Print About a month before the engine of a United Airlines Boeing 777 burst into flames last weekend after departing Denver International Airport, a Bombardier jetliner flying from Denver to Billings, Mont., declared an emergency when one of its engines failed shortly after takeoff. That plane landed safely 20 minutes after departure. Nearly a year earlier, the crew of an Airbus 321 jet operated by American Airlines flying from Charlotte, N.C., to Philadelphia had to abort the flight when one of its engines quit after takeoff. Again, the plane landed safely, 13 minutes after takeoff. And then there was the Feb. 3, 2020, Spirit Airlines flight from Fort Myers, Fla., to Chicago. Minutes after takeoff, passengers heard several loud bangs and saw streaks of flames from the disabled left-hand engine of the Airbus A320. The pilots landed the aircraft safely 15 minutes into the flight.