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Polish President and wife killed in Tu-154 crash

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  • There was some talk that since the base had been abandoned the trees were beyond the allowable height for commercial or conventional use when it came to the runway alignment.

    Perhaps a lot of flora and fauna were dug and removed during the recovery for remains of both persons and aircraft.
    Live, from a grassy knoll somewhere near you.

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    • Originally posted by guamainiac View Post
      There was some talk that since the base had been abandoned the trees were beyond the allowable height for commercial or conventional use when it came to the runway alignment.

      Perhaps a lot of flora and fauna were dug and removed during the recovery for remains of both persons and aircraft.
      Especially fauna

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      • Glad you caught that.
        Live, from a grassy knoll somewhere near you.

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        • On Sunday Polish prosecutors and experts are going to Smolensk to examine the wreckage of the plane. They are supposed to stay there till the end of September.

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          • Examining some data under a microscope can render surprising results. In the Russian report there is a plot showing vertical acceleration. If we analize the last section of it we can see a wild variation of g forces. In the area A the range of g forces is normal oscilating around 1g. From point 0 to point 1 there is an increase of g from 1 to 1.35 reflecting the gain af altitude during the GA procedure (7.7 sec). Then between point 1 and 2 there is a quick drop of g (0.2 sec) to 0.85. At point 3 the g value returns to 1.35 in 0.5 sec. Then g value dives to 0.22 in 0.2 sec (point 4). In the next 0.8 sec the g spikes to 1.38 (point 5) only to drop again to 0.32 (point 6). I would like to see anyone try to explain that.

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            • When I plot the g values on the trajectory I face the issue of two different timelines. Polish one ends at 10:41:07.5, the Russian one (at least the one from the graph) at 10:41:04.3. The QAR ended at 10:41:04 (the last recorded value was from 10:41:02.5, but there was 1.5 sec delay in writing data). But most likely the right plot will be the olive green, the green, or somewhere inbetween. Points 1, 2, 3, 4, and 5 are where the most violent vertical acceleration occured. A change from 1.35g to 0.22g in 0.2 seconds when the plane is flying 5m above the ground is unexplainable.

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              • Clipping trees with the wings (or the wings with trees) tend to do nasty things.

                --- 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 Gabriel View Post
                  Clipping trees with the wings (or the wings with trees) tend to do nasty things.
                  ...Yeah, but CFIT on approach when weather is below minimums is responsible for such a small percentage of crashes.
                  Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                  • Originally posted by guamainiac View Post
                    There was some talk that since the base had been abandoned the trees were beyond the allowable height for commercial or conventional use when it came to the runway alignment.
                    You mean the tops weren't far enough below runway elevation?

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                    • Originally posted by Evan View Post
                      You mean the tops weren't far enough below runway elevation?
                      ...or they were deliberately raised knowing that the Polish president's plane would be flying at said altitudes
                      Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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                      • Originally posted by Gabriel View Post
                        Clipping trees with the wings (or the wings with trees) tend to do nasty things.
                        I don't think any other tree outside the 30cm birch could have done anything like that to a 80 ton plane. And what we see here is a vertical acceleration, or actually several cycles of it. But I am not entirely discarding it.

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                        • It is difficult to place any event in the proper place with so many timelines used. I will try to use only one timeline that is the most reliable - the one extracted from the TAWS logs at the Universal Avionics Systems Corporation offices in Redmond with NTSB and FAA personell present. I am going to use 5 logs of TAWS events # 34,35,36,37 and 38.

                          TAWS #34 - 10:40:03 (CVR - 10:40:06.7)
                          TAWS #35 - 10:40:29 (CVR - 10:40:32.4)
                          TAWS #36 - 10:40:36 (CVR - 10:40:39.4)
                          TAWS #37 - 10:40:43 (CVR - 10:40:46.5)
                          TWAS #38 - 10:40:59

                          The average difference is 3.5 sec.
                          Event #38 cannot be read from the CVR.

                          With the exact position, time mark, and altitude assigned to each event I should be able to verify the horizontal and vertical position of the plane.

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                          • In order to verify the timing of the collision with the famous birch and the g forces spikes, I have created a pattern of events of sounds indicating hitting obstacles. Points A and B are where the sound indicates a single hit, point C the same but much stronger, points D and E are centered on noise events that sound like going through a lot of small branches. According to the Report the birch was hit at 10:40:59.375.

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                            • This shows the plane's horizontal path based on TAWS events. The trees, MM, and all events are per geo coordinates. The best match for the ABCDE pattern from the CVR is shown with event C matching the birch location. That would put the time of hitting the birch at 10:40:58.0 TAWS time or 10:40:58.48 CVR time. If we shift the pattern the way that event D matches the birch location (10:40:59.40 according to the Report) then we have events A and B not aligned with any ground obstacles. In any case the difference between the TAWS time and CVR time is 0.5 or 1.6 sec. accordingly. That's different than TAWS 34,35,36 and 37 discrepancy (3.5 sec.). This would indicate that the integrity of the CVR record has been broken.

                              The location of the g forces spikes (yellow zigzag line) is also interesting. If hitting the birch did not induce the spikes then flying through smaller branches could not have done it either.

                              One more thing that is very apparent: the plane flies straight up to the TAWS #38 point despite the loss of a part of the wing. The trajectory changes after that point.

                              Also it seems that the broken off wing section should travel more or less in the same direction as the plane.

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                              • Did you factor that they were in a ditch ... depression .... valley or swale or whatever and were below runway threshold?
                                Live, from a grassy knoll somewhere near you.

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