How to check landing gear alignment?

[Gilbert Pierce]

a long straight edge clamped midway to both wheel rims right at the axel. Measure the distance between the two straight edges as they project both forward and behind the airplane. The longer the straight edges the more accurate the measurements.

If distance is not equal between the front and rear porjection then you need to drop a plumb bob and find the center of the fuselage at the front and rear and draw a line on the floor connecting theses points. Then measure to your extended straight edges to see which wheel or wheels is off and by how much.

There are other ways to do it. That is how I do it.

After you get the numbers a little high school trig will tell you how many degrees you are off. You really don't need that number. Best to have both wheels point the same direction.

Toe in is better than toe out IMO. Some people believe in in Toe-IN. I don't. Just because automobiles have toe-in doesn't mean I want it on my airplane. Personal preference. Supposedly toe-in makes it less likely to wander. As the airplane starts to turn the wheel opposite the direction of turn has more scrubbing force and wheel in the direction of the turn has less so it is self correcting. That is why cars have toe-in. Less wander.

[walt.buskey]

70659: here's my "thousand words."DSC05600.jpg

[Semper Fi]

thank you gentleman and YES a picture is worth a thousand words!

[tloes]

The picture is exactly what I imagined. But I think the "best result" would be achieved with "tires off" (I'm imagining some "bulge" over the rim). Possibly with axles on jacks, it could be done simply with the tires deflated?

[Brian]

I always thought a little toe in was good because it keeps the bungees pulled up tight when rolling forward. Toe out would be bad since that would extend and stretch the cords. Neutral may be ideal but I would suggest a little Toe In as a starting reference, knowing the alignment will change over time and you could easily end up Toed Out, due to worn bushings, hard landings, etc, when starting perfectly neutral. With that said, I can't suggest how much Toe In, degrees wise would be good, so I'm no expert on the subject. Just an Opinion and we've all heard what Opinions are like and worth. :~)

[Semper Fi]

The picture is exactly what I imagined. But I think the "best result" would be achieved with "tires off" (I'm imagining some "bulge" over the rim). Possibly with axles on jacks, it could be done simply with the tires deflated?

yes the picture is what I imagined to, I couldnt understand how that would make an accurate measurement though because the tires are going to be out a little farther than the wheel.. so I thought what I was picturing in my mind was not correct... so now im picturing the strait edge clamped so it snuggly touches the tire sidewalls.. I will do this on top and bottom of tire since I have an extended cap on the axle right now for mounting wheel pants

[Jim]

Hi,

There's a picture above in comment #4 that shows the axels trapped on a bar. The bungees are removed and the tubes for them are hanging a little low. So, when things are reinstalled the tires will pull together a little creating some camber angle, out of plumb in the front view. This makes me think toe-in and out will be affected by the tail being raised or lowered. I'd think a tail wheel airplane would measure a different toe-in or out if the fuselage rear was raised to flying attitute if the wheels aren't plumb when viewed from the front. As the bungees wear out the camber will change a lot, start looking like the old VWs.

Should alignment on tail draggers only be done with the fuselage in flying attitude?

[bigjohnnie]

From experience, I know I like a little toe in. My tripe was a handful ( footull ? ) on almost every takeoff / landing rollout when she was toed out --- even in calm winds . Now with a little toe in, no issues. I can't tell you the exact degrees because my mechanic fixed it ..,, and I just watched.

[Semper Fi]

i dont have a strait edge right now.. and i am at the plane going to take the belly panel off and look around a bit.. i will just measure the distance between the front of the wheels and the back of the wheels and hope its not too different

[Semper Fi]

I didn't measure from the wheel I measured from the middle fatest part of the tire front left tire to front right tire and again back left tire to back right tire, the back distance was more by 1/4 to 3/8 inch, thats definitely toe-in.