When it comes to ICA (Instructions for Continued Airworthiness), the TC (Type Certificate) Holder usually provides limits for when certain inspections must be complied with. However, many TC holders refer to OEM intervals when it comes to required inspections on wheels.
Whether directed by the TC Holder or OEM, the inspections are generally based on the number of tire changes the wheel has been through. The inspections could range from a simple visual inspection, eddy current of the bead seat, to full inspection criteria. Sometimes the intervals can seem convoluted with no consistency of what inspections are done when.
One OEM requires eddy current on the 3rd, 9th, 14th, 19th and 21st tire changes and full overhaul at 6th, 12th, 16th, 18th and 20th tire changes, with just a visual inspection at all other tire changes.
Another OEM requires eddy current at tire changes 3, 6, 9, 12, 14, 18 and 21, but OH at tire change 20 and every other tire change thereafter.
One TC holder’s requirements for wheels is eddy current at tire change 5, 10, 15, 20, 23, 26 and 29 with OH at tire change 30 and every tire change thereafter.
So there are myriad of required intervals, but if you aren’t tracking your tire changes then you will be required to comply with the most stringent of the required inspections. That could leave you with unexpected downtime and missed flights waiting for your wheels to be overhauled, when all they probably needed was just a new tire and visual inspection.