The longest passenger flight ever operated was not a modern jet gliding from Singapore to New York. It was a lumbering World War II flying boat, cruising at 125 mph across a hostile ocean for up to thirty-three hours at a stretch — long enough for the handful of passengers aboard to watch the sun rise not once, but twice. They called it the Double Sunrise.

For two years, Qantas Catalinas flew this secret route in complete radio silence, navigating by the stars, to reconnect Australia with a Britain cut off by war. It remains, eight decades on, the longest scheduled airline service in history by duration.

A broken lifeline

When Singapore fell to Japan in February 1942, it severed the vital air link between Britain and Australia — the old “Kangaroo Route” that carried diplomats, mail and priority freight across the Empire. Something had to replace it, and it had to avoid Japanese-held territory entirely. The answer, agreed in secret between the two governments, was audacious: fly straight across the Indian Ocean, non-stop, in flying boats.

The history of the Consolidated PBY Catalina, the flying boat behind the Double Sunrise.

Thirty hours over the Indian Ocean

Five Catalinas were assigned to the job, each named after a star used to navigate the route — Rigel, Spica, Altair, Vega and Antares. They were stripped of every spare pound of weight and filled almost to bursting with fuel; the margin between the aircraft’s range and the length of the route was razor-thin. There was no radio — long-range wireless simply couldn’t reach across that much open ocean — so the crews flew in silence, fixing their position by the stars.

Each flight left Western Australia in the evening, so it would cross the most dangerous stretches in darkness, and pressed on for a day and a night and most of another day. Because the westbound trip lasted so long, passengers saw two dawns break over the water. The record crossing took 32 hours and 9 minutes — a mark for a scheduled passenger flight that still stands today.

Restored wartime footage of PBY Catalinas at work.

The Secret Order of the Double Sunrise

Space was so tight that a typical flight carried just three passengers and a few dozen kilograms of diplomatic mail. Those rare travellers earned something no airline offers today: on arrival in Ceylon, each was handed a certificate admitting them to “The Secret Order of the Double Sunrise” — proof that they were among the tiny number of people alive who had spent more than a day aloft on a single commercial flight.

Between 1943 and 1945 the Catalinas made 271 crossings, carried around 860 passengers, and delivered tonnes of mail — without losing a single life.

A surviving Catalina flying today — the sound of the machine that made the crossing.

The long shadow of the Double Sunrise

The secret service left a permanent mark. It was on these flights that Qantas first painted its now-famous flying kangaroo on an aircraft, and the operation was officially christened the “Kangaroo Service.” Faster Liberators and then converted Lancaster bombers eventually took over, and the Catalinas were quietly scuttled at war’s end.

But the name never faded. When Qantas set out to fly non-stop from Sydney to London — a goal it expects to reach around 2027 — it called the programme “Project Sunrise,” in tribute to the Catalina crews who did the impossible first. Their duration record has stood for over eighty years, and probably always will.

Sources: The Double Sunrise (Wikipedia); Luke Peters, AeroTime; Simple Flying; Return of the Catalina (2015); Qantas Founders Museum.