by Robert Gandt
The return voyage was less successful. With his copilot/navigator Jean Dabry and radio operator Léopold Gimie, Mermoz had been airborne for six hours when an oil leak forced him to make an open-sea landing. Still five hundred miles from Africa, Mermoz managed to set the Comte de la Vaulx down beside the Aéropostale weather ship, Phocée. Mermoz, his crew, and the mail were saved. The Comte de la Vaulx, damaged by the rough seas, was lost in the Atlantic.
The adventure convinced Aéropostale and the French Air Ministry that single-engined aircraft were inappropriate for South Atlantic operations. A requirement was issued for a transoceanic mail plane that could carry a 1,000-kilogram (2,304 pounds) payload between Dakar and Natal. Orders were placed for one model each of two advanced flying boats, the Latécoère 300 and the Blériot Model 1590. Thus was launched a decade of ambitious French flying boat development.1
The Laté 300 was a handsome craft, her long and slender hull fitted with Dornier-style sea wings and the large parasol wing-mounted on W struts above the fuselage. In appearance she bore a close resemblance to her two-engined Latécoère predecessors, the Laté 32 of 1927, and the Laté 38 that appeared in 1931.
The Laté 300 was powered by four Hispano-Suiza twelve-cylinder, water-cooled engines of 650 horsepower each, mounted in tandem configuration atop the wing’s center section. Each engine turned a fixed-pitch, three-bladed metal propeller. The trailing edge of the center section was recessed to permit clearance for the aft propellers.
In overall dimensions, the Laté 300 was comparable to the Martin M-130, though she preceded the American craft by nearly four years. Her large, low-aspect-ratio wing yielded a loading, at a maximum gross weight of 50,706 pounds, of 15.9 pounds per square foot of wing area, a kitelike statistic that contributed to her unimpressive cruise speed of only ninety-nine miles per hour. But in terms of efficiency, the French boat was constructed with disciplined use of weight. Her empty weight of 25,000 pounds afforded a fuel capacity of nearly 23,000 pounds and a mail load (as specified in her design requirements) of 2,204 pounds.2 These were impressive statistics for 1931 and placed the Laté 300 in a class shared by few transport aircraft of the day.
Though the prototype first flew in 1931, the aircraft sank after a takeoff accident, disrupting the project’s timetable. Not until October 1932 was the reconstructed and modified flying boat again flown. On 31 December 1933, bearing her new name Croix du Sud, she took off from Etang de Berre, near Marseille, and established a world’s record by flying to St. Louis, Senegal, on Africa’s west coast, a distance of 2,285 miles, in just under twenty-four hours. Two days later she made her first ocean voyage, crossing the South Atlantic to Natal, then continuing southward to Rio.
The success of the Croix du Sud prompted orders for three production aircraft, designated the Laté 301, for Air France, and another three, the Laté 302, for the French Navy. These aircraft differed only slightly from the original, their tail surfaces being enlarged and a greater dihedral added to the wings.
Air France’s Laté 301s took the names, Ville de Buenos Aires, Ville de Rio de Janeiro, and Ville de Santiago de Chile. By January 1936 all three had been delivered. A month later, the Ville de Buenos Aires was lost on the Dakar-Natal route. The other two Laté 301s continued in service until the occupation, as did the French Navy’s Laté 302s.
Aéropostale, in the meantime, had suffered financial straits. After an ongoing public scandal involving the company’s directors, the airline sank into bankruptcy. On 30 August 1933 a unified French airline, Air France, was formed from the assets and operations of five independent French airlines, including Compagnie Aéropostale.3
Air France’s most famous pilot was Jean Mermoz, who had become a French equivalent of America’s Lindbergh. He was a charismatic figure, a war hero and pioneering airmail pilot whose life had been a continuous tale of adventure. He had survived capture by Moors after a forced landing in the Moroccan desert. In South America, he had once been forced to land his mail plane atop a twelve-thousand-foot-high mountain mesa. Realizing that he would have to be his own rescuer, Mermoz and his mechanic finally rolled their damaged airplane, themselves in it, off the sheer precipice of the mountain, gathering airspeed as the airplane dropped, and flew to safety.
It was Mermoz who had made the initial pioneering transatlantic flight in the Comte de la Vaulx—and the ocean ditching on the return flight. It was Mermoz, again, in January 1933 who flew the Couzinet 71 land plane, Arc-en-Ciel, nonstop to South America (an event that foreshadowed the coming demise of the transoceanic flying boat).
On 7 December 1936 Mermoz and his crew of four took off from Natal, bound for West Africa, in the Croix du Sud. It was the twenty-third Atlantic crossing of the famous Latécoère flying boat. During the night, a message was transmitted from the Croix du Sud: “Coupons moteur arrière droit. . .” (“Shutting down the right rear engine. . .”). And then silence. Despite an intensive search, no trace of Mermoz or the Croix du Sud was ever found.
The loss of Mermoz was a heavy blow. “We were haunted for hours by this vision of a plane in distress,” wrote Antoine de Saint-Exupéry. “But the hands of the clock were going round and little by little it began to grow late. Slowly the truth was borne in upon us that our comrades would never return, that they were sleeping in that South Atlantic whose skies they had so often ploughed. Mermoz had done his job and slipped away to rest. . .”4
Also designed to meet the French Air Ministry’s requirement for a South Atlantic mail transport was the Blériot 5190 Santos Dumont. Because of financial troubles at the Blériot-Aéronautique company, this aircraft did not make her maiden flight until August 1933. By the middle of 1934 her test series had been completed, and on 27 November 1934 the Santos Dumont made her first Dakar-to-Natal flight.
The one-of-a-kind Blériot flying boat, though nearly equal in size to the Laté 300 and powered by the same engines, lacked the range and load capacity of the Latécoère boat. She was a metal-hulled aircraft, with the wing mounted on a turret-like cabane that housed the pilots’ cockpit and the engineer’s station. She had outrigger floats, which were attached to the hull by horizontal struts and to the wing by diagonal braces. Two of her four Hispano-Suiza, twelve-cylinder, 650-horsepower engines were mounted in tandem on the aircraft’s centerline, and the other two were installed on either side in the wing’s leading edge. Each engine drove a three-bladed, adjustable-pitch propeller and was accessible to the flight engineer while in flight.
The Santos Dumont was a large aircraft for her time. Her wings spanned 141 feet, and her fuselage was over eighty-five feet long. At her maximum gross weight of 48,502 pounds she could carry nearly 19,000 pounds of fuel with a payload of 1,322 pounds. With a wing loading of 20.3 pounds per square foot and the advantage of controllable-pitch propellers, she cruised at a respectable 118 miles per hour over a distance of 2,000 miles.
Though it was contemplated that on the Mediterranean routes she could carry up to forty passengers, she remained in service on the Atlantic. During her career, the Santos Dumont completed thirty successful Atlantic crossings.5
A medium-range flying boat, designed for service in the Mediterranean, the prototype Lioré et Olivier H 242 appeared in 1933 and was certificated in early 1934. Air France put this four-engined flying boat to work, staging from Marseille to Athens, Algiers, Ajaccio, Tunis, Tripoli, and Beirut.
The LeO H 242 was a high-winged monoplane with four 350-horsepower Gnome Rhone Titan radial engines mounted in tandem pairs and braced by an ungainly arrangement of N struts atop the wing’s center section. In the original configuration, the air-cooled Gnome engines, both front and rear, were uncowled. Twelve models of the H 242-1 then followed, and these had circular nacelles, an increased maximum gross weight, and a slightly greater speed.
The H 242’s wings were wooden with ply covering, attached to a single-step, V-bottomed, duralumin hull. In her bow were the usual mooring compartment, a traditional two-pilot cockpit, and radio and navigation compartm
ents. Her main cabin accommodated ten to fifteen passengers and was equipped with a lavatory and separate baggage hold.
With her blunt features and plethora of struts and braces, the H 242 was an aerodynamic ox. At best, she plowed through the sky at a stately cruise speed of 111 miles per hour. The H 242-1’s maximum weight of 19,180 pounds provided a respectable disposable load of 7,357 pounds, and her 3,714-pound fuel capacity allowed a still-air range of 633 miles.
Except for the loss of two aircraft in operational accidents, all the H 242s stayed in service on the Mediterranean until the German occupation brought an end to their commercial careers.6
The Blériot and Latécoère boats, for all their range and advanced technology, were courier craft. They were the world’s first transoceanic aircraft, but their function was limited to the transport of mail. As early as 1930, however, Latécoère had begun work on a large, passenger-carrying, transatlantic flying boat, designated the Laté 520. This giant craft was to be powered by four of the yet-unbuilt Hispano-Suiza 1,000-horsepower engines. With these power plants, the flying boat would have a maximum gross weight of 67,000 pounds—a statistic placing it in the behemoth class for 1930. When Hispano-Suiza peremptorily shelved their plans for the powerful new engine, Latécoère was then compelled to redesign the aircraft, using six of the available Hispano-Suiza 800/860-horsepower engines. This modified version was given the designation Laté 521.
At Etang de Biscarosse, near Bordeaux, the Laté 521 made her first flight on 17 January 1935. She had been designed to carry thirty passengers on transatlantic routes. On the shorter Mediterranean segments, she could be configured for as many as seventy. On her bow was the name: Lieutenant de Vaisseau Paris. Her aft fuselage bore the inscription 37 Tonnes (81,571 pounds).
Glenn Hammond Curtiss, “father of the flying boat.” (Smithsonian)
The Curtiss America on the day of her maiden flight. (Smithsonian)
The U.S. Navy’s NC-4, first airplane to cross the Atlantic. (Smithsonian)
Cy Caldwell and the Fairchild FC-2, La Niña. Caldwell flew Pan American’s first scheduled mail flight from Key West to Havana. (Pan American)
Ensign Juan Terry Trippe, who would later head Pan American. He was designated Naval Aviator Number 1806. (Pan American)
The graceful Consolidated Commodore was the flagship of the New York, Rio & Buenos Aires Line. (General Dynamics)
Though Ralph O’Neill’s dream of an international airline came true, his creation, NYRBA, was gobbled up by Pan American. (Smithsonian)
The little two-engined workhorse, the S-38, firmly established the Sikorsky company in the aviation business. (Pan American)
Igor Sikorsky with a model of the S-43 amphibian. (Smithsonian)
Dornier’s sturdy little Wal, like Sikorsky’s S-38, found employment around the world. (Dornier GMBH)
Professor Dr. Claude Dornier, German builder of a generation of advanced flying boats. (Dornier GMBH)
Dornier’s four-engined Super Wal entered the service of Lufthansa in 1928 on the Germany-to-Scandinavia routes. (Lufthansa)
The three-engined Rohrbach Romar, a medium-range boat operated by Lufthansa on Baltic services. Adolf Rohrbach, like Claude Dornier, pioneered the use of metal structures for flying boats. (Lufthansa)
The Dornier Do X, the world’s largest airplane when it was constructed in 1929, was intended to carry a hundred passengers in ocean-liner comfort over the Atlantic. (Lufthansa)
The Do X configured with its original power plants, twelve 500-horsepower Siemens air-cooled engines. These were soon replaced with the more powerful Curtiss Conqueror water-cooled engines. (Dornier GMBH)
Despite its great size and complexity, the Do X’s cockpit was ascetically equipped even by 1929 standards. (Dornier GMBH)
The Do X under construction at Altenrhein, on the Swiss shore of the Bodensee. (Dornier GMBH)
The Sikorsky S-40 was the forerunner of a generation of American-built, four-engined, long-range flying boats. (United Technologies Corporation)
Andre Priester, Pan American’s chief engineer, oversaw every aspect of the airline’s operations. (Pan American)
Because of its plethora of wires and braces, the S-40 was dubbed by Lindbergh the “flying forest.” (United Technologies Corporation)
Pan American chief pilot Edwin Musick shunned the publicity that attended his record-breaking flights. Despite his reticence, he became the most famous airline pilot in the United States. (Clyde Sunderland)
When it appeared in 1934, the Sikorsky S-42 set new standards for over-ocean airliners. (Pan American)
Sikorsky S-42 in foreground with her older sister ships, a pair of S-40s, all on beaching gear. (Pan American)
The Shorts S.23 was designed to fulfill the ambitious requirements of the Empire Mail Scheme, but it lacked the range to be a transatlantic airliner. (British Airways)
Imperial Airways’ fleet of elegant Empire-class boats carried the Union Jack to the outposts of the empire. (Smithsonian)
The first of the Empire-class boats, Canopus, in 1936. (British Airways)
Imperial Airways timetable. (Smithsonian)
Latécoère 300 Croix du Sud. (Musée de l’Air)
Latécoère 521 Lieutenant de Vaisseau Paris. (Musée de l’Air)
Jean Mermoz, pioneer airmail pilot and French national hero. In December 1936 he and his crew vanished in the South Atlantic with the Croix du Sud. (Musée de l’Air)
Antoine de Saint-Exupéry, writer and pioneer airmail pilot. (Museé de l’Air)
Lioré et Olivier 242. (Musée de l’Air)
Didier Daurat, legendary operations boss of the pioneering French airline, Aéropostale. Daurat was the model for Rivière in Antoine de Saint-Exupéry’s novel, Night Flight. (Musée de l’Air)
Blériot 5190 Santos Dumont. (Musée de l’Air)
The Latécoère 631 was the largest passenger-carrying flying boat ever to enter commercial service. (Musée de l’Air)
Glenn Martin’s mother, “Minta,” was his lifelong companion and only confidante. (Smithsonian)
Transpacific inaugural of the China Clipper 22 November 1935 in Alameda, California. (Pan American)
Postmaster James Farley and Juan Trippe during the China Clipper transpacific inaugural, 22 November 1935. Because mail subsidies provided the incentive for the Pacific route development, cynics called the Martin boat the “Taxpayer Clipper.” (Pan American)
During the takeoff for the transpacific inaugural flight, Ed Musick changed the script. At the last instant, he chose to fly beneath the spans of the still-unfinished Bay Bridge. (Pan American)
The China Clipper over the unfinished Golden Gate Bridge, 1935. (Pan American)
The Manila Tribune heralds the inaugural voyage of the China Clipper. (Pan American)
The China Clipper being serviced. The cowling flaps were an innovation to cope with the heating problems of the R-1830 engines. (Pan American)
The China Clipper’s second passenger compartment, aft of the main lounge. (Pan American)
Cockpit of China Clipper. Ed Musick sits on the left. Only in publicity photos did pilots wear their uniform caps in the cockpit. (Pan American)
Glenn L. Martin, builder of the China Clipper, remained a devotee of the flying boat until long after the era had ended. (Smithsonian)
The M-156 Russian Clipper. After Pan American declined to order derivatives of the M-130, Glenn Martin sold this only China Clipper variant to the Soviet Union where it entered the service of Aeroflot in the Far East. (Martin Marietta)
The Mercury-Maia composite was one of several schemes to provide Imperial Airways a transatlantic capability. (British Airways)
Mercury separating from Maia. (British Airways)
The G-class S.26 Golden Hind. The G-class boats were ordered for Imperial Airways’ North Atlantic service. (British Airways)
The Dornier Do 26 Seeadler (Sea Eagle) was a fast, long-range, four-engined courier plane. It transported mail over the North and South A
tlantic, landing and launching from depot ships in mid-ocean. (Smithsonian)
Refueled and serviced, the Do 26 Seeadler is catapulted from the depot ship Friesenland. (Dornier GMBH)
Weighing over 100,000 pounds at takeoff, the six-engined BV 222 Wiking would have been one of the most impressive commercial aircraft in the world. Though designed in 1936 as a North Atlantic airliner for Lufthansa, the big boat did not fly until 1940. All fourteen models went to war as supply and reconnaissance aircraft. (Lufthansa)
The last of the Sikorsky flying boats, the VS-44A Excambian of American Export Airlines, 1942. (F. L. Wallace)
Only three models of the VS-44A were constructed. All were delivered to American Export Airlines. (United Technologies Corporation)
Cutaway of 314 in its original single-finned configuration. (Pan American)
A dual-finned 314 “on the step.” This model, like the single-finned version, had directional stability problems. All were eventually configured with three vertical stabilizers. (Pan American)