sitting up monitoring mundane crap and checking in with operations.

                              The weather is severe VMC and you are on a visual approach, and have the auto throttles off.

                              You and your PNF are a bit zoned out with fatigue and you focus on the end of the runway- which (by the way you ARE aiming at pretty good)....

                              But your speed decays a little and you pull up a little and your speed decays a little more and you sink a little low- but you are still looking at that landing spot....suddenly you find yourself low and slow in a giant-ass airplane with giant ass engines that spool up oh so painfully slow...

                              There does seem to be some information suggesting nose-high-dragging-it-in as though he was trying to squeeze every last pit of energy out of the plane to make the threshold.....
                              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                              • The local media here is unbelievable. KCBS radio just reported. "More drama at SFO, a 747 just landed with three engines working instead of 4".

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