You generally can get off the plane if your flight has been delayed on the tarmac for three hours or more. This time extends to four hours for international flights. However, this rule may not apply if the delay resulted from a safety or security issue, or if air traffic control determines that leaving the plane would significantly disrupt airport operations. If you have been waiting on the tarmac for two hours or more, the airline must provide food and water. You also must have an opportunity to use the aircraft lavatories.