In this reality, Charles Xavier became the Juggernaut who formed the X-Men. Thunderbird is a member of Charles Xavier's X-Men who serves as a police force that aids the mutants and persecutes the sapiens.
The total flight duration from Sydney, Australia to Boston, MA is 20 hours, 41 minutes. This assumes an average flight speed for a commercial airliner of 500 mph, which is equivalent to 805 km/h or 434 knots. It also adds an extra 30 minutes for take-off and landing. Your exact time may vary depending on wind speeds.
Traveling to Boston from New York City is a quick, low-stress option. Trains travel from Penn Station in Manhattan to Boston's South Station. Acela service takes three and a half hours, while other trains take as long as five-and-a-half hours.