Question: Envoy Air is a wholly owned subsidiary of an airline group that flies to how many countries worldwide?

full_context: Document 1: UAL Corporation: UAL Corporation is the former name of United Continental Holdings, an airline holding company, incorporated in Delaware with headquarters in Chicago, Illinois. UAL held a 100 percent controlling interest in United Airlines, Inc., one of the world's largest air carriers, and is a founding member of the Star Alliance. It was announced on May 3, 2010 that UAL Corporation and Continental Airlines, Inc. would pursue a merger pending government approval. UAL Corporation would acquire Continental Airlines, Inc. and change its name to United Continental Holdings, Inc. (UCH). On October 1, 2010, UCH, formerly UAL Corporation, announced completion of the merger.
Document 2: Delta Air Lines: Delta Air Lines, 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, Korean Air, China Eastern Airlines, Virgin Atlantic, and Virgin Australia. Regional service is operated under the brand name Delta Connection.
Document 3: US Airways Express: US Airways Express was the brand name for the regional affiliate of US Airways, under which a number of individually owned commuter air carriers and regional airlines operate short and medium haul routes. This code sharing service was previously operated as USAir Express. Mainline carriers often outsource to regional airlines to operate services in order to increase frequency, serve routes that would not sustain larger aircraft, or for other competitive reasons. US Airways Express operations were conducted from smaller markets in the United States, Canada, and the Bahamas primarily centered on US Airways' major hubs and focus cities. Upon the completion of US Airways' merger process with American Airlines, US Airways Express was rebranded as American Eagle on October 17, 2015.
Document 4: Envoy Air: Envoy Air Inc. (formerly American Eagle Airlines) is an air carrier headquartered in Irving, Texas, in the Dallas-Fort Worth metroplex. It is a wholly owned subsidiary of American Airlines Group that, along with several carriers outside the group, feeds the American Airlines route network under the American Eagle brand. With over 1,800 flights a day, serving 159 cities across the United States, Canada, Mexico and the Caribbean, Envoy is considered to be the world's largest regional airline system. Envoy is an affiliate member of the Oneworld airline alliance.
Document 5: Thomas W. Horton: Thomas W. Horton (born 05/24/1961) was the Chairman, President, and Chief Executive Officer of AMR Corporation until it merged with US Airways Group to form American Airlines Group, Inc. and was the Chairman of American Airlines Group, Inc. and American Airlines. He also served as Chairman of oneworld, the global airline alliance, until March 2014.
Document 6: SkyWest Airlines: 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.
Document 7: US Airways Group: US Airways Group Inc. was an airline holding company based in Tempe, Arizona. US Airways Group operated US Airways, along with its subsidiaries PSA Airlines, Inc. and Piedmont Airlines, Inc., which are wholly owned but marketed under the branding of US Airways Express. It merged with America West Holdings Corporation, parent of America West Airlines, in 2005, and the combined company adopted the better-known US Airways name; the two airlines' operating certificates merged in 2007. It also operates additional companies that provide associated services. ACE Aviation Holdings, the Canadian parent of Air Canada retained a roughly 6.1% investment stake in US Airways Group. The route network covered destinations in 47 states, as well as international destinations.
Document 8: American Airlines: American Airlines, Inc. (AA) is an American airline headquartered in Fort Worth, Texas, within the Dallas-Fort Worth metroplex. It is the world's largest airline when measured by fleet size, revenue, scheduled passenger-kilometers 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.
Document 9: United Continental Holdings: United Continental Holdings, Inc. (formerly UAL Corporation) is a publicly traded airline holding company headquartered in the Willis Tower in Chicago. UCH owns and operates United Airlines, Inc. The company is the successor of UAL Corporation, which agreed to change its name to United Continental Holdings in May 2010, when a merger agreement was reached between United and Continental Airlines. Its stock trades under the UAL symbol. To effect the merger, Continental shareholders received 1.05 shares of UAL stock for each Continental share, effectively meaning Continental was acquired by UAL Corporation; at the time of closing, it was estimated that United shareholders owned 55% of the merged entity and Continental shareholders owned 45%. The company or its subsidiary airlines also have several other subsidiaries. Once completely combined, United became the world's largest airline, as measured by revenue passenger miles. United is a founding member of the Star Alliance.
Document 10: American Eagle (airline brand): American Eagle is an American brand name for the regional branch of American Airlines, under which ten individual regional airlines operate short- and medium-haul feeder flights. Three of these airlines, Envoy Air (formerly American Eagle Airlines), Piedmont Airlines and PSA Airlines, are wholly owned subsidiaries of American Airlines Group. Just like the regional brands of the other two major airlines (Delta Connection and United Express), American Airlines' regional brand accounts for more than 60% of American Airlines flights.
Document 11: American Airlines Group: American Airlines Group, Inc. is an American publicly traded airline holding company headquartered in Fort Worth, Texas. It was formed December 9, 2013, in the merger of AMR Corporation, the parent company of American Airlines, and US Airways Group, the parent company of US Airways. The airline groups together form the largest airline in the world, with more than 6,700 daily flights to 336 locations in 56 countries worldwide, about $40 billion in operating revenue, over 100,000 employees, and plans to take delivery of 607 new aircraft, including 517 narrowbody aircraft and 90 widebody international aircraft. The integration of American Airlines and US Airways was completed when the Federal Aviation Administration granted a single operating certificate for both carriers on April 8, 2015.
Document 12: US Airways: US Airways (formerly known as USAir) was a major American airline that ceased to operate independently when the Federal Aviation Administration granted a single operating certificate (SOC) for US Airways and American Airlines on April 8, 2015. Publicly, the two carriers appeared to merge when their reservations systems and booking processes were merged on October 17, 2015; however, other systems were still separate at that time. The airline had an extensive international and domestic network, with 193 destinations in 24 countries in North America, South America, Europe and the Middle East. The airline was a member of the Star Alliance, before becoming an affiliate member of Oneworld in March 2014. US Airways utilized a fleet of 343 mainline jet aircraft, as well as 278 regional jet and turbo-prop aircraft operated by contract and subsidiary airlines under the name US Airways Express via code sharing agreements.
Document 13: Delta Air Lines–Northwest Airlines merger: On April 15, 2008, Delta Air Lines and Northwest Airlines announced a merger agreement. The merger of the two carriers formed what was then the largest commercial airline in the world, with 786 aircraft. The merged airline is called "Delta Air Lines."
Document 14: International Airlines Group: International Consolidated Airlines Group, S.A., often shortened to IAG, is an Anglo-Spanish multinational airline holding company with its operational headquarters in London, England and its registered office in Madrid, Spain. It was formed in January 2011 after a merger agreement between British Airways and Iberia, the flag carrier airlines of the United Kingdom and Spain respectively. As British Airways was the larger company, those holding shares in British Airways at the time of the merger were given 55% of the shares in the new, merged company. British Airways and Iberia ceased to be independent companies and instead became 100% owned subsidiaries of IAG. It is the sixth-largest airline company in the world, producing €22.567 billion revenue in 2016. The company is listed on the London Stock Exchange and the Madrid Stock Exchange. It is a constituent of the FTSE 100 Index and IBEX 35 Index.
Document 15: America West Airlines: America West Airlines was a U.S. airline headquartered in Tempe, Arizona. Their main hub was at Sky Harbor Airport in Phoenix, Arizona, with a secondary hub at Las Vegas McCarran International Airport in Las Vegas, Nevada. The airline became part of the US Airways Group after it acquired the larger airline in 2005 and adopted the US Airways brand name. America West was the second largest low-cost carrier in the U.S. after Southwest Airlines and served approximately 100 destinations in the US, Canada, and Mexico. Service to Europe was provided through codeshare partners. In March 2005, the airline operated a fleet of 132 aircraft, with a single maintenance base at Sky Harbor Airport in Phoenix. Regional jet and/or turboprop feeder flights were operated on a code sharing basis by Mesa Airlines and Chautauqua Airlines as America West Express.
ground_truth: 56