Harer STC Questions

[N96337]

Re: Harer STC Questions

Brad,
Why would you want to go to stainless?????
John

[Pearson]

Re: Harer STC Questions

I understand you to be saying that the Attach Points on the FUSELAGE require reinforcement per the STC Dwg. G-115 & G-116.

Magman,

I am sorry for the confusion. The portion of the wing attach fitting on the FUSELAGE is not modified on the Harer STC. The part on the spar IS modified. there is a very small part described in drawing 115 that is welded between the two spar straps. Drawing 116 shows the part that is welded between the two rear spar straps.

[birdlegs]

Re: Harer STC Questions

Correction those should read 3/8 ID lines My Bad (but hey its my day off)
B

[birdlegs]

Re: Harer STC Questions

My fuel selector valves are under the Ip and a free path of 6 gallons on each side to fill the cockpit with unwanted fuel through aluminum 5/8 lines (yes Bill its an 85hp) was noticed as soon as I flew it. I'm installing valves at the tank
so I can avoid this life experience. Further is it allowable to change these feeder lines from aluminum to stainless? Its bad enough they insist I use the old brass valves.

[Ragwing nut]

Re: Harer STC Questions

No, there are no fuselage attach fitting modifications that I am aware of. The drawings deal with the fitting that bolts on to the root end of the wing spar. You need to increase the thickness of the metal from .065 to .095, and according to the drawings this thickness is not on the U shaped piece it is on the long straps.

Oh, you'll be cutting fabric, all right...

You have to modify the fuselage attach points on prewar models only. Postwar models already have the reinforcement installed.

[Hank Jarrett]

Re: Harer STC Questions

Anyone who is doing a Harrer mod and getting new fittings let me know. The ones for my 45 have some bad corrosion and I need some of the old ones. When I blasted them there was BONDO in the corrosion! Looked great till I sand blasted.
Hank

[Robert Lees]

Re: Harer STC Questions

Bill is right...these are the wing fittings that need to be made from 0.095":

[VictorBravo]

Re: Harer STC Questions

I understand you to be saying that the Attach Points on the FUSELAGE require reinforcement per the STC Dwg. G-115 & G-116.

No, there are no fuselage attach fitting modifications that I am aware of. The drawings deal with the fitting that bolts on to the root end of the wing spar. You need to increase the thickness of the metal from .065 to .095, and according to the drawings this thickness is not on the U shaped piece it is on the long straps.

Oh, you'll be cutting fabric, all right...

[Robert Lees]

Re: Harer STC Questions

"{snip}...The F-19 system with the cross over vent is the best with the larger pressure tube, make darn sure the little hole is in the back ...{snip}

Even the B models have the little hole at the back, often covered in paint.

If you fly in cold climes, make sure these are open in case the front of the J tube (great description, Forrest) closes up.

Photo below from my archives...note the brazing of the wings and J tube onto what was evidently a bog-standard fuel cap:

Purchase $5 fuel cap.
Drill #40 hole through cap.
Purchase & bend $0.60 copper tube.
10 minutes brazing wings & J tube
$120 please.
Money for old rope.


Rob

[N96337]

Re: Harer STC Questions

The STC calls out in drawing G-133, "Fuel Strainer, Koehler #K22008-3 or euiv. 3/8" NPT inlet & outlet".
Same style goes with the valve callout.... "Valve-Imperial #108-HD-3/8" or equiv. 3/8" NPT ports".
As far as the vent system goes...the only ones that I've seen have trouble are the ones that aren't set up like the drawings say. That being said, I've had them set up differently and work fine...but I've never seen them have trouble when set up exactly as drawing G-133 states. Alot of people throw flex tubing in there for fuel lines, or use rigid tubing, but have a dip in it somewhere...that's gonna screw you up every time...take a bit of time, keep it all flowing downhill everywhere, and it'll work fine.
John

[Pearson]

Re: Harer STC Questions

My 1946 BC12D has a gascolator with a glass bowl. I think they used tractor parts back then. I have heard of people getting replacements from tractor supply stores.

[GallagerG]

Re: Harer STC Questions

Hello Again, Thanks for all the responses. Another question to add to the rest,,,
What type/model/kind of fuel sump/gascolators were used on the original 46 BC-12-D, and what, if any, did the Harer STC call for? I have a glass bowl type, is this aviation technology of the 1940's or tractor parts??

Still looking for drawing or list so i can finish this baby!
Thanks,
"G"

[Forrest Barber]

Re: Harer STC Questions

"early" 45 was merely a BC-12-65 built very quickly, still had the three hinge tail. IT DID have the BC12D designation. Later on the two hinge tail and the correct fuel valves were added. REMEMBER the wing tanks were options at one point and "required" later on for the 85 HP. READ your Type Certificates. Fuel caps on wing with small J tube are fine, they do not :feed: the engine only the main tank. The F-19 system with the cross over vent is the best with the larger pressure tube, make darn sure the little hole is in the abck , yiou need it if you encounter icing . Yes Dorothy the front of the vent can ice over then you lose venting unless the little hole is open at the rear.

[magman]

Re: Harer STC Questions

Thanks Pearson

Probably only fabric we'll cut is the Butt Rib to get the "Tubing Bundle" out.

I understand you to be saying that the Attach Points on the FUSELAGE require reinforcement per the STC Dwg. G-115 & G-116.

Several people sent photos of the SPAR Beef-up .

Another reason we NEED drawings!

[Pearson]

Re: Harer STC Questions

Magman,

The wing attach fittings DO require reinforcement according to the Harer STC. Drawings G-115 and G-116 show a U shaped addition to the two original spar straps for the front and rear spar.

Also if you are going to cut into the fabric on the wings, you may want to consider a modification I did to my plane when I had the wing tanks out for leak repair. The mod replaces the fabric over the tanks with sheet aluminum attached with rivnuts in the ribs and #6 screws. There is a 337 form and about 5 pictures posted on this site somewhere. If you can't find it, email me, or Private Message, and I will see if I can find my digital version and email it to you.

Hi to Gallagher!