Couple of Nose Fork Questions

Hey - The last few landings, I have felt a shimmy on landing when my nose gear came down (somewhere around 30 kts or so). So, I have a couple of quick, and hopefully not too dumb questions on checking the breakout force for the front gear on my 7A.

1) What is the best way to get the nose up in the air so I can check the breakout force? I am assuming that the fastest way would be to have someone push down the tail (I'm assuming that putting a bag or 2 of sand on the HS might be helpful). Is there a good way to do this if you are alone?

2) I don't have my plans at home, but I can't remember where you attach the fish scale to the front fork to measure the breakout.

Thanks,
Jason

22 lbs
Pull point is wheel axle.

Takes between 75 - 100 lbs to hold the tail down.
Can be done many different ways.
One convenient way to do it solo is to drill the floor and install a screw anchor. Then thread in an eye bolt and use a ratchet strap to pull down on the tail tie down when you need to lift the nose wheel.

I use a small scissors jack

with a block of wood under the gear leg end --- this allows me to use my Walmart fish scale to pull on the fork and adjust the nut --- I always set my breakout at about 28lbs ---- works well on my -6A, and the -8A I previously flew.

I never was comfortable with placing weight on the HS or tying down with the tie-down ring on the tail.

RONSIM said:

with a block of wood under the gear leg end --- this allows me to use my Walmart fish scale to pull on the fork and adjust the nut ---

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Maybe I am not thinking of this correctly, but wouldn't having bottom nut of the fork sitting on a block of wood effect the breakout force?

UnPossible said:

Maybe I am not thinking of this correctly, but wouldn't having bottom nut of the fork sitting on a block of wood effect the breakout force?

Click to expand...

No, because when doing it that way, it is the stub end of the leg sitting on the block (stationary) with the fork pivoting around it.
I have done it this way to do a quick check. The drawback is it limits access to the cotter pin and nut so it is not very convenient if you need to make an adjustment.

What if you just use an engine hoist to take weight off the wheel?

LettersFromFlyoverCountry said:

What if you just use an engine hoist to take weight off the wheel?

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I agree - that would be the easiest solution.....If I had an engine lift!
I'm hoping that I can McGuyver this with out having to buy a lift.

Sandbags

Sandbags(or equiv.) on the tail works great. You can put a tire under the tail if you want to cushion it. The plane is very stable when the tail is on the ground. Sandbags are placed close inboard and over the spar of the HS.

For those reluctant to push down on the tail, you raise the nose gear with the tail every time you go flying..........

i have a lovely but useless (as an engine) 5.7 litre GM engine block in the hangar. A ratchet strap from the block to the tail tie down holds the nose wheel up very nicely. Just make sure your ratchets are heavy duty enough to take the force unless you have someone hold the tail down while you tighten the straps; cheap ratchets will bend and break. Unlike most people here I don't use a "pull type" spring scale to check the breakout force; I am fortunate enough to have access to a $1000 Chatillon force gauge that works in compression or pull mode; I push on the wheel axle with this gauge to get my reading. Works great if you can get your hands on a gauge.

Concrete Anchor

I drilled a hole in the floor in my hanger directly under the rear tie-down ring. Then I inserted an expansion anchor with about 0.5 inches of threads sticking up. When I want to raise the nose, I screw on a threaded eye, and use a cheap HF block and tackle rig to pull the tail down. Then I hook a pre-made chain with two hooks into the ring and eye and release the tension on the block and tackle. It only takes a minute.

You don't trip over the bolt in the floor because it is under the tail!

I also use a tie down ring that screws into a lead sleeve in the concrete floor. Push down on the tail and attach strap or rope to hold down from tie down ring on plane. Remove eye screw when finished. I use a fish scale inserted at the hole that lines up with the axel bolt. Set force to 23-28 lbs. Be sure NOT to lubricate Belville washers. Not recommended by Van to apply lubricant.