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Thread: Beringer Alaskan Landing Gear System

  1. #51
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Quote Originally Posted by David H View Post
    Great stuff Bob, very interesting.

    What equipment do you use to pressurize your struts? How do you measure the pressure? How do you add nitrogen? Where does your nitrogen come from? Do you have pictures of your fill set up?

    I will be using Acme Aero and may wish to adjust them.

    David
    Just use standard nitrogen bottle found at any aircraft mechanics shop to inflate struts on aircraft. Nothing special. To get the most precise measurement you have to lift the wheels off the ground and unload struts before changing pressure.

    Bob Anderson, CC11-00316, N382RA

  2. #52
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Continue to beat up the Beringer ALG as best I can. Below is a video of my hardest landing to date, though in the video it looks mild. In this video you can see the worst the Beringer ALG gives back after a hard landing is a skip after the first contact. I have seen this all through the testing. This gear will not throw you back in the air.

    The Beringer ALG has about 5 1/4" inch of strut exposed fully extended. On the ground after it settles with no air over the wings the struts will slowly relax to around 40 mm of extension.

    In the video below you will see the strut compress down to around 1/2 of the full travel for the strut (full travel 5 1/4") after the two good contacts with the ground. In all the video I have seen so far, I have never seen the strut come close to the 40 mm of extension typically seen in the ground rest position, no matter how hard I bang it in. So this strut's working travel for landing appears to be from full extension to around half extension.

    The testing continues. Short video below is in 4K so if you have enough bandwidth you can go full screen to see the gear do it's thing.

    Last edited by turbopilot; 03-01-2018 at 02:09 PM.
    Bob Anderson, CC11-00316, N382RA

  3. #53
    Senior Member Dan L's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Very cool video Bob. I can see they do suck up the downward energy well.

    Two things come to mind. How much air are you running in your tires? And I think I remember that they are 26” tires? The other observation is, with that much camber in the flying position, have you tried a one wheel landing like you might do in a strong crosswind or a beach landing?
    Flying Carbon Cub EX #11 since 2011

  4. #54
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Quote Originally Posted by Dan L View Post
    Very cool video Bob. I can see they do suck up the downward energy well.

    Two things come to mind. How much air are you running in your tires? And I think I remember that they are 26” tires? The other observation is, with that much camber in the flying position, have you tried a one wheel landing like you might do in a strong crosswind or a beach landing?
    Running 9 lbs in 26" tires.

    One wheel landings are as smooth and easy as two wheels. Will try to get some video. Wheel touches down then slowly moves outboard as strut compresses. Remember this landing gear system is built to handle the weight of a Super Cub. So a single Beringer strut could easily handle the full landing loads of a CC.
    Bob Anderson, CC11-00316, N382RA

  5. #55
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Three foot drop.

    Bob Anderson, CC11-00316, N382RA

  6. #56
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    More updates from my testing of the Beringer ALG on the CC.

    Been doing a series of downwind landings with the Beringer gear. No issues with this part of the envelope but it sure was good practice.

    The Beringer ALG modified to deal with roll issue on the ground are supposed to be run at lower strut pressures. My original gear had a nitrogen charge of 305 psi which resulted in about 40mm of strut extension at ground rest. It also resulted in a few degrees of negative wheel camber, which I did not like.

    Apparently I am running one of the first CC's with Beringer ALG and it is considerably lighter than the test airplane used by Beringer, so I am sort of on my own doing this testing. Beringer said to use 200 psi for my weight in the CC running the anti roll struts. That sounded low to me, so I put in 250 psi of nitrogen originally. That resulted in about 35 mm of strut extension at ground rest, 5 mm less than specification. Ride was delightfully soft and I never came close to bottoming out the struts. Still had 2 to 3 degrees of negative camber on the wheels. Was not happy with that.

    Today I took the struts up to 280 psi of nitrogen. That gave me about 44 mm of strut extension at ground rest and less than one degree of negative camber on the wheels. Ride is firmer than with 250 psi, but not bad.

    With the new pressures in the struts airplane rides a little higher (nose up). Gear retracts down 10 5/8" after takeoff. That distance is taken up on landing with the combination of gear widening and about 4" of strut compression.

    So by varying the strut pressures you can modify the firmness of the ride as well as change the nose angle of attack as the airplane sits on the tail wheel. Lots of variables to consider.

    This landing gear is really neat.
    Last edited by turbopilot; 03-07-2018 at 06:52 PM.
    Bob Anderson, CC11-00316, N382RA

  7. #57
    Senior Member turbopilot's Avatar
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    Default Re: Beringer Alaskan Landing Gear System

    Found this information on several sources around the internet. Looks like Beringer finally got an STC for their Alaska Landing Gear System. It appears to be the same system I am running on my ELSA Carbon Cub but the STC is for the Super Cub. Should be more at SnF.


    After 3 years of research and development,
    Real world tests on different airplanes
    And on various surfaces and parts of the globe,
    the Alaskan Landing Gear ALG has proved its strength and reliability
    and meets FAA Standards and Regulations !
    The ALG will be available as certified STC for SuperCub very soon…
    Introductory price $6,990

    Ultra-Light 10" Wheels/Brakes for Cubs (PA-18, Carbon Cub, Shock Cub, …)
    - Light weight superb design
    - Fully CNC machined from high grade aluminum billet
    - High braking torque
    - Install with 35" Alaskan Bushwheel OR Desser TL 31" Tundra tires
    Introductory price $2,980 (incl. 2 wheels, 2 brakes, 2 discs and bushings)
    Bob Anderson, CC11-00316, N382RA

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