Lost in Translation?
My theory, being a journalist: The "knuppel" might be referring to the German "Steuerknüppel" or just "Knüppel", meaning stick or yoke in an aviation context – as has been mentioned here before. "Knüppel" usually means "club".
The "knuypel" might have made it into the Russian news story by means of miscommunication between a journalist and his/her source. The source here probably being not a Russian, maybe German, and the journalist not well versed in aviation terminology. I write about tech and see something like that happen a lot when it comes to specific technological language.
I'd think the source may have meant something like trim was activated by a switch on the yoke or "ein Schalter am Knüppel" in German.