Searching an aircraft by its tail number tells you about the identity it wears today. Searching by manufacturer serial number tells you about the airframe itself, across every identity it has ever worn.
Why the difference matters
N-numbers are assigned to registrations and can be changed on request. Owners change them for all sorts of harmless reasons — vanity numbers, corporate branding, a new owner wanting their own. They also change after a rebuild, which is where the problem starts: the accident stays filed under the old number, and a search on the new number returns nothing.
The serial number is assigned by the manufacturer, stamped on the airframe, and does not change. It is the aircraft's actual identity.
Finding the serial number
Every FAA registration record includes it. Look up the tail number in the FAA Aircraft Registry and the serial number is listed alongside the manufacturer and model. It is also on the aircraft's data plate and in the logbooks.
Searching by it
- FAA registration data. The registry can be searched by serial number, which surfaces the current registration for that airframe — including one under a different N-number than the one you started with.
- FAA deregistration records. Cancelled registrations are kept as a separate public file and carry the serial number. This is where an airframe's previous identities surface.
- NTSB accident records. Accident dockets generally record the aircraft serial number as well as the registration. Searching NTSB CAROL by serial rather than by registration is what catches a pre-rebuild accident.
One caution: serial numbers are not globally unique
Manufacturers number their own production lines independently. A serial number like "980" exists at many different manufacturers, referring to entirely unrelated aircraft. A serial-number match is only meaningful when the manufacturer also matches.
This is not a small detail. Matching on serial alone will confidently attach another company's accident to your airplane. Always confirm the manufacturer agrees before you treat a serial hit as real — and be sceptical of any report that does not tell you which aircraft it matched and why.