The Romantic Days of Flying the Boats
Discussing the romantic PAN-AM Flying boat days of the 1930s with JR Hafer: The concept of “Flying boats” Did not belong to Juan Trippe the Founder and CEO of Pan American Airways. However, it was he that was able to make the concept “Romantic”. History will always treat the Pan Am Flying boat as a unique experience, though flying boats had been around for a while in a utilitarian form. Tripp just made it sexy…
When we think of the Flying boats of the 1930s, we automatically think of the Romantic stories we’ve heard about the Pan Am “China Clipper” and flying to the orient on the giant Martins or the grand Skorskys so aptly named for the occasion. Even the Vacation to Argentina on the South American Pan Am Flying boat just as Romanticly marketed by Juan Tripp who was the master of the concept.
However, the flying boats were around before Pan American Airways and Juan Tripp never owned the Flying boat concept at all. But what is a flying boat you may ask…
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage called sponsons. Flying boats were some of the largest aircraft of the first half of the 20th century, superseded in size only by bombers developed during World War II. Their advantage lay in using water instead of expensive land-based runways, making them the basis for international airlines during the war period as well. They also were also commonly used for maritime patrol and air-sea rescue.
The use of Flying boats gradually decreased following World War II, , partially because of the investments in airports during the war. In the 21st century, flying boats maintain a few niche uses, such as for dropping water on forest fires, air transport around archipelagos, and access to undeveloped or rural areas without roads. Many modern seaplane variants are still used, whether they are on floats or flying boat types are converted to amphibian planes where either with landing gear or even flotation modes may still be used to land and take off anywhere needed.
Henri Fabre, a French aviator, invented and successfully flight tested a seaplane which he named Le Canard; it is acknowledged as the first seaplane in history. It was a “landmark” invention that inspired other aviators. Over the next few years, Fabre designed “Fabre floats” for several other flyers. American pioneer aviator Glenn Curtiss had built experimental floatplanes before 1910, without proceeding to flight testing. But after Fabre’s successful seaplane flights, Curtiss focused mainly on land-based aircraft. He made only small experimental models of floatplanes, and slowly improved upon his earlier work.
In 1911 Curtiss unveiled a development of his floatplane experiments married to a larger version of his successful Curtiss Model D land plane, but with a larger engine and a rudimentary hull and fuselage, designated as the Model E. The was the first air plane with a hull, and arguably the creation of the “flying boat” type that dominated long distance air travel for the next four to five decades. Consequently he soon became acquainted with others interested in both seaplane based and long range commercial aviation development two aspects which were hopelessly interrelated in those days when airports were yet to be built throughout most of the world. The design also brought him in contact with Lieutenant Commander John Cyril Porte RN, an influential British aviation pioneer.
In February 1911, the United States Navy took delivery of its very first airplane, a Curtiss Model E, and soon tested landing and take-offs from ships using the Curtiss Model D
In 1913, London’s Daily Mail newspaper put up a ₤10,000 prize for the first non-stop aerial crossing of the Atlantic which was soon “enhanced by a further sum” from the “Women’s Aerial League of
Great Britain”. American businessman Rodman Wanamaker became determined that the prize should go to an American aircraft and commissioned the Curtiss Aeroplane and Motor Company to design and build two aircraft capable of making the flight. In Great Britain in 1913, similarly, the boat building firm J. Samuel White of Cowes on the Isle of Wight set up a new aircraft division and produced a flying boat in the United Kingdom. This was displayed at the London Air Show at Olympia in 1913. In that same year, a collaboration between the S. E. Saunders boatyard of East Cowes and the Sopwith Aviation Company produced the “Bat Boat”, an aircraft with a consuta laminated hull that could operate from land or on water, which today we call amphibious aircraft. The “Bat Boat” completed several landings on sea and on land and was duly awarded the Mortimer Singer Prize. It was the first all-British aeroplane capable of making six return flights over five miles within five hours.
In America, Wanamaker’s commission built on Glen Curtiss’ previous development and experience with the Model E for the U.S. Navy and soon resulted in the Model H. The H series began as a conventional biplane design with two-bay, unstaggered wings of unequal span with two tractor (pulling, not pushing) inline engines mounted side-by-side above the fuselage in the interplane gap. Wingtip pontoons were attached directly below the lower wings near their tips. The Model H resembled Curtiss’ earlier flying boat designs, but was built considerably larger so it could carry enough fuel to cover 1,100 mi (1,800 km). The three crew members were accommodated in a fully enclosed cabin.
Trials of the Model H (christened America) began in June 1914, with Lt. Cmdr. Porte as test pilot. Testing soon revealed a serious shortcoming in the design; especially the tendency for the nose of the aircraft to try to submerge as engine power increased while taxiing on water. This phenomenon had not been encountered before, since Curtiss’ earlier designs had not used such powerful engines nor large fuel/cargo loads and so were relatively much more buoyant. In order to counteract this effect, Curtiss fitted fins to the sides of the bow to add hydrodynamic lift, but soon replaced these with sponsons, a type of underwater pontoon mounted in pairs on either side of a hull, to add more buoyancy. These sponsons (or their engineering equivalents) would remain a prominent feature of flying boat hull design in the decades to follow. With the problem resolved, preparations for the crossing resumed. While the craft was found to handle “heavily” on take-off, and required rather longer take-off distances than expected, 5 August 1914 was selected as the trans-Atlantic flight date. Porte was to pilot the America.
Curtiss and Porte’s plans were interrupted by the outbreak of World War I. Porte was recalled to service with the Royal Naval Air Service. He became commander of the Seaplane Experimental Station at Felixstowe in 1915. Impressed by the capabilities he had witnessed, Porte persuaded the Admiralty to commandeer (and later, purchase) the America and her sister from Curtiss. This was followed by an order for 12 more similar aircraft, one Model H-2 and the remaining as Model H-4’s. Four examples of the latter were actually assembled in the UK by Saunders. All of these were essentially identical to the design of the America, and indeed, were all referred to as Americas in Royal Navy service. The initial batch was followed by an order for 50 more (totalling 64 Americas overall during the war). Porte also acquired permission to modify and experiment with the Curtiss aircraft.At Felixstowe, Porte made advancements to flying boat design and developed a practical hull design with the distinctive “Felixstowe notch”. The notch could be added to Curtiss’ airframe and engine design, creating the Atlantic or Type A flying boat (as it became known in Great Britain). After that initial mass upgrade Porte modified the H4 with a new hull with improved hydrodynamic qualities. This design was later designated the Felixstowe F.1, of which only four were built, as they were deemed underpowered for arduous North Atlantic patrol conditions.
Consequently, Curtiss was asked to develop a larger flying boat, which was designated the “Large America” or Curtiss Model H8 when it became available in 1917, but when some H8s were tested at Felixstowe, they too were found to be underpowered. Porte soon upgraded the H8s with 250 HP Rolls-Royce Eagle engines and replaced the hulls with a larger Felixstowe hull variant. These became the Felixstowe F.2 and F.2a variants and saw both wide use and long service.
The innovation of the “Felixstowe notch” enabled the craft to overcome suction from the water more quickly and break free for flight much more easily. This made operating the craft far safer and more reliable.
The “notch” breakthrough would soon after evolve into a “step”, with the rear section of the lower hull sharply recessed above the forward lower hull section, and that characteristic became a feature of both flying boat hulls and seaplane floats. The resulting aircraft would be large enough to carry sufficient fuel to fly long distances and could berth alongside ships for refueling.
After several years of war development and upon getting negative reports on the H-8, Curtiss produced upscaled flying boats which by 1917 were designated as the Curtiss Model H12. Porte then designed a similar hull for the H12, designated the Felixstowe F.2a, which was greatly superior to the original Curtiss boat. This entered production and service with about 100 being completed by the end of the War. Another seventy were built later, and these were followed by two F.2c also built at Felixstowe.
In February 1917, the first prototype of the Felixstowe F.3 was flown. It was larger and heavier than the F.2, giving it greater range and heavier bomb load, but poorer agility. Approximately 100 Felixstowe F.3s were produced before the end of the war.
The Felixstowe F.5 was intended to combine the good qualities of the F.2 and F.3, with the prototype first flying in May 1918. The prototype showed superior qualities to its predecessors but, to ease production, the production version was modified to make extensive use of components from the F.3, which resulted in lower performance than the F.2A or F.5.
The Curtiss Aeroplane and Motor Company independently developed its designs into the small Model “F”, the larger Model “K” (several of which were sold to the Russian Naval Air Service), and the Model “C” for the U.S. Navy. Curtiss among others also built the Felixstowe F.5 as the Curtiss F5L, based on the final Porte hull designs and powered by American Liberty engines.
A Curtiss NC-4 became the first aircraft to fly across the Atlantic Ocean in 1919, crossing via the Azores. Of the four that made the attempt, only one completed the flight.
In 1923, the first British commercial flying boat service was introduced with flights to and from the Channel Islands. The British aviation industry was experiencing rapid growth. The Government decided that nationalization was necessary and ordered five aviation companies to merge to form the state-owned Imperial Airways of London (IAL). IAL became the international flag-carrying British airline, providing flying boat passenger and mail transport links between Britain and South Africa using aircraft such as the Short S.8 Calcutta.
In 1928, four Supermarine Southampton flying boats of the RAF Far East flight arrived in Melbourne, Australia. The flight was considered proof that flying boats had evolved to become reliable means of long distance transport.
In the 1930s, flying boats made it possible to have regular air transport between the U.S. and Europe, opening up new air travel routes to South America, Africa, and Asia. Foynes, Ireland and Botwood, Newfoundland and Labrador were the termini for many early transatlantic flights.In areas where there were no airfields for land-based aircraft, flying boats could stop at small island, river, lake or coastal stations to refuel and resupply. The Pan Am Boeing 314 “Clipper” planes brought exotic destinations like the Far East within reach of air travelers and came to represent the romance of flight.
By 1931, mail from Australia was reaching Britain in just 16 days – less than half the time taken by sea. In that year, government tenders on both sides of the world invited applications to run new passenger and mail services between the ends of Empire, and Qantas and IAL were successful with a joint bid. A company under combined ownership was then formed, Qantas Empire Airways. The new ten day service between Rose Bay, New South Wales (near Sydney) and Southampton was such a success with letter-writers that before long the volume of mail was exceeding aircraft storage space.
A solution to the problem was found by the British government, who in 1933 had requested aviation manufacturer Short Brothers to design a big new long-range monoplane for use by IAL. Partner Qantas agreed to the initiative and undertook to purchase six of the new Short S23 “C” class or “Empire” flying boats.
Delivering the mail as quickly as possible generated a lot of competition and some innovative designs. One variant of the Short Empire flying boats was the strange-looking “Maia and Mercury”. It was a four-engine floatplane “Mercury” (the winged messenger) fixed on top of “Maia”, a heavily modified Short Empire flying boat. The larger Maia took off, carrying the smaller Mercury loaded to a weight greater than it could take off with. This allowed the Mercury to carry sufficient fuel for a direct trans-Atlantic flight with the mail. Unfortunately this was of limited usefulness, and the Mercury had to be returned from America by ship. The Mercury did set a number of distance records before in-flight refueling was adopted.
Sir Alan Cobham devised a method of in-flight refueling in the 1930s. In the air, the Short Empire could be loaded with more fuel than it could take off with. Short Empire flying boats serving the trans-Atlantic crossing were refueled over Foynes with the extra fuel load they could make a direct trans-Atlantic flight. A Handley Page H.P.54 Harrow was used as the fuel tanker.
The German Dornier Do-X flying boat was noticeably different from its UK and U.S.-built counterparts. It had wing-like protrusions from the fuselage, and was called Sponson and used to stabilize it on the water without the need for wing-mounted outboard floats. This feature was pioneered by Claudius Dornier during World War I on his Dornier Rs. I giant flying boat, and perfected on the Dornier-Wal in 1924. The enormous Do X was powered by 12 engines and carried 170 persons. It flew to America in 1929, crossing the Atlantic via an indirect route. It was the largest flying boat of its time, but was severely underpowered and was limited by a very low operational ceiling. Only three were built, with a variety of different engines installed, in an attempt to overcome the lack of power. Two of these were sold to Italy.
The military value of flying boats was well-recognized, and every country bordering on water operated them in a military capacity at the outbreak of the war. They were utilized in various tasks from anti-submarine patrol to air-sea rescue and gunfire spotting for battleships. Aircraft such as the PBY Catalina, Short Sunderland, and Grumman Goose recovered downed airmen and operated as scout aircraft over the vast distances of the Pacific Theater and Atlantic. They also sank numerous submarines and found enemy ships. In May 1941 the German battleship Bismarck was discovered by a PBY Catalina flying out of Castle Archdale Flying boat base, Lower Lough Erne, Northern Ireland.
The largest flying boat of the war was the Blohm & Voss BV 238, which was also the heaviest plane to fly during World War II and the largest aircraft built and flown by any of the Axis Powers.
In November 1939, IAL was restructured into three separate companies: British European Airways, British Overseas Airways Corporation (BOAC), and British South American Airways (which merged with BOAC in 1949), with the change being made official in 1 April 1940. BOAC continued to operate flying boat services from the (slightly) safer confines of Poole Harbour during wartime, returning to Southampton in 1947.
The Martin Company produced the prototype XPB2M Mars based on their PBM Mariner patrol bomber, with flight tests between 1941 and 1943. The Mars was converted by the Navy into a transport aircraft designated the XPB2M-1R. Satisfied with the performance, 20 of the modified JRM-1 Mars were ordered. The first, named Hawaii Mars, was delivered in June 1945, but the Navy scaled back their order at the end of World War II, buying only the five aircraft which were then on the production line. The five Mars were completed, and the last delivered in 1947.
The Hughes H-4 Hercules, in development in the U.S. during the war, was even larger than the BV 238 but it did not fly until 1947. The “Spruce Goose”, as the H-4 was nicknamed, was the largest flying boat ever to fly. That short 1947 hop of the “Flying Lumberyard” was to be its last, however; it became a victim of post-war cutbacks and the disappearance of its intended mission as a transatlantic transport.
In 1944, the Royal Air Force began development of a small jet-powered flying boat that it intended to use as an air defence aircraft optimised for the Pacific, where the relatively calm sea conditions made the use of seaplanes easier. By making the aircraft jet powered, it was possible to design it with a hull rather than making it a floatplane. The Saunders-Roe SR.A/1 prototype first flew in 1947 and was relatively successful in terms of its performance and handling. However, by the end of the war, carrier based aircraft were becoming more sophisticated, and the need for the SR.A/1 evaporated.
During the Berlin Airlift (which lasted from June 1948 until August 1949) ten Sunderlands and two Hythes were used to transport goods from Finkenwerder on the Elbe near Hamburg to isolated Berlin, landing on the Havelsee beside RAF Gatow until it iced over. The Sunderlands were particularly used for transporting salt, as their airframes were already protected against corrosion from seawater. Transporting salt in standard aircraft risked rapid and severe structural corrosion in the event of a spillage. In addition, three Aquila flying boats were used during the airlift. This is the only known operational use of flying boats within central Europe.
After World War II the use of flying boats rapidly declined, though the U.S. Navy continued to operate them (notably the Martin P5M Marlin) until the early 1970s. The Navy even attempted to build a jet-powered seaplane bomber, the Martin Seamaster. Several factors contributed to the decline. The ability to land on water became less of an advantage owing to the considerable increase in the number and length of land based runways during World War II. Further, as the speed and range of land-based aircraft increased, the commercial competitiveness of flying boats diminished; their design compromised aerodynamic efficiency and speed to accomplish the feat of waterborne takeoff and landing. Competing with new civilian jet aircraft like the de Havilland Comet and Boeing 707 proved impossible. BOAC ceased flying boat services out of Southampton in November 1950.
Bucking the trend, in 1948 Aquila Airways was founded to serve destinations that were still inaccessible to land-based aircraft. This company operated Short S.25 and Short S.45 flying boats out of Southampton on routes to Madeira, Las Palmas, Lisbon, Jersey, Majorca, Marseilles, Capri, Genoa, Montreux and Santa Margharita. From 1950 to 1957, Aquila also operated a service from Southampton to Edinburgh and Glasgow. The flying boats of Aquila Airways were also chartered for one-off trips, usually to deploy troops where scheduled services did not exist or where there were political considerations. The longest charter, in 1952, was from Southampton to the Falkland Islands. In 1953 the flying boats were chartered for troop deployment trips to Freetown and Lagos and there was a special trip from Hull to Helsinki to relocate a ship’s crew. The airline ceased operations on 30 September 1958.
The technically advanced Saunders-Roe Princess first flew in 1952 and later received a certificate of airworthiness. Despite being the pinnacle of flying boat development none were sold, though Aquila Airways reportedly attempted to buy them. Of the three Princesses that were built, two never flew, and all were scrapped in 1967. In the late 1940s Saunders-Roe also produced the jet-powered SR. A-1 flying boat fighter, which did not progress beyond flying prototypes.
The shape of the Short Empire was a harbinger of the shape of later aircraft yet to come, and the type also contributed much to the designs of later ekranoplans. However, true flying boats have largely been replaced by seaplanes with floats and amphibian aircraft with wheels. The exciting to watch Beriev Be-200 twin-jet amphibious aircraft has been one of the closest “living” descendants of the earlier flying boats, along with the larger amphibious planes used for fighting forest fires. There are also several experimental amphibians like the Volmer Sportsman, Glass Goose, Airmax Sea Max, Aeroprakt A-24, and Seawind 300C.
The History and the Romance of the early days of the “flying boats” will be talked and written about for many years to come. Authors like Jamie Dodson, Captain David MClay and Those of the PanAm Association, Inc who base their stories on those days are very successful in portraying in wonderful memories in the days of yesteryear. Those were the days…