- Passenger complaints increased 70 percent year-over-year in April, the same month a passenger was dragged off a United plane.
- There were other high-profile incidents that may have prompted more passengers to complain to the Department of Transportation.
To say April was a bad one for airline customer service would be a huge understatement. New data from the U.S. Department of Transportation shows a 70 percent spike in complaints by passengers compared to April 2016.
The surge in complaints may have been sparked by a couple of high-profile incidents that gave the industry a black eye — most notably, cell phone video showing a United Airlines passenger being dragged off of a plane.
That event happened on April 9, and intense coverage for several days afterwards made United Airlines a punching bag on social media and on late-night TV shows.
While United was repeatedly criticized for its customer service, there were other events in April involving altercations between passengers and flight crew including an American Airlines passenger with a baby stroller accidentally being hit after an argument with a member of the flight crew.
Collectively, the focus on poor customer service may have prompted more passengers to complain to the DOT.
Still, it has not hurt airline business nor the performance of airline stocks, including United Continental, which has climbed since April to hit an all-time high.
—By CNBC's Phil LeBeau; Follow him on Twitter: @Lebeaucarnews
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