Reno Air Races 2011.... Serious Crash

Discussion in 'Hangar Talk' started by Geico266, Sep 16, 2011.

  1. PittsDriver

    PittsDriver Cleared for Takeoff

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    There's an interesting situation at Reno that derives from the configuration of the course and the location of the grandstands. On the course, there's a straight section into the final turn before the grandstands where the planes are moving about as fast as they do anywhere on the course. In that turn, pilots are sometimes faced, because of overtaking/passing other aircraft at that point, with the decision to pull a really hard turn to stay on the course or go wide to fly over or behind the grandstands and be disqualified.

    So my question would be why is this set up this way? If people want to sit really close to the action, why not put all the spectators inside the course and have the planes lapping around them with their energy always pointed away from the crowds? Let the airplanes go as wide as they want around the turns and leave that decision to the pilots about what's the correct balance between the quickest vs. safe line around the course.
     
  2. John Baker

    John Baker Final Approach

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    I have not read all of this thread, so this may already have been posted. It's an e-mail I received yesterday from pilot friend, it was forwarded to him. Scott, you may want to skip this.

    John

    Sent: Wednesday, September 21, 2011 9:36 AM
    Subject: Not sure how to title this - two bits of info

    From another source:

    A friend of mine was at the Reno air races. He is a P-51 mechanic for Chuck Greenhill who races a P-51 in the stock class. Mike was watching the unlimited class and specifically had his eye on Leeward's plane since Greenhill and Leeward are very good friends. He heard the propeller governor let go with a screaming whine. The P-51 pitched up violently to vertical, did a split S at the top, came over inverted straight down. Somewhere in all this, he heard a tremendous explosion which he interpreted as the engine blowing up because the prop was no longer connected to the engine holding down the rpm's. In his opinion, it's irrelevant as to whether or not Leeward was unconscious as he had no control of the plane anyway and at such a low altitude he didn't have any time to do anything.
    The idiot reporters who say he is a hero because he "steered" the plane away from the grandstand have no clue; at least they didn't identify the plane as a Piper Cub.
     
  3. Fearless Tower

    Fearless Tower Touchdown! Greaser!

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    As much as I hate reporters, I don't know that I'd blame them for trying to call Jimmy a hero. They are not making that up - they are just repeating what alot of folks in the crowd were saying. They were saying it because the crash obviously could have been alot worse and with all the devastation, people naturally want to find something good to hold on to in the aftermath.....real or imaginary.
     
  4. Skylane81E

    Skylane81E Final Approach

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    Granted I was watching/listening with cuddy speakers but the audio of the crash I've heard the engine sounded fairly normal for a mustang right up to impact,

    but I wasn't there, and am far from an expert on P-51 sounds.

    I will offer the theory that 10+Gs of loading will change the sound of the propeller cutting through the air.
     
  5. PittsDriver

    PittsDriver Cleared for Takeoff

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    That's not been my experience after having judged hundreds of competition aerobatic flights. Snap rolls, tumbles, ...maneuvers that rapidly change the orientation of the aircraft you definitely hear some change. But a 10 g pull to vertical will just sound like an airplane going away from you.

    The report that I saw said that the telemetry showed that the airplane engine temporarily lost power due to low fuel pressure and resumed full power on the down line. That would have been pretty obvious except for the fact that there are other unlimited class racers making a lot of noise at the time as well.
     
  6. Skylane81E

    Skylane81E Final Approach

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    And the telemetry will tell all.
     
  7. dmspilot

    dmspilot En-Route

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    I'd like to know to. I would have assumed that the regulations for air races were the same as air shows which specify that energy may not be directed at the crowd. Apparently that is not the case?
     
  8. Inverted

    Inverted Cleared for Takeoff

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    The course is set up in a way that yes, for a split second the noses pass through the direction of the crowd. If you notice at air shows, whiles a performer will not perform a maneuver directed towards the crowd, the will make turns towards the crowd.

    Watch a high G turn performed by any military demo team, it will do the same.
     
  9. BellyUpFish

    BellyUpFish Cleared for Takeoff

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    His energy didn't carry him into the crowd. He was flying away from the crowd.
     
  10. brcase

    brcase Pattern Altitude

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    It probably would have some advantages, but also some logistics problems like how to you get people in an out of the spectator area. Also in this particular accident the airplane could have just as easily rolled left rather than right and now you have the potential of this happening anywhere around the course instead of the from one location.

    Brian
     
  11. kyleb

    kyleb Final Approach PoA Supporter

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    Inside the course is problematic because you can only see a <relatively> small portion of the course if you're inside of it, with grandstands behind you. Inside the course is also problematic for providing in and out access to spectators.

    Besides, at least in last week's accident, it wasn't like debris sprayed wide after a crash on the course - the aircraft left the course and crashed. IMO, when an aircraft loses control like that, it is a coin flip whether it'll come down inside or outside the course.
     
  12. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    That's what I saw too, but no way to validate it:

     
  13. Fearless Tower

    Fearless Tower Touchdown! Greaser!

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    Prelim is out:

    Wonder why they listed it as 'substantially damaged' vs 'aircraft destroyed'. Has the NTSB just dropped the 'destroyed' description from use?
     
  14. OtisAir

    OtisAir Line Up and Wait

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  15. BillTIZ

    BillTIZ Final Approach

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    Depends on what was instrumented. I thinking speeds and engine data and g forces. Maybe not control deflections or fuselage vibrations. I also think perhaps GPS position as part of the telemetry.
     
  16. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    Snippet from part of a thread on one of my homebuilder forums, with some comments by the Rutans. 22 Gs?! Wow.

    Of course, the sensor itself, and its mounting, would have to be looked at in detail to see if the number is realistic. I believe the sensor may have recorded a 22G data point, but then it comes back into how the sensor was designed and implemented. The sensor might have flexed or ripped from its mountings, hitting the sensor against part of the aircraft structure. Or, the printed circuit board inside the unit might have ripped from its mount points at 12G's, but the sensor hit the housing and recorded 22G's.

     
  17. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser! PoA Supporter

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    I wonder how many pounds of stick force would be present when the tab is suddenly lost at 500 mph. Even if you could be aware it was coming you might not be able to hold it forward.
     
  18. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    I think the stick would be ripped from your hands...
     
  19. Jay Honeck

    Jay Honeck Touchdown! Greaser!

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    Well, if you figure your arm weighs between 8 and 12 pounds (yes, even THAT is available on The Google), 22Gs would make your arm suddenly weigh between 176 and 264 pounds.

    Sure, you might have a grip on the stick, but -- aside from the fact that you would be rendered instantly unconscious -- there is little chance of hanging on under those kinds of G forces.
     
  20. N801BH

    N801BH Touchdown! Greaser! Gone West

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    I thought the exact same thing...... It's not like they will be able to salvage anything off that aircraft.:no::no::no::no:..

    Substantial my A$$....:confused:
     
  21. Everskyward

    Everskyward Experimenter PoA Supporter

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    The data plate?

    As far as Gs go, There seems to be many videos of this accident. I'm no physicist but if an airplane flying at a certain speed changes direction by a certain amount in a certain length of time isn't there a way to compute the Gs? Not that it matters, it was obviously too many.
     
  22. weilke

    weilke Touchdown! Greaser! PoA Supporter

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    Because 'substantial damage' has a definition in the FARs, 'pulverized' doesn't.

    But yes, the first thing that came to my mind after reading that prelim was a similar thought, 'what does it take to be called 'destroyed', splitting into subatomic particles ? '
     
  23. weilke

    weilke Touchdown! Greaser! PoA Supporter

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    Yes.

    http://en.wikipedia.org/wiki/Photogrammetry
     
  24. N801BH

    N801BH Touchdown! Greaser! Gone West

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    I bet the data plate can't be found either,,, at least in less then 100 pieces..:sad:
     
  25. Everskyward

    Everskyward Experimenter PoA Supporter

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    Funny that you should direct me to a link about photogrammetry since I was involved in that industry for a long time but mostly having to do with topographic mapping. I never related it to crash investigation.
     
  26. weilke

    weilke Touchdown! Greaser! PoA Supporter

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    It's measuring stuff off images.

    In this case, there are a number of video frame series shot from different projections. Each of these provides a series of 2D coordinates (by being able to relate to fixed objects like the pylons or grand-stands included in the shots). By using several 2D trajectories, a skilled investigator will be able to create a 3D trajectory and speed profile. This is done for car accidents if they are caught on surveillance camera, e.g. from gas stations on opposite sides of an intersection. Insurance companies will gladly pay for those studies if serious money is at stake.

    I think 'videogrammetry' is the more precise term for the method.
     
  27. Let'sgoflying!

    Let'sgoflying! Touchdown! Greaser! PoA Supporter

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    Let's say you somehow knew the stick-snatch was about to occur and were braced with both hands to push on it. Roll your eyes, I know it's impossible.
    What I am trying to discover is, how many lbs of force would the pilot experience at the instant the tab departed?
    100? 500? Both arms broken?
    Completely a theoretical question, but it would put into perspective for me the events at that moment.
     
  28. Everskyward

    Everskyward Experimenter PoA Supporter

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    Interesting. We would take photographs looking straight down from an airplane with 60% overlap. These would be put in instruments called stereoplotters and the operators would follow each contour elevation, one by one, along the ground. It was very tedious. I have tried it. I'm sure it's all computerized now.
     
  29. Jim Logajan

    Jim Logajan En-Route

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    Wouldn't the stick whip back to center? If that is what happened, the movement of the stick might hurt his left hand and that is about it. (I'm assuming his right hand would be on the throttle, trim, or elsewhere - unless the layout of his P-51 controls favored right hand on the stick.)

    His head and upper torso probably lurched downward (relative to the fuselage) to the extent the harness would allow body movement. His head would have been forced towards his knees during the entire event I suspect, irrespective of whether he was conscious.
     
    Last edited: Sep 24, 2011
  30. TangoWhiskey

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    Here's the most detailed video I've seen (starting at 7:38, then several slow motion playbacks)... nothing graphic is shown (not even his final descent). The tailwheel appears to either have popped out on the initial pitch up, or even before (when the first "wobble" appeared). If the tailwheel had popped out during a high speed, high G turn, could it have precipitated all of this?

    The trim tab did not depart the aircraft til near the top of the ascent.

    http://airpigz.com/blog/2011/9/24/final-flight-of-the-ghost-video-by-jason-schillereff.html
     
  31. Let'sgoflying!

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    I don't know Jim.
    I read that, at race speeds, the tab is adjusted for more down trim, which I take to mean that forward stick was being applied and down trim took out that stick pressure.

    And when the trim pressure applied was by removed, I was thinking the stick would snap backwards because nothing was holding it forward any longer.

    The stick movement in all this is surely very small but the pressure involved, great.
     
  32. ScottM

    ScottM Taxi to Parking

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    Even though the trim tabs does not come off until the top of the ascent you can see that it is just hanging there a little before it comes off. What is not clear is if there was something wrong with that initiated the abrupt climb or if it was the result of the climb. Still a major piece of the puzzle.
     
  33. Geico266

    Geico266 Touchdown! Greaser!

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    I wonder if the seat broke during the turn causing him to pull back on the stick first, breaking the trim tab, and he was unable to get to the controls.

    I still cannot figure out why we can't see him in the side pictures. Even if he passed out we would still see him from what I have read. Any thoughts? :confused:
     
  34. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    You might be right... he's not even visible in the initial pitch-up after the "wobble". Here's a snap from 7:40 in the above video, immediately after he lost control.

    [​IMG]
     

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  35. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    Is there a separate tailwheel release control in the Mustang? If so, where is it? Might have tried to "grab onto something" if seat back failed??
     
  36. Ddayle

    Ddayle Line Up and Wait

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    Yesterday I talked with a friend who had been 300 feet from the in impact, seeing the glazed over look on his face as he recalled it, brought home the horror of the unfortunate accident. I am glad My friend was uninjured, and offer my sincere condolences to those injured or the family's of those killed. Dave
     
  37. yakdriver

    yakdriver Cleared for Takeoff

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    1 The seat cannot break and go back. It is mounted to vertical seat tracks that are mounted to very strong upper and lower cross members. The seat only adjusts up and down about 6".
    2 Tailwheel has a mechanical uplock. After the initial bobble the tailwheel was out when he initiated a slight climb. Speculation is that this might have been the first part of the sequence of events followed by the trim tab. Or trim tab flutter could have caused enough vibration too cause the tailwheel unlock?
    3 10+ gs would black out anyone not prepared for it.
    4 Probably had the shoulder harness unlocked forcing him to double over on the left side of the stick causing the right bank.
    5 The trim tab rod probably broke first causing the abrupt pitch up with the trim tab staying connected and fluttering severely until it broke free. Initial stick force probably exceaded 100lbs.
    6 The Mustang has standard right hand stick left hand throttle.
    7 Since there was probably over 5gs through the whole sequence after the initial 10g pull up the pilot probably had no chance to recover from the blackout.
     
    Last edited: Sep 25, 2011
  38. TangoWhiskey

    TangoWhiskey Touchdown! Greaser!

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    Thanks... Sounds much more plausible than what I was thinking...
     
  39. denverpilot

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    I read somewhere that the tailwheel mechanical uplock either releases or typically fails somewhere around 10G, but I can't find the reference link now. Could be bogus. Just sharing.
     
  40. Fearless Tower

    Fearless Tower Touchdown! Greaser!

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    I don't have a reference either, but several knowledgeable folks on the WIX forum seemed to refer to the mechanical uplocks failing as low as 8-9 gs.