Flying boats opened up travel destinations around the world—then they went to war.
Twilight glimmered in the western sky as the large aircraft began its descent to the Tagus River in Lisbon, Portugal. As it flew into view, the shores erupted in a cacophony of cheers, gun blasts, and tolling church bells. The euphoria reached a crescendo when the unusual craft finally landed on the water and glided to a stop. Genuine Crusher
On that lovely evening—May 27, 1919—an ambitious and daring feat had been achieved. The U.S. Navy’s Curtiss NC-4, a massive “flying boat” crafted by pioneering designer Glenn Curtiss, became the first airplane to cross the Atlantic Ocean, making a stop in the Azores before setting down in the river on the European continent.
“We are safely across the pond. The job is finished!” wrote Lieutenant Commander Albert C. Read, captain of the historic flight, in a message to his superior officers.
Engineers tinker with two of the four Liberty 12 engines that powered the Curtiss NC-4.
Front page headlines dominated newspapers across the United States and around the world. “Twentieth century transportation has reached a new pinnacle, and the United States navy has led the way,” raved the Associated Press.
The Curtiss NC-4—in the collection of the National Air and Space Museum and on loan to the National Naval Aviation Museum in Pensacola, Florida—led the way for the era of the flying boat. At the time, the lack of airports with hard surfaces in the world’s major destinations meant overseas service had to be handled by airplanes that could land on water.
“Before World War II, a lot of the airlines were using seaplanes,” says amphibious aviation aficionado Lawrence Reece. “You didn’t have airport infrastructure, so it just made more sense. If you can land on the water, then you have the largest runway in the world.”
Originally built as a long-range antisubmarine warfare aircraft, the NC-4 could fly as far as 1,470 miles.
The flying boat—so named because the bottom of the fuselage looks like the keel of a waterborne vessel—dominated the prewar era of transoceanic flight. From the United States to South America, Europe, Pacific Islands, Asia, and beyond, this class of airplane went where others could not. It had the range, capacity, and ability to reach faraway, exotic locales that were inaccessible to most other aircraft of the day. The world’s militaries likewise embraced the adaptable aircraft, using it to patrol the world’s oceans and rescue downed fliers.
Then, flying boats all but disappeared. Larger land-based aircraft capable of carrying more passengers and cargo replaced it and transformed the way the world traveled.
Now it seems the flying boat is on the verge of a comeback, as countries seek them for missions as diverse as fighting fires to ferrying tourists to remote islands. Flying boat enthusiasts worldwide dare to wonder if they will see the magnificent machines soar and sail once again.
At its zenith, traveling on a commercial flying boat was like sailing on the Queen Mary 2. Private sleeping rooms, silver dining service, chef-prepared meals, and white-gloved waiters were all part of the upscale treatment passengers could expect on these ocean liners of the sky.
The cost? In 1940, a one-way ticket from San Francisco to Hong Kong was $760—about $15,000 today. The main advantage? The trip took days by flying boat versus weeks by passenger ship.
The aerial luxury afforded by flying boats was best epitomized by Pan American Airways. In a symbolic nod to the majestic sailing ships that plied the oceans in the 19th century, the airline’s flying boats were named “Clippers” by the company’s cofounder. The comparison did not stop there.
“That was exactly what Juan Trippe, the founder of Pan Am wanted,” says Bob van der Linden, a National Air and Space Museum curator who specializes in air transportation and special purpose aircraft. “He knew his customers were the equivalent of first-class passengers onboard a high-end steamship. They expected the best service with stewards and pursers. The airplane was operated by a captain and navigator, terms that came from the navy. If you look at the old Pan Am uniform, it’s the same as a U.S. Navy uniform, including rank insignia. They were trying to emulate ocean liners.”
In the 1920s and ’30s, flying boats came in a multitude of shapes and sizes—from small craft holding just a few people to massive airplanes with room for scores of travelers. In addition, airmail delivery was an essential part of commercial aviation at the time. Lucrative postal contracts from the federal government helped airlines reach profitability at a critical time of development while expanding routes across the Caribbean, South America, and the rest of the world.
Flying boats are a unique style of vessel. Whereas a floatplane is basically a regular airplane mounted on pontoons, the flying boat is essentially a hybrid between a ship and an airplane. It features durable wings capable of withstanding strong winds and rough seas, as well as a sturdy hull—usually V-shaped like a boat—so it can withstand the rigors of landing on choppy waves. Designing such an unusual craft required a precise balance between two very different disciplines.
“A flying boat must satisfy many of the same requirements for performance, efficiency, strength, and reliability as a landplane but, in addition, must possess some qualities of a boat in water and some qualities unique to the flying boat itself,” wrote the late Laurence K. Loftin Jr., former director of aeronautical research at NASA Langley, in his 1985 book Quest for Performance: The Evolution of Modern Aircraft. “It must be seaworthy, maneuverable, and stable on the water and have low water and air drag. The hull must be designed with sufficient structural strength to withstand the various loads imposed by rough water in landing, taking off, and taxiing.”
In other words, a flying boat had to be sleek and rugged. Finding the proper parity between these two opposite fields of performance was crucial if a proposed design was to be successful. A miscalculation in either area could have disastrous results. Such were the challenges faced by Pan Am as it prepared to launch transoceanic service.
A postcard depicts Pan American’s route maps. Prior to World War II, flying boats had the range and ability to reach faraway, exotic locales that were inaccessible to most other airplanes of the day.
For Trippe and Charles Lindbergh, a key advisor, size was important. They wanted aircraft large enough and tough enough to handle the demands of flying over long expanses of ocean and through fluctuating weather conditions. Aeronautical engineers responded with some of the largest aircraft built in those years.
“If you’re going to fly over water, you had to do it in a flying boat in case something happens,” says van der Linden. “Also, for that kind of range you need a big airplane, which meant they needed a lot of power and a lot of fuel. You needed a really, really long takeoff run to get the airplane airborne. In those days, there were no airfields long enough to do it. Plus, they were mostly grass and dirt then, and a heavy airplane would go right through that.”
One of the earliest large models was the Sikorsky S-40—the first to get the nautical treatment by Pan Am. Known as the American Clipper, it had a wingspan of 114 feet, a gross weight of 34,000 pounds, and it could carry up to 38 passengers. The largest airplane built in the U.S. at the time, the S-40 required four powerful Pratt & Whitney Hornet radial engines to break free of the water’s drag and reach the sky. It made its first flight to the Caribbean on November 19, 1931.
Pan Am and other airlines would go on to bigger and heavier flying boats. Pan Am opened transpacific service in 1935 with the Martin M-130 (one of which was christened the China Clipper) and began transatlantic service in 1939 with the Boeing B-314, which had a wingspan of 152 feet and a gross weight of 84,000 pounds.
The dining salon of a Pan American Boeing 314—circa 1940—was part of the luxury experience passengers could expect while flying with the airline.
With a range of 3,500 miles, the B-314 could reach Europe without refueling, and it could span the Pacific with a just few stops at islands along the way. In fact, Pan Am’s Pacific Clipper (which was briefly named the California Clipper) is considered the first commercial airliner to circumnavigate the globe. Stranded in New Zealand on December 7, 1941, the crew was forced to fly west across Asia and Africa to New York City to avoid capture by Japanese forces.
“What’s important about the flying boat is that it had range,” says van der Linden. “In the 1930s, land-based airliners could fly 400 to 600 miles, if you’re lucky. The big flying boats could go 3,000 miles or more. In the Pacific, you needed to fly a minimum of 2,400 miles, which is the distance between San Francisco and Hawaii.”
The JRS-1, the military version of the Sikorsky S-43, was in service from 1937 to 1944.
As the world wound its way to war in the 1930s, militaries in many countries turned to the flying boat to meet the aviation demands of an impending two-ocean conflict. All nations with access to the sea utilized these aircraft in wartime operations. Among Axis aircraft, Germany’s Blohm & Voss BV 138 Sea Dragon was a primary long-range maritime patrol aircraft, while Japan flew the Kawanishi H8K for naval reconnaissance and bombing missions.
The island realm of Great Britain relied on the Short S.25 Sunderland for its patrol bomber needs and it served with several Commonwealth military branches. Powered by four Bristol Pegasus XVIII nine-cylinder engines, the aircraft bristled with up to 12 machine guns and could carry 2,000 pounds of bombs, mines, or depth charges for anti-submarine warfare.
The National Air and Space Museum acquired one of the JRS-1s that survived Japan’s attack on Pearl Harbor.
Flying boats were part of the U.S. war effort from the very beginning. Ten Sikorsky JRS-1 aircraft were at Pearl Harbor when the Imperial Japanese Navy attacked. All of them survived. They were immediately pressed into service and flew many missions patrolling for Japanese submarines and searching for the enemy fleet. (One of the surviving JRS-1s is on display at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Virginia.)
Perhaps the most iconic flying boat of World War II was the Consolidated PBY Catalina (see “Bombs, Beer, and Black Cats”). Affectionately called “Dumbo” by those who flew it because of its resemblance to Disney’s animated flying elephant, the large two-engine aircraft was not very nimble, but it was extremely durable and versatile. It played a crucial role for the U.S. Navy in the Atlantic and Pacific theaters as both a bomber and a search-and-rescue aircraft. The Catalina also performed reconnaissance missions.
“The PBY was in the vanguard of the fight across the Pacific,” says W. Hill Goodspeed, an author and historian for the National Naval Aviation Museum, which has two Catalinas on display—one of which has been on loan from the Smithsonian since 1973. “It was the eyes of the fleet in World War II.”
A sky-high view proved decisive in 1942, when two
spotted the Imperial Japanese Navy fleet just prior to the Battle of Midway. Early detection provided the U.S. Navy with a significant edge in that pivotal showdown early in the war.
With more than 3,300 units built, the PBY was the leading flying boat of World War II. It was also the most effective. Catalinas destroyed upward of 40 enemy submarines and sank more ships than any other aircraft.
Other flying boats served the U.S. military during the conflict, including the Martin PBM Mariner. By 1945, it was flying more missions than the PBY Catalina. Of the 1,366 constructed, only one remains today: It is part of the collection of the National Air and Space Museum, and currently on loan to the Pima Air & Space Museum in Tucson, Arizona.
While World War II demonstrated the capabilities of flying boats, it also led to their decline. “The one thing that was holding back the development of all large airplanes in the 1930s was the lack of concrete runways,” says van der Linden. “All bets were off in World War II. We built concrete runways everywhere for the war effort. That killed the flying boat.”
A Grumman HU-16B Albatross (foreground) is accompanied by two HU-16Cs over Lake Conroe in Texas. The Albatross was designed to meet a U.S. Navy requirement for an amphibious utility aircraft that could also operate from snow and ice with skis. In 1955, Grumman developed an improved variant (16B) with a 16.5-foot increase in wingspan and larger aileron and tail surfaces. A Navy version, the 16C, operated as a search-and-rescue aircraft.
Still, some flying boats continued military service. The Grumman HU-16 Albatross, which was first manufactured in 1949, was deployed to Vietnam for search-and-rescue missions during the war. Legendary singer-songwriter Jimmy Buffett owned a decommissioned model, known as the Hemisphere Dancer. Buffet’s airplane became famous in 1996 when it was shot at by Jamaican police, who mistakenly believed it was smuggling drugs. Buffet, who was the pilot that day, recounted the event in the song “Jamaica Mistaica.”
The ShinMaywa US-2 is a search-and-rescue aircraft developed on behalf of the Japanese Maritime Self-Defense Force.
Some countries continued to manufacture flying boats although in limited numbers for very specific functions, including the ShinMaywa US-2, used for search and rescue by the Japan Maritime Self-Defense Force, and the DHC-515 Firefighter, manufactured by De Havilland Aircraft of Canada. Russia also makes a few flying boats (some of which utilize jet engines)—mainly for firefighting. “There is a niche market for flying boats and always has been,” van der Linden points out.
The US-2 is one of the world’s largest amphibious aircraft, capable of landing in 10-foot swells.
Lawrence Reece is a hardcore fan of flying boats. For his aircraft restoration service, he flies around the country and beyond in search of spare parts for 80-plus-year-old PBY Catalinas. Keeping these vintage aircraft flying and floating has been his avocation and vocation for several years. Now, he is working to reintroduce the legendary airplane to meet the demands of modern travelers who want to visit remote locales accessible only to flying boats.
“In the past 10 years or so, tourism has been growing,” says Reece, founder and president of Catalina Aircraft in Longboat Key, Florida. “People want to go places. Guess what you’re missing in a lot of places they want to go to? Airport infrastructure. A lot of islands today are not big enough to include room for that.”
Reece plans to introduce what he calls the NGAA (Next Generation Amphibious Aircraft) Catalina by the end of the decade. Using the same airframe made sense, he says, because of its ruggedness and functionality—not to mention its continued appeal.
There is, however, another, more economical, reason for pursuing the platform: The basic aircraft already has approval from the Federal Aviation Administration. Even though the new version will have modern avionics and engines, Reece can save millions of dollars in development costs by sticking with a known concept. “This is a variant of an existing approved design,” says Reece, who owns the rights and plans to the original PBY Catalina. “I’m making some limited changes to it. I only have to recertify those limited changes to the overall aircraft.”
Interested individuals and companies, as well as the military, have contacted Reece about his plans, which could include building variations for putting out wildfires, cargo and troop transport, passenger service, science exploration, and search and rescue.
“Aerial firefighting is huge business,” he says. “Everybody wants planes for firefighting because it’s such a big concern these days. It will be scoop-on-the-fly, along with some new technology. We’ve got a drop computer system we’ve been developing that utilizes a spotter airplane with a [laser-based detection system] so we can map out our drop points and trajectories.”
Not to be outdone, Amphibian Aerospace Industries of Darwin, Australia, is currently retrofitting older aircraft with modern components as it works on a planned release of the new Albatross 2.0, more properly known as the G-111, by the end of the decade. Coveted by collectors today, the Grumman HU-16 Albatross was originally introduced in 1949 and remained in active use through 1995. It featured a wingspan of 96 feet and could carry a crew of four with 15,000 pounds of cargo or passengers.
According to CEO Dan Webster, his company is eyeing a global market for commercial cargo and passenger service, medical transport, and multiple other uses. He sees the tourism industry, especially among the thousands of smaller islands without airport infrastructure in the South Pacific, as an important focal point.
Canada’s De Havilland DHC-515 Firefighter can land on a body of water and take on a full load of fresh or saltwater in just 12 seconds.
“Many resorts are operating marginally at the moment,” he says. “This changes the business model for them. They can bring in a weekend customer in a fraction of the time it took to get there before by ferry or other means. Now they can fly direct to the resort. The thing about the Albatross is its capacity. With room for 28 passengers and their luggage, it will be the largest certified flying boat on the market once we get it running.”
With midrange flying boats preparing to take off again, is there hope for a return of the big “ocean liners of the sky”? Probably not. Though magnificent, the Clippers and other passenger ships were old and slow compared to the modern jetliners that dominate air travel today. “As graceful and luxurious as the flying boat was, it was terribly inefficient compared to a land plane,” says van der Linden. “You can’t run an airline if you can’t make money.”
Sadly, none of the deluxe flying boats of that bygone era remain. All were scrapped, destroyed, or just fell victim to abandonment and neglect. A full-scale replica of the Boeing B-314, built to original specifications, is on display at the Foynes Flying Boat & Maritime Museum in Limerick, Ireland, once an important terminus for flying boats on the way to Europe.
Today, about the only place you can view most of these majestic relics is at museums. I saw firsthand the NC-4 and PBY-5 Catalina on loan from the National Air and Space Museum at the National Naval Aviation Museum, as well as a PB2Y-5R Coronado.
The size of these aircraft is stunning. For example, the wingspan of the NC-4 is 126 feet. By comparison, the Wright brothers’ flight on December 17, 1903, was just 120 feet. I learned that the Wright Flyer could have taken off and landed on the wings of the NC-4—with room to spare.
The size of the Coronado is also impressive. I felt insignificant standing next to this flying sea monster, which is more than 27 feet tall. You can see why it required four gigantic engines to power free from the suction-like grip of the ocean and make altitude.
Equally inspiring is the Catalina. Smaller than the other two, it has a wingspan of only 104 feet and required just two 1,200-horsepower engines to reach the skies. But what the PBY lacked in size, it made up for in toughness.
Seeing these remarkable aircraft up close is a memorable experience. I can only imagine what it would be like to fly in one of them. Sadly, the chances of doing so these days are slim. Thank goodness, a new generation of flying boats is on the horizon. Maybe, just maybe.
As I walked out of the museum, I could only wonder what the future would hold. I looked back at the airplanes one last time and was reminded of the words of Jimmy Buffett, a true fan of the half plane, half boat: “Taking off and landing in the water held a romantic fascination for me.”
Dave Kindy is a journalist, freelance writer, and book reviewer who writes about aviation, space, military history, and other topics.
This article is from the Summer 2024 issue of Air & Space Quarterly, the National Air and Space Museum's signature magazine that explores topics in aviation and space, from the earliest moments of flight to today. Explore the full issue.
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