According to the Transportation Security Administration (TSA) in the United States, you are not allowed to carry a sword in your carry-on luggage on a plane due to safety concerns. However, you can pack a sword in your checked baggage. The sword should be securely wrapped and sheathed to prevent injury to baggage handlers and inspectors.

In other countries, the rules can vary. However, most airlines and aviation authorities around the world follow similar regulations due to international safety standards.

Before packing a sword in your checked baggage, it's a good idea to check with both the airline and the airports you will be using to ensure you comply with all rules and regulations. Keep in mind that even if an item is allowed in checked baggage, it may still be subject to additional screening or restrictions.