I'm not a regular for the airlines but the couple of times I've traveled with my pack I haven't put it in any duffle or other "protective" bag. What I have done (based on suggestions I read long ago) is tighten up my compression straps and tuck the remaining strap under itself; tighten up my shoulder straps to the back of the pack; wrap my hip belt around the front of the pack and snuggly tighten the belt, tucking any remaining strap under the buckle (hope that all makes sense). So far I've done this without any incidents or problems with a Lowe pack to/from Ireland & the Boundary Waters plus a canoe pack (like an old Duluth pack) for a trip to the Okefenokee NWR via Jacksonville, FL from Albany, NY w/ a stopover in Baltimore.

That's all for now. Take care and until next time...be well.

snapper