One set of grades was based on the frequency of flights being delayed more than three hours. The group graded each airline based on delays per total flights. So, JetBlue got an F for having one flight delayed for every 2,776 flights, while Alaska earned an A for one three-hour-plus delay for every 137,322 flights.
New York's John F. Kennedy International Airport won the dubious distinction of having the most flights -- 195 flights -- delayed more than three hours.
An airline's on-time performance has taken on new importance since federal regulators adopted penalties last year for airlines that leave passengers stranded on the tarmac too long.
Under new federal regulations that take effect next month, airlines must give passengers the option to disembark if a flight is stuck on the tarmac for more than three hours. Airlines that fail to comply could be fined up to $27,500 per passenger. That could amount to $5.5 million for a jet carrying 200 people.