One Tuesday in August, every torque wrench in the hangar lied to me
We had a Piper Cherokee in for annual, and I was doing the landing gear retraction test. I torqued the bolts to spec, 65 ft-lbs, marked them, moved on. Later that afternoon the owner calls, says he heard a pop on the way home. Brought it back, and the bolt was loose. I grab my torque wrench, test it against the calibration checker, and it clicks at 52. All six wrenches in the tool room were off by anywhere from 8 to 15 ft-lbs. Nobody had sent them out in over a year. The shop foreman went pale. We spent the next three days re-torquing every control surface bolt on every plane in the hangar, about 12 aircraft total. That was a slow, painful week, but honestly, I'm glad we caught it before a flight control let go. Anyone else ever found a whole batch of tools drifting at once? How did your shop handle the rework?