Musicians travelling by air have long struggled with figuring out how/if/when they will be allowed to bring their instrument in the cabin, rather than expose it to the not-so-tender mercies of baggage compartments and handlers. The US government recently passed this law creating uniform rules for allowing instruments into the passenger cabin:
BUT… as of this date it is not actually in effect, because it set a deadline
Not later than 2 years after the date of enactment of this section, the Secretary shall issue final regulations to carry out subsection (a).
In the meantime, here are some ideas to help make your instrument-toting travel smoother:
Before buying tickets, read carefully each possible airline’s stated rules for musical instruments. Note their maximum allowed dimensions for carryon items, and whether they restrict it to a specific shape (e.g., 10″x16″x24″) vs a total linear inches of any shape (e.g., “45 total linear inches, i.e. length+height+width”).
If the airline appears to allow you to buy a seat for your cello or other larger instrument, check for any additional limitation, e.g., do they only allow it on certain size/model aircraft, do they only allow one person per plane to do this, etc. Do NOT assume that if they will sell you the ticket you are guaranteed the use of the seat for this.
Whatever your research yields, print out everything you find, both from the airline’s own site and the US law above, and carry with you throughout your trip to show to gate personnel who may not be familiar with their own company’s rules.
Use the smallest, and smallest-looking, case you can. If possible use one with backpack straps and wear the case on your back – this looks smaller than carrying it in your hand next to another bag.
Remove from the case any items that could confuse or alarm a security inspector, e.g., the knife you use for trimming your reeds.
If allowed to reserve your seat ahead of time, choose one near the tail of the plane so that you can board early and find a free overhead bin.
Arrive at the gate in plenty of time, and await boarding calmly. Airport staff are trained to watch for travelers who look around, appear hyper-alert and nervous, and/or are in a rush to get on board.