Qantas performed its longest-ever commercial passenger flight this week, repatriating Australian citizens from South America on behalf of the Australian Department of Foreign Affairs and Trade. The flight departed Buenos Aires, Argentina bound for Darwin, the location of one of Australia’s supervised quarantine facilities. The 787-9 carried 107 passengers, 4 pilots, and 17 cabin crew and other staff, including engineers and ground staff. En route the flight passed over Antarctica, reaching just north of 75 degrees southern latitude.

Qantas’ longest-ever commercial passenger flight

QF14 was Qantas’ longest ever non-stop flight for which passengers could purchase a ticket. The Project Sunrise test flights from New York and London to Sydney were longer, but it was not possible to purchase a seat onboard. Buenos Aires to Darwin is 14,683 km, 184 km longer than London-Perth, Qantas’ previous longest commercial flight. Take a closer look at the top 10 longest flights in the world and see which of those flights Qantas operate >>

The flight, operated by Boeing 787-9 VH-ZNH, departed Buenos Aires at 15:44 UTC on 5 October and arrived in Darwin at 09:10 UTC on 6 October spending 17 hours and 26 minutes in the air. The flight reached its maximum southern latitude of -74.992844 at 22:35:51 UTC.

Flight planning QF14

Not only are the distance and flight time a factor on such a long flight, but the location of this flight poses challenges as well when constructing the flight plan. Intercontinental flights operated by twin-engine aircraft, like the Boeing 787, are usually operated under Extended Operations (ETOPS) regulations. ETOPS regulations provide specific technical and procedural guidance for ensuring safe flights farther from diversion airports than would otherwise be acceptable. The regulations specify a time interval during which an aircraft can operate at single-engine cruise speed before reaching an alternate airfield. In the case of the 787, that interval is 330 minutes.

Thanks to its ETOPS 330 rating, Qantas’ 787 can operate over Antarctica between South America and Australia. But there is a still a small portion of Antarctica that is outside the area allowed by the ETOPS rating, and thus QF14 is unable to exactly follow the Great circle route, which demonstrates the shortest route between two points on the earth.

The yellow line in the image above is the Great circle route, which passes overland in Antarctica. The actual flight path, in red, shows the flight’s path hewing closely to the Antarctic coast to avoid the small area outside the ETOPS allowable area. Over the Southern Ocean between Antarctica and Australia the flight made use of favorable winds and avoided adverse weather, adding distance, but reducing time in flight. The Great circle distance between Buenos Aires and Darwin is 14,683 km, while the actual distance flown was 15,037 km. As the flight progressed, the 787 also increased its cruising altitude to maintain maximum efficiency. Beginning with a maximum fuel load of  126,000 liters, QF14 climbed to an initial cruising altitude of 34,000 feet and then step climbed to 40,000 feet as it burned fuel and reduced weight.

Tracking flights over Antarctica

To track QF14 and other flights like it, we rely on satellite-based ADS-B for positional updates. For QF14 satellite-based tracking allowed us to get position updates from the aircraft, every 1, 10, and 30 minutes through separate channels. Qantas pilots also provided helpful ACARS updates along the way.

Update from #QF14

"It's cold -75C
Greetings fm Antartica
Over the Walker Ranges
Def no polar bears
All going well
Cheers fm QF14
Damien and Alex on deck"

Follow the journey here: https://t.co/5LDJDScTLK pic.twitter.com/QdmRV212SC

— Qantas (@Qantas) October 5, 2021