During an annual inspection last year I discovered (through oil analysis) that my main rotor trans was making metal. ****….. pulled it out and sent it off. A year later a brand new trans finally shows up. I install it go for an hour long hovering test flight.
Lose the tail rotor…double ****.
bent the landing gear and broke the bubble on surprisingly good landing. Turns out that some idiot not only didn’t refill the oil in the tail rotor gearbox a year ago, but same idiot didn’t catch it on the preflight.
I now use/recommend a U-V flashlight for all sight glass inspections.