If you are going to be flying with your cat, contact the airline you will be using as soon as possible. Each airline has different rules and regulations regarding pets.
Some airlines have pet embargo rules, which result in times during the year that pet travel is not allowed. Other airlines no longer accept pets and rely on special pet carrier or animal transport companies.
Make sure you check with the airline well in advance regarding their pet travel rules, as they can change without notice.
For more information, please read Air Traveling with Your Cat