aileron trim stiffness

[johnr]

Hi All The CTsw ex N537AT took to the air 11th May. There does appear to be a problem with the aileron trim. before the centre it starts to bind & before any right trim can be applied locks up completely.

left trim is free & light. The balance at the central point seems good with the ailerons level with the flaps at -6 degrees.

There is another CTsw on the field & I checked that . It is exactly the same freely adjustable left trim but no right trim adjustment. The wheel becomes tight & locks before any right trim can be applied.

I noticed that the crank at the opposite side that the cable attaches to has 3 holes & the rod is attached to the out side hole. If the rod was moved to the inner hole that would give greater leaverage to the adjustment wheel.

Can anyone advise me as to how to enable the tension to be adjusted to allow full right aileron trim? I would loke to check the spring tensions but I have been unable to find what they are supposed to be.

John R

[Roger Lee]

Howdy John,

 

How's the weather way down there?

The aileron trim wheel is hard to turn in the CTSW compared to the others. One way is harder than the other. It seems to be the nature of the beast. Usually once you set it it rarely needs to be moved. So long as the plane trims I believe what you are experiencing is normal and would leave it alone.

 

Does your plane trim up? That said many over trim and end up in a cross control situation with their trim settings and think their plane is out of rigging. The fix is to take the rudder and aileron trim back to neutral. Then set the aileron trim first to get the wings level then add a little (usually right bias) on the rudder trim.

[johnr]

Hi Roger, Weather is woeful wet n windy our winter is early. I had a good day Friday when I flew with Dave for 1st time.

I think it was flying with left wing down ( thats my excuse for the fuel transferring to the left tank when Dave pointed it out. It would be near impossible to trim it with a right bias its so tight & if I could I could never move it with one hand to trim left.

The other one on the field is much the same. There does not appear to be any tightness in any components, nor any where lubrication would help. John R

[coppercity]

Sometimes the silver indicator button comes loose or is tightened at the wrong location on the indicator cable so where you may see it centered it is actually at the full right trim point and cannot go any further. That silver indicator just screws down to clamp on the cable. Just something to check.

[Runtoeat]

Eric's (sorry Erik, I first said "Tad's suggestion" but corrected this) is a good one. My rudder trim indicator was moving on the cable. Make sure the silver trim indicator has not moved on the cable and no longer shows "center" trim. I have recently been back in the area where the aileron trim springs and cables are located. I had to loosen the aileron trim fully to take the pressure off of my auto pilot aileron servo so this could be removed. When the aileron trim wheel is fully backed off, the springs and cables become slack. Here's something that may work and if I'm all wet with this, someone please jump in and say so. My recommendation would be to first make sure you've completely backed off the trim to a point where the springs are obviously loose. As the trim wheel is first loosened by a helper ,have another person stick his head inside the luggage compartment and see how the trim works with the springs. Have the assistant start turning the trim wheel to a point where the trim springs just start to become tensioned. I would operate the ailerons and observe if they have a tendency to not return to a neutral position. Add some trim tension if they don't. If they seem to be OK, I would take a flight and keep in mind I may need to be vigilant and keep pressure on the stick to provide possible compensation if the trim is way off. If a wing wants to stay low, crank the trim wheel as needed, + or -. This method should allow you to start at a minum amount of trim and determine if there is enough adjustment to provide trimmed flight.

 

A sanity check before doing this. Center the sticks so they appear straight up. Look at the triangular aileron rocker bracket in the luggage compartment and make sure that the top of this bracket is parallel to the cabin tunnel or roof. If the triangular bracket is parallel to the top of tunnel or roof while the stick is centered (vertical), next insure that the aileron trailing edges are aligned with flap trailing edges when flaps are set to -6. If this is not the situation, I would say to stop here and get a knowlegeable mechanic to properly rig your control surfaces.

[johnr]

The first thing I did was to check the triangulated bar was level & the stick was vertical as per manual, At that point the trim indicator is central. It is not possible to turn the wheel to get any right aileron trim.

My original question was is there any way to reduce tension or increase the leaverage ,ie moving the cable to the inner hole where the cable is attached to the arm. There are 3 holes & mine is on the outer, moving the cable to the inner would not alter the tension of the springs, it should give the trim wheel a greater leaverage advantage . I would appreciate any one telling me that there cable is connected to one of the inner holes, especially if they were able to adjust the trim to near the trim limit on the right aileron.

Moving the cable to one of the inner holes would not effect anything except the indicator would need to be moved.

John R