parent_company midwest connect
___MASK92___ , Inc ., commonly referred to as United , is a major American airline headquartered in Chicago , Illinois . It is the world ' s second - largest airline when measured by number of destinations served , operates a comprehensive domestic and international route network , and has significant presence in the Asia - Pacific region . In the late 1920s , just prior to the use of the United Airlines name , The ___MASK55___ Company , currently one of the world ' s largest aircraft manufacturers , operated a predecessor airline . United was previously known as United Air Lines ( UAL ). ___MASK70___ , Inc . ( AA ), commonly referred to as American , is a major American airline headquartered in Fort Worth , Texas . It is the world ' s largest airline when measured by fleet size , revenue , scheduled passenger - kilometres flown , and number of destinations served . American together with its regional partners operates an extensive international and domestic network with an average of nearly 6 , 700 flights per day to nearly 350 destinations in more than 50 countries . ___MASK52___ , Inc . is an American airline holding corporation based in Indianapolis , Indiana , that owns Republic Airline , an American regional airline operating in the United States . Midwest Connect was the brand name for the regional airline service of Midwest Airlines , rather than a certificated airline carrier . Skyway Airlines was the sole operator of Midwest Connect since its inception in 1989 , until SkyWest Airlines began additional Midwest Connect service on April 1 , 2007 . SkyWest took over all Midwest Connect operations following Skyway ' s shutdown of operations on April 5 , 2008 . In October , 2008 , Republic Airlines also began operating for Midwest Connect . On November 3 , 2009 the Embraer 170 and Embraer 190 operated by Republic Airlines were rebranded as Midwest Airlines operated by Republic Airlines . Later , during Midwest ' s merger with Frontier Airlines under the ownership of Republic , Chautauqua Airlines oprerated as Midwest Connect . Midwest Airlines ( formerly Midwest Express ) was a U . S .- based airline and , for a short time , an operating brand of ___MASK52___ based in Oak Creek , Wisconsin , operating from Milwaukee ' s General Mitchell International Airport . On April 13 , 2010 , parent company Republic announced that Midwest Airlines and Frontier Airlines would merge , with the Midwest brand disappearing in late 2011 . Frontier Airlines is a United States ultra low cost carrier headquartered in Denver , Colorado , USA . The carrier , which is a subsidiary and operating brand of Indigo Partners , LLC , operates flights to 54 destinations throughout the United States and 5 international destinations . The airline maintains a hub at Denver International Airport with numerous focus cities across the United States . Also , under a code - share agreement with Great Lakes Airlines , the airline connects passengers to surrounding Rocky Mountain States through their Denver hub . Denver International Airport , often referred to as ___MASK28___ , is an airport in Denver , Colorado , United States . At 33 , 531 acres ( 52 . 4 sq mi ), it is the largest airport in the United States by total land area . Runway 16R / 34L , with a length of , is the longest public use runway in the United States . As of 2015 , DEN was the 18th - busiest airport in the world and the 6th busiest in the United States by passenger traffic with over 54 million passengers . It also has the third largest domestic connection network in the country . The airport features 133 gates spread out over three detached , yet internally connected , linear concourses ( A , B & C ). SkyWest Airlines is a North American airline owned by ___MASK16___ and headquartered in St . George , Utah , U . S .. Financially speaking and 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 203 cities , in 43 states ; five Canadian provinces and five cities in Mexico and the Bahamas . 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 . Alaska Airlines is an American airline based in the Seattle metropolitan area of the state of Washington . The company was founded in 1932 as McGee Airways , offering flights from Anchorage , Alaska . Alaska Airlines has flights to more than one hundred destinations in the contiguous United States , Alaska , Hawaii , Canada , Costa Rica and Mexico . The airline is a major air carrier and , along with its sister airlines Horizon Air , and Virgin America , is part of the ___MASK57___ . The airline has been ranked by J . D . Power and Associates as having the highest customer satisfaction of the traditional airlines for nine consecutive years . ___MASK16___ is the holding company for two scheduled passenger airline operations , SkyWest Airlines and ExpressJet , and an aircraft leasing company and is headquartered in St . George , Utah , USA . ___MASK4___ , Inc . (" Delta ") is a major American airline , with its headquarters and largest hub at Hartsfield  Jackson Atlanta International Airport in Atlanta , Georgia . The airline along with its subsidiaries and regional affiliates operate over 5 , 400 flights daily and serve an extensive domestic and international network that includes 319 destinations in 54 countries on six continents , as of October 2016 . Delta is one of the four founding members of the SkyTeam airline alliance , and operates joint ventures with Air France - KLM , Alitalia , Virgin Atlantic , and Virgin Australia . Regional service is operated under the brand name Delta Connection . Republic Airline Inc ., operating as Republic Airline , is a regional airline subsidiary of ___MASK52___ that operates service as American Eagle , Delta Connection , and United Express using a fleet of Embraer 170 and Embraer 175 regional jets . It is headquartered in Indianapolis , Indiana .