PA12 flaps

TurboBeaver · Jun 28, 2022

I think &#55358;&#56596; you will find that is simply a PA-14 front seat, and part of the package that the Piper factory suppled in the " conversion kit" (all PA-14 parts)THEY put togeather for "Marden Airways" modification. Had Piper ever installed the larger 0290D2 engine on the 12/14 series airplanes they would have been wildly popular, and stayed in production for many years longer than they did.
Good Luck of the projects, here is our Cruiser with a
160hr SMOH 0290D2.
E

skukum12 · Jun 28, 2022

Flap handle on the right side? Gonna need quick hands.

Colorguns · Jun 28, 2022

I need to get the drawings copied and posted for the Marden flaps from Piper.

Doug

Well I found everything. Prints - 2 of them with the parts listings, 337, and the drawings to put them installed.

Flap handle is on the left side and it uses the -18 seat in my drawings.

Kahles56 · Jun 28, 2022

flybynite said:
How long are the -14 flaps? Does anyone have the print specifically for the -14 flap?

Univair lists a different part number and prices for -14 and -18 flaps.

Dakota Cub says they have flaps for a -18, but not a -14.

I purchased a flap kit from Dakota a number of years ago. The flaps were pma'd for a -18 and 62.5" long as specified in the Sullivan STC.

Regarding routing of cables around the bellcrank and pushrod for actuating the flaps on the -12, the -14 wing drawing (just purchased from Univair) shows the same standoff made of phenolic for the aileron balance cable that the Sullivan STC shows. As far as I can see from the drawing, the forward aileron cable is routed under the bellcrank through a fairlead.

I believe these are pics of the Marden install of the flap handle on a -12 seat

http://www.supercub.org/forum/showt...t-to-add-Flaps&p=555976&viewfull=1#post555976

The never-ending drama regarding flaps on a -12 continues...

My plans state that the flaps are (65 and 5/16 ") Obtained from Piper plan # 11686, Drawing dated 01/22/1948 By RTM, checked 01/23/1948 By MRK.

jromero0307 · Aug 2, 2022

TurboBeaver said:
Pete,
We have located the Marden Airways documents required
for the flap modification. I will see if we can get them to SJ to list in tech section as you requested.
E

So I am looking at installing flaps on my PA 12 and following this thread. Are these documents available?

Gordon Misch · Aug 2, 2022

I used Ron Sullivan's flap STC on my -12. it's a bit of a challenge to get the bellcranks and cables in the wings to play nice, and if I recall correctly I had to re-clock the flap handle for full 50 deg deflection. It's very do-able though.

jromero0307 · Aug 2, 2022

I have been trying to contact Sullivan with contact information on Univair with no sucess. How did you get the STC?

Gordon Misch · Aug 2, 2022

I either called or wrote to him, don't remember which. That was about 12 or 13 years ago. Maybe give Atlee Dodge a call, I think they have contact info for a bunch of different STC holders. Right now their website appears to be down. Also, Charly Center, Crosswinds Stol would likely know.

Kahles56 · Aug 2, 2022

TurboBeaver said:
Pete,
We have located the Marden Airways documents required
for the flap modification. I will see if we can get them to SJ to list in tech section as you requested.
E

Pete,
Could you get with the powers that be and post the drawings and paperwork as discussed for
THIS INFORMATION IS FOR EDUCATIONAL PURPOSES ONLY.
It would be of great help in the history of flap installations on the PA-12 .

Thanks,
Ken :lol::roll:

jromero0307 · Aug 2, 2022

Gordon Misch said:
I either called or wrote to him, don't remember which. That was about 12 or 13 years ago. Maybe give Atlee Dodge a call, I think they have contact info for a bunch of different STC holders. Right now their website appears to be down. Also, Charly Center, Crosswinds Stol would likely know.

Thanks. I haven’t written to him I will try that next. How do I contact Attlee Dodge ?

stewartb · Aug 2, 2022

907-344-1755

skywagon8a · Aug 3, 2022

Kahles56 said:
Pete,
Could you get with the powers that be and post the drawings and paperwork as discussed for
THIS INFORMATION IS FOR EDUCATIONAL PURPOSES ONLY.
It would be of great help in the history of flap installations on the PA-12 .

Thanks,
Ken :lol::roll:

It was Turbobeaver who said he had the information and would get it to sj.

TurboBeaver · Aug 3, 2022

Pete,
Turnbull has the original drawings from his Cruiser. Doug told me he has submitted those Marden drawings, to SJ. So I am not sure where they are listed on here but SJ has them I am told.????
E

jromero0307 · Aug 3, 2022

Thanks, I Finally got a hold of Ron Sullivan, and He gave me an address of 4801 East 147 Avenue, Anchorage, AK 99516. the STC is $450. He has two different STCs one for the PA 18 flaps and the other has the longer flaps.

AK56 · Aug 6, 2022

Flaps

jromero0307 said:
I have been trying to contact Sullivan with contact information on Univair with no sucess. How did you get the STC?

If you call Ron and leave a message he will usually get back to you.

moneyburner · Aug 8, 2022

My 12 has 14 flaps installed in the 40s per CAA rules, no 337 or STC (or FAA) then. That option is no longer available, of course. Ron Sullivan and Charlie Center have better-designed STCs anyway.

Curtis Craig · Mar 28, 2023

I have these flaps on a PA-12 project but no installation instructions in paperwork.. If you have any luck on the cable rigging I would love a copy. Thanks

algonquin · Mar 28, 2023

The cable route is messed up so you will need to adjust to make it work. There was a good guy ,Mike , posted drawings of how he reinforced the pulleys brackets in the frame. There were a lot of good pic’s in his post.
Look for: Mike MCS Repair

flybynite · Mar 29, 2023

Certified or experimental? Until we can get the paperwork for the Marden install, you will need an stc from Crosswinds or Sullivan.

The routing of the aileron cables is like Piper did for the PA-14. The bracket for the bellcrank is near the top of the web of the spar like on a PA-18, the aileron control cable goes through a fairlead mounted on the arm that holds the flap hinge. The balance cable is held high over the flap actuator with a phenolic block riveted to the reinforcement where the actuator passes through the false spar.

I borrowed these pics as being the clearest. Credits to the original poster.

Aileron cable fairlead on hinge bracket.

Phenolic block for balance cable

skywagon8a · Mar 29, 2023

flybynite said:
View attachment 65243 Phenolic block for balance cable

Pay close attention for wear on the cable where it passes over that phenolic fairlead. It is likely to wear with that sharp bend on the phenolic. If it were mine, I would replace the phenolic fairlead with a pulley.

flybynite · Mar 29, 2023

skywagon8a said:
I would replace the phenolic fairlead with a pulley.

I am not arguing about the potential for wear. Is deviating from the stc design (or Piper's on the PA-14) likely to cause a problem with the IA who is asked to sign off?

I agree that a pulley or conventional fairlead in that location would be a better solution. The angle of deflection is not as severe as it looks in the photo.

skywagon8a · Mar 29, 2023

flybynite said:
I am not arguing about the potential for wear. Is deviating from the stc design (or Piper's on the PA-14) likely to cause a problem with the IA who is asked to sign off?

I agree that a pulley or conventional fairlead in that location would be a better solution. The angle of deflection is not as severe as it looks in the photo.

Just pointing out what 60+ years of wrenching airplanes has taught me. I have seen angles of deflection which are less than this one chafe the cable exposing loose strands. Some which just touch the phenolic. If any IA has a problem with installing a pulley in this location, that IA has a lot of other issues.

Hardtailjohn · Mar 29, 2023

skywagon8a said:
Pay close attention for wear on the cable where it passes over that phenolic fairlead. It is likely to wear with that sharp bend on the phenolic. If it were mine, I would replace the phenolic fairlead with a pulley.

I was just thinking of this today. The phenolic block is what Ron Sullivan shows in his extended flap STC, and I'm just not wanting to go that route. I'm pretty sure a small pulley would be a great solution there, and what I'd planned on doing to the one I'm working on. I'll do it, then talk to my PMI later and see if he want's it written up as a deviation to the STC.

I have a set of the Marden drawings. They leave a lot to the imagination, but I'll see if I can get them scanned and put them on here. It wont happen right away as I have to go to town to do it and I'd almost rather have a tooth pulled. ;-)
John

flybynite · Mar 30, 2023

I tried many iterations using fairleads and pulleys. Keeping the bellcrank as high as possible on the spar, and pulleys mounted on the 1st rib outboard of the root rib seemed to work. I used some scrap aluminum to make a few mockups.

The actuator pushrod does not move parallel to the hinge bracket, so the balance cable has to be held as high as possible to clear the pushrod through it's range of motion. Going below did not seem to be possible while maintaining clearance. When I finally got a PA-14 wing print and saw how Piper did it, I was surprised to see the use of the phenolic block.

Paul Heinrich · Mar 30, 2023

Correctly installing PA18 flaps on a 12 is one of the hardest jobs you’ll do on your plane.

Working with the extremely limited area available for the cables’ pathway while the flaps are in the up position is just the start of the nightmare. Routing the cables and positioning the flap hardware, fittings, and tie rods correctly to allow the flaps to work throughout the range of motion without structural interference or excessive cable wear is critical.

A hole drilled in the ever-so-slightly wrong spot in the spar webbing is something that can’t be repaired easily.

Curtis Craig · Mar 30, 2023

I have these flaps on a project I just bought to build and would love to have a copy of the installation paperwork.

Hardtailjohn · Mar 30, 2023

Flybynite, the drawing you posted today is what Mike Skup and I talked about a long time ago. He said with the extended flaps, to use a regular flap hanger, mount it the same height on the spar as what the aileron hangers were mounted, then mount the bellcrank all the way up on the spar. Just like what your drawing shows.
I mocked that up today and I barely have contact with the flap push pull rod, and I can easily take care of it with a couple of fairleads, so I'm not going with pulleys. I thought about a couple of very small diameter pulleys, (like on a Stinson 108 aileron control cables, right in front of the seat,) but the more I thought about it, it's just one more thing to have to keep an eye on, so I think a couple fairleads are going to be my solution. With the extended flap, it moves the bellcrank outboard to the center of the flap, so just a little different setup. I'll try to get some pics later.
John

TurboBeaver · Mar 31, 2023

Update: Just spoke with Turnbull about the Marden paperwork.......he says SJ somehow misplaced it!
However he has promised to pin all of it to this thread today! It is like 8 pages of stuff so tnx for your patience.