Working on a Citation's autopilot in a hangar in Wichita, I finally got why torque specs matter.

I was putting the pitch servo back in and just went by feel, like I always did. The thing flew fine for a week, then the pilot called about a slight, constant roll. Found the mounting bolts were just a bit loose, letting the whole unit shift. The manual said 35 inch-pounds, which I'd always skipped. Tightened them to that exact number and the drift was gone. Anyone else have a simple spec they ignored that came back to bite them?

2 comments

2 Comments

the_sean19d ago

Oh man, yeah. Did the same thing with a drain plug on a mower engine. "Good and tight" seemed fine until it vibrated out and dumped all the oil. That spec sheet wasn't just a suggestion.

rosethompson19d ago

I mean, "good and tight" has always worked for me though.