Question: Republic Airways Holdings, Inc. is an American airline holding corporation based in Indianapolis, Indiana, that owns which 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?
Sentence (from "Republic Airline"): Its call sign "Brickyard" is derived from the nickname of the Indianapolis Motor Speedway.
Relevant evidence: No