My daughter flew from NY to Florida with a pup as carry on and everything was fine until Phildelphia. Airline employees said the carry on was too small for the puppy and made her buy a full size airline crate and he had to go as luggage for the rest of the trip. She didn't tell me about it for 3 years. So I agree that you should act like you know what you are doing and I wouldn't get too chummy with other passengers or the airline employees.