Know the Rule
If your plane is delayed for any reason other than weather, Peter says you need to invoke Rule 240. "It is the one rule airlines never want you to know about," he says. "If you invoke Rule 240, that means the airline has to take the ticket and endorse it over to the next available flight." The next available flight can be on any major airline, Peter says. Almost all the big domestic airlines participate in Rule 240, he says.