N21451 is reserved. Post-cancellation hold held by Cancelled/Not Assigned — if it isn't renewed, the FAA releases it on Oct 28, 2028 (in about 2.3 years).
This tail was recently cancelled. The FAA holds cancelled N-numbers before releasing them back to the public.
Reservations lapse more often than you'd think. Check back around Oct 28, 2028 — if the holder doesn't renew, it becomes available. See everything scheduled to free up in October 2028.
N21451 has been worn before. Past registrations from FAA deregistration records:
Tails one nudge away from N21451 that aren't assigned or reserved: