-
Over 10 years ago the FAA created a regulation with an exception to the baggage rules you’re reading.
https://www.transportation.gov/airconsumer/final-rule-musical-instruments
As long as it’s a domestic flight and you board early enough you have the right to bring it on board IF there’s room. If the case won’t fit in the overhead ask if there’s room in the crew closet. I’ve flown numerous times with a full sized guitar and rarely have had an issue. Only a few times … usually connecting flights…I arrived too late and had to “gate check” it. That means they take it from you as you board at the end of the jetway and hand bring it down with strollers and such. At the end of the flight they bring it up to the gateway again for you. Do NOT allow them to simply check it as luggage. It isn’t! Only a couple of times have I had to ask for a supervisor and that usually resolves the issue of an officious gate attendant who insisted the guitar needed to be checked and refused to comply with the FAA regulation which I carry in the guitar case for just such an occasion.
So… in summary… hard case is always best (just in case you need to gate check it), a sturdy and well attached name tag on the outside and a copy of your contact info inside the case, arrive very early (worth it for the peace of mind), board early, carry the regulation, stand your ground but be nice to the folks at the gate and NEVER check it as regular luggage. Some of the gate people have even been players themselves and I’ve had some good discussions with airline personnel about playing guitar. Once or twice I’ve even been called up with the first boarding group (though I wasn’t part of it) because they wanted to make sure my guitar made it on with room before the masses.
Good luck and safe travels!