Need skylight STC info for BC12-D

[Doc]

Howdy: I know...old request...but it would help if someone could give me the contact for the STC (? Alaska). Thanks. Doc

[t-crafter]

Re: Need skylight STC info for BC12-D

The stc for the skylight is held by gregory H. Clayton Box 73204 Fairbanks AL. 99707. I cant find his phone #. He is very helpfull and informitive. Good luck! Carlton

[Doc]

Re: Need skylight STC info for BC12-D

Thanks a bunch! Doc

[tim]

Re: Need skylight STC info for BC12-D

i know him he is a really great guy any way his number is 907 488 4125

[Doc]

Re: Need skylight STC info for BC12-D

Howdy: Just spoke with Mr. Clayton: STC cost is $375.00 and his current address is: PO Box 56102, North Pole AK 99705. CP Number is: 907-460-7036 and other phone is: 907-488-4125. Thanks. Doc

[marc]

Re: Need skylight STC info for BC12-D

Howdy all,I spoke to clayton last night and order a sky light and if you need some info he the man to ask.he knows a lot on doing mods

[Doc]

Re: Need skylight STC info for BC12-D

Howdy: 12/24/2006 Just received the skylight STC for N43306. It should be a breeze to make the conversion...Doc

[VictorBravo]

Re: Need skylight STC info for BC12-D

Howdy: 12/24/2006 Just received the skylight STC for N43306. It should be a breeze to make the conversion...Doc

Hey Doc, does the Clayton STC involve welding a bunch of steel tabs on the upper longerons?? How is it held in?

[Doc]

Re: Need skylight STC info for BC12-D

The STC is simple...and designed for an already covered bird...there are simple tabs to weld to hold down the AN screws, a transverse wooden former with AN hardware to accept AN screws, and a formed aluminum piece for where the aft section of the skylight meets. There is already a formed piece where the windscreen and skylight meet. The builder supplies the plexiglas. The drawings and STC are on one sheet of paper. Doc

[MNJoe]

Re: Need skylight STC info for BC12-D

Doc,

You mention it can be done on a covered bird however you mention that tabs do need to be welded on? how many tabs need to be welded on?

Joe

[Len Petterson]

Re: Need skylight STC info for BC12-D

Fabric is very flamable and welding on a coverd aircraft would need spesial care.
Do NOT use a electric welding method Mig, Tig or stick, as it will drasticly change the magnetic fields in the airframe and the compass will/can be renderd useless!
Could adel clamps or similar be used instead?
Len

[VictorBravo]

Re: Need skylight STC info for BC12-D

Could adel clamps or similar be used instead?
Len

YES! That is exactly what I am in the process of getting approved on my skylight now. Adel clamps and one or two other clever ideas that do not involve welding on a covered airplane.

If you are rebuilding a T-craft from the ground up, I recommend you buy Mr. Clayton's STC. On a bare tube frame, welding a few more steel tabs on is not a big deal then.

If you don't want to weld (for mechanical or historical reasons), then my method might be something you want to investigate.

Bill

[rcefird]

Re: Need skylight STC info for BC12-D

Bill
I keep waiting for your approval. Where does it stand currently? I have a 1941 BC-65 and would prefer not to weld if possible. I am fairly tall and would like to have a good skylight.
Randy

[tim]

Re: Need skylight STC info for BC12-D

you are about to !@#$!!@#$!!@#$!!@#$! up u have to do as per the stc some one on here did this and did not take with the faa

[VictorBravo]

Re: Need skylight STC info for BC12-D

Bill
I keep waiting for your approval. Where does it stand currently? I have a 1941 BC-65 and would prefer not to weld if possible. I am fairly tall and would like to have a good skylight.
Randy

I am very sorry this has taken so long! Unfortunately it has, and not for the right reasons. That being said, I am working with one and potentially two DER designees and one very very highly qualified engineer. I anticipate getting the DER approval within a month, and however long the FAA takes to rubber stamp that approval afterward.

The engineer, a friend from my Formula One racing days, has actually done some basic calculations and agreed that my method of holding in the skylight is adequate and should not fail. This is not because my attachment is overbuilt, but because the loads are very low on the skylight attach.

In short, in order to get an increase in dynamic pressure of just 1 PSI over atmospheric, you have to be going about 200 mph and then have the dynamic pressure acting directly on whatever you are worried about.

So, if you wanted to apply a 1 PSI pressure to "blow out" the skylight off of the roof, you'd have to get the old T-craft going 200 mph, remove one door and lock the other door, then get it going completely sideways at that speed. If you did that, and got an increase of 1 PSI pushing the skylight upward, that 1 PSI would be acting on 1080 square inches (36 x 30 inch plastic window), creating a maximum force of 1080 pounds.

My skylight, Mr. Clayton's skylight, and Taylorcraft's F-22 factory option skylight would all of course fail under that condition. Therefore I cannot advise flying a Taylorcraft sideways at 200 mph with one door closed. At least open the other door to let the pressure out, and your skylight will survive the crash intact.

The reality is that the Taylorcraft windows open either a very little amount (pre-war swing out window) or a little amount (post war sliding window). The reality is that you cannot get a Taylorcraft completely sideways, and the Taylorcraft type certificate says you can't apply full rudder at much over 100 mph (maybe less). So the odds of generating more than a hundred or two pounds of "blow out" force on the skylight are slim in my opinion.

If you divide a couple of hundred pounds of blow-out force by the 26 fasteners that hold the skylight in place, you are loading those fasteners at 10 or 15 pounds each, which means that very small wood screws in soft blocks of Balsa wood would probably hold it. The plastic window (which is the same as the skylight window certified by Taylorcraft as an option) would crack and break before a #8-32 machine screw and nut would fail, or before a #6 wood screw into a block of Spruce would rip out of the wood.

So, this is why I am reasonably confident that my skylight mod will be approved eventually. But it is still PENDING approval, the FAA turned turtle and quit, DER #1 went silent for over a month, and DER #2 is going to see the airplane shortly.

Randy, you are of course free to do your own no-weld skylight on your own 337. This is actually not a bad choice, since I can tell you how to easily avoid the problems I had with the FAA. All you have to do is get the F-22 skylight drawings copied by the Taylorcraft Foundation for a nominal fee as I did. Instead of doing it the way I did, just use the factory style aluminum fairings as shown in the factory drawings (they're really easy to make), and just substitute Adel clamps for welded tabs to attach those four fairings to your upper tube frame. Re-use the welded U-channels and welded tabs that are already there on the upper longerons... attach the aluminum fairings to those with 8-32 screws and nuts. Use Adel clamps for the front and rear fairings, and for the center hold-down. Then use the Tinnerman clip-nuts and sheet metal screws around the perimeter of the aluminum fairings to hold the plastic.

This would make it almost an exact duplicate of the factory approved skylight installation... so your IA can probably sign this off as a minor alteration, or sell it to the local FSDO as a one-shot 337 field approval without too much grief. Because you are only changing one thing (using approved aircraft hardware Adel clamps in place of SOME of the welded tabs on the later T-craft installation) INSTEAD of what I did (substituting wood for the aluminum fairings as well), you will have FAR FAR less problems than I am having.

The FAA does not recognize an Adel clamp as a structural attach fitting (they were designed to support wire bundles). So on your drawings call them out as "strap clamps made from 2024 T3 or T4, 1/2 inch wide by .050 inch thick, min. 50,000 psi tensile strength". This multiplies out to well over 1000 pounds of load carrying capability per clamp.

Seriously, if you're in a rush to get the skylight done I'd do it that way, don't wait around for me, and just only change that one thing from the approved F-22 skylight drawings. Where I got in trouble with the FAA was the wood strength, the glue holding blocks in place, and the forces trying to pull the screw threads of a wood screw out of the wood blocks. This is because I wanted to do the skylight supports in wood because a pre-war Taylorcraft skylight would have been excecuted in wood.

Bill