The Double Sunrise

The Double Sunrise service was formed in 1943 to re-establish the Australia–England air link that had been cut due to the fall of Singapore in 1942. The service initially operated from its base in Nedlands in Western Australia to the Royal Air Force base at Lake Koggala near Galle in Sri Lanka. It was later extended to Karachi in Pakistan, which was the terminus for the BOAC service from England. The name of the service was derived from the crew observing two sunrises on each flight.

History
In 1943, Royal Australian Air Force personnel were seconded to operate Catalinas under the banner of Qantas. The plan called for flights between Crawley, Western Australia, and RAF Base Koggala in southern Ceylon (now Sri Lanka). The flights were the longest non-stop air route of any airline, over 3,500 nautical miles (6,480 km, 4,020 mi) across the Indian Ocean. Navigating without the aid of radio, the crews relied solely on rudimentary navigation by compass and stars during the trip.

Taking between 27 and 33 hours, with departure timed so that the flight crossed Japanese occupied territory during darkness, the crews would observe the sunrise twice, which led to the service being known as "The Double Sunrise". The flight route flown was along the coast from Crawley to Exmouth then setting out towards Cocos (Keeling) Island or Christmas Island (though neither was actually sighted during the flight) and onto Galle, a journey of approximately 3580 nmi. After the success of the initial flights, it was decided to run a weekly service, with some services flying over Rottnest Island and then taking a direct line to Galle. As part of the Australia-England air route there was a surface component from Galle to Karachi that added considerable time to the service. This was later replaced by the Double Sunrise service, with Karachi to England flown by BOAC. Air crews would change in Galle taking the next plane in either direction minimising the time taken to complete the journey.

Though stripped of all non-essential equipment, including de-icing equipment and insulation, the average takeoff weight was 35100 to 35300 lb (maximum takeoff weight for a PBY Catalina was 35400 lb); this included 1988 gallons of fuel, which gave the Catalina a range of 3600 nmi. The service made 271 crossings, delivered over 10000 lb of mail and carried 860 passengers, including among them British MP Edith Summerskill and the journalist Keith Murdoch.

After the war the five modified Catalinas that had flown The Double Sunrise service were scuttled.

Secret Order of The Double Sunrise
The Secret Order of The Double Sunrise was an illustrated certificate given to passengers aboard the flying boats of the Australia-England air link, to attest they had been airborne for more than 24 hours.