N421MM is not assigned to an aircraft right now: the number is reserved in the FAA registry. The FAA files list 1 earlier registration of this number, shown below.
Reserved N-number
- Reservation
- Reserved (fee paid)
- Reserved on
- Jun 19, 2026
- Reservation expires
- Apr 19, 2027
Earlier registrations of this number
| Canceled | Aircraft | Serial | Year | Exported to | Same airframe today |
|---|---|---|---|---|---|
| Mar 17, 2021 | CESSNA 421B | 421B0804 | 1974 |
NTSB accident and incident records
| Date | Place | Aircraft (as NTSB recorded it) | Damage | Highest injury | NTSB no. |
|---|---|---|---|---|---|
| Jun 5, 2018 | Rock Sound, BS | Cessna 421B | Destroyed | Fatal | ERA18WA159 |
From the NTSB aviation accident database (events since 2008, data through Oct 28, 2026), matched by N-number. An N-number can move between aircraft, so each row is checked against the serial number on the current registration.