Originally Posted by JDiver

Technically, "gas" (gasoline or petrol?) is not used by today's aircraft, which use a petroleum derivative more closely related to kerosene, "Jet A" fuel. Ticket prices do not track petroleum (e.g. Brent crude etc.) as they would be quite volatile; as well, it's in the airlines' interests to have relatively fixed prices, given fuel is only one portion of their expenses.