Inspector reported over flight of a major repair conducted by the previous owner concerning a wing attach fitting repair that was not documented correctly.

Narrative

Released aircraft for service with exceeded life limited structural major repair of the R/H aft wing attach fitting that was previously installed. The repair was unknown at the time because no record of it was entered in the aircraft maintenance logs nor was there a form 337 filed with the FAA. It wasn't until after the aircraft had been in operation for one season that a engineering order for the repair was discovered at the previous owners location during a records search. The engineering order placed a life limit of 500 cycles or 1 year whichever occurs sooner on the repair with 100HR recurring visual inspections in the interim. Since its discovery the repair has been evaluated with a damage tolerance assessment by a Structural Designated Engineering Representative and incorporated into our structural inspection program. FAR 91.417 states that any life limited item or item requiring recurring inspection shall be recorded in the aircraft maintenance records and 91.419 requires that owner operator who sells an aircraft to transfer the permanent aircraft records to the purchaser at the time of sale. I believe the failure to follow these rules by the previous owner/operator led to the problem we have today. Moving forward documenting maintenance in accordance with FAR 91.419(a) in the permanent records such as the maintenance log books and submitting a form 337 would appropriately mitigate this problem.