Cruisair Gear Alignment

M

meat n the seat

New member
This has probably been covered in detail but I could use some advice. As far as main landing gear alignment is concerened I assume that toe in and toe out is accomplished by shiming the drag link scissors. I'm not sitting here looking at the aircraft at this minute but that seems to be the only way to adjust it. I think the drag links are assembled on this aircraft with one inside the other which would prevent shimming from side to side. Is this correct? Anyway words of wisdom or pictures of the draglink assembly would be appreciated. Oh, and what are your opinions on gear alignment? Toe in, toe out or neutral? Thanks in advance.

Pete Nadon
Aztec, NM
 
I don't think this is the last word on this subject. As I have pointed out in prior discussions, if the plane should swerve to the right, centrifugal force would put force on the left wheel . If it were toed in, it would like the skier doing a "wedge", force the plane to go more to the right. I discussed this with several knowledgeable mechanics at the last west coast meeting and this was what I was told. However, there are people who are convinced that toe in is correct, so there is a difference of opinion. I keep thinking that if we take a poll we will get a consensus. (but then again if we took a poll of what is the "correct" religion in God's eye, would we necessarily get the right answer?) I would like an explanation of why toe in is good.. I've told you why it's bad-now perhap Allain can give us an answer as to how it is helpful.
 
I'm on the road right now...(BOS), but when I get home, I'm going to try to align thde gear to 0 Degrees. I'll let you know what I come up with... Until then any IAs here please chime in. Peter...thanks for your input. Maybe we will be able to put this topic to bed after we get it right.

Pete Nadon
Aztec, NM
 
I checked my gear alignment on my Cruisemaster and it is basically zero degrees. There is also a small amount of twist to the leg but well within two degrees. Toes in ,toes out. My IA 2 cent is set it to Zero or you will not be doing the HOOCHIE Coochee down the runway. Lynn N9818B the crate :wink:
 
Lynn, Kevin, Peter
Thanks for your replies. I still am not home and haven't been able to work on it yet. Zero toe-in toe-out is the goal.or I'll post the results when I do. If you don't hear from me, I probably rolled the plane into a ball. Kevin sound like you may have the highly coveted "crosswind gear"!
 
I tried different ways and ended up with 0. For me it seemed like it was les likely to walk left or right on take off when the tail started up. Now I am a 3 point man so that might make a difference. There is very little movement in the siccors. Mine would only take a thin washer after I rebush the links. :lol: :lol: :lol:
 
Here is my 2 cents, call me an idiot if you want, I dont care, this will mean I am allowed to make mistakes. Idiots are allowed. :roll: But here how it is understood by the old timers here and in other places. and me!
Let say your are coming in with some wind on the right. You will lower your wing on the right before touch down right? And wind slapping your fin on the right will require you to go a little left rudder if you want to keep on going straight down the runway. If the wheel is toe out a bit, Where do you thing you will go. Right wing low, wind gusting on the right side of the fin forcing you to go right! fighting it with left rudder and on top of that you will have your right wheel toed out, pointing to the right of the runway? That's where you'll go. If anything, 0 deg or toe in a litte degree or two. From what an engineer eplained, the way the gear are made, many airplane will have toe in when level and closer to 0 when tailwheel on the ground but still in. Geometry...
So, here is one of the many theories. But this one is proven. :lol:

Alain.
 
Taking your example of the plane slipping in with the wind from the right, so you have right wing down and left rudder -the plane is facing slightly to the left when the right wheel first contacts the ground. If you were to have it track straight, ideally, it should have toe out. I think zero degrees is the correct way.
 
Actually, when using side slips to maintain runway alignment with a crosswind, the longitudinal axis of the plane should always remain parallel to and (preferably) on the extended runway centerline. It shouldn't be cocked to the opposite side of the side slip at touchdown.

Rudder is used to maintain the airplane's heading so as to remain parallel to the extended center line. The amount of the bank controls the movement to the left or right to keep you on the extended centerline.

As the crosswind component increases or decreases, the wing is put in a steeper or shallower bank to match the crosswind value and keep the plane on with the centerline of the runway or move it left or right to return to the centerline. Meanwhile, opposite rudder is used as needed to keep the longitudinal axis parallel to the runway centerline.

This procedure will keep the plane on the extended runway center line through the approach, flare and touchdown.

During the approach, you get also a good idea of the amount of crosswind and whether or not you will have enough rudder to handle the crosswind after landing. If you are running out of rudder holding the nose straight during the slip, there is a good chance that you will not have enough rudder to hold the nose straight after landing.

If the side slip has been done properly, at touchdown there will be no side motion for the gear to absorb (and start the ground looping tendency), the wing and ailerons and rudder will already be in the best position for the existing crosswind and the plane will be pointed straight down the runway.

Of course, once the wheels are on the ground you still get to enjoy all the thrills of a tailwheel plane rolling out with a crosswind.

After some evaluation, I think I have to agree with the 0 degree toe in/out guys. With zero degrees, there would be no tendency for the plane to want to go left or right with only one gear touching. It will just go straight in the direction that the plane is pointing, which should be straight down the runway.

Dave York
 
I only have about 1100 hrs on taildraggers, Wheels and skis, from Tiger Moth to Champion,, Stinson, Jodel, 120/140 and others, and 500+ in my Bakeng Deuce which are not the most docile ones in crosswind. Now flying this Bellanca 14-13-2. On all tail draggers, I never touched down during a crosswind with the nose opposite to the wind and away from centerline of the runway. If anything, i just do my aproach with the nose in the wind and in the very last portion of the final, kick it staight and keep the wing low to the wind and nose very straight down. And we have plenty of these condition here. If you ever let the nose go away from the center line opposite to the wind, you'll never have problem bringing it back because the wind is slapping the side of the fin which will push the nose into the wind with no help, the other way is another story, you might very well run out of rudder especially if toe out. Anyway, so much for crosswind tecnique 101 for tailgragger.

But you're right, after tought, I absolutely agree with the 0 degree, but if there is to be some toe-in/toe-out, the toe-out will get you a nice pic-nic on the snow bank or in he grass... 0 or IN. Never out. And we're talking a degree here! this ain't much!

Hey this is not the first time we discuss about this! isn't it entertaining.?
:lol:
I am getting exited, the cold is breaking here up north and I'm starting to plan going to do some potsing around on the airplane. Can't wait for the spring. Had very little flying this winter. Was just too busy to pre-heat and prepare 1 and a half hour for an hour flight. You guys down south! You have it made :lol:

I will order my paint for the wings and start preparing in a month or about. Then slowly start doing the interior. A panel at the time, I want to keep flying while doing it.

Looking forward to meet some of you this summer in the north east.

Alain.
 
I know this is a very old thread, but I just checked the wheel alignment on 9800B, with a tape measure, from the edge of the center rib on the main gear tires, front & back.
7/8" toe in!! No wonder it's got that Hootchie Kootchie!
How is this adjusted? :?: This discussion just sort of died off before a detailed explanation was offered.....
 
I hope Dan Torrie is at Columbia this weekend. I would like his opinion. I am working on my gear right now and if it needs adjusting, I would like to do it now.____Grant.
 
I spent some more time on the gear yesterday. I simply put a long straight 2X4 along the edge of each tire, and looked down the board toward the tail to see the point on the horizontal stab where it would intersect.
The right gear is pretty much right on. The left gear is obviously toe'd in. About 3.8 degrees!
As for shimming to align, 9800B has very tight gear and does not have enough room to add shims at the scissors sufficient to correct it.
I'm looking forward to Columbia, I'm sure someone will have an idea what to do.
 
Just before the Columbia fly In, I took the left gear scissors apart and added some shim shock to reduce the extreme toe in.
It did help a lot. The landings at Hillsboro, Roseburg and Columbia were 'less scarey'. Too bad I can't get more adjustment.
I'll talk to Dan C. and my IA. I think I'm going to have to weld up the outer bolt hole on the lower gear leg, and re-bore it slightly forward.
I have a plan, which includes a tig welder and drill guide. I wonder what the official rules are. I'll try to follow up when I get more info.
 
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