Control Cable inspection and replacement.
Per AD54-26-02 and SB49 the control cable should be inspected at every 100 hours.
The AD mentions the difficulties in this inspection:
After every 100 hours of operation remove control cables P/N 415-52148 or P/N 415-52172 and inspect them for any signs or indications of fraying or failure. Replace any cables which are not found to be in perfect condition. It is important that the cables be removed for the inspection since it has been found that inspection of the cables while in place will not always reveal defects. Also determine whether the aileron stop screw may be bearing on the cable, and, if so, it should be replaced by new stop bolt Erco P/N 415-52164-2. Here is where it is: number 39 in red on the image below.
My personal exerience shows that a cable can start to fail after just 350 hours of operation.
A close up shows the first strand broke. This makes the cable assembly unairworthy.
The replacement cables come ready to install with the hardware attached from Skyport or Univair. Currently they deliver only the newer style cable that is shorter and has an "s" added at the part number. This is for the new style quadrant. You need to change the quadrant (number 40 in the picture above) if you have the old style one. Or have a new cable made. Important here is that the cable made is neither too long or too short.
I strongly encourage everybody to have these cables checked. When the cable breaks, you will loose directional control and that ruins your day.