The River Airport in Lisbon

The River Airport in Lisbon

This year marks the centenary of the first flight from Lisbon to Rio de Janeiro, and it is appropriate also to remember the crucial part played by Portugal in the communications between Europe and America during the Second World War.

The first flight in Portugal had taken place over Lisbon’s river in 1912, when Alberto Sanches de Castro took off from Mouchão da Póvoa in the estuary of the River Tejo.

Before Duarte Pacheco founded the airport at Portela in Lisbon in 1942, there was already another airport in the city. It was located on the river itself. In 1938, the Salazar government had decided to create an air terminus for flights from the United States, since Lisbon was in the perfect geographic position for an air connection. The coming war turned this new terminus into the start of the air bridge over the Atlantic for the many rich people fleeing from German aggression.

At a time when mechanical failures were common, it was thought that seaplanes or flying boats were the safest means of crossing the oceans. In the case of mechanical failure, these machines could alight on the surface of the ocean. Although there had been a military and civil airfield (the Campo Internacional de Aterragem) at Alverca, 15km to the north of Lisbon, since 1918, the authorities wanted a river terminus, and wanted this terminus closer to the city centre.

The River Airport in Lisbon
Diagram of the interior accommodation

The government’s airline business partner Pan American had a monopoly of transatlantic flights, and also wanted the terminus to be closer to the city.  There was a study for an airport and river port not too far from each other, and the choice was for an airport at Portela (now Humberto Delgado airport in Lisbon) and a river port only 3km away at Cabo Ruivo, where the Lisbon Oceanarium now stands. The two termini were connected by the Avenida Entre Aeroportos, nowadays Avenida de Berlim.

The Aeroporto Marítimo de Cabo Ruivo opened in 1938. The flights from America alighted on the river among the fishing boats, and passengers disembarked and passed through the customs post before making their way by road to Portela, where they could take a connecting flight to another European destination. The Avenida Entre Aeroportos was a hotbed of spies during the first years of the war, as agents struggled to identify the incoming and outgoing passengers and the river became the runway to safety for thousands.

The River Airport in Lisbon
The Short Sunderland Flying Boat – Photo RuthAS

In May of 1939, Pan Am inaugurated the regular air service between the US and Europe, using the brand-new Boeing B-314 Flying Boat. Although these huge aeroplanes were able to cover 3,500 miles in one stage, that range was not considered adequate for a non-stop crossing of the Atlantic.

Pan Am management had had their eye on the Azores ever since Charles Lindbergh’s first solo crossing in 1927, and they surveyed the islands for the most appropriate and protected area to serve as a staging post for the transatlantic service.

As the agent of Pan Am, Lindbergh considered and discarded Ponta Delgada because it was not protected enough, and preferred Horta on the island of Faial, where the harbour was relatively protected from Atlantic swell and strong currents.

The River Airport in Lisbon
BOAC Clipper Berwick alighting

For these huge aircraft, alighting was less of a problem than taking off since, on touching the sea, the aircraft rapidly lost speed. When taking off, on the other hand, a high swell buffeted the aircraft as it gathered speed, and the airframe was not strong enough to withstand the repeated shocks.

Accidents on the river

A major accident at Cabo Ruivo occurred on January 9, 1943, when a British Short Sunderland flying boat (named ‘Golden Horn’) on a test flight experienced a fuel leak, exploded and fell into the river. Of the 15 people on board, 13 died. Many were employees at the airport who had taken the rare opportunity to take a joyride on the short flight over the Mar da Palha (the Straw Sea, the widest part of the river).

The tugboat ‘Cabo Sardão’ successfully pulled three people from the freezing water, one being the radio operator, and two Portuguese, one of who died of hypothermia on his way to hospital. The wreckage of the aircraft washed ashore on the riverbank from Xabregas right down to Cascais.

The River Airport in Lisbon
Yankee Clipper in 1939

Because it was against the rules (both British and Portuguese regulations) to take non-essential personnel on a test flight, the dead aircraft captain was held to blame. The crash highlighted the fact of an RAF aeroplane operating at Lisbon in 1943, and this event was an embarrassment to the nominally neutral Portugal.

Just six weeks later, the Yankee Clipper, on its arrival from the States, somehow managed to hit the water with its wing and cartwheeled into the river. The aircraft smashed itself to smithereens, and 24 of the 39 passengers and crew did not survive.

The flight had arrived over Cabo Ruivo at about 18:35 GMT (6.35pm Lisbon time), three hours and 52 minutes after take-off from Horta and 15 minutes ahead of its estimated arrival time. Since official sunset was at 18:20, Pan Am’s ground crew at Lisbon had set out, as usual, a string of landing lights.

The River Airport in Lisbon
Plan of Aeroporto Marítimo de Lisboa – Cabo Ruivo

At the time the flight arrived in the area, it was still light enough for the aircraft to be observed plainly from the Pan Am launch and from the shore.  The aircraft made a descending turn to the left which continued until it was headed in a westerly direction when the left-wing tip skimmed along the surface of the water, dug in and the plane crashed into the river. It remained partially submerged for about 10 minutes, before disappearing below the surface of the water.

The Pan Am launch, which had been standing by for the landing, rushed to the scene of the accident, arriving some 10 minutes later, and began rescue operations, and was soon joined by the British BOAC launch and another Pan Am launch. The actress Tamara Drasin and the novelist Ben Robertson, both American, were killed in the crash and the actress Jane Froman was seriously injured.

The Boeing Clipper

The Boeing Clipper inaugurated the world’s first transatlantic heavier-than-air service and carried passengers and cargo around the globe in the late 1930s and 1940s. Early in 1936, Pan American had sought proposals for the next generation of airliners for Atlantic service, and to stimulate interest among aircraft manufacturers, the company had offered a $50,000 cash prize for the winning design.

The winner of Pan Am’s competition was the Boeing Aircraft Company of Seattle, Washington, which had been initially reluctant even to submit a proposal. But under the leadership of a relatively young engineer, Boeing eventually constructed an aircraft widely recognised as the zenith of flying boat design and technology.

The River Airport in Lisbon
B-314 taking off

On July 31, 1936, Pan Am signed a contract for six of the Boeing 314 clippers, with an option for six more. The B-314 was large, luxurious, and reliable and with an astounding range of 3,500 statute miles, it made intercontinental passenger airline service a practical reality.

Although the B-314 was able to carry 74 passengers and 10 crew, in its overnight sleeper configuration the aircraft accommodated 40 passengers in seven luxurious compartments, including a 14-seat dining room and a private “honeymoon suite” at the tail end of the plane.

A giant aircraft for its day, the B-314 weighed over 40 tons and had a wingspan three quarters that of a Boeing 747. It had a maximum speed of 199 mph, and a cruising speed of 183 mph, and a range of 3,500 miles, while the subsequent B-314A had a range of 5,200 miles.

Among the technical innovations pioneered by the B-314 were the fully-feathering propellers which also allowed mechanics to take advantage of the B-314’s unparalleled in-flight engine access made possible by the wing’s thick chord. The wing was thick enough to allow access through a walkway to the engines, where the fully-feathering propellors made it possible for a mechanic to perform repairs in flight. In the two years between June 1939 and June 1941, B-314 engineers performed 431 in-flight engine repairs.

The River Airport in Lisbon
Issue nº1 of The Horta Swell

Over the course of their careers, the B-314’s operated by Pan American made approximately 5,000 ocean crossings and flew more than 12.5 million miles, and each of Pan Am’s Boeing clippers accumulated more than 18,000 flight hours.

During World War II alone, B-314s carried more than 84,000 passengers, almost all of whom were on journeys of importance to the war effort.

Boeing built 12 Clippers in total, nine to be operated by Pan Am (B-314 – Honolulu, California, Yankee, Atlantic, Dixie, American; B-314A Pacific, Anzac and Cape Town) and three by BOAC (B-314A – Bristol, Berwick and Bangor).  The B-314 entered service in 1939, and its variant B-314A in 1941. These aircraft were called Clippers as a link with the speedy cargo ships of the past.  As the range of aircraft increased after the war, it was no longer necessary to use flying boat technology, and the era of passenger-carrying seaplanes came to an end in 1950. And the Aeroporto Marítimo at Cabo Ruivo also closed in the same year.

Christmas in Faial

On December 23, 1939, two of the transatlantic Clippers were stranded at Faial. The local paper reported that the two aircraft (Atlantic Clipper and Dixie Clipper) had arrived and were refuelling preparatory to departing again for New York. But the surface swell was too high to allow take-off.

Everyone disembarked, and Horta suddenly played host to more than 50 foreigners, crew included. The passengers were all VIP, since only the very rich could afford aircraft ticket prices, and the people of Horta made their unexpected guests very welcome for their Christmas.

Three of the passengers decided to run a newsletter describing their predicament. Entitled ‘The Horta Swell’, six editions of this newsletter were printed by the press of the local newspaper, O Telégrafo, and it ran from December 30 until the aircraft were able to leave on January 7, 1940, after sixteen days of enforced inactivity.

Winston Churchill and Franklin Roosevelt

The three Boeing B-314A aircraft joined BOAC in 1941 and remained in service until 1948. One of them, the Berwick, was used in January 1942 to ferry Prime Minister Winston Churchill together with Lord Beaverbrook, Minister for Aircraft Production, from the United States back to Britain.

They had been on an extended visit to Washington following the Japanese attack on Pearl Harbor.

Churchill thus became the first head of government to make a transatlantic crossing by air. A year later, Franklin D. Roosevelt flew the Atlantic in Dixie Clipper in order to attend the Casablanca Conference in Morocco, and he became the first President of the United States to make a transatlantic flight.

By Lynne & Peter Booker
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Lynne Booker, along with her husband Peter, founded the Algarve History Association. [email protected]