SWIFT WINGS

WING ATTACH FITTINGS...  (11299)
From: Pete King <peetking@earthlink.net>
CC: arbeau@napanet.net
Did the long wing fittings come just on the upper fitting? -- was there a particular period of time when they were used? I think 80518 has them too!

Pete,  N80518 had long fittings top and bottom. If you look at S.B. 27 you will see they started the short fittings at s/n 32. From 32 thru 158 the upper fitting needed to be changed to the longer conversion fitting, 11-010-3554 to convert to a GC-1B. At least that's what the S.B. says, I still find an occasional later s/n with short fittings! The legal G.W. with the short fittings is 1570 lb. -- Jim

COMIN' IN ON A WING AND A PRAYER... (11499)
Subject: Re: Swift Wing
From: Larry LaForce <LaForce55@aol.com>
Jim... What would be the proper technique of reassembling an outer wing panel that has been completely disassembled? Is there a fixture or a jig that needs to be used to maintain the proper shape and form?

Larry,  Are the old skins available? Straighten them out as much as possible if they are damaged. Cleco them in place, at least the ones between the spars. That should give you the proper twist, or lack of it, because the Swift wings are "straight" - no washin or washout. There are no jigs available that I know of, nor should a jig be necessary if you have the old skins. Use a string between the aileron hinge bearings to make sure they are aligned. If you don't have the old skins, back drilling the holes in the new skins is a difficult job, but not impossible. If you have to do this, jig up the wing leading edge down and align the inboard and outboard ribs to "0" washout. Then backdrill the skins thru the holes in the structure. You might want to use an extension drill about a foot long for many of the holes. -- Jim

"STRIP SHOW"... (010300)
Subject: Re: Swift speed
From: wasinc@northpro.net
Monty,
Flew the swift late this afternoon both double occ. and solo but pretty full of gas, the side to side yaw seems to be gone and airspeed shows 185 at 25/25 Gps showed about 178, did notice that the wing to center section straps were flying" pretty good even though we just tightened them today. What is the best way to hold them down flat. You also mentioned foam between ailerons/flaps and tail surfaces, could you explain that in more detail like what kind of foam. Is this air pressure in the wing making those strips fly up? and the foam blocks some of that? Temp was about zero so speed could be from that difference since last flight of 28 degrees. I just bought a digital camera so when I figure it out I will send you a picture. Steve

Steve,
The gap strips "flying up" are one of the biggest potential drag producers on the Swift. That area has a really low pressure, I've had them so tight you could hardly pry them up, and the next flight they rode up considerably. With them off, tape up the gap between the wing and center section, the reinstall the gap strip. You can even make the upper surface of the gap strip semi-permanent by application of some sealant, (over tape) they vary somewhat, sometimes you just have to install some screws to hold them down. The foam seals I mentioned can be made out of common hardware store foam that they sell for insulating doors, windows etc. (3M or whatever) They sell it in rolls, 3/8"x 1/2" or whatever fits between your wing upper trailing edge and the aileron or flap. It is best installed with the surface off with contact cement. -- JM

BE SURE TO GET THOSE WING BOLTS TIGHT... (040500)
Subject: Torque
From: Perry Sisson <diamond055@email.msn.com>
Hi Jim,  I have a question. Do you know if the torque for the wing bolts is listed in any of the manuals. I have most of them , but I could not find it. The mechanic doing my annual is pretty picky about certain things. So if this is all he wants , then I want to get it for him. If it's not in print could you let me know what they are? Thanks, Perry

Perry,
I have not seen it in print either, but I use 40 -- 50 foot/lbs. Check your standard torque tables. I don't think that is too far off for a 1/2" bolt. I didn't make it to SnF but I would like to make Swift National. I started some new medication last week which I hope will improve my condition. - Jim

PLAYING THE SLOTS... (050200)
From: Richard G MacInnes <rmacinnes@juno.com>
Is there someone out there who has a real life experience with closing the wing slots only. I've heard so many stories but they are usually "that won"t work" or "it's too difficult to handle" etc. or they did the mod in conjunction with other, more dramatic changed.( Like horsepower, canopies, fillets, small wheels, stall strips.etc.) Just looking for info, not opinions. Dick MacInnes N80923

Dick,
I don't feel there was a whole lot of engineering involved with the wing slots. At Denton, TX in 1979 someone asked Bud Knox why the Swift had wing slots, he answered, "because the Culver Cadet had wing slots." In other words, it was the "in" thing to do for a while. The Stinson and some other WW2 types had wing slots also in that era. I have flown Swifts both ways, and don't see a whole lot of difference. I closed them (temporarily) on my first GC-1A in 1966. It didn't go any faster, or seem to make much difference in the stall either. I flew a friends Swift once that had closed slots, Buckaroo wing tips, and the stall strip removed. That was the only Swift I ever flew that I can say had a mean stall. Gear and flaps down, it would hang on to about 45 mph and in the stall it would break sharply, if it were accelerated at all it would break inverted. Not good! Thankfully, he took my advice and put a stall strip back on. I have flown big engined Swifts with closed slots and think they might gain 2 or 3 mph. I don't see much difference in the ailerons. Maybe these are just opinions! -- Jim

(Swift expert Don Bartholomew also replies...)

Hi All,
Here are my personal experiences with slots. First, I have no experience with closed slots on a stock airplane. The first plane I flew with closed slots was a plane similar to my own. It had a 150 Lyc and half stall strips. What I looked for when I flew it was to check aileron response at stall. I found with both planes, mine open slots, other closed slots, that aileron response was good down into the stall buffet. I didn't see any detectable difference in that respect.

I have never taken a plane and just closed the slots without doing anything else to see if there was any speed change, either in cruise or at stall. I have closed the slots on 210 hp planes with half stall strips and machined stall strips. I had no experience flying these planes prior to slot closure so I can't give any before/after comparison. The planes with the slots closed seemed to fly fine.

It has been said the slots were installed as handles to drag the plane around on the ground. They can be effective for this. If the slots are closed, it is harder for two people to each grab a wing and move the plane.

Dick, this probably doesn't answer your question, and may cause more confusion, but this has been my experience. I am open to other thoughts on the subject. Don and Helo

(Editor's note: Jim mentioned Bud Knox. For those of you new to the World of the Swift, Bud was Chief Engineer for Globe Aircraft. He was still around in the late 70's and early 80's so he was able to answer a lot of questions from Swifters regarding why things were done on the Swift the way they were. Now... not to disagree with what Jim recalls about his conversation with Bud Knox, but... In 1985 I asked Bud why the Swift has slots and he said that they didn't want to take the time, tooling, and effort to put "twist" in the wing to keep the outboard part of the wing flying and ailerons effective while the inboard part was stalling. They felt that the slot was simpler. Bud also said that in his opinion it didn't do any good, drag reduction wise, to cover the slots unless the cruise speeds were gonna be over 170 mph.)

GENTLE PERSUASION DINGED THREAD...  (060300)
Subject: NAS 58-16 Bolts
From: Bob Runge <ejectr@javanet.com>
Hi Jim:
Glad to hear you made it to the Nationals. Someday I'll be there. Pulled my fuel tank out yesterday and it didn't go too bad. I didn't remove the aileron or the flap other than the control cables to the bell crank for the aileron and two attach bolts on the flap. Wing came off like gang busters EXCEPT........ I had to use some gentle persuasion on the NAS 58-16 bolts and dinged the thread on one. Where can I get these bolts? Didn't see them in Aircraft Spruce. Thanks Jim. Best regards....... Bob Runge

Bob,
Did you call Swift Parts? Joe is not there anymore, but someone will be there! I know they have the bolts. I think the old NAS number is obsolete. I think the current number is NAS 1308-16.  Perhaps just a cleanup of the end treads of your present bolt will suffice, use a 1/2" NF die. If you do replace the bolt(s), try them in the wing attach fittings first. If they are too tight, chuck them in a lathe or drill press and polish them down to the diameter of the fittings. They should tap in freely, not have to be driven in with a large hammer! -- Jim

GENTLE PERSUATION PART II... WELL, OK, MAYBE SWIFT PARTS DOESN'T HAVE THE BOLTS... IN WHICH CASE HERE'S WHAT YOU DO...  (060300)
In the email above, I had told Bob to call Swift Parts. He then posted a note on the Yahoo Globe Temco Swift Club message board that they didn't have any. Well, they usta have 'em at Swift Parts! You don't necessarily want close tolerance bolts. The 1308 NAS bolts are high-strength and mike about .498 I believe. The old 1946 bolts mike about .496. That's why I mentioned polishing them down to the diameter of the fittings. Of course, it's possible your wing and centersection fittings may have worn a thousandth or two in 50 years. I think Aircraft Spruce will have them even if they don't list them in their catalogue. There are other aircraft bolt suppliers, look in Trade-A-Plane if Aircraft Spruce can't help you. -- Jim

GENTLE PERSUATION PART III...  (060300)
From: Jared Smith <jedswift@aol.com>
The online Aircraft Spruce catalog has the NAS 1308-16 as NA. I would try Spensor Aircraft in Seattle ((206) 763-0800), they had those conical washers for the control surfaces on the wings when no one else had them. AD Swayne ((206) 762-2510), also in Seattle, has many difficult to find items

GENTLE PERSUATION PART IV... BOB FINDS THE RIGHT BOLTS...  (060300)
From: Bob Runge <ejectr@javanet.com>
Here's the deal on the bolts. Called AD Swayne in Seattle and he gave me the number for Aircraft Supply in Dallas (214-637-3598). They have them but are out of stock and are ordering them for me. The number in the Swift book is NAS 58-15 (-16 on SN 2- 31) That was replaced by NAS 1308-15 (or 16) which is now replaced by NAS 6608-15 (or 16). If you want a drilled shank it's -D15 (or-D16). Many thanks for the numbers, Jared and the help Jim! -- Bob Runge

BUT GARY, THEY MAKE SUCH GOOD HANDLES!!!  (060600)
Subj: CLOSING OF SLATS/SLOTS
From: GARY WILLIAMS <garyjw@Intekom.co.za>
Dear Jim,
I am thinking of closing my slats/slots on my Swift, and replacing the rivets with flush rivets up to but excluding the rivets on the main spar. Please from your experience can you tell me the difference in cruise speed I can expect to gain, and what my expected stall speed may be. Regards, Gary Williams e-mail: <garyjw@intekom.co.za>

Gary,
With the bigger engines, such as your 210, most guys figure they gain 4 or 5 mph. In my personal experience, with the smaller engines, like a 145, you don't notice much, if any difference. The stall speed will decrease slightly. (more effective wing area) The stall may break a little sharper, and there may be a little more tendency to roll off at the break. The ailerons remain effective to the stall. The "old" STC method of closing the slots involved simply filling the slot opening with .025 Aluminum, using cherry rivets. Many guys now make up new ribs and skin that area back to the spar, but the US FAA is not too keen on using flush rivets. -- Jim

RUBBER "BUTTON" GROMMENTS... (090300)
From: "Tim Eyster" <teealme@jps.net>
Subject: information request
>From Bill Merwin in Clarksburg, CA:
My Swift has access holes in the top and bottom of the wing where rubber "button" grommets were used to cover the hole. Being various diameters, it is difficult to identify a single item. I am in search of a set (if such a thing still exists) or ideas from other Swifters of how ingenious they have been to address this situation.  I haven't found any exact replacement buttons, but there may be some that might work. We had a guy in this area who has a plastic molding company and he gave us a quote which was pretty high. (like a couple bucks apiece in quantities of a thousand) I think there must be something available from the antique auto suppliers for just a few cents each. I will check out Bob Drake, he has a lot of rubber parts for old Fords. -- Jim  (Editor's note: I've seen Swifts with hole covers made out of metal. Correct me if I'm wrong but I think they are called "Wilkie Buttons"???)

SOME RUBBER BUTTON SOLUTIONS... (090400)
From:James Ray <James.Ray@tbe.com>
Subject: RE: RUBBER "BUTTON" GROMMETS...
Denis,  In reference to RUBBER "BUTTON" GROMMETS... From: "Tim Eyster" - try the fastener section at Lowes. I've had great success using the little black plastic buttons to fill in small antenna and access holes. These buttons are a bit more flush than the original rubber ones. The steel buttons or plugs used for electrical panels fit nicely in the exposed end of the gear axle. Flying off a grass field (well, some of the year) necessitated closing the hole to keep out grass, dirt, and bugs. -- Jim Ray - N99B

From: Richard Aaron <raaron@pica.army.mil>
Subj: Comments
Jim,  Re: Bill Merwin's query about rubber "button" grommets. I've used some plastic hole covers that I got from the local hardware store. They come in either black or white but can be spray painted and have a nice low profile. However, they snap into place and may be a little difficult to remove without marring them. On the other hand they're cheap to replace. Also, the max size at the hardware store may not be large enough. Years ago I got some custom made stainless steel hole covers that are flat and have a small access hole for an Allen wrench to install them. They were available from the Swift Parts Dept. and are very nice but to my knowledge they've been long gone. Another thing I've done is to use circles cut from a roll of aluminum foil tape. This works well, especially for polished aluminum Swifts. On painted ones there may be a problem of peeling the paint when removing as the adhesive holds pretty well. They form a shallow dimple, and for improved appearance I make an aluminum disc from thin sheet to fill the hole, using the tape to hold it in place. I found that some holes had to be dressed to get perfectly round. It takes a little technique to get everything concentric and neat looking and you have to be careful not to accidentally drop the disc into the hole when dealing with holes on top.  Regards, Dick, N2405B

From: Larry Owen <T081763@sphn.com>
Subject: Access covers -Reply
I use two different "access covers" for my Swift. One is a stainless steel "pop in" cover, flat with springy tabs that pop into the hole and lock in. These can be gotten at the larger hardware stores (Home Depot, Home Base, Builders Square, Etc.). They come in several sizes from 3/8 to 1&1/4. Prices are generally less then a dollar.  The problem with them is that the access hole must not be irregular in shape or they are vibrate loose.  The other method is to get some button snaps" from your larger Auto parts stores (Pep Boys, Checker, Auto Zone, Etc.). These black plastic "giant thumbtacks" are used on cars in the interior and the engine compartment to hold insulation down. I cut off the "tack" part and lightly glue them down over the access hole with clear silicon glue. Lightly glued is the key, as they can be removed and cleaned up with your fingernail. The silicon glue also keeps rainstorms, or in my case, sandstorms, from getting past the seal and getting into the push rods and other interior wing parts. They come in dozens of sizes and can cover just about any normal or irregular wing access hole. The prices are very reasonable and you get several in each package. Larry Owen, N78287, El Paso, Texas <T081763@sphn.com>

WING, ONE EACH, EXCHANGE... (090400)
Subj: Wings
From: Donald Williams <donaldwilliams@prodigy.net>
Monty,  I am afraid that I need to get my wing overhauled!!! Do you know a shop, a good one that can disassemble a Swift wing and inspect them including the spar and reskin!! This job will probably require some ribs as well. This is not a job that I would even consider taking on myself. Thanks Don Williams. N80901

Don,  The Swiftworks in Athens, TN is your best bet. <swiftwks@bellsouth.net> The Swift Parts Company has some wings for sale on an exchange basis if you're in a hurry. -- Jim

YOU CAN'T FIX THIS KIND OF "WEB" WITH NEW SOFTWARE...(120400)
Subj: Spar web
From: Mark Fischer <mark@aviationresearch.com>
Hi Monty:
What does it mean to have a "wrinkled" spar web? As I understand it, the web is a thin piece of aluminum connecting the top and bottom spar caps - like the long tall part of an "I" beam. I heard that early Swifts did not even have one, or had one with lightening holes. I guess this occurs after a "drop-in" landing, which could have occurred back in an Eisenhower administration, or last year. Is this a structural concern? Will it impact resale? Should it be fixed? -- Mark R. Fischer

Mark,
The later Swifts, made after about July 1946, had a one-piece spar web. it is the full width of the centersection between the wing attach fittings (about 10 feet) and the height is the depth of the centersection. The earlier serial numbers, like your N80787 have a 3 piece web, a left and a right, from the fuselage outboard and a center portion which is actually a fuselage bulkhead. When these early centersections are removed from the fuselage there is nothing between the spar caps in the center portion, the web, which is a fuselage bulkhead stays behind. Yes, it has big lightening holes. If yours is wrinkled it is probably in the wheel well area. I had a Temco letter, detailing limits for the wrinkles. As I recall, the limits are pretty liberal, like about 3/8". Sorry I don't know what happened to that letter, maybe there is another one out there. Removing the wrinkles is a big job, involving removing the wings and fuel tanks, but really is not too bad once you gain access. Vertical stiffeners are usually riveted to the .040 web and all that shows in the wheelwell is an extra rivet row. If within limits, it should not be a structural concern but if anywhere near limits it does not look very good and may be a justifiable reason for a future buyer to reject the airplane. I would get it fixed. -- Jim

DICK FOUND SOME SPAR WEB REPAIR INFO FOR MARK...(120500)
Subject: Web repair
From: Richard G MacInnes <rmacinnes@juno.com>
In the "Maintenance and Operation Information of the Swift" on page 21 it refers to a Temco drawing R-11-020-0001 for a "standard repair". Swift may have this drawing. Good luck, Dick MacInnes N80923

WING RESKIN... (120101)
Subj: question for Monty the Answer Man
From: Paul Ross <ross9290@aol.com>
Marshall Nash and I are restoring a Globe Swift, N2336B. The left wing was damaged with one upper outboard wing panel in tact. Upon opening the wing, minor corrosion was found. Could you advise us of the proper sequence for reskinning this fixture mounted skeleton? Thank you for any assistance you can give us, as this will speed 36B back to flight worthy status. Paul Ross

Paul
If you make up new skins, back drill them off the old removed skins, then if you cleco the wing together it should not have any twist to it. If the old skins are damaged, hammer them back to their original shape as much as possible. If this is not possible, jig up the wing with the leading edge down and drop a plumb line down at the end ribs. A Swift wing has no twist to it. The sequence would be: 1. The top beaded skins 2. The leading edge skins 3. the bottom beaded skins. You need one set of beaded skins open to buck the rivets along the main spar for the leading edge, then close it up working your way aft. -- Jim

REPAIRING THE REAR SPAR ATTACH...120101)
Subj: wing attachments
From: Austin Smith <P51pilot44@cs.com>
Dear Mr. Montigue,
What is the best way to repair a "wrinkled" rear wing attachment point? clamps, or just buy a new one? I'd like to hear ur expert opinion on this problem of mine. Thanks again for all ur help. swift flying, ---Austin Smith

Austin
The rear spar attach point is relatively easy to repair. There is an aluminum fitting riveted to the spar, which has the one hole for the 1/4" bolt which attaches it to the centersection. If this fitting is broken or cracked a new one can be duplicated from 2024 T3 Alclad, I forget the thickness, but it is about 1/4" thick I think. If the spar is damaged, it should be straightened as much as possible and a doubler installed per AC43.13-1B figure 4-22. Rivet everything back together and it should be fine. -- Jim

RIVETING UNDERSIDE WING PANELS...(030202)
Subj: wing skins
From: P51pilot44@cs.com
Dear Mr. Montague,
I've got another small problem. What would be the best way to rivet together the underside wing panels, the bottom of the leading edge piece and the panel under it that are both riveted to the main and rear spar web (respectively)? It's quite a ways into the wing to get myself into to buck the rivets. what's the best way to do this? How did the factory do it? Should we rivet as far as my arm can reach to buck the rivets, and then do the rest with blind rivets? My grandfather had taken your advice and sent off for those oversized rivets (about two weeks ago). We have so far riveted the top side leading edge ribs and main spar. Those rivets helped out alot on those old holes in the spar. Thanks for the info on reskinning the wing! Thanks for your help. swift flying, ---Austin

Austin
You need one skin, either the top or bottom, off. If you are repairing or replacing the leading edge skin do that first. Install the rivets in the spar, bucking thru the open side. That's the easy part! On the last skin you need to shoot the rivets in the spar first, then close up working aft along one of the ribs, then work inboard or outboard and finish up along one of the end ribs. There are many "tricks" -- like the oversized 1/8" rivets I mentioned a while back. (sorry, I don't have the p/n in front of me but I can get it if you need it) You might have to make up a few special bucking bars. To summarize, to get at the rivet row in the spar near the center of the wing, you either need a long bucking bar or drill out the rivets along the trailing edge and open up the whole skin. I don't believe in blind rivets. They are necessary in a few places in a control surface but not in the wing. If you need further advice please write back. -- Jim

FRONT AND CENTER...(060102)
Subj: Wing center section
From: Keoki Gray <jankeoki28@aol.com>
You may have seen the ad for the Swift that requires work on the center section (in the current "For Sale" listings). It states that the wing spar angles have corrosion and need to be replaced, but it comes with a serviceable center section/angles. I am an A & P, and was wondering what was involved in the required work. I assume it would be much easier to simply replace the center section than to disassemble and reinstall the angles. Could you please give me a rough estimate of man-hours required either way? Thanks. Keoki Gray

Keoki
Yes it might be easier to change the whole center section, but maybe the spar cap angles are all that is serviceable on the replacement. There are a lot of big rivets to shoot in the spar caps The angles can be replaced with the centersection in place if the fuselage is separated at sta. 35 and the firewall and whole forward bay is removed. This of course entails separating all the control cables, wiring and fuel lines. The subject aircraft is s/n 11 and be aware that there are two styles of centersections -- the bolted on type and the riveted on type. S/N 11 would be the earlier (GC-1A) style. (Riveted on) I recall laying on my back in a gravel parking lot in New Jersey drilling out rivets to remove the centersection from s/n 8, 25 years ago. I did not separate the fuselage at sta. 35 but in retrospect, it would have made the job easier! I hesitate to guesstimate the man hours either way as I have not done those jobs for at least 15 years. Working part time, I recall it took over a month to change a center section. -- Monty

SOME TORQUE ABOUT WING ATTACH FITTING BOLTS... (JAN 03)
Subj: Wing attach fittings
From: Doc Moore <darladoc@sport.rr.com>
Hi Jim: What are your thoughts on the torque values for the wing attach fittings? The bolts are all AN-6's with the exception of 1 AN-5 on each fitting. I've researched at length and talked to Mark Holliday, Scott Anderson, and Vaughn Armstrong. Each of them say tighten them 'til you can't turn them with a wrench (meaning the tightened bolts) The 43-13 says the AN-6's should torque in the 180 inch pound range. That's with an AN365 nut and lower value than the normal 125,000 on the bolt. It also shows max at 390 inch pounds on the top side with the stronger bolt. After much research on the web concerning torque I came to the conclusion that 300 inch pounds was a good compromise with 225 on the AN-5's. I called my A.I. who inspects my work and signs me off and he came and checked them and said that they were plenty tight and he agreed with the 300 number on the AN-6's. Thanks for your input. Doc Moore

Doc
I certainly agree with those other guys but I'm wondering something. Might the nuts be bottomed on the threads? If you are using AN bolts or NAS 1300 bolts you have the long threads. If you have NAS 1100 bolts they have the short threads. Even with AN bolts one more washer might be appropriate. Standard torque should work fine. -- Jim

WING ATTACH BOLTS... (MAR 03)
Subj: Wing Attachment Bolts
From: Mark Oltjenbruns <moltjenb@bellsouth.net>
Hi Jim ,
I have a question about the wing attachment bolts . On the left wing there is a slight movement . Can these bolts just be tighten or should these bolts be replaced ? If replaced should I turn down the bolts to fit or slightly enlarge the bolt hole in the attachment area ? The number in the Swift book is NAS 58-15 (-16 on SN 2- 31) That was replaced by NAS 1308-15 (or 16) which is now replaced by NAS 6608-15 (or 16). It looks like Aircraft Supply in Dallas (214-637-3598). Has them. Regards , Mark Oltjenbruns Swift 78311

Mark
If there is movement, the bolt(s) should be replaced. You've got the number right I believe. When you get the new bolt, it will mike around .499. DON'T ream out the fittings. With the wing off, try the new bolt in the attach hole. If it is too tight, (good!) chuck it in a lathe or drill press and turn it or polish it down for a tight fit. The bolt should fit tight but freely in the hole. Mark the head to show yourself where the cotter pin hole is. Torque the nut to 40 ft. lbs. min. Use washers if you can't get the proper torque with the cotter pin hole lined up. I think I have some 6608-16 bolts, if you have trouble getting them I could borrow them to you until you get some. -- Jim

GC-1A vs -1B... (FEB 04)
From: Bill Stein <wrstein@earthlink.net>
Subject: RE: February #2 GTS Internet Update
Can a sn#47 be a GC-1B? My understanding is that it will always have GC-1A wing attach (I don't know if the earlier attach is better or not...). -- Bill

Bill
If you read SB #27 you will see the steps necessary to convert a GC-1A to a GC-1B. Early GC-1A’s need new upper wing attach fittings (p/n 11-010-3554). The early airplanes had a short (about 6") fitting. The later airplanes had about a 12" fitting. The lower fittings are all 6" fittings after s/n 32. The Merlyn gross weight STC adds an additional 6" strap to the lower wing attach. SB #27 says the upper wing fittings must be replaced on s/n 32 thru 158. This is not exactly right as I have seen many later GC-1A s/n's with the short upper fitting, like your s/n 182. But don't get excited, I believe your fittings have been changed. The wing/fuselage attach is superior on the earlier GC-1A's and the first 100 GC-1B's. (s/n 1000 - 1100) On these airplanes the fuselage is riveted to the centersection. About June 1946 when Temco started their production, the wing/fuselage attach was changed to a bolt on style. -- Jim