Wings of Creation

Six friends work to stave off a war that will cross five planets.
Together again after being separated for years, six heroes are banished from their Fremont...and they may have accidentally started a war in their home system. Their mentor, Marcus, stops them halfway home and tells them they must go to the planet Lopali, home of humans who have been genetically enhanced to fly. But although they can fly, they cannot reproduce, and they are held as pseudo-slaves by the people who created them.
Marcus leads them into a last-ditch effort to stave off full-out war over the right for one being to own another.
From the Endeavor Award Winning Author of The Silver Ship and the Sea