Sounds good to me, I hope that the 10 will be back in the air soon----this radio upgrade has turned into a lot more work than expected.
Excellent, will be good to see ya! Boy do I understand project creep though!
Bob, We were going west bound across the SF Bay heading back to the San Carlos Airport at 1000'. I couldn't believe the speed either. We could have been doing a slow decent, but don't remember that, and could have had a slight tail wind too, but I would guess the prevailing wind comes from the west. I will race you so you can gloat. I have done no speed mods on my plane as you have and I think you are 60# lighter too. Look forward to it. Steve
All good info Steve...thanks! And no gloating at all. You are the closest (geographically) benchmark I have to seeing if any of the work is paying off! Well paying off speed-wise anyway. Along the way I'm learning a ton...about building, re-building, maintaining...and the airplane itself. Probably the best part of all the effort (hair-pulling notwithstanding!
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When are we gonna see the Barnes-Stormer out at a race?!?!
I could be wrong, but I seem to remember Bob put an eight tail on his bird last summer.
That is correct Mike. I was encouraged to do so by SARL and AVC racing buds. Adding the counterbalance was one of the main goals. I also incorporated a couple strengthening measures after considering some mods others had done on RV-4 and Rocket Rudders and VS's. I also sought some engineering consultation. Here's what I did (not an official recommendation from me or anyone, just a couple data points...sorry, gotta say that!):
.020 skin (versus the old .016...I believe .020 is now standard. .025 was considered, but was felt to be too heavy for the rudder. As you add weight, it would require adding more weight to the counterbalance. If the added weight is significant, the stress on the counterbalance horn attachment point becomes a concern.)
Pinning the leading edge of the rudder stiffeners together, essentially making them ribs. A famously fast RV-4 did this...where I got the idea. A fellow Reno Racer did the same with his Rocket, on which he used an RV-4 tail that he modified to have a counterbalance (the fast 4 did the same thing too). The Rocket gent used tabs and RTV to pin the stiffeners together. I used .032 tabs carefully made to fit between the stiffener pairs. This added 5 ounces of weight 2 inches aft of the hingeline. I then glassed in 2 ounces of shot to the counterweight edge, 5 inches forward of the hingeline, so that it had a zero-sum effect on balance.
After adding that slight amount of weight, I added a 90 deg doubler to the hingeline connection for the counterbalance horn.
During the design and mod discussion, with a now-stiffer rudder planned, attention was shifted to the stress on the VS, and the rudder-VS attachment. I added a .050 doubler the full length of the aft VS spar, sandwiched under the standard doubler (the one with the pre-fabbed lightening holes). Careful attention was also paid to the length and alignment of the rod-end bearings for the rudder attachment as it all went together (as would be required in any install, modified or not!)
All this was to add a degree of stiffness to the rudder and the rudder/VS connection, with the addition of the absolute minimum of weight; and all were based on design features of that 260+ MPH RV-4 and the 255+ MPH Rocket.
So Michael, the questions are very valid. There has been much discussion on using TAS as the limiting speed, and that's what I do. Discussions with multiple aero engineers indicates that flutter speed appears to actually track about halfway between IAS and TAS as DA increases, so using TAS appears to be a conservative approach (and one I choose to adhere to). I'm not aware of the written documentation of Rocket Vne versus RV Vne. I know testing and evaluation has been done, and the theoretical flutter speed is much higher than published Vne, but that margin belongs to the engineer, so I respect that...in my case, the Rocket numbers as established by the original builder.
Again just one data point.
Cheers,
Bob