There are 4 Air Tractor AT-501 aircraft on the U.S. registry that TailWiki has a page for. Every one is built from the public FAA record — year, serial, engine, home base, and registration history — and owners and pilots add photos, trips, and stories on top.
N7314R
1987 Air Tractor INC AT-501
Hector, MN
N1004B
Air Tractor INC AT-501
Hickory Ridge, AR
N501BR
Air Tractor INC AT-501
Argyle, MN
N7314Q
Air Tractor INC AT-501
Page, ND