You searched a tail number on the FAA registry and it returned nothing, or it returned an airplane that clearly is not the one you are looking at. Neither is a glitch. Both have ordinary explanations, and one of them matters a great deal if you are about to buy something.
The registration was cancelled
The FAA maintains two files: currently registered aircraft, and deregistered ones. The public search most people use only looks at the first. An aircraft leaves the current file when its registration is cancelled, and that happens for very different reasons:
- The owner did not renew. Registration has to be renewed periodically, and plenty of perfectly sound aircraft lapse — an owner died, a corporation dissolved, the paperwork went to an old address. Common and usually fixable.
- The aircraft was sold and re-registered under a new owner or a new N-number.
- The aircraft was exported to another country's registry.
- The aircraft was destroyed, scrapped, or written off.
Those last two are the ones to care about. "Cancelled — exported" and "cancelled — destroyed" say very different things about an airframe whose serial number you are being offered today.
The N-number now belongs to a different airplane
This is the one that fools people. A tail number is assigned to an owner, not welded to an airframe. When an assignment is cancelled, the number does not vanish — it goes back into the pool:
- The last owner of record can reserve it for one year by asking and paying the fee.
- If nobody reserves it, the number is unavailable for five years, and after that it can be assigned to someone else entirely.
So an accident, an owner, or a service history attached to "N12345" in 1996 may belong to an airplane that no longer exists, while today's N12345 is a different make, a different model, and innocent of all of it.
What to do instead
Search the serial number
The manufacturer's serial number stays with the airframe for life. If you have a serial number, you can trace the aircraft across every registration it has ever worn — including into the deregistered file, which is where the interesting history usually is.
Check the deregistered file, not just the live one
An airframe that was wrecked and rebuilt typically leaves a very readable trail: the old N-number sits in the deregistered file carrying the same serial number, with the cancellation reason attached. A serial number that appears under two registrations is not automatically bad news — but it is something you want to understand before you make an offer, not after.
Check what you typed
The mundane causes are worth ruling out first. US registrations start with N and the registry expects the number without it. Letters I and O are not used in US N-numbers, so a "1" or "0" is almost always what was meant. And a number painted on the airplane may simply be out of date.
The rule of thumb
A tail number tells you what an aircraft is called right now. A serial number tells you what it has been. When those two disagree, believe the serial number.