TIL a loose trim tab bolt can shake a plane apart

I was putting a Piper back together after a routine inspection. Everything seemed tight, but I rushed the final checks on the elevator trim. On the next flight, a fierce vibration started right after takeoff. It got so bad the pilot thought we might lose control. We landed and found one bolt on the trim tab hinge was almost out. I had not torqued it to spec in my hurry. Now I always use a torque wrench and put a paint dot on each bolt head after tightening. This simple visual check takes seconds and stops you from missing a loose fastener.