There are 3 Northwestern PORTERFIELD LP-65 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.
N32374
1940 Northwestern PORTERFIELD LP-65
Maspeth, NY
N27291
Northwestern PORTERFIELD LP-65
Nevada City, CA
N37776
Northwestern PORTERFIELD LP-65
Evanston, IL