Reno Air Race - Reply to Topic

Reply to Thread

Post a reply to the thread: Reno Air Race

Your Message

 

Send Trackbacks to (Separate multiple URLs with spaces)

You may choose an icon for your message from this list

Register Now

Please enter the name by which you would like to log-in and be known on this site.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Please select your insurance company (Optional)

Log-in

Additional Options

  • Will turn www.example.com into [URL]http://www.example.com[/URL].

Topic Review (Newest First)

  • 10-13-2011, 11:05 AM
    SoldHondaBoughtHondo
    Quote Originally Posted by steelcomp View Post
    All very well stated and good points. So others might understand what a trim tab is and does: When I was in A&P school we had a really lengthy debate one day and the question was do control surfaces work off of lift/pressure differential, or deflection? It was an interesting discussion and I think the answer was a little of both. A control surface when moved, does change the length of the chord and mean camber line of the airfoil thus changing the perssure differential, but it also does work on simple deflection, especially the rudder which really isn't an airfoil. These surfaces can change the charaacteristics of the wing when moved because they represent a large enough percentage of the wing's total surface. A trim tab, however, does not. It's located at the very trailing edge of the airfoil after all the "lifting" has been accomplished. Trim tabs are used to assist the pilot during flght manuvers where a constant pressure of a control input is required outside what is normally required for straight and level flight. If a pilot has a long climb out or wants to gain altitude, he can adjust the trim tab to help relieve holding constant elevator pressure at the controls. Same with a slow decent. Adjust the trim, and it takes pressure off the controls. If the trim tab came off, the controls would just go back to the normal condition. Now, having said all that, we don't really know how the trim tab was being used in this application. Most oval track cars have their front alignment and tire stagger set so the driver doesn't have to fight the car through the turns. Tha car is set up to want to turn left. If the aiprplane was "trmmed" for the turns, it would be adjusted to help reduce the needed back pressure on the controls that is used in a 90* banked high speed turn. Basically, you're climbing the airplane, only horizontally instead of vertically. with a lot of back pressure. The result would be to require some downward pressur during straight and level flight after coming out of the turn, just like the oval track car fighting the car's wanting to turn left while gong straight. IF the trim tab came off suddenly, there might be a momentary slight climb of the airplane, but it would be something a vetran pilot could and would react to the instant he felt it. I think what happened was that he did feel it, knew there was a problem, and as per the rules, he did exactly as he was supposed to and pulled upward and off the race course...unfortunately possibly in too agressive of fashion, and just passed out.
    I spent that entire Saturday and a lot of Sunday following the accident just watching every video and looking at every picture I could find. I know the owner of the other P51 (Voodoo) in the race and it really hit home with my aviation backround.
    I agree .. I was thinking that if the trim tab had only partially
    broke free, like at the hinge points and just for a second it was held on by just the linkage it could cause a sudden movement of
    the control surface and the feedback on the stick caused him to loose his grip.

    As for the value of a trim tab on the elevator on a race plane, I
    would think the plane would be balanced to the point it's need would be minimal. Needing to add a bunch of trim to get a plane to fly flat and level is nothing but unnecessary drag
  • 10-12-2011, 10:39 PM
    scott foxwell
    Quote Originally Posted by snoc653 View Post
    My .02......This was a terrible tragedy, but if you are at an air race you should know that if something breaks it is coming down. Enter at your own risk. If something comes off a plane, it will be coming down. ENTER AT YOUR OWN RISK. And unless you are flying the plane, once you've entered your risk is out of your control. There is nothing you can do about the risk so accept it or leave.

    As for the AFT CG comments, unless they've redesignated the propeller to be the aft of the plane, the aft has always been at the rear. So the elevator trim tab (on the back of the plane) coming off (removing weight from) the aft of plane would not shift the CG Aft. It would shift it forward. It would affect the total lift and the relative lift vector of the plane but that is not CG.

    The trim tab being shaved down, would tend to minimize the effect of loss of a trim tab as the tab would be less efective. As the plane flew faster than originally designed, less trim tab was required to generate the same lifting force. These planes are designed to the Nth degree to wring every fraction of a knot of speed out of them. It had no more, nor no less trim tab than it needed, until one came off.

    Now at the speed they fly, the loss of lifting surface on the tail would cause the nose to pitch up. From what I've read it is probable that the pich up generated enough Gs to cause the pilot to black out. The plane was probably flyable without the trim tab, but not without a concious pilot. It was a tragedy, and certainly should not be drug through the mud of the legal battles. But even more so, it shouldn't be subjected to sensless guesstimates as to the cause and reason for the accident.
    All very well stated and good points. So others might understand what a trim tab is and does: When I was in A&P school we had a really lengthy debate one day and the question was do control surfaces work off of lift/pressure differential, or deflection? It was an interesting discussion and I think the answer was a little of both. A control surface when moved, does change the length of the chord and mean camber line of the airfoil thus changing the perssure differential, but it also does work on simple deflection, especially the rudder which really isn't an airfoil. These surfaces can change the charaacteristics of the wing when moved because they represent a large enough percentage of the wing's total surface. A trim tab, however, does not. It's located at the very trailing edge of the airfoil after all the "lifting" has been accomplished. Trim tabs are used to assist the pilot during flght manuvers where a constant pressure of a control input is required outside what is normally required for straight and level flight. If a pilot has a long climb out or wants to gain altitude, he can adjust the trim tab to help relieve holding constant elevator pressure at the controls. Same with a slow decent. Adjust the trim, and it takes pressure off the controls. If the trim tab came off, the controls would just go back to the normal condition. Now, having said all that, we don't really know how the trim tab was being used in this application. Most oval track cars have their front alignment and tire stagger set so the driver doesn't have to fight the car through the turns. Tha car is set up to want to turn left. If the aiprplane was "trmmed" for the turns, it would be adjusted to help reduce the needed back pressure on the controls that is used in a 90* banked high speed turn. Basically, you're climbing the airplane, only horizontally instead of vertically. with a lot of back pressure. The result would be to require some downward pressur during straight and level flight after coming out of the turn, just like the oval track car fighting the car's wanting to turn left while gong straight. IF the trim tab came off suddenly, there might be a momentary slight climb of the airplane, but it would be something a vetran pilot could and would react to the instant he felt it. I think what happened was that he did feel it, knew there was a problem, and as per the rules, he did exactly as he was supposed to and pulled upward and off the race course...unfortunately possibly in too agressive of fashion, and just passed out.
    I spent that entire Saturday and a lot of Sunday following the accident just watching every video and looking at every picture I could find. I know the owner of the other P51 (Voodoo) in the race and it really hit home with my aviation backround.
  • 10-12-2011, 10:13 PM
    daMoose
    Quote Originally Posted by steelcomp View Post
    OK...this really chaps my ass when people do this. The pilot never said any such thing as "we don't even know if it'll fly" or anything to that literal effect and if you're using that as a premise for your reasoning and logic, you're way out of line.
    Have you ever been to an air race? Do you know the first thing about these planes or the modifications or how they're done? Do you know anything about the sanctioning bodies that over-see any of this sport? There is no guarantee on any day, at any event, in any circumstance that something terrible won't happen and these air races are no different. Any one of those aircraft could have had the same fate, and in fact, the aircraft itself is most likely not the reason for this incident.
    Please voice an opinion, but don't repeat such nonsense as fact or take such a rediculous stand when you really know nothing about what you're talking about.
    I'm repeating what I heard, read and saw on tv-The attorneys position is going to be that the average Joe who bought a ticket to the races had no idea as to the level of risk involved in attending said event because it wasn't made known the level of trial and error that takes place in this sport- that's not my opinion that's what I've read and heard- all I'm telling you is this is the
    attack that the lawyers are going to take. I saw the interview it was a light hearted comment
    but it will re surface according to the article I read by a lawyer. I'm not arguing for or against anything just telling you about what I've read and discussed amongst my friends-
  • 10-12-2011, 09:45 PM
    Rayzor
    In both of my posts, I am only relaying what was discussed with the professional pilots (one active, one retired) that I talked to about this accident. Both said the same thing though, that at the speeds the 51 was flying (450 range), loss of that trim tab would have caused the nose to pitch up violently as it did - the pilot would not have been able to do a thing to correct it. The bottom line is that it was a real tragedy and the first time since the '50s that spectators were killed at an aerial demonstration/race in the US. Now in Europe, it's a whole different story - there have been mass spectators killed at several different shows up until not that long ago................
  • 10-12-2011, 09:15 PM
    snoc653
    My .02......This was a terrible tragedy, but if you are at an air race you should know that if something breaks it is coming down. Enter at your own risk. If something comes off a plane, it will be coming down. ENTER AT YOUR OWN RISK. And unless you are flying the plane, once you've entered your risk is out of your control. There is nothing you can do about the risk so accept it or leave.

    As for the AFT CG comments, unless they've redesignated the propeller to be the aft of the plane, the aft has always been at the rear. So the elevator trim tab (on the back of the plane) coming off (removing weight from) the aft of plane would not shift the CG Aft. It would shift it forward. It would affect the total lift and the relative lift vector of the plane but that is not CG.

    The trim tab being shaved down, would tend to minimize the effect of loss of a trim tab as the tab would be less efective. As the plane flew faster than originally designed, less trim tab was required to generate the same lifting force. These planes are designed to the Nth degree to wring every fraction of a knot of speed out of them. It had no more, nor no less trim tab than it needed, until one came off.

    Now at the speed they fly, the loss of lifting surface on the tail would cause the nose to pitch up. From what I've read it is probable that the pich up generated enough Gs to cause the pilot to black out. The plane was probably flyable without the trim tab, but not without a concious pilot. It was a tragedy, and certainly should not be drug through the mud of the legal battles. But even more so, it shouldn't be subjected to sensless guesstimates as to the cause and reason for the accident.
  • 10-12-2011, 08:30 PM
    Bruise Brothers Dad
    Quote Originally Posted by nice pair View Post
    2 tigers are walking thru the jungle when the one in back licks the other ones butt, the tiger in front says wtf, the tiger in back says ....... I just ate a lawyer ...and i can't get the taste out of my mouth.
    good one
  • 10-12-2011, 08:18 PM
    Rayzor
    I talked to my neighbor (who flys a Cessna Sovereign for a living) today, and he said a friend of his was there (who ran for his life and was hit by P51 parts) who knew the pilot of the Galloping Ghost. Didn't have much good to say about the pilot, other than it's too bad that he augered into the crowd. He was known to sandbag qualifying races and several times not even show at pilot's meetings during the events. The trim tabs having been cut down to half the original size probably didn't help any. I'm only posting what I discussed today with my neighbor, and this is by no means my personal opinion or firsthand account. Just giving a little insight into the bigger picture of the man and machine that malfunctioned in Reno..............
  • 10-12-2011, 08:10 PM
    scott foxwell
    Quote Originally Posted by Rayzor View Post
    That was great, thanks for posting. Interesting that today I just talked to a retired "heavy" UA Captain, and he said he read a current report that the finding of the cause of the crash was that the CG of the P51 was too far aft (outside the limits of the design parameters of the P51) which caused the violent upward turn when the trim tab came off. They surmise that the climb put a 10G stress on the aircraft and the rest is as the video just stated. All of the these racers tend to run a far aft CG, as it produces greater speed. If this race does continue on, don't be surprised if some new rules are in place for the planes...............
    I would tend to disagree with that assessment. The trim tab just doesn't contribute that much control or represent enough percentage of the overall area of the control surface. Design limits and parameters of "the P51" pretty much go out the window when you alter the design as much as these guys do. This isn't the first or only P51 to have it's wings clipped, the belly scoop removed and the canopy moodified. Anyone ever heard of teh Red Baron? These are purely racing vehicles no different than the most exotic, highly modified race cars and there really is no "norm" for weight and balance other than what the revised engineering and aero will dictate.
  • 10-12-2011, 07:59 PM
    scott foxwell
    Quote Originally Posted by daMoose View Post
    Myself and some friends have been discussing this quite a bit since the horrible tragedy occured. The first thing you heard was "there's gonna be lawsuits" I said not neccessarily and brought up that buying a ticket to a Nascar race-is a ticket to a Nascar race-not a guarantee of safety. Then the lawyers started saying that the airplanes are so heavily modified that every time out is an experiment- in fact the pilot was interviewed prior to the race that ended his life and he said something to the affect of we don't even know if it will fly. This is much different then a Nascar race and believe me that quote alone will have it's day in court. Did the people sitting on the Tarmac in those VIP seats know the extent of the expirementation that takes place on those airplanes?
    OK...this really chaps my ass when people do this. The pilot never said any such thing as "we don't even know if it'll fly" or anything to that literal effect and if you're using that as a premise for your reasoning and logic, you're way out of line.
    Have you ever been to an air race? Do you know the first thing about these planes or the modifications or how they're done? Do you know anything about the sanctioning bodies that over-see any of this sport? There is no guarantee on any day, at any event, in any circumstance that something terrible won't happen and these air races are no different. Any one of those aircraft could have had the same fate, and in fact, the aircraft itself is most likely not the reason for this incident.
    Please voice an opinion, but don't repeat such nonsense as fact or take such a rediculous stand when you really know nothing about what you're talking about.
  • 10-12-2011, 11:56 AM
    Nice Pair
    Quote Originally Posted by Bruise Brothers Dad View Post
    And if it were not for some financial reward the lawyers would not touch this. Accidents happen everyday, this was just another unfortunate accident. I am sure this pilot didn't jump in his plane wanting to kill himself let alone others. I am sorry for the loss the families incurred but these people could have been killed coming to the races or on the way home, you just never know when it's your time........
    2 tigers are walking thru the jungle when the one in back licks the other ones butt, the tiger in front says WTF, the tiger in back says ....... I just ate a lawyer ...and I can't get the taste out of my mouth.
  • 10-12-2011, 10:59 AM
    Bruise Brothers Dad
    And if it were not for some financial reward the lawyers would not touch this. Accidents happen everyday, this was just another unfortunate accident. I am sure this pilot didn't jump in his plane wanting to kill himself let alone others. I am sorry for the loss the families incurred but these people could have been killed coming to the races or on the way home, you just never know when it's your time........
  • 10-12-2011, 05:55 AM
    daMoose
    Myself and some friends have been discussing this quite a bit since the horrible tragedy occured. The first thing you heard was "there's gonna be lawsuits" I said not neccessarily and brought up that buying a ticket to a Nascar race-is a ticket to a Nascar race-not a guarantee of safety. Then the lawyers started saying that the airplanes are so heavily modified that every time out is an experiment- in fact the pilot was interviewed prior to the race that ended his life and he said something to the affect of we don't even know if it will fly. This is much different then a Nascar race and believe me that quote alone will have it's day in court. Did the people sitting on the Tarmac in those VIP seats know the extent of the expirementation that takes place on those airplanes?
  • 10-12-2011, 05:27 AM
    SoldHondaBoughtHondo
    Quote Originally Posted by zombie View Post
    IMO I suspect that race insurance companies will not want to take this risk any longer without really cost prohibitive increases in premiums. I think the current Reno or any air races are finished with spectators anywhere near the path of the race course. 1/4 mile away viewing will be much safer but not be very exciting.
    A qtr mile from where? I would think the safest place would be the infield....As far as insurance, F it.....i'll sign a waiver....They have a better spectator safety record than most motor sports....Although i was never to keen on actually being directly under an airplane when it's standing on it's ear at 450 mph (well maybe just for a lap or two)...seems safer to be inside the race course with some kind of tunnel access.

    It's kinda like taking down the fence at indy....the bleachers would be the last place i would want to be.

    I wonder if that will affect the red bull pylon deal? I don't think they fly directly over spectators but they all fly a path directly
    at people...seems like the same issue...out of control is out of control....speed has little to do with it...150 or 450...if something hits somebody the outcome would be similar...
  • 10-11-2011, 11:37 PM
    Rayzor
    That was great, thanks for posting. Interesting that today I just talked to a retired "heavy" UA Captain, and he said he read a current report that the finding of the cause of the crash was that the CG of the P51 was too far aft (outside the limits of the design parameters of the P51) which caused the violent upward turn when the trim tab came off. They surmise that the climb put a 10G stress on the aircraft and the rest is as the video just stated. All of the these racers tend to run a far aft CG, as it produces greater speed. If this race does continue on, don't be surprised if some new rules are in place for the planes...............
This thread has more than 14 replies. Click here to review the whole thread.

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •  
 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95