The flight distance from Allen Army Air Field (BIG) in Delta Junction Ft Greely, United States to Sydney Kingsford Smith International Airport (SYD) in Sydney, Australia is 12,200 kilometers (7,581 miles / 6,588 nautical miles). The estimated flight time for this route is approximately 15h, flying southwest at a heading of 232°.

This is an ultra-long-haul route, one of the longest in aviation. It requires wide-body aircraft with extended range capability such as the Airbus A350-900ULR or Boeing 777-200LR. Passengers should prepare for an extended flight with multiple meal services.

This is an international route connecting United States with Australia. It is an intercontinental flight between North America and Oceania. Travelers should check visa requirements, customs regulations, and any travel advisories before booking.

Time zone information: When it's 23:10 in Delta Junction Ft Greely, it's 19:10 in Sydney. With a 20-hour time difference, travelers should plan for significant jet lag. It typically takes one day per hour of time difference to fully adjust.

There is a significant elevation difference of 1,264 feet between the two airports. Sydney Kingsford Smith International Airport sits lower than Allen Army Air Field.

The return flight from Sydney (SYD) to Delta Junction Ft Greely (BIG) follows a heading of 25° (north northeast). Actual flight times may vary depending on wind conditions, air traffic, and the specific aircraft used.

For more information about these airports, visit the Allen Army Air Field (BIG) and Sydney Kingsford Smith International Airport (SYD) detail pages, or use our flight duration calculator to compare other routes.