By Chris Isidore

NEW YORK (CNNMoney) -- United Airlines boss Oscar Munoz faces a grilling in Congress on Tuesday over the violent removal of an airplane passenger and the bungled apology that followed.

Munoz is one of four airline executives appearing before a hearing of the House Transportation Committee on Capitol Hill. The others are lower-level executives from American Airlines, Southwest and Alaska. An aviation consultant from Consumers Union is also scheduled to testify.

The hearing will be on oversight of U.S. airline customer service, and will deal with consumer protection for passengers.

United came under harsh public scrutiny last month when a passenger was dragged off an overbooked flight in Chicago. After initially blaming the passenger as "belligerent," Munoz apologized and promised changes in airline procedures.

The airline settled out of court with the passenger, Dr. David Dao.

TM & © 2017 Cable News Network, Inc., a Time Warner Company. All rights reserved.