Civil Aviation

Double Sunrise – Exploring the Fascinating Story of the Longest Passenger Flight in History

In modern times, we associate long-haul flights with state-of-the-art Boeing or Airbus aircraft, offering comfort and various amenities throughout the journey. However, few are aware of a bygone era when a particular service endured significantly more hours than any present-day long-haul flight. Today, we delve into the details of this extraordinary and record-breaking operation – the Double Sunrise.

Cathay Pacific win the title of the world’s longest passenger flight from Singapore Airlines, with its preferred North Atlantic route from New York to Hong Kong covering approximately 16,618 kilometres (10,300 miles) and lasting between 16 to 17 hours.

However, in 1943, a unique operation was launched under the auspices of a commercial airline service, which to this day holds the distinction of being the longest-ever passenger airline service in terms of duration.

This groundbreaking endeavour, famously known as the ‘Double Sunrise’ operation, was inaugurated in 1943 to restore air connections between Australia and England, severed due to the fall of Singapore to the Japanese in 1942.


The PBY Catalina

The PBY Catalina, renowned for its exceptional endurance, was an aircraft that truly pushed the boundaries of long-distance flying. Its remarkable capability to remain airborne for extended periods of time made it an invaluable asset during World War II and beyond.

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Equipped with large fuel tanks housed within its expansive wings, the Catalina had the capacity to carry substantial amounts of fuel, granting it an impressive range. This, combined with its ability to take off and land on both water and land, gave the Catalina unmatched operational flexibility.

The Consolidated PBV-1A Catalina, Miss Pick Up is still flying today.
A PBV Catalina. Photo credit – Alan Wilson CC BY-SA 2.0.

The aircraft’s endurance was further enhanced by its stripped-down configuration for ultra-long flights. Non-essential equipment, including de-icing systems and insulation, was removed to reduce weight and increase efficiency.

With an average take-off weight of around 35,000 lbs, the Catalina could reach a maximum take-off weight of 35,400 lbs, accommodating a fuel load of up to 1,988 imperial gallons. Such capabilities allowed the Catalina to cover an impressive range of 3,600 nautical miles.

However, the trade-off for its extraordinary endurance was limited payload capacity. The high fuel requirements for long oceanic flights, coupled with the aircraft’s weight limitations, meant that the Catalina’s cargo and passenger capacity were significantly restricted. On average, each flight carried only three passengers and approximately 159 lbs of essential mail, often of a sensitive nature.

Despite these constraints, the Catalina consistently demonstrated its ability to fly for over 24 continuous hours, with flight times often exceeding 27 hours and occasionally stretching to 33 hours due to challenging headwinds. This remarkable endurance enabled the Catalina to conquer the vast distances encountered during the Double Sunrise flights, solidifying its reputation as an aircraft capable of enduring the most demanding long-haul operations.

Whilst slow, the Catalina had exceptional edurance.
Whilst slow, the Catalina had exceptional endurance.

The enduring legacy of the PBY Catalina lies not only in its record-breaking flights but also in its contributions to maritime patrol, aerial surveillance, search and rescue missions, and reconnaissance efforts during wartime. Its longevity in service and its ability to conquer vast distances have cemented the Catalina’s place in aviation history as an enduring symbol of endurance and reliability.

The Double Sunrise

From its inception, the service operated from a seaplane base near Perth in Western Australia, specifically in Crawley. The flights transported passengers to the well-established Royal Air Force base at Lake Koggala, situated close to the city of Galle in what was then Ceylon, presently known as Sri Lanka. The service earned its nickname from the awe-inspiring experience of witnessing two sunrises during each flight.

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Subsequently, the trailblazing route was extended to Karachi in British India (now part of Pakistan), serving as the southernmost point on the vital empire route from London, operated by the British Overseas Airways Corporation (BOAC).

In 1943, as the Second World War continued to ravage various parts of the globe, the need to reestablish a secure air route between England and Australia became evident to the governments of both territories.

There was a genuine demand for transporting passengers, mail, and other essential goods between these two nations, which, as wartime allies and historically close cooperating members of the Commonwealth, had previously enjoyed well-established air links.

The Double Sunrise Catalina, docked.
The Double Sunrise Catalina docked.

Following extensive collaboration between the two governments and their armed forces, it was decided that personnel from the Royal Australian Air Force (RAAF) would be seconded to a newly formed special division responsible for operating the flights.

This division, under the Qantas name and brand, would operate Consolidated PBY Catalina flying boats, embarking on the journey from Western Australia to the RAF base located at Lake Koggala in southern Ceylon, a heavily fortified British colony in the Indian Ocean at the time.

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Once operational, these flights became the longest non-stop air route offered by any airline during that period. Covering a distance of just over 3,500 nautical miles (4,020 statute miles or 6,480 km), the route was predominantly over the vast expanse of the Indian Ocean, with minimal sections flying over land.

These epic flights were conducted without radios, as wireless radiotelephonic equipment had not yet advanced sufficiently to provide coverage over extensive oceanic areas. Similarly, lacking radio navigation equipment, the flight crews relied solely on rudimentary navigation techniques utilizing maps, compasses, and celestial navigation, with stars as their guiding tools.

The Antares Star on a Double Sunrise mission. Photo credit - IWM.
The Antares Star on a Double Sunrise mission. Photo credit – IWM.

The Royal Australian Air Force (RAAF) received a generous supply of five Catalina aircraft from the British Air Ministry. Each of these remarkable planes was given a name corresponding to stars used for navigation during their extensive journeys.

The celestial-inspired names assigned to these Catalinas were Rigel Star, Spica Star, Altair Star, Vega Star, and Antares Star. Cruising at an average speed of 125 mph (200 kph), each flight spanned a duration of 27 to 33 hours. Meticulous planning ensured that departures from Western Australia coincided with the aircraft crossing Japanese-occupied territories in East Asia under the cover of darkness.

The Catalinas embarked on a route that began from Crawley, heading towards Exmouth in Western Australia. From there, they ventured out towards Cocos Island or Christmas Island in the vast Indian Ocean before charting a direct course to Galle.

Once the service was established, these flights operated on a weekly basis. Eventually, they joined forces with the BOAC service from London to Karachi, creating a comprehensive UK-Australia air route.

Initially, the segment between Galle and Karachi relied on surface transport. However, to optimize efficiency, the Catalinas soon replaced it, flying directly from Galle to Karachi. Given the timing of westbound flights, both crews and passengers experienced the captivating sight of witnessing two sunrises during their prolonged time in the air.

Thus, the operation earned the fitting moniker of the ‘Double Sunrise.’ RAAF/Qantas crews would swap planes in Galle, ensuring seamless transitions and minimizing the overall journey length for passengers.

The Catalinas chosen for the Double Sunrise operation were originally ordered by the UK Air Ministry for use by the Royal Air Force. During the war, RAF Catalina squadrons were deployed in various roles, including aerial surveillance, search and rescue, and reconnaissance missions.

With their distinctive design, characterized by spacious wings capable of carrying large fuel volumes, Catalinas were the perfect aircraft for long-haul flights. Their ability to take off and land on water provided an operational flexibility that conventional aircraft did not possess.

Specialist Catalinas

To ensure maximum efficiency during their marathon journeys, the Catalinas were stripped of all non-essential equipment, including de-icing gear and insulation. As a result, their average take-off weight hovered around 35,000 lbs (16,000 kg).

The Catalinas had a maximum take-off weight of 35,400 lbs (16,100 kg), including a fuel load of up to 1,988 imperial gallons (9,040 litres). This allowed them to cover an impressive range of 3,600 nautical miles (4,100 statute miles or 6,700 km).

However, the weight of the fuel required for these lengthy oceanic flights, coupled with the flight duration itself, severely limited the payloads. On average, each flight carried a mere three passengers and approximately 159 lbs (69 kg) of essential, often sensitive, mail.

The Double Sunrise certificate.
Upon taking a flight, you’d receive a certificate.

Catalina flying boats proved to be the ideal aircraft with their extraordinary ability to remain airborne for over 24 continuous hours. These remarkable planes regularly undertook flights lasting over 27 hours between Australia and Ceylon, occasionally enduring up to 33 hours due to challenging headwinds along the route. Qantas officially named this route the ‘Kangaroo Service,’ marking the debut of their now-famous ‘Flying Kangaroo’ logo on the aircraft’s side.

Between 1943 and 1945, the Double Sunrise Catalinas completed an impressive total of 271 crossings. In 1944, Qantas bolstered the fleet with converted Consolidated Liberator bomber aircraft, further enhancing their capabilities. By 1945, both Catalinas and Liberators were eventually replaced by Avro Lancastrians.

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Following their tireless service, the five Catalinas utilized in these historic flights were retired as stipulated by the original contract with the UK Air Ministry. Their fate entailed being scrapped through scuttling, deliberately sunk beneath the waves.

Passengers fortunate enough to experience the Double Sunrise flights received a coveted certificate depicting one of the Catalinas used in these remarkable journeys. These certificates granted them membership in the exclusive ‘Secret Order of the Double Sunrise,’ signifying that they were among the select few in history to have spent more than 24 hours in continuous flight.

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