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05-21-2010, 07:45 PM
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Join Date: Jan 2008
Location: Ashland, OR
Posts: 2,574
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Bad to lift or push down on tail
My main concern is that the H-tail only has 3 ribs. If you push down near the leading edge, you are putting considerable load in through the very few ribs. Flight loads have a more distributed load path into the two spars, and yes, can take many hundreds of pounds of lift that way. I'm not at all concerned about the attach point loads.
__________________
Steve Smith
Aeronautical Engineer
RV-8 N825RV
IO-360 A1A
WW 200RV
"The Magic Carpet"
Hobbs 625
LS6-15/18W sailplane SOLD
bought my old LS6-A back!! 
VAF donation Jan 2020
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09-23-2013, 09:36 AM
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Join Date: Aug 2012
Location: UNION
Posts: 17
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More or Less pressure
Quote:
Originally Posted by jsharkey
I have the habit of moving my -6 around by standing in front of the empenage and pushing it backwards using the leading edges of the VS and HS. These are way sturdier on a Van's than anything else I have flown but I'm sure that this practice applies more load than they ever see in flight and have wondered if it could cause damage that might eventually lead to an inflight failure.
How do others maneuver their Van's tail draggers on the ground?
Jim Sharkey
RV-6
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Jim & Gaggle:
Just my thoughts on this:
The question being: Does pushing the plane around by the tail feathers cause forces equal to the G rating, or greater of the plane ?
I would have to say NO considering 'Normal' pushing... Normal pushing, well that has to be defined; I would say smooth ground or turf. When you talk about mud or snow or up hills, normal becomes a variable.
I put the forces required much less than normal flying forces. Consider this: A plane in straight & level flight has a downward force on the tail equal to the counter balance weight required to keep the nose up. Work out your W&B as the CG being your pivot point and consider that the downward force has to be equal to that nose weight JUST to keep your nose level. No go into a climb... Until the climb is stabilized the forces are greater than the nose weight. Now let's take it to the next level - - - What happens when you do a maneuver such as a loop. Yes, the forces increase even more. In design the plane is stress to cover what the G rating of the plane is. So if there is 100 Lbs of flying force on the tail just to keep it S&L and you do a 3 G maneuver (pull out) you now have 300 Lbs on the tail. You pushing around of the tail is no where near 300 Lbs of force.
Another way to consider this force is: What is your Tail Weight? You know, the weight of your tail when placed on a scale. Well, in flight you have a lifting force equal to that force just to keep the plane S&L. Would you say your tail is 100 Lbs? And that is without any pilot or passage or baggage.
So, does moving your plane around by the tail feathers damage anything? NO - Not under normal conditions. Just don't shoulder block your vertical stab to get it to move.
Barry
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09-23-2013, 11:05 AM
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Join Date: Jan 2005
Location: Ontario, Canada
Posts: 1,544
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Although I push on my tail to move my airplane on the ramp if I have to move it through tough conditions I steer with the tail and get others to push on the wing. As for the 300 lb push, I must debate that number. When I am at the gym on a regular basis I can easily do leg bench presses of over 500 lbs. The action is not unlike bending forward and pushing hard with your legs and with hips against the HS stab. I am not a large man, 5'8", 175lbs, nor am I a super strong guy. Watch some young fellows at the gym and you will see how much energy your legs can create.
__________________
Tom Martin RV1 pilot 4.6hours!
CPL & IFR rated
EVO F1 Rocket 1000 hours,
2010 SARL Rocket 100 race, average speed of 238.6 knots/274.6mph
RV4, RV7, RV10, two HRIIs and five F1 Rockets
RV14 Tail dragger
Fairlea Field
St.Thomas, Ontario Canada, CYQS
fairleafield@gmail.com
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09-23-2013, 12:52 PM
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Join Date: Feb 2005
Posts: 426
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Maneuvering on the ground
My simple low cost tool for maneuvering my tail dragger is a 5 ft rope and wood handle (like on a small engine starter rope). I loop the rope on the tail wheel spring and pull it around with ease. Wrap the rope up and it takes less space in the plane than a can of Coke.
__________________
John Adams
Seattle
RV7 600+hrs
Paid 12/2014
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09-23-2013, 02:03 PM
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Join Date: Feb 2005
Location: LSGY
Posts: 3,199
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Rope
Quote:
Originally Posted by RV7AV8R
My simple low cost tool for maneuvering my tail dragger is a 5 ft rope and wood handle (like on a small engine starter rope). I loop the rope on the tail wheel spring and pull it around with ease. Wrap the rope up and it takes less space in the plane than a can of Coke.
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This is a really clever idea! Pull on the rope to move left/right/back, pull on the prop to move forward.
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09-23-2013, 06:21 PM
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Join Date: Apr 2006
Location: Tauranga, New Zealand
Posts: 27
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Rudder failure
To answer the original thread question, the Transportation Safety Board of Canada accident report on Vans RV-7A C-GNDY is available.
The web link is a bit long to post.
Google search "C-GNDY" and it should appear as [PDF] AVIATION INVESTIGATION REPORT A10O0018 IN-FLIGHT ...
[ed. Link HERE. dr]
Last edited by DeltaRomeo : 09-23-2013 at 06:24 PM.
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09-23-2013, 07:51 PM
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Join Date: Jun 2006
Location: Ohio
Posts: 1,686
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Quote:
Originally Posted by RV7AV8R
My simple low cost tool for maneuvering my tail dragger is a 5 ft rope and wood handle (like on a small engine starter rope). I loop the rope on the tail wheel spring and pull it around with ease. Wrap the rope up and it takes less space in the plane than a can of Coke.
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That's what I use. We have horses so I just use a lead rope to pull my little 'stang around. I still push on the horizontal sometimes, but I'm conscious when I do.
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09-23-2013, 09:31 PM
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Join Date: Dec 2009
Location: Boulder, CO
Posts: 4,435
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Note that pushing on the tail generally means applying an aft or side force. The forces the tail is designed for usually are perpendicular to that.
Dave
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09-25-2013, 08:06 PM
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Join Date: Oct 2009
Location: woodbine, NJ
Posts: 18
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Amazing accident report
http://www.bst-tsb.gc.ca/eng/rapport...8/a10o0018.pdf
I have never read such a through accident report. The US NTSB does not produce anything close to this report.
Thank you for sharing.
Quote:
Originally Posted by jimski9
To answer the original thread question, the Transportation Safety Board of Canada accident report on Vans RV-7A C-GNDY is available.
The web link is a bit long to post.
Google search "C-GNDY" and it should appear as [PDF] AVIATION INVESTIGATION REPORT A10O0018 IN-FLIGHT ...
[ed. Link HERE. dr]
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09-25-2013, 09:18 PM
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Join Date: Sep 2007
Location: Central IL
Posts: 5,516
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Quote:
Originally Posted by exp2ex
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The NTSB file for the Georgia crash had all the collected flight data as attachments. That was very helpful for this (VAF) group to inspect/analyze and discuss to reach a conclusion. The Canadian data is mentioned, and indeed analyzed, but it was not attached. I looked to see if they had it on the canadian site, but could not find it. So, although the Canadian report is better (ok, much better), their availability of attached data is (apparently) not.
update: The data is available upon request, Thanks Snowflake
__________________
Bill
RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Last edited by BillL : 09-26-2013 at 05:25 AM.
Reason: more complete information.
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