How to Cross-Reference Aircraft Part Numbers

Part numbers supersede. Vendors rebrand. PMA holders use their own family. Finding the right equivalent can turn a ten-minute parts order into an afternoon of research. Here is the workflow we use on every cross-reference request at American Aviation Parts.

Step 1: Start with the OEM IPC

Your aircraft’s Illustrated Parts Catalog is the authoritative starting point. Look up the subsystem, find the figure, locate the item number, and record every OEM P/N listed — including revision letters (dash numbers), “when available” notes, and any kit part numbers that supersede loose parts.

Step 2: Check the Manufacturer Service Bulletins

Service Bulletins routinely supersede P/Ns. A part listed in the IPC as 0521-010 may have been superseded to 0521-010-A via MSB 2016-3. Installing the old number after the SB was mandated is non-compliant.

Step 3: Search PMA catalogs

For most common GA parts, at least one PMA holder produces an FAA-approved equivalent. The PMA holder publishes their P/N alongside the OEM P/N in their product catalog. Major PMA families to check: Tempest, Superior Air Parts, Champion Aerospace, Concorde, Rapco, Bogert.

Step 4: Confirm eligibility by aircraft serial

Some parts apply to a serial-number range. A cylinder that fits early O-320-D serials may not fit later serials after a mid-production change. Always confirm with the eligibility chart on the PMA holder’s website or on their 8130-3 cover sheet.

Step 5: Ask your IA

For anything load-bearing, primary structure, or engine-critical, your IA makes the final call. They will sign the logbook, so they choose what they are comfortable installing.

Cross-reference it in the catalog

Enter the OEM P/N in the catalog search to see every matching OEM and PMA option in stock, with live pricing and availability side by side. Filter by airframe with the Aircraft Finder when you know the make and model.

AAP search tips

• Our catalog stores the manufacturer part number in the model field on each product. Searching REM38S will match the Champion spark plug; searching URHM38S will match the Tempest equivalent.
• For airframe-specific browsing, the Aircraft Finder filters by make and model.
• Old part numbers with spaces or dashes sometimes list with neither. Try both 4200-121 and 4200121.