Nose wheel shimmy on amphibs

W

Wayofftrack

FRIEND

• Sep 14, 2021

• #1

When I land on grass with our Wipline 2100a floats all is good, but I landed recently on a hard runway and got a severe nosewheel shimmy.
It all looks OK, tire pressures are good, jacked it up and there's nothing loose. The centering springs and balls seem OK and keeps the wheels running straight. Any ideas what might cause this?

 

AkPA/18

MEMBER

Big Lake Ak

• Sep 14, 2021

• #2

Are they an earlier set of floats before they put the shimmy dampners on them? I had the same problem and ordered a set of their newer parts. The shimmy was brutal but all is good now. Grant or Amy will probably chime in here and give you the specifics..

 

mvivion

SPONSOR

Bozeman,MT

• Sep 14, 2021

• #3

What he ^^ said. That said, don’t let those nose gears come down till you absolutely HAVE to. I see way to many folks plunking tosecnipose gears down as soon as mains are on……don’t be that guy.

 

AkPA/18

MEMBER

Big Lake Ak

• Sep 14, 2021

• #4

By the way on tire pressure, most of us are running 60 pounds for mains and nose gear. This filtered up to us from the guys running them in South East. Seems to work well for tire wear.

 

W

Wayofftrack

FRIEND

• Sep 15, 2021

• #5

My floats are old, 2003, so that’s probably the answer, no shimmy dampeners. I run all the tyres at about 55 psi and have the stick hard on the backstop until I’m parked up so it has to be the lack of dampeners. I’ll contact Wip. Thanks for the advice.

 

aktango58

FRIEND

18AA

• Sep 15, 2021

• #6

mvivion said:

don’t let those nose gears come down till you absolutely HAVE to. I see way to many folks plunking tosecnipose gears down as soon as mains are on……don’t be that guy.

Click to expand...

The other part of keeping the nose gear up also requires you to GENTLY set them down on the runway under control, don't hold them off until you get so slow it drops down with a serious impact... so set the fronts down gently once slowed, but still under control. (Yes, it takes lots of practice!)

 

P

pouellette

Registered User

WesternMassachusetts

• Sep 15, 2021

• #7

Was that you landing at Greenville Saturday? I could hear that shimmy clear across the airport...right wheel from what I could see in the binos..

 

skywagon8a

MEMBER

SE Mass MA6

• Sep 16, 2021

• #8

Check your entire nose landing gear assembly for minimum clearances. Too much slop somewhere can accentuate shimmy. Also sometimes when you taxi down a ramp or off a beach with the nose wheels cocked when they float then land on land, they can shimmy since when they touch the pavement they will be trying to find their alignment with the direction of travel.

Some gears are more prone to shimmy than others. Get it fixed properly or you may be surprised at how quickly the nose gear can depart the floats.

 

Amy

SPONSOR

WI/MN/SD

• Sep 16, 2021

• #9

Check to see if you have service kit #48 installed—that is the shimmy dampener kit that others are referencing. Your floats would be right on the cusp of having this incorporated from the factory. The service letters and service kits typically have a warranty period so yours may have been retrofitted after they left the factory as well. The tech support line is 651-306-0459 or customerservice@wipaire.com and they can hook you up.

All that said, things wear out so the recommendation to go through everything is a good one. It can be a sum of several little things being out of alignment/spec.

—Amy

 

W

Wayofftrack

FRIEND

• Sep 17, 2021

• #10

Thanks again. I'll check those clearances, and I have the shimmy dampers on order so should be fixed now.

Not me at Greenville, I was landing in Scotland. But they probably heard it in Greenville, it was violent.

 

aktango58

FRIEND

18AA

• Sep 18, 2021

• #11

Any surface that is not perfectly hard and smooth will cause extra wear. I always consider amphibs on other than pavement or water a risky business.