hulikner

I have a 3DHS 74' Edge with DLE 30 and 20x6 Xoar Sword prop. I know I have the regular front to back CG correct and the lateral CG is pretty close but probably not right on. The issue is when I put it into a harrier it wants to turn right pretty hard. Not bank, but turn to the right, as if I had been giving it rudder. Now the trims may not be perfect but Ive tried everything 1000 times so if someone has seen this before and then I'd know what to work on to get it right.


It is possible to trim the rudder to where it will harrier straight but then it flys way out of wack regularly and inverted harrier is even worse. P-factor, lateral imbalance, procession, I've looked at it all and haven't found an answer.


Another thing Ive noticed if it helps, on the ground the lateral balance seems that its slightly heavy on the left wing, just barely, but doing the nose dive pull up test it makes the right wing dip and shows the opposite wing is heavy. This is my first gasser so it may be something common that I just haven't dealt with before.




Thanks you very much

basimpsn

My Feedback: (5)

Same problem with the my E/F Extra 300 104" Very scary when it's close to the ground.

xtraflyr

My Feedback: (11)

Most planes need rudder correction in a harrier. Pretty sure it has to do with the P Factor? I never had a plane that I didn't need to use rudder to fly straight.

daveopam

My Feedback: (9)

I wonder if your elev are flat? Did you use the joiner or two servos? I have the same plane and I have a little wing rock if the AOA is not pretty high. But I use only a touch of rudder to keep it going straight. The SFGs also help it in a harrier. If you have not put them on you should try that. Lastly and please dont take offense. Have you had someone else try it with your plane? I have a friend who gives a little rudder when he advances the throttle. You might be adding some Aile with elev input.

david

hulikner

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[TD="class: alt1, bgcolor: #F5F5FF"]I think I found it, Ill fly it tomorrow and see. Looking from behind the plane, the top left screw that attaches the engine to the firewall had come loose about .25 of an inch. So hopefully, under torque, it was making the engine move slightly to the right causing this issue. I guess I didn't emphasize enough how much it turns to the right...
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daveopam

My Feedback: (9)

Good deal! I hope you cured it.

david

hulikner

That was it. So simple, thank you everyone

airwayman

My Feedback: (2)

Most planes need rudder correction in a harrier. Pretty sure it has to do with the P Factor?

Yes they do but it's right rudder that's needed to counteract the effects of P factor. P factor is created by a positive angle of attack and the increased pitch of the down traveling right prop blade combined with the decreased pitch on the left blade. This causes the airplane to yaw to the left. In straight and level or vertical flight there is no P factor because there is no positive angle of attack. Hold a prop by the hub and look sideways at the blades, now raise the prop as if it was in a climb. Very obvious that the right blade increased in pitch while the left blade has almost no pitch.