Takeoff roll

[perbgyro]

Does anyone else have this experience in their CLT AC?

On the takeoff roll, there is a point where the nose wheel gets light and skips around a little in between the point where there is enough airspeed on the rudder and rocking back on the mains.

The rudder is set for level flight and feet off the rudder, but not for too long. More like no pressure. If there is a gust or something, it will yank on the rudder a bit. With rudder cables, the freedom of movement is much greater than the push rods.

At some point during the takeoff roll I need to input left rudder pedal, so if the nose is not completely off and balancing on the mains, you get that darting to the left when the nose wheel touches that becomes a bit severe in very light head winds.

With a little more nose weight provided by the AUX saddle tanks, it seems to get beyond that point and tracks down the runway until on the mains.

[ckurz7000]

Can't you keep some pressure on the nose wheel by holding the stick slightly forward until you have sufficient flow over the rudder? Then you'd pull the stick back slightly, lift the nose wheel off smartly while at the same time steering with the rudder. There wouldn't be any danger for the nose wheel top come back down.

-- Chris.

[TansAir]

My buddy and I, both with CLT A/C's, had exact same thing happening to us during our early balancing practices & transition work. We first made adjustments to the rudder offset, but as you mention it will effect normal flying and undesirable yaw at cruise speed. So we did as much as we could do with rudder offset to lessen that darting effect (which really sucked ... was like nose comes up and goes one direction, and when nose wheel grazes the runway it darts in the other direction, like a goofy carnival ride). The rest of adjustment we made with the small piston spring assemblies that connect the bottom of the rudder pedals to the nose fork channels for steering. If you shorten one side and lengthen the other side you can effectively change the nose wheel to have slight turn built in while rudder peddles remain in neutral position, rudder offset is not changed, and if those are tightened and loosened by same amount then cable tension is not changed either.

Make sure to test your adjustments during no wind or winds right down the runway, much easier to dial things in without the mixed signals of x-winds.

If you're doing a lot of adjustments to rudder, or foresee having to, you should get some turnbuckles somewhere on the cables out back by the rudder. We picked up the ones that use the snap in safety clips instead of safety wire. They are not cheap, but well worth the time saved making quick adjustments (and sometimes cutting cables too short is avoided). Let us know if you get it to track better - Good luck! -Kevin :yo:

[perbgyro]

Thanks for the tips! I've already got turnbuckles in the lines.

I've also noticed that I don't have much right rudder throw so in a power out situation, go left! I'm looking at modifying the bell crank on the rudder so that both lines terminate at the same point so rudder input would yield the same amount of rudder throw either way.
Neutral rudder position would be with the normal left rudder input for prop wash. I'll have to order another turnbuckle swedge for that fix. Also looking at attaching the right rudder higher on the pedal to give it the extra throw and let the springs handle the differential for those situations where you need more rt. rudder, which involves drilling a hole and adjusting the turnbuckle... much less $$$.
One day I'll have it completely wired.

[mark treidel]

I am unable to tell by your avatar which nose wheel you have (single or dual fork) but it appears that you are attempting to treat the symptom, not the cause. Had nose wheel steering on my old A/C. Worst idea ever!! Had to change out the entire fork and went with free castering (with centering spring) and anti-shim adjustment. Steering was done by independent differential rear brakes. Result, no front wheel (shopping cart) wobble, no side snap on take off or landing caused by rudder pedal position (cross wind or engine torque compensation) and turning radius was shortened to rotating on one main wheel. Never a problem after that.
Ask Chris Spadafora (CLS447) here on the forum...He is a whiz on the subject.
My personal opinion, (for safety) I would never go with nosewheel steering again.

[EI-GYRO]

Spring-linked ( soft connection ) rudder /nosewheel might help.
A well adjusted rudder trim tab might help too.

[Bill]

Hey Mark,

Do you have any pics on how you did the independent differential rear brakes and pics on the front wheel set up?
Any info on the parts and places to buy would be appreciated.
Thanx
Bill
Mach .06

[perbgyro]

Hey Mark,

Do you have any pics on how you did the independent differential rear brakes and pics on the front wheel set up?
Any info on the parts and places to buy would be appreciated.
Thanx
Bill
Mach .06

Here is one example...
http://www.rotaryforum.com/forum/showpost.php?p=307451&postcount=21
Jake (gyrojake) is the builder and sells them.