Juice

I'm installing my Robart 615's into my TF Corsair. I've been searching and reading previous threads saying that toe-out is bad, toe-in is good, and straight also seems to be good.

How much toe-in is good? Some threads say "slightly toe in". But I'm an engineer, and us engineers get confused with qualitative descriptions. We like quantitative descriptions. How many degrees is "slightly"?

Thanks,
Juice

Richard L.

My Feedback: (24)

I like to have around 1° of toe-in for improved ground handling and tracking. I always try not to go above 2° of toe-in. Your plane will tend to wander without any toe-in, just like a real car on the road would.

GlennisAircraft

My Feedback: (1)

We recommend 1 degree or 2 of Toe In. Straight works fine - but slop in the gear quickly changes it to Toe Out, then you can have problems.

More Toe In (or Out) leads to excessive tire wear - not so much on the warbirds, but if you ever look at the 'jets', you'll notice a lot of them with the top of the tires worn at about a 20 degree angle -

Dennis

paladin

My Feedback: (9)

When I set up a plane I rubber band a yard stick to each wheel. Then push on the tips of the yard sticks to take up all the slop then measure accross front and back of the yard sticks. I want the front measurement (Engine side of the yard stick) to be smaller than the back. The only other thing to check is that they are not both turned to the same side by eye ball.

Good Luck!

Dig it

I'm confused on this topic. I know this is an old thread but could someone take a few minutes to explain to me why toe out is bad?

paladin

My Feedback: (9)

The wheel alignment is as important here as on your car! Make sure you have toe in on both wheels after all the slop in the retract mechanisum is taken up. The reason isvery seldom do both wheels lift off togeather, one wing gets flying first and in that split second when only one wheel is on the ground which way will it pull you plane. We know that in a twin engined plane if one engine dies we need to turn into the good engine to keep the other wing flying. Well the same aplies here, if the one wheel that is still on the ground is toed in it will turn the plane into the wing that is already flying increaseing the speed of the non flying wing. If it is toed out it it will turn into the non-flying wing and increase the delta in lift between the two wing hlves (I don't know of a way for this to end well).

Good Luck!

Dig it

Ahhh, the light goes on. Thanks for the input Paladin

BiteTheDust

Hi Dig it,

Paladin is right. But one thing to consider is what happened to me and a flying buddy of mine. We are both flying Spitfires - narrow gears. With 2 degrees toe in we got very nasty landings on tarmac (no problems on grass). One wing would rise and a turn in the opposite direction was uncontrollable. The result was a scratched wing underside.

A very seasoned pilot fixed our problem by telling us to use a couple of degrees toe-out. This really worked!

What happens is that when a wing rises on a landing - say the left one - the toe-in on the right wheel causes the plane to turn to the left. You compensate by using left aileron and right rudder. In our cases the rudder will keep the path straight but the aileron can't lift the left wing due to the low speed. The result is a scratched right wing.

A toe-out will counter-act the lift on the left wing and you can land straight ahead by using the rudder. Note that this is only true when we are dealing with narrow-track taildraggers. Mustangs and Thunderbolts are very different.

Happy landings,
Anders

GlennisAircraft

My Feedback: (1)

The examples of lifting off may be correct, but they are not the actual reason for toe in / toe out or how it functions. If the toe out, etc. has helped - leave it be.

When the aircraft tracks down the runway (as with a car, but, slightly different) we will take toe-in as the first example:

If the aircraft turns slightly to the left (nose left) the right wheel will drag more, while the left wheel is now presented as straight, will have less drag (it's rolling straight now), thus the right wheel tends to scrub, and pull the aircraft straight.

example:

/ \

Dig it

Ok, I think I understand this. Basically if I leave my Mustang with toe out I'm going to cause myself all sorts of hardship on takeoff and landing on an already not so easy to land aircraft (or so I've read).

So, I guess the next question is, how much can you grind off of your strut before you need to replace it.

Ya know, sometimes the best part of this hobby is the stuff you learn along the way...