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 A part listed in the IPC as 0521-010 may have been superseded to 0521-010-A via MSB 2016-3.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.

Short-cut: let us do the cross-reference

Tell us the aircraft make, model, serial number, and the OEM P/N (or a photo of the old part’s data plate). We will respond with every matching OEM and PMA option in stock, with pricing and lead time. Contact us.

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.