Explanation according to the user who posted the video
According to the user comment in Youtube, a flight scheduled to friday 18 was cancelled due to radio problems and transfered to saturday 19. On saturday, with the same a/c, there was an issue with the right engine. The user said that it "failed to start". After 1 hour maintenance, they announced that everything was ok and the flight would proceed. Several passengers complained that the right engine "sounded funny". The crew told the passengers to shut up, and the disturbance begun. Eventually the federal police was called and removed a flight attendant and some passengers to get their statements.
The flight took off, but 3 minutes later there was a smell of something burning. The crew shut off the right engine and returned to Galećo. At least two tires blew up during the landing. That last information is confirmed by some news agencies.
Today, it was announced that two other UA flights had to return to Guarulhos due to "technical problems", less than 24 hours apart from each other. Both flights landed without incidents. No further information available.
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