Crews use handheld card readers to swipe credit or debit cards for purchases, such as cocktails, headphones and snacks.
In December, US Airways began testing card-scan devices on about 600 flights. Since Jan. 5, passengers on most of US Airways' 1,300 mainline flights can pay with cash or credit cards.
"The only complaint is from that occasional customer who doesn't have a credit card," said Cara Maggio, USA3000 flight attendant, "but that's not too often."
When that happens, a nearby passenger often will offer, " 'Give me your $5, and I'll put it on my card.' They help each other out," she said.
Travelers tend to spend more if they put purchases on a card - running a tab, or buying a round of drinks for family and friends.
"We did a lot of customer communication leading into it," said Whitney Eichinger, spokeswoman for Southwest, Philadelphia's second-largest airline, which went cashless in September. "The transition was seamless."
USA3000, an affiliate of Apple Vacations, in Newtown Square, said the battery-operated machines have made it easier to track and adjust inventory. "We can take things out that are not selling well, and add other items in," said director of operations Jack Eastman.
Midwest Airlines, in Milwaukee, went cashless in March 2007 to avoid crews' carrying large amounts of money and storing it in hotel rooms.
"We were dedicating a large amount of resources to accounting for this cash," said Midwest spokesman Michael Brophy. "Our onboard sales actually increased when we no longer accepted cash."
Switching to credit cards also boosted onboard sales for Alaska Airlines.
