Severe summer storms in Chicago were blamed for most of the 18 lengthy delays that kept passengers stuck on grounded planes in July, the U.S. Department of Transportation reported Monday.
Federal rules that took effect in 2010 prohibit airlines from keeping passengers stranded on a grounded domestic flight for more than three hours without allowing passengers to return to the terminal. On international flights, the limit is four hours. Airlines that violate the rules can be fined up to $27,500 per passenger.
The Department of Transportation is investigating 18 tarmac delays of more than three hours for domestic flights that took place in July and one international flight that was delayed for more than four hours.
Of those delays, 16 took place during stormy weather on July 13 involving flights landing or departing from Chicago O'Hare International Airport. The other two were flights from Washington, D.C., to Detroit and from Philadelphia to Los Angeles.