Thorp Air Command - T18.net

Guys,

I was wondering if anyone has a drawing of the Trusty tail spring? After seeing a bunch of them at Fredricksberg, I thought I could make one for my Thorp.

Thanks,

Jim Mantyla

Hi Jim
Here is a copy of some drawings, not the best reproduction as it is missing some numbers of the bottom of the page but it might get you started, others might be able to provide a better copy.
How would you feel about making a few tail springs? I would be interested and have been looking to get a trusty style tail spring myself and there may be a couple of others interested if someone was doing a "production" run!

Cheers
Stuart

Hello Stuart,

I guess all I need is the lengths on the second page. If anyone else has these, I will be able to see what sort of job this will be.

Thanks again,

Jim

FWIW, a possible alternative would be to buy a Van's tailspring http://vansaircraft.com/cgi-bin/catalog ... ct=tailspg , bend it and re-heat treat it. Or make an angled front and rear mount like I did. I also used the Van's tailwheel mech, which I like, but there are some aftermarket alternatives, like the Screaming eagle, http://www.flyboyaccessories.com/store/ ... 0190073d39
Also, to avoid tailwheel shimmy, it is recommended that the tailwheel pivot have a positive caster.

_________________
Dave M
Sacramento
ex-T-18 owner

At T82 I noticed a few A/C that had the "straight rod" for the tail wheel.

RB

Another suggestion You might want to contact Tom Hunter he had a batch of springs made a few years ago, but he's got none left unfortunately. Anyway he should have the extra dimension detail. More recently Tom said he was going to investigate some of the alternative rod style springs.
Stuart

Anyone interested in a trusty tail spring upgrade?
I have been in contact with Langair Engineering they are prepared to make some. Their quote was $155USD each and less if a batch order of 10 or more was placed. Seems reasonable.
Any interest in a group order?

Can anyone tell me what the advantage is with the trusty tail spring, I have the leaf spring that looks like its from a small trailer, I know its not but just trying to paint a visual image

The original spring I found too stiff and transmitted a LOT of noise thru the airframe. The "rod" gives a smoother landing...not as stiff. I think it handles better on the ground.

RB

I have not noticed any change in handling ... The primary reason I see for the rod spring is drag reduction. You probably gain a couple of knots by taking that flat plate out of the slipstream.

_________________
Lee Walton
Houston, TX
N51863,N118LW
KEFD

As has been discussed before, the Trusty spring allows the tail to sit lower for a better chance at a three point landing. The taller plans-built leaf spring can hit the ground first on a soft/rough field landing. This is particularly apparent on the original short main gear. The rod spring is also softer and rolls better on rough taxiways and runways.

_________________
Bob Highley
N711SH
SN 835
KLAL

HI All, After some emails with Stug - I have followed up with Langair about a production run. They would prefer to do a run of 10 as the heat treat process cost could be spread over 10 items instead of 5. Harmon seemed to indicate that the price that was quoted earlier in this thread would hold. We could get the number down if we can get to 10 rods. I told him that I'll need 2 for my projects, Stug is good for 1...We just need 2 more interested parties to get to the 5 number. Anyone else a player?

T

I'm in for one. let me know how much.

Jim

Terry thanks for chasing up with Langair.
Put me down for 3.
I'm anticipating a couple of other Oz T18s will be interested.

_________________
Stug

Put me down for one as well. Let me know much and how to get payment to you.
Brian