ValuePenquin survey finds 56% of Americans find decline in airline customer services has announced its recent survey found that 56% of Americans who have flown in the last year think airline customer service is diminishing, the company said.

Millennial passengers are more likely than Generation Xers and baby boomers to complain about airline service issues and are twice as likely to issue a formal complaint about their flying experience, according to the survey. Airing a complaint on social media (Facebook, Twitter, Snapchat and LinkedIn) is more common among this generation than other generations, and the lack of response or untimely responses by airlines only fuel millennial negativity regarding airline customer service.

Almost 45% of Americans who flew in the past year said they issued a complaint against an airline. When discussing specific airlines´ customer service, respondents rated American Airlines and Southwest as the best and Spirit Airlines as the worst.

Flyers expect the worst from budget airlines. Thirty-six % of millennials felt that budget airlines treat passengers poorly, and that they have a right to complain.

ValuePenguin commissioned Qualtrics to conduct an online survey of 657 Americans who flew on an airplane in the past 12 months., part of LendingTree (NASDAQ: TREE), is a personal finance website that conducts in-depth research and provides objective analysis to help guide consumers to the best financial decisions.