Prior to becoming a world-renown helicopter-maker, Sikorsky delivered to the United States military and civilian markets many fixed-wing aircraft types. One product of the pre-World War 2 years was the "S-43" flying boat / amphibious boat which arrived during the middle part of the 1930s. Fifty-three examples were competed with most of the stock taken on by Pan American World Airways to service passenger routes between the United States, the Caribbean and Central America. During its time in service, the aircraft came to be known as the "Baby Clipper".
The aircraft, on the whole, relied on proven flying boat qualities such as a high-wing mainplane, boat-like hull and deep fuselage. The high-wing arrangement mounted the twin air-cooled radial piston engines well-above the waterline to protect them from the salty sea spray. The boat-like hull was necessary for water landings and take-offs to which outboard pontoons ensured that the aircraft did not tip over in seas. The S-43 also became a true "amphibian" in that a wheeled, retractable undercarriage was also part of its base design which allowed for operation from traditional airstrips. Beyond its standard operating crew of two, the passenger cabin accommodated up to 25 in relative comfort. A conventional tail unit was featured showcasing a single vertical fin and low-set horizontal planes. However, the "S-43B" variant introduced a twin-fin appearance.
Beyond its service in and around Latin America, S-43 aircraft were featured as an inter-island flyer over Hawaii and was one of the aircraft types present at the Japanese attack on Pearl Harbor in December of 1941. Some operated over Alaska and portions of South America while American aviation pioneer Howard Hughes thought enough of the type to purchase one for his collection. At least five examples were taken on by the U.S. Army in 1937 as the "OA-8" and the U.S. Navy operated some seventeen of the type from 1937 onward under the designation of "JRS-1" (a pair from this stock was also in use by the USMC for a time).
S-43s were in active use up until the latter part of the 1940s by which time most were given up for better alternatives or lost to accident and not reclaimed.
As completed, the S-43 design was powered by 2 x Pratt & Whitney R-1690-52 series radial piston engines of 750 horsepower each. Maximum speed was 190 miles per hour with a range out to 775 miles. Its service ceiling reached 20,700 feet. An S-43 carrying 1,100lb in cargo set an altitude record for a flying boat / amphibian on April 14th, 1936, reaching 27,950 feet over Stamford, Connecticut.
- Navy / Maritime
- Commercial Market
- Search and Rescue (SAR)
- Reconnaissance (RECCE)
51.18 ft (15.6 m)
85.99 ft (26.21 m)
17.65 ft (5.38 m)
12,754 lb (5,785 kg)
19,092 lb (8,660 kg)
190 mph (306 kph; 165 kts)
20,702 feet (6,310 m; 3.92 miles)
775 miles (1,247 km; 673 nm)
S-43 - Sikorsky Company Model; initial production model.
S-43B - Twin-Tailed Design
OA-8 - US Army Air Corps Designation; five aircraft acquired.
JRS-1 - US Navy / USMC Designation; 17 aircraft acquired; 2 examples serving with USMC.
"Baby Clipper" - Nickname