Question: Air Canada Flight 797 started out at what largest hub for American Airlines?

full_context: Document 1: 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 2: United Airlines Flight 232: United Airlines Flight 232 was a DC-10, registered as N1819U, that crash-landed at Sioux City, Iowa in July 19, 1989 after suffering catastrophic failure of its tail-mounted engine, which led to the loss of all flight controls. The flight was en route from Stapleton International Airport in Denver, Colorado to O'Hare International Airport in Chicago. Of the 296 passengers and crew on board, 111 died in the accident and 185 survived in total. Despite the deaths, the accident is considered a prime example of successful crew resource management due to the large number of survivors and the manner in which the flight crew handled the emergency and landed the airplane without conventional control.
Document 3: CAAC Flight 2311: CAAC Flight 2311 was a scheduled passenger flight from Changsha Huanghua International Airport to the former Guangzhou Baiyun International Airport. On 24 December 1982 it was flown by an Ilyushin Il-18B (registered in China as "B-202"), when after landing at Baiyun Airport a cabin fire produced toxic smoke whereupon the crew stopped the aircraft on the runway and evacuated the passengers. The fast-developing fire killed 25 passengers and seriously injured 22 passengers and four crew members. The fire, which was started by a passenger's cigarette, destroyed the aircraft.
Document 4: UPS Airlines Flight 6: UPS Airlines Flight 6 was a cargo flight operated by UPS Airlines. On September 3, 2010, a Boeing 747-400F flying the route between Dubai International Airport and Cologne Bonn Airport developed an in-flight fire, with the fumes and subsequent crash resulting in the death of the two crew members. The aircraft had departed Dubai International earlier, but returned after reporting smoke in the cockpit. It was the first fatal air crash for UPS Airlines. The crash caused an examination of safety procedures protecting airliners from cockpit smoke.
Document 5: Air Canada Flight 797: Air Canada Flight 797 was a scheduled trans-border flight that flew from Dallas/Fort Worth International Airport to Montréal–Dorval International Airport, with an intermediate stop at Toronto Pearson International Airport. On 2 June 1983, the McDonnell Douglas DC-9-32 operating the service developed an in-flight fire behind the washroom that spread between the outer skin and the inner decor panels, filling the plane with toxic smoke. The spreading fire also burned through crucial electrical cables that knocked out most of the instrumentation in the cockpit, forcing the plane to divert to Cincinnati/Northern Kentucky International Airport. Ninety seconds after the plane landed and the doors were opened, the heat of the fire and fresh oxygen from the open exit doors created flashover conditions, and the plane's interior immediately became engulfed in flames, killing 23 passengers who had yet to evacuate the aircraft. Blood tests showed some of the passengers had inhaled lethal amounts of toxins from the in-flight fire, likely meaning they were already dead in their seats before the plane touched down.
Document 6: 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 7: Denver International Airport: Denver International Airport (DEN), (IATA: DEN, ICAO: KDEN, FAA LID: DEN) , 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 16000 ft , is the longest public use runway in the United States. As of 2016, DEN was the 18th busiest airport in the world and the sixth busiest in the United States by passenger traffic with over 58 million passengers. It also has the third largest domestic connection network in the country. s of 2017 , the airport features 135 gates spread out over three detached, yet internally connected, linear concourses (A, B & C).
Document 8: Aloha Airlines Flight 243: Aloha Airlines Flight 243 (AQ 243, AAH 243) was a scheduled Aloha Airlines flight between Hilo and Honolulu in Hawaii. On April 28, 1988, a Boeing 737-297 serving the flight suffered extensive damage after an explosive decompression in flight, but was able to land safely at Kahului Airport on Maui. There was one fatality, flight attendant Clarabelle "C.B." Lansing, who was ejected from the airplane. Another 65 passengers and crew were injured. The safe landing of the aircraft despite the substantial damage inflicted by the decompression established Aloha Airlines Flight 243 as a significant event in the history of aviation, with far-reaching effects on aviation safety policies and procedures.
Document 9: Dubai International Airport: Dubai International Airport (IATA: DXB, ICAO: OMDB) (Arabic: مطار دبي الدولي‎ ‎ ) is the primary international airport serving Dubai, United Arab Emirates and is the world's busiest airport by international passenger traffic. It is also the 3rd busiest airport in the world by passenger traffic, the 6th busiest cargo airport in world, the busiest airport for Airbus A380 and Boeing 777 movements, and the busiest airport in the world operating with only two runways. In 2016, DXB handled 83.6 million passengers, 2.59 million tonnes of cargo and registered 418,220 aircraft movements.
Document 10: Dana Air Flight 992: Dana Air Flight 992 was a scheduled domestic commercial passenger flight from Abuja to Lagos, Nigeria. On Sunday, 3 June 2012, the McDonnell Douglas MD-83 aircraft operating the flight crashed into a furniture works and printing press building in the Iju-Ishaga neighbourhood of Lagos. The crash resulted in the deaths of all 153 people on board and 10 more on the ground. The crash of Flight 992 is the deadliest aviation disaster involving a McDonnell Douglas MD-83, as well as the second-deadliest involving an MD-80 series aircraft, behind Inex-Adria Aviopromet Flight 1308. It is also the second-deadliest aircraft crash on Nigerian soil, behind the Kano air disaster of 1973.
Document 11: 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 12: Dallas/Fort Worth International Airport: Dallas/Fort Worth International Airport (IATA: DFW, ICAO: KDFW, FAA LID: DFW) is the primary international airport serving the Dallas–Fort Worth metroplex area in the U.S. state of Texas. It is the largest hub for American Airlines, which is headquartered near the airport. 2016 was a record year for DFW, as the airport served 65,670,697 passengers.
Document 13: Air Canada Flight 189: Air Canada Flight 189 was an Air Canada flight from Ottawa to Vancouver via Toronto and Winnipeg. On June 26, 1978, it crashed on takeoff in Toronto killing two passengers.
Document 14: Southwest Airlines: Southwest Airlines Co. () is a major U.S. airline and the world's largest low-cost carrier headquartered in Dallas, Texas.
Document 15: Delta Air Lines Flight 191: Delta Air Lines Flight 191 was a regularly scheduled Delta Air Lines domestic service from Fort Lauderdale, Florida, to Los Angeles, via Dallas that crashed on August 2, 1985, at 18:05 (). The Lockheed L-1011 TriStar operating this flight encountered a microburst while on approach to land on runway 17L (now marked 17C) at Dallas/Fort Worth International Airport (DFW). The pilots were unable to escape the weather event and the aircraft struck the ground over a mile short of the runway. The flight hit a car driving north of the airport and two water tanks, disintegrating. The crash killed 136 people on board, including 128 of the 152 passengers and 8 of the 11 crew, and the driver of the car. The National Transportation Safety Board (NTSB) determined that the crash resulted from the flight crew's decision to fly through a thunderstorm, the lack of procedures and training to avoid or escape microbursts, and the lack of hazard information on wind shear.
ground_truth: Dallas/Fort Worth International Airport