Thorp Air Command - T18.net

I have a drawing by Lou Sunderland that shows the three bolts.

The two internal weights came with my project and I "assume" they came from Phil Tucker or Ken Knowles . I have 2 sets of S-18 plans and could not find out how to attach the "fishing weights ?" So I did the CS NAS screws and to this day they are still in place and I have not caught any fish !

RB

The drawing is 502 an dated 15 Nov 84 and was drawn by LS. It shows 3 AN507R-1032 screws holding the weight. I have been told this internal weight was approved by JT.
I have found when the plans set were sold to the builder, not all received the same drawings in their set. As a note you will note in the bottom left corner it will refer to the next drawing. Several times this drawing would be omitted as not needed. I I would call Phil and have him send it to me just for reference.

Trim tab is started!!!
I found small aluminium spare to build these parts.


The small rib ready to install.


First is completed...


And with the ''right click'' I do the copy and paste.


Et voila 2 pieces identiques
Next step is cutting the small triangular aluminium plate 1/4 or 3/8 thick and drill the two hole for the AN3 bolt. I see the specification on the plan but for this moment I dont remember...
I take a closer look tomorrow morning.

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Thierry
French Canadian T-18
C-FPVE #091

.016 or .020?

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

I made both trim skin with 2024T3 0,025.
Under 0,020 is looks like cigaret paper...

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Thierry
French Canadian T-18
C-FPVE #091

Well done .. The .016 gets a bit serarnwrap ish

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

To clarify most older thorps with any .016 skins suffer hangar rash ... I limit .016 to templates or interior usage.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Absolutely true!!!
Under 0.020 when the skin is corrugated it's more stronger.
My 2 cents

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Thierry
French Canadian T-18
C-FPVE #091

I made mine from .016 as per the prints, & I think they look fine. They've held up well for 23 years, & pretty much look the same as when I built them. My personal opinion is that you should be very careful about making any structural changes to critical parts of the stabilator assembly especially. I believe it's likely that thicker skins are PROBABLY just fine... stronger & heavier is all. But keep in mind that the testing done by John Thorp after the flutter issues pointed out how important seemingly minor changes were, and how they had a drastic effect on flutter vulnerability.

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John Evens
Arvada, Colorado
T-18 N71JE (sold)
Kitfox 7 SS N27JE

Thanks Jrevens for the inquiry about the extra weight. I want to weight my new trim in 0.025 versus my original in 0,016. I keep you posted about the result.
Trim ready to riveting and the SS starp was installed inside.


When I installed the stab on the fuselage for the first time I sing the 2001 Space Odyssey sound track, you know with the big drum sound!!!!!
I'm so happy to see the complete tail section!!!


I finished to cleaned all the welding areas. Now I have a new old canopy rail. I have to make a small jig to fix all the frame tubing before the last welding process.




I found the canopy rail drawing and I start the design in the SS strip.


Some trimming to do, but I'm pretty sure the second rail need no adjustment.


Et....Voila....

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Thierry
French Canadian T-18
C-FPVE #091

Thierry, Mike Archer sells front and rear canopy rails for cheap. ~$16 ea if I remember right.

I call Mike Archer and he has no parts in stock. I take almost an hour to design, cut and bend the two rails. Today I do the rear, I bend a long part and I cut the piece in two!

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Thierry
French Canadian T-18
C-FPVE #091

Wow Thierry.
It looks like you can build parts faster than you can buy them!
The S2 looks great.
Based on my own experience, I worry about folks getting into small planes because they are quick and landings can be a bit intimidating if the stall speed is high.
I'd say you have that training well covered for the T-18, having flown the S2!!

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Scott Emery
EAA Chapter 326
T-18 N18TE

Thierry, you are too quiet! We need a Christmas update to rekindle the motivational fires.

D