John Elway -- Broncos Honcho Forced to Fly Coach

John Elway is proving he'll go to any length to make the Denver Broncos better ... 'cause the Hall of Famer was spotted on a recruiting trip today ... flying coach!!!

Of course, Elway -- along with Broncos coach John Fox -- didn't have a choice. They were flying the low cost Greyhound of the skies ... Southwest Airlines.

A team rep tells TMZ ... Fox and Elway, VP of Football Operations, were scouting college prospects at the Senior Bowl in Mobile, AL -- and hopped the only available connection from New Orleans to Denver.