Thorp Air Command - T18.net

LOL... might just do that! I'm having fun, anyway.

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In theory, theory and practice are the same. In practice, they are not.

OK...I give you the Air Force has nice O-Clubs and forgiving long runways, but the Navy guys get the women ! Ref; Top Gun..."I feel the need for speed !" [8D]

I "attended" the Miramar Club in its heyday. The place was full of kiwis and wannabes. I WILL give you the uniquness of the "birdwatcher" at Pt. Mugu, however. I know, this may seem to have little to do with folding wings other than those resulting form Navt style landings. Get the Red Bird flying!

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Bob Highley
N711SH
SN 835
KLAL

Having spent many hours in Army, Air Force and Navy O club's, I have to say that pre-tailhook Oceana was in its own league.

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Scott Hinton
Elizabeth City, NC
N78WG

Rich - Hasn't been much activity on the thread for a few months but hope you can reply.

I, with much needed help, removed the wings from N551CM in preparation for a condition check -- first time in 7 years during which time it was in the hangar and never flown. This time was worse than the day you helped Steve and I. I have now polished the rear spar tubes so there is a real nice smooth fit. But the "catch" (Sunderland part # 225-2) was badly dis-formed along with the AN3 bolt holding it to the wing spar end. The 225 drawing calls out the catch, main spar hook material as 4130 steel. The existing part is aluminum (2024T3 I would guess) I was very intrigued by your statement on an earlier post:

"The wings may also be hung up on the "catch" at the main fittings. If it was an early build, it may have it. Later S-18's did not have it on the plans. Mine does not. When was the last time the wings were removed or folded ? I'am guessing it has been a while."

It appears that the "catch" serves to hold the outer wing somewhat in place when the pins are removed and to help in the alignment when re mating the wing sections but adds nothing structurally when the pins are in place. Is that your take also? If so, I could make another "catch" of 2024 or leave it and the spacers out entirely. Your thoughts. Cheers, Thom Steury

PS: I read over a few times the bit in Ken Knowles catalog on how one person could remove or install both wings in 5 minutes. Has not been my experience so far.

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Thom Steury
N551CM GOYAbird
KCNO

Thom,
If you're planning on folding the wings much you want the catch (2024T3) and the stop (.25 4130) in there. That being said I'm still pretty nervous when the pins are out. In reality it's a two man job for that reason. I always have a "spotter" at the wing tip with his hands under the wing in case the "catch/stop" no longer want to do their job.

As far as it being a 5 min job I can honestly say that if timed I could have the wings off N51863 and in a rack in 5 mins (we do not fold them, we pull them off and put them in a rack). For that airplane there's an AN-4 (backed up by a nutplate) at the rear spar, the single screw holding the gap cover on, a fuel line, the two main spar pins, a bnc connector, and a couple of molex connectors to disconnect. After that the wing is free to go.

Sounds like you may want to inspect and perhaps replace some of the wing fold components at the main spar as you indicate. It should not be a chore to pull the outer panels.

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Lee Walton
Houston, TX
N51863,N118LW
KEFD

Thom: I remember that day at Chino like it was yesterday and I learned a lot on that visit. From the difficult time we had removing the wings to fitting them back in place and buggering up part of the skin on one wing. The rear "tubes" were way too tight and you smoothing them down to slide easier was a big improvement. They are not structural. Now as far as the "catch" is concerned it is there to support the wing(s) while the (4) pins are removed/installed. If I remember right Steve said they did not build the LS wing for the "folding feature" only for the improved performance numbers. This might explain your "catch" or lack of.

The plans call for the 225-2 catch main spar hook to be made out of 4130 steel condition "N". You said yours might be aluminum ? During my building phase and the Testing period, I've had my wings from the "flight position" to the folded position about a dozen times. During this last time at home I have noticed that the "catch" is not holding and have found that it has rounded at the corner not allowing the "hook" to catch. I reversed the 225-2 and it appears to be working now. An improvement on the catch would be to make it full width and remove the 225-4 spacers. This would allow the main spar hook to rest on more material. I think you do not want to remove the catch and or spacers as I believe they help maintain the correct distance between the (2) main inner wing fittings allowing for proper pin insertion. While the catch is a pretty easy fix, my concern is with the mating of your outer and inner wing skins...this was my biggest fear during my construction phase and I had the same skin interference during the maiting phase as we had. I made to slight adjustments (bending) to the 2 skins and the operation is much better, but I can see why some folks use the full length gap cover to avoid this problem.

You are correct in that the "5 minute" procedure is a bit of a stretch. While I still have a couple mods to make to my trailer and have only done the wing unfold/fold procedure for real once at Brown field, it still only took 20-25 minutes to get the A/C off and on the trailer. It was a 1 hour round trip in the car to and from the airport ! Now that the testing is done, I can use KSEE which is about 12 miles trailering rather than 30 miles each way. Not sure if this answers any of the questions you have ? E-mail me direct rx115@cox.net if you have more questions. Hope to see ya at KVIS this year.

BTW...when I was constructing the 225 bushings, catch and stop I talked with CSA and they said they no longer use the "catch" 225-3, so I did not use it. I may rethink that. Lee is correct about using a spotter and not trusting the catch. This area could use a little more R & D. I plan to make a simple support to place under the wing during the morphing phase as I will be a man operation 98% of the time.

RB
NX115RX

Lee and Rich, Thanks for the information. This will be short -- I had a long day. I made a new "Catch" 225-2 and after some filing-to-fit I was able to attach the wing with the spar pin holes lining up perfectly. No help but conditions were ideal -- in the hangar, no wind, nice level floor, lots of padding under the wing in case it got away from me, etc. Earlier I had removed all the paint and treated the rear spar tube with alodine. Much nicer fit. I almost have a procedure worked out.

My interest in removing the wings is more than just a condition check. I would really like to reduce my hangar rent and folding or removing the wings may just be the answer.

I'd be interested in how your improvement ideas work out.

Tomorrow I start the condition check with an A&P.

Best regards,
Thom Steury
N551CM

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Thom Steury
N551CM GOYAbird
KCNO

I'll keep you posted when I make the new and improved full width "catch."

RB

Have the pip pins in my plane. Changed them once. Almost 30 years of flying and haven't felt the need to have a bolt. It must be really hard to get a bolt out to do a wing fold. Of course, like many others, I have rarely folded the wings on my T18C.

Bruce,

If I'm looking at the right part on print 228 it shows reaming to .311

Bob MO

I too Rack my wings, its about a 15 min operation for myself and the wife to add or remove the panels. I do like to have someone at the wing tip when I yank the pins even though the panels dont move with the pins out. At the rear spar I have a Stainless socket head, I slip this onto a allen wrench that has the screw driver handle the just poke it in there in place and turn, goes in easy and is removed easily without fumbling. I keep my wing firrtings lightly coated with grease as they are tight, the pins are lightly coated with grease as they are super tight. The whole assembly is very tight, the grease staves off any corrosion and aids in assembly. I think Rich could probably give us all some lessons in this area, his trailer is nothing shy of slick, and it looks faster that my Bird!!...........Dan

I couldn not find the plans called for pip pin (MS #). I did find an alternate double acting pip pin 1/4" D x 1/2" L. So far it is working as advertised. Got the last (4) at my surplus place for $2.50 each.

RB