Getting a free beer on a flight is not all that hard. According to White, there are a few reasons why she'll give a customer a free drink, but it all comes down to one thing: being nice – really nice. If there are mechanical problems, and it's the airline's fault and you've been sitting on the tarmac forever without being rude, she'll comp you a drink. "I'm sure they need it," she says. If you only have cash (most airlines only take cards) and have been nice during the flight, she'll just give you the beer. "Basically, kindness goes a long way," says White.