In Flight Lateral Trim Adjustment Systems

[skippydiesel]

I did my BFR a few days ago.

I have flown with my 65Kg wife in the Sonex but this was a first with a full sized person - my 78kg instructor/examiner.

I was a bit concerned about how the aircraft would perform, weight & balance being right on the edge. The ground role & climb out were very diffrent to my usual solo experince but she got there.

The bit that really surprised me was how out of lateral trim the aircraft was.

I don’t usually need any rudder in Cruise or gentle turns - the ball remains centered.

With two up I needed to carry left aileron (understandably ) but also a lot of rudder. The changes, in flight characteristics, made my performance in TO/Climb Out/Tums less than “smooth”.

I have been thinking about  KISS  in flight adjustable aileron & rudder trim modifications.

My last aircraft had a simple elastic cord/ pully & sailing cleat to adjust aileron left up to accomodate a passengers weight.

Other than a fixed trim tab on the rudder, I have not used a rudder trim.

Wonder what, in flight lateral trim adjustment, ideas you may have employed ???😈

[bushcaddy105]

My centre stick is attached to a torque tube which runs aft to behind the seats. It was relatively easy to add a short lever below this tube, attached by a hose clamp, which connects to two opposed springs and a cable. A control wheel below the left seat alters the amount of this spring bias in either direction while still allowing full roll commands to over-ride the weak springs. This setup has worked well for many years.

If desired, I could take some pics when I next head to the hangar.

[skippydiesel]

10 hours ago, bushcaddy105 said:

My centre stick is attached to a torque tube which runs aft to behind the seats. It was relatively easy to add a short lever below this tube, attached by a hose clamp, which connects to two opposed springs and a cable. A control wheel below the left seat alters the amount of this spring bias in either direction while still allowing full roll commands to over-ride the weak springs. This setup has worked well for many years.

If desired, I could take some pics when I next head to the hangar.

Thanks Bushcaddy105 - Sounds like the longitudinal (elevator) trim I already have (see below).  This wheel moved a cable attached to a spring, which in tern is attached to my elevator torque tube. The movable/adjustable spring is apposed by a fixed spring.

 

I have a mental image/plan of how to set up an aileron trim, using a bungee cord onto my aileron torque tubes. Still working on rudder trim, which cable actuated.

 

Unlike the elevator trim (above), which must accomodate varying air loads, generated by speed, the aileron & rudder adjust need only be in one direction as trim on these surfaces is only needed when I am carrying a full sized adult.😈