Tom: You are 100% correct on the write up requirements. But that was not the context of my replies to you or Salty. All maintenance, alteration , or preventative maintenance must be performed in accordance with 43.13 and inspections to 43.15. When completed you make the required entries per 43.9 and 43.11. As far as I know the word "airworthy" in a write up is only required in an annual sign off, and as for the "approve return to service" your signature constitutes that per the same 43.9. So to stick with your oil change example, if you perform half an oil change and find metal, but your customer is not concerned and demands you finish the oil change... what would be your regulatory defense to signing off half a maintenance task if the owner takes your entry to the fsdo and cites you violated 43.13(a)? While the FARs may seem disorganized, there is a defined hierarchy. The owner is responsible for the overall airworthiness 91.403(a) to include how that airworthiness is documented in his record 91.405(b). Cherry pick at your peril.