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replacement nose gear leg has different angle?

seagull

Well Known Member
After installing the new nose gear leg per SB19-08-26 I noticed the nose wheel pant was angled tail down. Before the replacement it was level to flight. I measured the vertical part of the leg where the wheel fork pivots, and the replacement leg is angled forward 2.5 degrees compared to the one I removed. I had to add .400 spacers under the rear bolts of the faring to bring it back to level. I wonder if the forward cant on the fork will affect stability. Is this typical tolerance for these parts?
 
That sounds odd. My replacement nose strut appears to be spot on the money. You might want to give Van's a phone call...
 
One would assume if the original had been bent it would have been before the first flight. The wheel pant was installed level then and has been level until the leg change.

The new leg is angled forward when measured from the firewall.

The measurements with the equipment I have;
Original leg is angled .75 degrees to the rear.
New leg is angled 1.75 degrees forward.
 
My original-style nose wheel pant is slanted somewhat tail downward on the new-style nose strut/fork combination. I think that the top of the new-style nose gear fork is not angled the same as the original-style fork. Looks like I'll have to make a new pair of brackets to correctly reorient the pant. Wish Van's had provided for this with appropriately angled brackets.
 
My original-style nose wheel pant is slanted somewhat tail downward on the new-style nose strut/fork combination. I think that the top of the new-style nose gear fork is not angled the same as the original-style fork. Looks like I'll have to make a new pair of brackets to correctly reorient the pant. Wish Van's had provided for this with appropriately angled brackets.

Making new brackets is what I did. I replaced the fork at the same time and the angle brackets that are riveted to the fork were the ones I remade with the required angle to realign the pant.

I compared the new and old fork and they are the same angle. I found the mismatch in the leg lower bend.
 
I checked with the engineer that did the design work on the new version nose gear leg and he says that the dimensional geometry is identical to the original. There is of course some tolerance allowance (not sure what amount) so any one leg could vary by a small amount.

For those of you that think it is misaligned, are you checking the nose wheel pant alignment relative to the ground when the airplane is sitting on its wheels? If so, that is incorrect.

The RV-12 sits at a positive pitch angle of about 1.5 degrees on the ground, so the nominal nose wheel fairing pitch alignment should be about the same when referenced to the ground. That would make the nose wheel fairing look a bit trailing edge low, parked on the ground.

In level cruise flight, the cockpit side rail is pretty close to level, so the wheel fairing pitch alignments should be close to matching that.
 
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I checked with the engineer that did the design work on the new version nose gear leg and he says that the dimensional geometry is identical to the original. There is of course some tolerance allowance (not sure what amount) so any one leg could vary by a small amount.

For those of you that think it is misaligned, are you checking the nose wheel pant alignment relative to the ground when the airplane is sitting on its wheels? If so, that is incorrect.

The RV-12 sits at a positive pitch angle of about 1.5 degrees on the ground, so the nominal nose wheel fairing pitch alignment should be about the same when referenced to the ground. That would make the nose wheel fairing look a bit trailing edge low, parked on the ground.

In level cruise flight, the cockpit side rail is pretty close to level, so the wheel fairing pitch alignments should be close to matching that.

My measurements were made from the firewall to the vertical axle where the fork pivots. I believe they should be parallel, mine isn't.

I have noticed a wheel shimmy on landing since the leg was replaced and thought I wasn't getting the friction correct. I think the forward cant may be causing this.
 
I have the same problem.
The pant is not parallel at all which looks bad.
I made new brackets to correct this but the tow bar holes do no longer align.
I never had shimmy problems but since the new leg I have a shimmy in take off and during landing roll which I cannot suppress. Nose wheel has been staticcally balanced.
 
There have now been more than one reports of a nose wheel shimmy after replacing the nose gear leg. The misalignment of the fairing and the shimmy are not acceptable. This needs to be looked at in detail.

Hotscam, please be sure to report this to Van's engineering using the Feedback Form on page 18-27 of the RV-12 MM.

I have not done the update yet and am hesitant to do so. These issues being reported seem worse than the unlikely possibility of a gear leg failure based on only one event which happened on a high hour training airplane.

If there were to be a correctional part or SB to come later on this I would be unhappy!
 
If there were to be a correctional part or SB to come later on this I would be unhappy!

There is always SB's coming later. Look at latest salvo of dynamic balancing every time prop is disassembled for inspection. Used to be when I owned a GA certified aircraft I hated to walk out to the mailbox for fear of AD note. Stooped shoulders - looked like a caveman walking out to get the mail.

Now you get SB's via email from some nice lady at Van's. The same drudgery only sitting in my recliner drinking a morning coffee...
 
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