Biplane

Sikorsky S-38 / C-6 / RS-4

09/04/202509/04/2025TerryLeave a comment

The S-38 was a nine-seat commercial amphibian powered by two 313kW Pratt & Whitney Wasp radial engines. A sesquiplane wing arrangement was employed and the tail unit was carried on two outriggers running aft from the main wing and braced to the heel of the hull by two struts. It was a successful design and many were built for airline use (including Pan American Airways, entering service in October 1938), private use and for the US Navy/USAAC. The type also set several world records for speed and altitude with specific loads. Over 100 were built from 1928 on.

By 1929 the company, having become a division of United Aircraft Corporation, occupied a large modern plant at Bridgeport, Connecticut, and was producing S-38 twin-engined amphibians. A ten-place prototype was built, NC5933, and eleven S-38A were built; NC8000, NC8005, NC8019 to NC8022, and NC8043 to NC8044, with ATC60.

One special luxury model was built as a personal transport for John H Whitney; NC8005.

The S-38-AH of 1928 (ATC 2-36) was powered by 525hp P&W Hornet A.

A single 12-place S-38A was procured by the USAAC in 1929 for evaluation as XC-6 29-406, also as Wright Field s/n XP-588. Eventually the aircraft, which had a length of 41’0″, was used as a VIP aircraft.

The XC-6 was followed by 10 C-6A production aircraft (30-397 – 30-406), used mainly for transport duties and target towing.

Two S-38A were impressed from Pan American (37854 and 37855) as RS-4.

Two went to the USN as XPS-2.

First flying on 13 March 1928, the 2-10 place S-38-B (ATC 126, 2-74) was priced from $50,000+. Seventy-sic were built; NC1V to NC3V, NC5V, NC7V, NC11V, NC15V, NC18V to NC21V, NC23V, NC25V, NC40V, NC73K to NC75K, NC113M, NC141M to NC146M, NC158H to NC160H, NC196H to NC199H, NC300N to NC304N, NC306N to NC309N, NC943M to NC946M, NC9105 to NC9107, NC9137 to NC9140, NC9143 to NC9144, NC9151, NC9753, NC9775 to NC9776, of which NC9140 was another -38-B Special with two 450hp P&W Wasp C under (2-74), but crashed before its delivery to Colombia.

1929 S-38-B Special NC9143 and NC9144 (ATC 2-68, 2-69) were S-38-A approved for eleven-place with 450hp P&W Wasp C engines and four-place with Wasp SC, NC9137.

Two S-38-B, NC25V and NC40V (DoC records show as NC16V c/n 314-20 and NC17V c/n 414-8), were converted to S-38-BH in 1929 with ATC2-190 (superseded by ATC356). They sold for $53,000.

The 1932 S-38-BL NC24V c/n 414-15 was a modified S-38-B.

The 1932 S-38-BS NC29V c/n 414-20 (ATC2-434) was a seven-place with two 450hp Wasp SC engines. It was built for a 1933 African wildlife survey, flown by pilot Osa and photographer Martin Johnson, with a “Zebra” paint job.

The 1933 S-38-BT NC22V c/n 414-23 (ATC 2-446) was an 8-10 place with two 525hp P&W supercharged Wasp T engines.

Selling for around $50,000, ten 1929 S-38-C (ATC 158) were built; NC4V, NC6V, NC10V, NC26V, NC28V, NC111M and NC112M, NC160H, NC199H, and NC305N. By now, 111 S-38 had been built.

Two S-39-B (NC809W and NC1933/NC14326) were refitted with 400hp P&W Wasp S1 engines in 1931 as S-39-C in 1931. They received ATC 2-391 and 2-436,

The 1932 S-39-CS Special (ATC 2-436) was a four-place with 375hp P&W Wasp S2 engines. The one built, NC52V c/n 914, was for Osa and Martin Johnson.

Gallery

S-38-A, -B, -C (ATC 60)
Engines: 2 x Pratt & Whitney Wasp, 313kW / 400hp
Wingspan upper: 21.8 m / 72 ft 6 in
Wingspan lower: 11.0 m / 36 ft 1 in
Length: 12.3 m / 40 ft 4 in
Height: 4.4 m / 14 ft 5 in
Wing area: 66.9 sq.m / 720.10 sq ft
Max take-off weight: 4753 kg / 10479 lb
Empty weight: 2970 kg / 6548 lb
Max. speed: 200 km/h / 124 mph
Cruise speed: 175 km/h / 109 mph
Stall: 57 mph
Ceiling: 5480 m / 18000 ft
ROC: 1000 fpm
Range w/max.fuel: 965 km / 600 miles
Crew: 2
Passengers: 10

S-38-AH
Engines: 2 x 525hp P&W Hornet A.

S-38-B
Engines: 2 x P&W Wasp, 410hp
Wingspan: 71’8″
Length: 40’5″
Useful load: 3930 lb
Max speed: 125 mph
Cruise: 110 mph
Stall: 55 mph
Range: 750 mph
Ceiling: 18,000′
Seats: 2-10

S-38-B Special
Engines: 2 x P&W Wasp C, 450hp or Wasp SC
Seats: 11 or 4

S-38-BH
Engines: 2 x P&W Hornet B, 575hp
Useful load: 3580 lb
Max speed: 143 mph
Cruise: 120 mph
Stall: 55 mph
Range: 600 mi
Seats: 10

S-38-BS
Engines: 2 x P&W Wasp SC, 450hp
Seats: 7

S-38-BT
Engines: 2 x P&W supercharged Wasp T, 525hp
Seats: 8-10

S-38-C
Engines: 2 x P&W Wasp, 420hp
Wingspan: (upper) 71’8″
Wingspan: (lower) 36’0″
Length: 40’3″
Useful load: 3630 lb
Max speed: 125 mph
Cruise: 110 mph
Stall: 55 mph
Range: 600 mi
Ceiling: 18,200′
Seats: 8-12

S-39-B convert. S-39-C
Engines: 2 x 400hp P&W Wasp S1

C-6 / C-6A
Engines: 2 x P&W R-1340-7
Wingspan: 71’6″
Length: 40’3″
Max speed: 112 mph
Seats: 12

Sikorsky S-37

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Despite the S-35 tragedy, Capt. Rene Fonck decided to try again, in a new Sikorsky aircraft, the S-37 NX1283 Ville de Paris. Powered by two 500hp Jupiters, it cruised at 190km/h and had a designed range of over 6400km, which would have taken it to Paris with fuel to spare.

Tests at progressively increased loads included the overload weight needed for the transatlantic flight, but the planned attempt was abandoned after the Orteig prize had been won by Charles Lindbergh.

The S-37 was sold by Fonck’s sponsors to American International Airways of Argentina as the Southern Star airliner for twenty passengers. During its delivery flight, begun on 30 June 1929, it became the first commercial transport to cross the 5700m Andes mountains, carrying eight people and a total useful load of 2300kg. Further flights over the Andes, between Buenos Aires and Santiago, became routine for several years.

First selling for $15,955, R1283 was modified as a sixteen passenger with 525hp P&W Hornet engines (the Jupiters went to S-37-B) for service in South America. It was scrapped by PAA in 1930.

The 1927 S-37-2 NX3698 (ATC 2-170) was built under a contract from Consolidated Co as their Model 12, for Army evaluation as five-place XP-496 bomber with two 525hp P&W R-1690 engines.

Sikorsky amended the suffix to “-B,” but while in the service it never did get an official Army designation.

It did not meet Consolidated’s requirements, either, and was rebuilt in 1929 by Sikorsky from eight passenger to 21 passenger transport with two 675hp P&W Hornets, which were replaced by the Jupiters from the S-37-1.

Rebuilt again and re-registered in 1934 as NR942M, it crashed at sea in 1934.

Gallery

S-37-1 Guardian
Engines: 2 x Gnôme-Rhône Jupiter, 520hp
Wingspan upper: 100’0″
Wingspan lower: 58’0″
Length: 44’0″
Useful load: 7000 lb
Max speed: 135 mph
Cruise: 115 mph
Stall: 57 mph
Capacity: 20 pax

S-37-2 / S-37-B / Model 12
Engines: 2 x P&W Wasp, 500hp
Wingspan upper: 100’0″
Wingspan lower: 58’0″
Length: 45’6″
Useful load: 7000 lb
Max speed: 140 mph
Cruise: 120 mph
Stall: 53 mph
Ceiling: 15,000′
Capacity: 8 pax

S-37-2 / S-37-B / XP-496
Engines: 2 x P&W R-1690 Wasp, 525hp
Useful load: 6315 lb
Max speed: 108 mph
Stall: 57 mph
Range: 575 mi

S-37-B
Engines: 2 x P&W Hornets, 675hp
Capacity: 21 pax

Sikorsky S-35

09/04/202524/05/2025TerryLeave a comment

The S-35 was designed as a twin-engined transport with a range of about 1600km.

In the spring of 1926 Capt. Rene Fonck, a French First World War fighter ace, persuaded Sikorsky to redesign it in an attempt to win the $25,000 Orteig prize for the first non-stop New York-Paris flight. It became a very different aircraft, with three 400hp Gnome-Rhone Jupiter engines and vastly increased fuel load. The first test flight, by Fonck and Igor Sikorsky, was made on 23 August 1926. Later, pilot Frank LaVista of the Department of Commerce reported that the aircraft handled very well, could climb on two engines, and lost only 15m of height while flying at 132km/h for 35 seconds on one engine.

Jettisonable auxiliary landing gear was fitted to the S-35 for take-off on its transatlantic attempt, at an overload weight of 8400kg, on 20 September 1926. Fonck insisted on having a radio operator, Charles Clavier, and veteran Sikorsky mechanic Jacob Islamoff, in addition to his co-pilot Lt Lawrence Curtin of the US Navy. Watched by a huge crowd, part of the auxiliary landing gear broke away as the aircraft gathered speed. It plunged down a steep slope beyond the runway and burst into flames. Only the two pilots escaped. The S-35, which had cost $100,000 to build, was destroyed.

The original wingspan, before extra bays were added, was 76’0″. This was increased to 101’0″.

Gallery

Sikorsky S-35
Engines: three 420hp Gnôme-Rhône Jupiter
Wingspan (upper): 101’0″
Wingspan (lower): 76’0″
Original load: 6600 lb
Load: 15,710 lb
Ceiling: 16,800 ft
Seats: 4

Sikorsky S-33

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Two S-33 Messengers were built, the first in 1926 as a racing aircraft with a 60hp Wright Gale aircooled engine, the second in 1927 as a two-seat utility aircraft with a 60hp Lawrence. The racer was flown by Al Krapish, one of the company’s earliest employees and a passenger on the first unhappy flight of the S-29A. It spanned 9.75m and had a speed of 165km/h.

S-33 Messenger
Engine: 60hp Anzani
Wingspan (upper): 32’0″
Wingspan (lower): 20’0″
Useful load: 500 lb
Max speed: 115 mph
Stall: 35 mph
Ceiling: 15,000′
Seats: 1

Sikorsky S-32

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The 1925 one-off S-32 was a large fabric-covered metal biplane, with a 400hp Liberty engine, built for the Andean National Corporation, a subsidiary of Standard Oil Company, for extra-heavy duties in Colombia.

It carried the pilot in the rear cockpit and two pairs of passengers in the forward cockpits. In landplane form it had a top speed of 215km/h and endurance of more than four hours, but was flown mainly on floats.

Engine: 400hp Liberty 12
Wingspan: (upper) 58’4″ / 17.78m
Wingspan (lower): 38’0″
Length: 36’0″
Maximum weight: 2450 kg
Useful load: 2100 lb
Max speed: 133 mph
Stall: 40 mph
Ceiling: 16,000′
Seats: 5

Sikorsky S-31

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The 1925 five-seat S-31, with a 200hp Wright J-4 Whirlwind engine, was used by the Fairchild Company for aerial photo-mapping work in South America.

Up to four passengers, or photographic equipment, could be carried in the semi-closed centre cabin.

During flight testing, the S-31 climbed to 4680m in 47 minutes with a pilot, two passengers and fuel for four hours of flying.

The sole example built was shown in a publicity photo shows it with a machine-gunner in the rear cockpit, suggesting plans for a military export version.

S-31
Engine: 200hp Wright J-4
Wingspan (upper): 45’0″
Wingspan (lower): 32’0″
Length: 26’0″
Useful load: 1200 lb
Max speed: 124 mph
Cruise: 110 mph
Stall: 35 mph
Range: 500 mi
Ceiling: 15,000′
Seats: 3

Sikorsky S-29-A

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In New York, Sikorsky formed a small company and started to build the S-29-A, a twin-engined 14 passenger and freight carrier. With $5,000 finance from the great pianist and composer Sergei Rachmaninoff the S-29-A was completed. The suffix “-A” denoted “Made in America,” as 28 previous S-numbers were all built and utilized in Russia. First Sikorsky built in the US, originally had 220hp Hispano-Suizas

Rachmaninoff accepted the position of first vice-president of the struggling corporation. The engines were old, some of the parts from junkyards. On 4 May 1924 a take-off was attempted. With too many loyal passengers the aircraft flew, but crashed. The aircraft was rebuilt repowered with Liberty 12 engines.

It was owned by Roscoe Turner and made many long-distance flights in the East and Midwest 1925-27, was even used to deliver two grand pianos.

In 1928, Howard Hughes bought the S-29A for use in his epic film “Hell’s Angels”. To simulate a First World War German Gotha bomber, he painted it black, with Maltese cross insignia and with machine-guns above the mid-fuselage cockpit, at side hatches and above and below the nose. In the film, the aircraft is seen to spin down and crash. Few of the viewers realized that the pilot had parachuted to safety, but that the man releasing the smoke trail from the rear fuselage had not known that the S-29A was out of control and died when it slammed into the ground.

S-29-A
Engines two 400hp Liberty 12
Wingspan: 69’0″
Length: 49’10”
Useful load: 4225 lb
Max speed: 115 mph
Cruise: 100 mph
Stall: 56 mph
Ceiling: 12,300 ft
Seats: 16

Sikorsky S-22 Ilya Mourometz

09/04/202510/07/2025TerryLeave a comment

In August 1913 a military Voisin biplane broke up in the air over the airfield and its engine fell onto the Grand. Sikorsky subsequently redesigned the aircraft as the Ilya Muromets which was even bigger. Its wing span was 10 ft greater than that of Le Grand and it weighed 10,000 lb.

A four bay biplane with braced extensions of upper wings. With two spar wooden wings and wooden fuselage, all fabric covered, ailerons were fitted to the top wings.

The first flight of Ilya Mourometz No. 1, in January 1914, was made with a skid undercarriage. On 11 February 1914 this machine set a new world record by carrying aloft 16 people and a dog. A familiar picture of it shows the big biplane landing with two fur-coated passengers taking a stroll along its fuselage top promenade. Five months after the first flight, it flew several times as a seaplane.

With the threatened outbreak of hostilities ten were purchased by the Russian Army for military trials.

The Ilya Muromets went into production as a heavy bomber for the Imperial Russian Air Service Eskadra Vozdushnykh Korablei (Squadron of Flying Ships) built at the Russo-Baltic Wagon Works. Seventy three were built, and few of these production aircraft were identical, improvement and developing being continuous, and short engines meant they were flown with a variety of powerplant which, in some cases, involved a mix of engines on one aircraft.

The first version used in combat was the Type B, with Salmson engines of 135-200 hp and an armament of only two machine guns. The largest of the series was the Type IMYe2, with a wingspan of 34.50m and a gross weight of 7,000kg.

After experimenting with various types of armament and bomb racks it was found to be too slow and with limited altitude for offensive purposes. Sikorsky designed a lighter version, the Il’ya Muromets Type V, and deliveries of these began in early 1915.

Sikorsky S-22 Il’ya Murometz Article

They were so effective on more than 400 bombing raids against Germany and Lithua¬nia in 1915 that Great Britain and France sought permission from Czar Nicholas II to produce the design under licence, though nothing came of the scheme before the 1917 Russian Revolution sent Sikorsky fleeing to the United States.

They made 400 successful raids for the loss of only one aircraft, shot down by German fighters after it destroyed three of the enemy aircraft.

Engines: 4 x Argus, 100 hp
Wingspan: 30.9/22.0 m / 101 ft 5 in / 72 ft 2 in
Length: 17.1 m / 56 ft 1 in
Wing area: 148.0 sq.m / 1593.06 sq ft
Max take-off weight: 5100 kg / 11244 lb
Max. speed: 110 km/h / 68 mph
Range: 600 km / 373 miles
Armament: 8 machine-guns, bombs
Crew: 10

Ilya Muromets E
Engines: 4 x Renault, 200 hp
Props: 2 blade
Wingspan: 102 ft 8 in
Wing area: 20050 sq.ft
Length: 59 ft 8 in
Empty weight: 10,600 lb
MTOW: 17,600 lb
Max speed: 85 mph at 5000 ft’
Endurance: 4 hr
Armament: up to 7 mg
Bombload: 1000-1500 lb

Sikorsky IM-W Ilya Muromet
Engine: 4 x Argus, 138 hp
Length: 56.102 ft / 17.1 m
Wingspan: 97.769 ft / 29.8 m
Wing area: 1345.5 sq.ft / 125.0 sq.m
Max take off weight: 9812.3 lb / 4450.0 kg
Max. speed: 67 kts / 125 km/h
Service ceiling: 12139 ft / 3700 m
Wing loading: 7.38 lb/sq.ft / 36.00 kg/sq.m
Endurance: 5 h
Crew: 5
Armament: 3-7x MG, 700kg Bomb.

Sikorsky Le Grand / Russkii Vitiaz (Russian Knight)

09/04/202518/09/2025TerryLeave a comment

In 1912 Igor Sikorsky began construction of an aircraft with a wingspan of 28 m (92 ft) it was at that time by far the largest heavier than air craft to fly; the first to have four engines; the first with a fully enclosed passenger cabin; and the first designed specifically as an airliner.

Officially known as Russkii Vitiaz (Russian Knight), the big biplane was dubbed the Grand or Bolshoi before its first flight on 13 May 1913. The Grand weighed 4080 kg (8000 lb) and was powered by four 100 hp water cooled Argus engines arranged initially in tandem pairs, but after the first ten minute test flight the two rear mounted engines were moved outboard on the wings. In June 1914, Sikorsky piloted the 10,000-1b. S-22 named Ilia Mourotz on a 1,600mi. round trip from St. Petersburg to Kiev.

Czar Nicholas II inspected LeGrand with Sikorsky in the summer of 1913.

Numerous difficulties were encountered in the design and construction; there were no wheels of adequate size to support the Grand, so a 16 wheel bogie undercarriage had to be built. The cabin incorporated some novelties. At the front was a large open balcony with a searchlight mounted on a gimbal; next came the cockpit with dual controls for two pilots; behind this was the passenger cabin, luxuriously appointed with four seats, sofa, table, washroom and wardrobe.

The Grand flew well and subsequently made 53 flights including a record breaking duration flight of 1 hour 53 minutes with eight people aboard on 2 August 1913. Later that month a military Voisin biplane broke up in the air over the airfield and its engine fell onto the Grand. Sikorsky subsequently redesigned the aircraft as the Ilya Muromets.

Engines: 4 x 100 hp Argus four cylinder in line piston
Wing span: 91 ft 10.25 in (28.00 m)
Length: 62 ft 4 in (19.00 m)
Gross weight: approx. 9,039 lb (4,100 kg)
Max. speed: approx. 59 mph (95 km/h) at 3,280 ft (1,000 m)
Accommodation: Crew of 2 + 8 passengers
Typical endurance: 1 hr 45 min

1913 Sikorsky “Grand”
Span: upper 89′ lower: 66′
Length: 66′
Weight: 8800 lb gross
Speed: 56 mph