stek79

Hello Don!

How is the pattern season going?

Recently I read an old post of yours in which you explain the trimming features of your Brio. There is one sentence that I don't understand, if I can I ask you the reason...

Regarding yaw trimming, you say that: "rudder carries about 1/8 left rudder at idle, about 1/16 right rudder at full throttle, and about center at half throttle".

The question is: why at idle do you carry some rudder trim? Shouldn't it be centered at idle and then off as we increase the throttle (with the mix)? How can the plane go straight at idle with some rudder trim?


Thanks Don for any replies! And good luck for your pattern contests!!!!!!!!!!!!!!

Don Szczur

My Feedback: (1)

At half throttle the rudder is in the middle, on an upline just a little right- 2% and at low its 3% but only comes in bewteen 1/4 throttle and idle and eases out above 1/4 throttle. The plane was yawing to the right on a vertical downline, plus during flight the plane would yaw to the left during low throttle. Right rudder mix, again comes in at 3/4 throttle and then it stays constant through full throttle. This permits a little less right thrust required.

Why? it makes the plane fly straighter. Less pilot workload during maneuvers. Uplines and downlines.

Don

stek79

Don, many thanks for sharing this with us!

There is one thing I can't figure out: why with low throttle and rudder centered your plane yaws???

Am I understanding correctly?

THANKS and good pattern flying!!!

Don Szczur

My Feedback: (1)

With throttle at about 1/4, Place your aircraft in a left hand bank 360 degree turn to the left. Then place the plane in a 360 banked turn to the right. You will notice that the right thrust will "hold" the plane up during the left turn, and the plane will want to falll off during a right banked turn (requiring a little left rudder to hold the same amount of turn radius without it dropping off. The left rudder at low throttle, coming in around 1/3 throttle, keeps the fuselage pointed straight during horizontal and down line maneuvers with low or small throtlle inputs. No mix is in between 1/3 and 2/3 throttle. Then the right rudder mix allows less right thrust required on an upline.

Regards,
Don

Billa2.5D

Why not just add right thrust and take the top end rudder mix out of the equation - aren't the vertical rolls affected by these slight rudder trim mixes ?

Aamer

Don Szczur

My Feedback: (1)

Throttle to rudder corrects during faster airspeed. At slower airspeed, such as at the tops of verticals or after a snap roll and at full throttle, the engine thrust takes over. Thrust change will assist, but rudder reduces the amount of thrust needed and does not seem to have any adverse effects in vertical rolls.

All the best,

Don

Billa2.5D

So, given a choice, would you add more right thrust (so that the additional benefits of no variation across the board can be achieved) or would you go with the mix ? Is there a benefit to going with the mix ?

Thanks,
Aamer

Don Szczur

My Feedback: (1)

Its two related, but not totally interdependent things. The throttle to rudder will not require as much right thrust but if you use it in place of right thrust all together I believe you will be pulling left at the tops of lines and steering right at the beginnings of the uplines. I guess the throttle to rudder allows you to get away with not as much right thrust, but I still put in the right thrust and then use the throttle to rudder mix to do the fine-tuning. This is particularly helpful if you switch from, say a 2 blade to a 3 or 4 blade. The throttle to rudder mix can get you fixed without having to re-do the right thrust if you change props.

Cheers,

Don

Billa2.5D

I've never used a 3 or 4 blade prop ( since there are no noise restrictions here ) but compared to a two blade prop do you need more right thrust or less to counter it.

TIA,
Aamer

Don Szczur

My Feedback: (1)

Need less right thrust with 3 and even less with 4 blade prop.

All the best,
Don