Sidestick spring repair!

Uh… I did not use them much but the F/O sidestick had a squeaky sound in elevator/pitch movement! This squeaky spring sound was getting only worse and louder. I figured that sound must be coming from within pitch artificial feel spring rods (p/n D2731013000000).

AMM chapter 27, Flight controls (27-92-41)

I had to tackled that and try to repair it, squeak is just annoying… Airbus cockpits are not that loud to suppress that sound! When I gathered the courage I started removing the spring rods. That was a test of skills because there is so little room to work. I wanted to take apart as little as possible because all components in there are fine-tuned for stick null zone. After some ,*?#°@ words I managed to get them out.

Now the nerve wracking part, taking the spring cylinders apart. I was not totally sure whether the springs inside are under tension or not. Will this go apart nicely or will springs burst out and I’ll have trouble getting them together again? I didn’t want to do damage while doing it. Mechanically it felt like there is no tension, so “Luck always favours the brave”! The lower part unwinds when you get the safety wires away. Ok, the feeling was right, springs are not under tension and went apart nicely. Inside the cylinder case there are two springs for stick getting harder with second spring at greater deviations.

I first noticed that cylinder interior is full of abrasion particles and dust. When taking spring apart I found the problem. It turned out the inner spring was rubbing against the spring base for quite some time and those abrasion particles were scraping against the outer walls of the cylinder and together with springs making the squeaky sound. I guess also during the transport in all possible positions some of problematic particles from the cylinder bottom got back up within the sliding parts and worsen scraping!

A good clean and minor lubrication on inner spring base did the job. Put them back together and they work like new, not a peep.

Sidestick spring repair!
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