Sutton exhaust / ski bungees

[JMBreitinger]

My partner and a friend were out Saturday ahead of the storm in Patrick's Super Cub. He had just installed the new Sutton exhaust and made his annual switch to skis. After a short time, the exhaust had burned through he middle of the bungee. I guess that makes an interesting sound when one lets go in flight.

After seeing it, I was considering the mod.

Anyone know how to protect the bungee in this case?

Also, Keith said that he thought the Sutton system would not produce enough heat. Anyone else in cold climates have experience with this.

[behindpropellers]

My partner and a friend were out Saturday ahead of the storm in Patrick's Super Cub. He had just installed the new Sutton exhaust and made his annual switch to skis. After a short time, the exhaust had burned through he middle of the bungee. I guess that makes an interesting sound when one lets go in flight.

After seeing it, I was considering the mod.

Anyone know how to protect the bungee in this case?

Also, Keith said that he thought the Sutton system would not produce enough heat. Anyone else in cold climates have experience with this.

John-

Did you cut the pipe off or is it long??

Tim

[JMBreitinger]

It is not on my plane. They did not cut it off. The installation is right out of the box.

[behindpropellers]

It is not on my plane. They did not cut it off. The installation is right out of the box.

I'm pretty sure it says you can cut it off in the STC.

Tim

[Cubus Maximus]

per the STC you can cut it short or bend it.

[Icarus]

Just replace the Bungees with Springs from Atlee Dodge. You will probably have to change the forward rigging. Let me Know what skis you have & stock gear or 3'' extended I am sure I have measurements for the rigging for Landes 2500's or Dodge's 2500 skis

[JMBreitinger]

These are Wip retractable wheel skis.

[mvivion]

Installing the springs in lieu of bungees should be field approvable anywhere. I'd still try to keep the exhaust away from them as well, but they'll hold up better than bungees, and springs don't care what the temperature is outside.

MTV

[irishfield]

Exact same thing happens on Husky's running Wip retractibles.

I stopped using bungee for skis 13 years ago. My experimentals all run the 140lb tension garage door closer spring from Home Depot.

[mvivion]

Irishfield,

Have you ever had a problem with the ski toes wanting to go over with the springs attached to the gear fittings?

I like em installed to the engine mount bracket. It's a straighter pull from there, and virtually no chance of them going over.

Atlee Dodge sells "airplane" springs, as does Aero Ski. Both are probably from Home Depot, though.

MTV

[irishfield]

Hasn't been an issue Mike. Pretty much a 45* angle on my set up shown. I've even intentionally gone from level flight... hard stick forward.. dive and a hard pull out to see if they move, but they don't even dip in the +G pull out.

I have however attached others further forward on the nose section.. alla C180/185 and the latest set is going on a Smith 180 HP SCub..and I've suggested to him to mount the front cables/spring to the lower engine mount or similar to be absolutely sure as I won't be on hand for the installation... Ie.. I wanna sleep at night ! Thanks for the concern... it is warranted in many installations.

[4380zmike]

put sutton exhaust on my super cub has great heat.better then the old

[PPI Brian]

Hi Guys,
The curved tailpipe should definitely solve your bungee problem. It does not seem to be an issue with the ski's that use a tip bungee which runs up to the landing gear bolt. However, the ones which fasten to the lower engine mount bolts may be another story. Its pretty hard to imagine all the different scenarios when engineering these things, but I promise to keep trying... Just let me know if you need the extension or any other help.

Brian

Brian Sutton
Professional Pilots Inc.
www.propilotsinc.com

[aktango58]

after seeing the response from PPI Brian to Louis and here, I am sorry I bought the Atlee!

About skis...

I am tired of dealing with ski tabs on my mains. How much trouble is it to get approval to mount aero retracts to the engine mount bolt????

Anybody tried?

[mvivion]

aktango,

That's the way we installed all our skis on Cubs, Huskys, Scouts, all done by specifying the forward attach point on the 337. Those were done in ANC and FAI FSDO. Those guys should understand skis, and attaching to the engine mounts makes a lot of sense, geometry-wise.

We never had any problem doing this. My Super Cub had the forward cables attached to the engine mount with Aero straight skis. We approved one Cub with Aero retracts that way as well.

MTV

[aktango58]

Sorry to hijack this...
Mike,

Any clue as to the N number of the one approved? and do you run one or both to the engine mt?

I remember the 180 was this way, liked it. Also my first cub had the aft cable to the float mt.

Thanks

[mvivion]

Mine was N102TC. I had both forward cables attached to the engine mount, and the aft attached to the rear float fitting.

Should be a no brainer getting this approved, in fact, I'd think it would be a minor, although we got in trouble once on this airplane for not submitting a SEPARATE 337 for the change to springs from bungees, even though Aero Ski provided the springs, not bungees....so who knows?

MTV

[aktango58]

Thanks, I will call the FSDO this morning and do the prelim. asking...

Did you say that the Corsair was on Skis?????

Love the pics of the Electras on skis on Weeks field. Imagine a F-4U?

[Super Sportsman]

Hello i have a similar set of skis and set up I used the tabs attached to the gear and also a pulley and double bungee set up never had a problem , works great in deep snow

[aktango58]

If I use the engine mount, I have the same trouble as this thread discusses.

I do not want to cut my tube down, because the plane is a bit cleaner.

So maybe just go to the rear float fitting...

Unless you can really convince me to cut it down...

SS: Do your ski tailwheels retract?

What is the blue bar behind the tire?

[Super Sportsman]

The blue bar behind the tire is the pivot arm , the hydraulic cylinder pushes the plate under the wheel in flight !

I attach the rear cable to the bolt on the back of the wheel gear with a tab.

I also use a wheel penetration ski !

Gerry

[Super Sportsman]

I just use the rear gear bolt and a ski tab

[Super Sportsman]

Here I have a 12 volt hydraulic pump and a 2 way switch
[img]
http://www.supercub.org/photopost/da.../100_03801.jpg

[Super Sportsman]

Here is my 2 way switch

[d dyre]

My cub has Sutton Exhaust and the Wip retracts. It came with some firesleeve over the bungee and I have never had any problem. I would also recommend going to the 3 inch intake setup for the heat shroud if you can. I took the feed off the baffle like a Cessna though. More heat is better!

Dan

[cabinflyer]

Here's a stupid question... Ive seen the bungee's on cubs in flight. To me they seem to vibrate back and forth some. Could the cord actually be rubbing on the outer sharp edge of the exhaust pipe? The Sutton pipe is longer than stock.

Steve

[Patrick Fox]

This post is actually concerning my bird. I was meaning to start it, but I got jammed up at work. I logged on and there was the topic, I didn’t even need to do a search! Thanks John for getting the ball rolling and the responses.

D dyre, is your exhaust the stock length or was it cut and the bend installed? Also what is the fire sleeve made of? Any chance you can send me a picture? That was my first thought, to install something around the bungee and the cable.

Cabinflyer: I don’t think that the bungee was that close. The bungee showed signs of melting, not fraying.

The Sutton folks think that cutting the stack and installing the pipe with a bend will do the trick. It seems like the exhaust will still be close to the bungee. The exhaust itself was a nice setup, a nice improvement over the stock.

[aktango58]

Cabin Flyer....

The vibrations keep the ice from building up! (stupid answer)

[cabinflyer]

Cabin Flyer....

The vibrations keep the ice from building up! (stupid answer)

Yep.... No ice build up on me when I'm flying in the winter... Commonly called "uncontrollable shaking"

[aktango58]

Years ago when I spent lots of time in Anchorage, I was talking to Atlee himself about airplanes, (always good for an opinion he was), and someone came in and asked about his springs compared to bungees.

Atlee explained that he had taken a new bungee years ago to a spring shop and did a pull test, measuring the elasticity of the bungee at different lengths, then had the springs designed/approved using those numbers...

Now, that may be how these springs come into view, but I have never researched the spring company to see which garage door spring most nearly met the spec. so was supplied

But just so you don't think that Atlee went to home depot to get them in the first place... :P

[d dyre]

Patrick:

Sorry to be so long getting back. I guess I'm not sure about the stack length, I don't know what stock length is. It sticks down about 4-6 inches, if I remember right. It is not bent at all. The firesleeve is just the standard orange stuff you put on engine fuel or oil lines. It's about a foot and a half long and starts at the engine mount lug. It's all covered with exhaust stains but the bungee is OK.

Dan

[Patrick Fox]

Dan,

Thanks for the reply, we'll be doing the mods this weekend.

--Patrick

[Icarus]

Sorry didn't post more originally, but Atlees STC for Springs allows direct replacement for BUNGEES on all Approved skis on the PA-18, PA-12, PA14, J-3 etc. You would leave the rear check cables the same. Install Atlees springs Fabricate the front cable & a New Check cable Make sure you are within limits of ski deflection, Fill out the 337, Logbook entry and Minimal weight & balance change and NEVER have the problem again.