Passengers checking in for their flight using www.airtran.com may now upgrade to Business Class for $ 49 to $ 99 one-way , depending on the length of the flight . With the option of onboard upgrades , passengers will be allowed the opportunity to move to Business Class if seats are available on their flight . Flight attendants will offer customers the opportunity to upgrade at time of boarding , time permitting , or at cruising altitude . The onboard upgrades will be available to all customers , regardless of the fare class of their ticket purchased .