Hovering Crooked

[flyin woodbutcher]

what the help huh ? When I am hovering the plane wants to drop the left wing all the time. I have to hold lots of rudder to keep the plane pointing up. Lots of rudder and too much elevator will caues a nasty snap out of the hover.

The plane is dead nuts in normal flight. The lateral bal is perfect, up line are perfect and down is real good also.

Anyone think maybe the engine thrust could cause this ? I know someone out there has a good answer for me.

The plane is 35% Carden Cap

Thanks FWB

[bryan01601]

have you ballanced the plane laterally?

[TonyThomasian]

CG? Prop? And i always tell people that the most important way to enter a hover is w/ straight and level wings. Dont just go into a hover when your wings are not level.

[bryan01601]

when you come strait and level full power into the wind and pull to a 90 degree upline and go straight up. does the plane also go to the left ? If so it may be a thrust issue?

[flyin woodbutcher]

Plane is bal lateraly and up lines are perfect, The plane has been trimed out for normal flight.

FWB

[Breakstuff5050]

what you need to do to test the thrust, trim at full throttle and level into the wind, then throttle back and watch. If the thrust is off it will start turning to the right. The best time to do it is with no wind, then it'll be alot easier to tell if its the plane or wind. Also look at your rudder on the ground with the trim set when you were full throttle, if it isnt straight, then i think it is safe to say its thrust. Just make sure you do all this at full throttle so that if the thrust is off, it will easily be noticed.

[Oh Yeah!!]

Do you have any right thrust at all? If not...then you need some. If you do have some...then you need some more.
I agree with the rest of the guys. Has' to be a thrust issue.

[flyin woodbutcher]

Oky Doky I am going to shim the left side a 1/16 so as to give it some more right thrust . Cant find the plans but think it had 2.5 degrees stock , rt thrust.

FWB

[3Dprodigy]

I fly 3d models with 0-0 inline wing-tails that spend most of their time constantly rolling or as much time upside down as rightside.

As torque applies 360 degrees I can't see how a fixed right and down offset would be any better than say up and left. I can see how it would help on a non 0-0 model.

Next model I build I'm gonna take out the thrust offsets and add in some mixes:
throttle-aileron
throttle-rudder
throttle-elevator

Any thoughts?

[Baron]

	Quote: Originally Posted by 3Dprodigy
	I fly 3d models with 0-0 inline wing-tails that spend most of their time constantly rolling or as much time upside down as rightside. As torque applies 360 degrees I can't see how a fixed right and down offset would be any better than say up and left. I can see how it would help on a non 0-0 model.

It's not the torque that necessitates right thrust... it's the spiral slipstream effect. The spiraling airflow hits the upper vertical fin, causing a yaw to the left, but there's no other vertical area it hits to counteract the yaw moment. Since the vertical fin rolls with the airplane, the right thrust requirement holds in any attitude

On the Shark (see avatar), no right thrust was required (and no computer radio mix) thanks to the near-symmetrical vertical fins and it tracks straight up with no rudder required on a calm day.

One thing to keep in mind, though, is hovering requires a different amount of right thrust than a high speed vertical upline. The forward flight airflow tends to straighten the spiraling flow somewhat. In a hover, you don't have that so the spiral slipstream effect is greatest, requiring more right thrust. This just goes to show that when you get nitpicky about setups, you have to choose what type of flying to set it up optimally for. That being said, most 35-40% planes require such little difference in right thrust between vertical upline and hover that it's hardly noticable.

Good luck on getting it straightened out.

-Baron