The guy who helped turn an unruly American Airlines passenger into a human duct-tape roll has been identified ... and he's a New Jersey gun range owner who says stepping in was a no-brainer.

Richard O'Lenick -- owner of Gun for Hire in Woodland Park -- was one of the passengers who restrained Arthur "Layne" Lundeen during his alleged midair meltdown last week, according to the The Daily Voice.

Waiting for your permission to load the Twitter Tweet.

The 53-year-old was traveling with his employee Juan Mejia, a retired cop, when Lundeen allegedly started hurling slurs and getting physical with people aboard the plane.

Once things turned violent, O'Lenick says he and Mejia jumped in and held Lundeen down as flight attendants brought over duct tape and zip ties.

O'Lenick says Lundeen fought them the whole time and even bit Mejia ... leading them to tape his head to the seat.

As TMZ previously reported ... witnesses told us Lundeen allegedly struck another passenger, hit the man's computer and pushed a woman who tried to intervene.

The flight was diverted to Baltimore, where cops took Lundeen into custody.

He was charged with second-degree assault and disorderly conduct ... and, as we reported, later lost his job with a Tucson real estate company over the incident.

O'Lenick says he and Mejia simply trusted each other and did what needed to be done.