Altimeter Knob Came Off

[ETres]

I was setting the altimeter today, turning the knob counter-clockwise, and it just started unscrewing from the threaded part of the knob sticking out through the panel. There's the threaded part, then the panel, then a nut, and then the knob.

How do I fix this? What keeps the knob on when I turn it counter-clockwise? All I can think of is Loc-Tite, but saw no evidence of it being on there before. And I'm not sure it would do the job anyway, at least not for the long term.

It's probably something simple that's still too complex for me.

 

[Greg Bockelman]

A picture would be nice. I think the nut is a jam nut that tightens against the knob to keep it from coming loose. There really should be a set screw in the knob to hold it on the shaft but without a picture I can't say for sure n

 

[ETres]

A picture would be nice. I think the nut is a jam nut that tightens against the knob to keep it from coming loose. There really should be a set screw in the knob to hold it on the shaft but without a picture I can't say for sure n

I really didn't examine it closely enough to see if there was a missing set screw. The reason why? I had a flat nose tire half way to taxiing out. Soooo... I spent the next 30 minutes getting a dolly and then pushing the plane back to the hangar (my dose of exercise for the day). At the end of that, I kind of forgot about the knob until this evening.