PHOENIX, AZ –A Phoenix-bound flight was forced to return to Houston Sunday evening because of weather conditions in the Valley of the Sun. Passengers who were on the plane said the flight crew told them the record-breaking heat is to blame.United flight 6186 — operated by Mesa Airlines — departed from Bush Intercontinental Airport at 2:30pm and was minutes away from landing at Sky Harbor Airport when the flight crew notified passengers it would be turning back around because of the weather. MORE