Regional airline that kicked off United passenger has had troubles

United Airlines has faced severe backlash in the days since it dragged a passenger off of one of its planes.

But the real cause of the problem may be attributable to the regional carrier that operated the flight in its name, and which also operates for other major airlines, including Delta and American.

Republic Airline, a regional airline that operates flights for United, Delta Air Lines and American Airlines, recently recovered from bankruptcy and a prolonged fight with its pilots.

The problem on Sunday’s flight out of Chicago stemmed not from overbooking as some have reported, but from the airline trying to squeeze on four extra crew members, according to a letter from United CEO Oscar Munoz to employees. United needed the extra crew in Louisville, Ky., so it could operate a flight from there.

Delta sued Republic in 2015 for not operating the number of flights it had agreed to. About 350 of Republic’s 2,100 pilots live in Chicago, according to the Chicago Business Journal, and the airline was experiencing a pilot shortage at the time. The company emerged from bankruptcy in 2016. United’s regional flights had a worse on-time record than its mainline flights.

A spokesperson for Republic confirmed that it did operate the controversial flight but is referring all questions to United.

A recent news release stated that Republic operated 165 aircraft from 105 cities on about 850 flights per day and employs roughly 5,200 aviation professionals.

Contributing: Jerry Siebenmark of The Eagle: 316-268-6576, @jsiebenmark

This story was originally published April 11, 2017 at 6:33 PM with the headline "Regional airline that kicked off United passenger has had troubles."