Landes rigging installation

Ive always dreaded the yearly ski install as it isn't to hard to get into trouble or strain some muscles when working alone.
Then a couple of years ago while trying to think of something better / easier / quicker to install the stiff endless loop bungees I discovered that I already owned one.
This is a 4 ft long Irwin bar clamp with the reversible end so that you can also push as well as compress. I figured what the heck, its worth a try.
I found that it is very light weight and fast but it does require a bit of a strong squeeze grip, especially out toward the end.

Using this is not without a few obvious risks... in that if you accidentally trip the release trigger you will quickly find your self with a 4 ft long projectile. So always think about the line of fire.

I was able to do the complete change over in less then an hour by myself using this.

I would like to see what others are using for cords as well as the springs as I am always looking for a "safer way" and still be somewhat easy to use.
Thanks

Need is the mother of all invention... you could also lift the tail up and kick a saw horse under the tail spring... and make life a bit easier putting those bungees on.

If you're able to lift the airplane off the ground you don't have to stretch the bungees at all. I have a chain hoist in the hangar and lift the Cub high enough so that the tail of the ski drops down and the front pivots up enough to attach the bungees to the front gear bolt. The check cable needs to be unattached at this time too.

I made a simmilar rig to the clamp with threaded rod.Use my cordless drill to stretch the bungee.Takes me about 15 minutes a side to go from wheels to skis.

Bill

willyb said:

I made a simmilar rig to the clamp with threaded rod.Use my cordless drill to stretch the bungee.Takes me about 15 minutes a side to go from wheels to skis.

Bill

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Bill:
Do you have any photos?
I like the idea of using a drill.

Irishfield:
I have used a stand under the tail many times and even having ropes tied to it to lift it overhead but without some help it can be difficult. The spreader clamp made this unnecessary.

Thanks for the ideas. Keep them coming.

I am not strong enough to lift my tail. Your reversible clamp is a great idea! Cool!

My bungie disconnects from the cable that attaches it to the ski via a small shackle and pin. I attach the bungee to the gear tab first then pull the bungee toward the ski with a small winch. Not sure it would work for you on snow since the plane might slide toward you but it's the only no drama way that I have found so far. I like your idea but I bet I could find a way to hit the release lever and give the doctors something new to remove from my body.

Jerry

cubflier said:

My bungie disconnects from the cable that attaches it to the ski via a small shackle and pin. I attach the bungee to the gear tab first then pull the bungee toward the ski with a small winch. Not sure it would work for you on snow since the plane might slide toward you but it's the only no drama way that I have found so far. I like your idea but I bet I could find a way to hit the release lever and give the doctors something new to remove from my body.

Jerry

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I have been thinking of a way to put a safety latch on the release so as to prevent any unplanned excitement. Shouldn't be too difficult.

FYI the Irwin clamp that I have is an older style. The new ones have larger grips and clamp ends etc and may not work as well. I remove the pads on the clamps and slip the small plastic heels into the bungee loop.

An ideal world to be to have a hangar to lift the cub, but the Lord has not chosen to bless me with one of those. Therefore I get to do things the normal Alaskan way and improvise. Just got done using the Red Dragon heater and blankets (and anything else that would help) to remove 1/8 to 1/4 inch of ice from the cub just so that I could at least think that I might be able to go flying. I understand that the ice in the valley is well over a foot thick in most areas and the Biglake Ice roads are open.

Amazing to think that I was flying to the cabin on floats Nov 4th.

I disconnect my bungess by hand daily. Not overwhelming stress on them but I do have to "lean into it". Are my bungees not tight enough? How tight should they be? Jim

cruiser said:

I disconnect my bungess by hand daily. Not overwhelming stress on them but I do have to "lean into it". Are my bungees not tight enough? How tight should they be? Jim

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Your best friend is Timmy, we know your bungees not wrapped tight enough.

Glenn

I would change from wheels to skis in less than ten min. Like Jim's it took a little bit to pull but not crazy. I would say as long as it has enough strength to pull the tips up your good. What do you say Glenn

If you blow up the pix on the first post you'll see that cp2 has a doubled bungee, twice as much pull.


Glenn

The ideal setup would be a pully top and bottom and 3 passes with a single long bungee cord. Like a block and tackle. You could easily hook up the single bungee end to go flying and unhook at the end of the day so that the bungees could rest

Glenn

RaisedByWolves said:

I would change from wheels to skis in less than ten min. Like Jim's it took a little bit to pull but not crazy. I would say as long as it has enough strength to pull the tips up your good. What do you say Glenn

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My 2500 Landis skis originally came with a single shock cord and were well used when I got them so I didn't know what new cords felt like. I was able to connect the cords by hand but with lots of force. After the cords were stretched out awhile then it was much easier and especially when cold.

Over the years the cords would still look ok, but it got to where I could almost use one hand to connect them. That was the "clue" that it was time for a change. I had been hearing too many horror stories of these things breaking as well as springs and then going into the prop. The outcome was usually wreckage.

When I got the newer continuous loop style cords from Landis I was surprised at how stiff they were and didn't think that I would ever get them connected. No mater how hard I pulled by hand I could not stretch them. It was like trying to stretch by hand a 1280HD landing gear shock cord. (If you haven't tried it you should) (If you can stretch a new 1280HD then I don't want to shake your hand )

When connected the skis now really "snap to attention". I feel lucky that I never had a problem.

I can only assume that Landis chose this style and their tension for a reason so I will try to maintain it.

Below is what AC4313-2B has to say about the shock cords.

c. Tension Required in Main Ski Shock Cords.
(1) Apply sufficient shock cord tension to the forward ends of the skis to prevent flutter and "dumping" throughout the range of airspeeds and attitudes at which the airplane will operate on skis. Because of the various angles used in attaching the shock cord to the skis, shock cord tension cannot be specified. It is possible to specify the downward force that must be applied to the forward end of the ski in order to overcome the shock cord tension and cause the check cable to slacken when the ski is in the normal flight attitude. That downward force is commonly referred to as the shock cord tension force, or simply the tension force. In most installations on rigid, truss type landing gear, the tension force should be approximately as listed in Table 5-2.

TABLE 5-2. APPROXIMATE MAIN SKI TENSION FORCES
(transcribed as would not copy properly)

Ski limit Load Capacity vs. Downward force in pounds
1500 to 3000 ---------------- 20 - 40
3000 to 5000 ---------------- 40 - 60
5000 to 7000 ---------------- 60 - 120
7000 to 9000 ---------------- 120 - 200

Here's an alternate technique. I copied our mechanic's pulley set up. And made a second set for him, as 185 skis & springs are easier to install with two pulley rigs.
His pulley makes switching gear very easy for one guy in one afternoon. Time estimate assumes ya brung proper cotters, correct tools, etc. to the party.
Dwayne

Bring two people, leave the rear cable off, lift up the tail and have the other person hook the spring cable up. Forget the bungees....

Airglass told me they wanted an 80# pull on the bungee for the 2000 ski so that's what I use.I have the one piece loop style bungees.If I can get a pic of my stretcher I will post it later.

Bill