Question: Where is the airline company that operated United Express Flight 3411 on April 9, 2017 on behalf of United Express headquartered?

SkyWest Airlines is a North American airline owned by SkyWest, Inc. and headquartered in St. George, Utah, U.S..  According to the Airlines for America definitions, SkyWest is a North American major airline.  SkyWest however, operates on a regional airline level and is a member of the Regional Airline Association.  SkyWest Airlines flies to 238 cities, in 45 states; Washington, D.C., six Canadian provinces and five cities in Mexico.  The airline serves as a feeder airline, operating under contract with various major carriers.  It flies as SkyWest Airlines in a partnership with Alaska Airlines, as United Express on behalf of United Airlines, as American Eagle on behalf of American Airlines, and as Delta Connection on behalf of Delta Air Lines.  SkyWest also provides ground handling services for airports across the United States. <SEP> Air Wisconsin Airlines is a regional airline based at Appleton International Airport in the town of Greenville, Wisconsin, United States, near Appleton.  Air Wisconsin is the largest privately held regional airline in the United States.  It currently operates regional jet flights as American Eagle under contract to American Airlines via a code sharing agreement, serving cities in the U.S. and Canada with hubs at Boston Logan International Airport (BOS), Charlotte Douglas International Airport (CLT), Philadelphia International Airport (PHL) and Ronald Reagan Washington National Airport (DCA) .  Air Wisconsin previously operated United Express service on behalf of United Airlines followed by US Airways Express service on behalf of US Airways prior to becoming an American Eagle regional air carrier.  The company has announced it will once again partner with United Airlines as a United Express code sharing air carrier with primary hubs to be located at Chicago O'Hare International Airport (ORD) and Washington Dulles International Airport (IAD) beginning in September 2017 and will be "exclusively operating" as United Express by March 2018. <SEP>  It is headquartered in Indianapolis, Indiana. Republic Airline Inc., operating as Republic Airline, is a regional airline subsidiary of Republic Airways Holdings that operates service as American Eagle, Delta Connection, and United Express using a fleet of Embraer 170 and Embraer 175 regional jets.  Its call sign "Brickyard" is derived from the nickname of the Indianapolis Motor Speedway. <SEP> On April 9, 2017, O'Hare International Airport police violently and forcibly ejected passenger David Dao from United Express Flight 3411 after he refused to depart the airplane upon the demand of management.  Dao screamed as officers pulled him out of his seat, and his face hit an armrest during the struggle.  Officers then dragged him, apparently unconscious, by his arms on his back along the aircraft aisle past rows of onlooking passengers.  He was later seen with blood around his mouth.  Prior to the confrontation, managers offered travel vouchers to passengers to vacate their seats to make room for four airline employees who needed to travel to the destination, Louisville International Airport, but none of the fliers accepted.  Four passengers were then selected for involuntary removal from the flight.  Three other passengers complied, and Dao was selected to be fourth.  Republic Airline operated the scheduled passenger flight on behalf of United Express, a United Airlines regional branch.