Igor Sikorsky piloting his pontoon-equipped VS-300, 17 April 1941. (Sikorsky Historical Archives)
17 April 1941: Igor Sikorsky’s Vought-Sikorsky VS-300 helicopter went through various rotor configurations during development as he searched for a combination that would give stability, anti-torque control, as well as lateral and yaw control. By April 1941, the VS-300 was configured with a single main rotor for lift and three smaller tail rotors to provide anti-torque and directional control.
This was not the ultimate solution, but he had the aircraft fitted with three inflatable pontoons and on 17 April, made a successful water landing, demonstrating that the helicopter could be a practical amphibious aircraft. During a lecture to the Rotating Wing Section of the Tenth Annual Meeting of the Institute of Aeronautical Sciences, Igor Sikorsky gave a brief description of the flight:
Igor Ivanovich Sikorsky (Sikorsky Archives)
“On April 17 the helicopter, mounted on rubber floats, was repeatedly taken off from water and landed on water and then landed on ground, demonstrating for the first time a direct lift aircraft with excellent amphibian characteristics on which no adjustments whatsoever are needed when going from water to land and vice versa.”
The VS-300 had a welded tubular steel airframe and used a 28-foot (5.34 meters) diameter, fully-articulated, three-bladed main rotor, which turned clockwise (as seen from above) at 260 r.p.m. (The advancing blade was on the left. This would later be reversed.) The main rotor had collective pitch control for vertical control, but cyclic pitch (Sikorsky referred to this as “sectional control”) for directional control would not be developed for another several months.
The tail “propellers” (what we now consider to be rotors—one vertical and two horizontal) each had two blades with a diameter of 7 feet, 8 inches (2.337 meters) and turned approximately 1,300 r.p.m. The vertical rotor provided “torque compensation” (anti-torque) and the blade pitch was fully reversible. The horizontal rotors were mounted on 10-foot (3.048 meters) outriggers at the aft end of the fuselage. For lateral control, the pitch on one rotor was increased and the other decreased. For longitudinal control, the pitch of both rotors was increased or decreased together.
Igor Sikorsky banks the VS-300 through assymetric pitch of the horizontal tail rotors. (Sikorsky Historical Archives)
The VS-300 was originally equipped with an air-cooled, normally-aspirated 144.489-cubic-inch-displacement (2.368 liter) Lycoming O-145C-3 four-cylinder horizontally-opposed engine which was rated at 75 horsepower at 3,100 r.p.m. According to Mr. Sikorsky, “early in 1941,” the Lycoming engine was replaced by an air-cooled, normally-aspirated 198.608 cubic inch (3.255 liter) Franklin 4AC-199-E, a four-cylinder horizontally-opposed overhead valve (OHV) direct-drive engine with a compression ratio of 7:1, rated at 90 horsepower at 2,500 r.p.m. It is not known if this change was made prior to 17 April.
Pan American Clipper NR823M over San Francisco-Oakland Bay Bridge, en route to Hawaii on the first survey flight, 1935. Photographed by Clyde Herwood Sunderland, Jr. (1900–1989). (National Air and Space Museum SI-90-3001)
16 April 1935: At 3:42 p.m. Pacific Standard Time (23:42 Greenwich Mean Time), Pan American Airway’s Sikorsky S-42 Clipper, NC823M, pulled away from the dock at Alameda, California, on a survey flight to determine the feasibility of long range passenger flights across the Pacific Ocean.
After a 30 second takeoff run of about 1,700 feet (518 meters), the S-42 lifted from the waters of San Francisco Bay at 3:50 p.m., Pacific Standard Time (23:50 G.M.T.).
Crew of the first Pan American Airways Sikorsky S-42 survey flight in Hawai’i , 7 April1935. Left to right: Radio Officer Wilson Turner Jarboe Jr.; Junior Officer Harry R. Canaday; First Officer Robert Oliver Daniel (“Rod”) Sullivan; Captain Edwin Charles Musick; Navigator Fred Joseph Noonan; Engineer Officer Victor A. Wright. (SFO Museum)
The Clipper’s crew were Captain Edwin Charles Musick; First Officer Robert Oliver Daniel (“Rod”) Sullivan; Fred Joseph Noonan, navigator; Victor A. Wright, flight engineer; Harry R. Canaday, junior flight officer; and Wilson Turner Jarboe, Jr., radio operator.
The airplane carried 150 pounds (68 kilograms) of mail and two tons (1,814 kilograms) of mechanical and engineering equipment for Pan Am’s base in Hawaii. Postage for the approximate 10,000 letters varied from $1.00 to $2.50. ($22.80 – $56.99 in 2024 U.S. dollars). The Clipper carried 3,000 gallons (11,356 liters) of gasoline and 300 gallons (1,136 liters) of oil.
The flight was made at altitudes varying from 4,000 to 8,500 feet (1,219 to 2,591 meters).
Pan American Airways’ Sikorsky S-42 NC832M passes Diamond Head on the island of Oahu, Territory of the Hawaiian Islands, in 1935. (Smithsonian Institution National Air and Space Museum PP-1-8-013/Hawaii State Archives)
NC823M arrived overhead Diamond Head, Territory of the Hawaiian Islands, at 7:05 a.m., Hawaii Standard Time (17:35 G.M.T.), 17 April. [In 1935, Hawaii Standard Time was G.M.T. + 10 hours, 30 minutes] The S-42 was joined by an escort of five patrol planes from the U.S. Navy Patrol Squadron 10 (VP-10) and ten “pursuit” planes. (These were not not specified in contemporary newspaper articles, but the Navy planes were probably Consolidated P2Y-1s, while the “pursuits” were most likely U.S. Army Boeing P-26 monoplanes.)
The Clipper circled the city at about 1,000 feet (305 meters). It spent 52 minutes circling the city, Waikiki Beach, the Ewa plantation, and the U.S. Army’s Schofield Barracks.
A U.S. Navy Consolidated P2Y-1 of Patrol Squadron 10, circa 1934. (U.S. Navy)
The S-42 touched down at Pearl Harbor at 7:57 a.m., H.S.T., 17 April, (10:27 a.m., P.S.T./17:27 GMT.) after a flight of 17 hours, 45 minutes.¹ Flying a Great Circle Route, the total distance flown was approximately 2,090 nautical miles (2,405 statute miles/3,870 kilometers).² The average speed was about 117.75 knots (135.5 miles per hour/218 kilometers per hour).
This image depicts the Great Circle Route from the Alameda Naval Air Station (NGZ) to Honolulu International Airport. (Great Circle Mapper)
After landing, the flying boat shut down two of its engines and taxied to the seaplane ramp at Ford Island.
Pan American Clipper NR823M at Pearl Harbor, Hawaii, 17 April 1935. (Pan Am Historical Foundation)
NC823M was only the twelfth airplane to successfully fly from California to Hawaii. The first was the U.S. Army’s Atlantic-Fokker C-2, Bird of Paradise, on 29 June 1927.³ For reference, VP-10s six P2Y-1s had taken 24 hours, 45 minutes to reach the islands in 1934.
The Sikorsky S-42 was a four-engine long-range flying boat built for Pan American Airways by the Vought-Sikorsky Aircraft Division of United Technologies at Stratford, Connecticut. It was 67 feet, 8 inches (20.625 meters) long with a wingspan of 114 feet, 2 inches (34.798 meters). The S-42 had an empty weight of 18,236 pounds (8,272 kilograms) and gross weight of 38,000 pounds (17,237 kilograms). It could carry up to 37 passengers.
The S-42 was powered by four air-cooled, supercharged, 1,690.537-cubic-inch-displacement (27.703 liters) Pratt & Whitney Hornet S1E-G nine-cylinder radial engines with a compression ratio of 6.5:1. The S1E-G had a Normal Power rating of 750 horsepower at 2,250 r.p.m., to 7,000 feet (2,134 meters), and 875 horsepower at 2,300 r.p.m., for Takeoff. The engines drove three-bladed Hamilton Standard constant-speed propellers through a 3:2 gear reduction. The S1E-G was 4 feet, 1.38 inches (1.254 meters) long, 4 feet, 6.44 inches (1.383 meters) in diameter, and weighed 1,064 pounds (483 kilograms).
The S-42 had a cruise speed 165 miles per hour (266 kilometers per hour) and maximum speed of 188 miles per hour (303 kilometers per hour) at 5,000 feet (1,524 meters). The service ceiling was 16,000 feet (4,877 meters). It could maintain 7,500 feet (2,286 meters) with three engines. Its range was 1,930 miles (3,106 kilometers).
Ten Sikorsky S-42, S-42A and S-42B flying boats were built for Pan Am. None remain in existence.
¹ “Flight time” is generally defined as from the time the aircraft first moves under its own power for the purpose of flight until it comes to rest after landing. In this case, the flight time commenced when the S-42 pulled away from the dock in Alameda, not the time it actually lifted from the water of San Francisco Bay.
² In actuality, the S-42 taxied on San Francisco Bay before taking off, then flew west over the Golden Gate Bridge before turning on its course to Hawaii. It arrived overhead Diamond Head on the island of Oahu before landing on the waters of Pearl Harbor. The actual distance flown is therefore an approximation.
³ Please see This Day in Aviation at https://www.thisdayinaviation.com/28-29-june-19/
First Lieutenant Harold Ross Harris, Air Service, United States Army, 1922.
17 April 1923: At Wilbur Wright Field, Dayton, Ohio, First Lieutenant Harold Ross Harris set two Fédération Aéronautique Internationale (FAI) World Speed Records, flying a modified de Havilland XDH-4L powered by a Hall-Scott Liberty 375 engine. Lieutenant Harris averaged 184.03 kilometers per hour (114.35 miles per hour) over a 1,500 kilometer (932.1 miles) closed circuit,¹ and 183.82 kilometers per hour (114.22 miles per hour) over a 2,000 kilometer (1,242.7 mile) course. ²
Harold R. Harris was an important figure in the development of aircraft following World War I. He served as Engineering Officer for the U.S. Army at McCook Field and flew many experimental aircraft, setting records for speed and altitude, and worked on the development of airplanes, engines and other equipment. Harris was the first man to use a parachute to escape an airplane during an actual in-flight emergency.
In civil aviation, Harris was an executive with the company that would become Pan American World Airways. During World War II, he was chief of staff of the Air Transport Command, retiring with the rank of brigadier general, and then returning to commercial aviation as a vice president of Pan Am and later president of Northwest Airlines.
de Havilland XDH-4L A.S. 64593, FAI World Speed record holder. (FAI)
The XDH-4L was a variant of the Airco DH.4, designed by Geoffrey de Havilland. It was a two-place, single-engine biplane intended as a bomber, but the type served in virtually every capacity during World War I and the years following. At McCook Field, American-built DH-4s were commonly used as test beds for engines and other aeronautical equipment.
The standard Airco DH.4 had a crew of two. It was 30 feet, 8 inches (9.347 meters) long with a wingspan of 43 feet, 4 inches (13.208 meters) and height of 11 feet (3.353 meters). Empty weight was 2,387 pounds (1,085 kilograms) and loaded weight was 3,472 pounds (1,578 kilograms). British-built DH.4s were powered by a 1,240.54-cubic-inch-displacement (20.33 liter) liquid-cooled Rolls-Royce Eagle overhead cam 60° V-12 engine which produced 375 horsepower. A gear-reduction system kept propeller r.p.m. below engine speed for greater efficiency.
American-built DH.4 airplanes were produced by the Boeing Airplane Company, Dayton-Wright Airplane Company, Fisher Body Corporation, and Standard Aircraft Corporation. Most were powered by the Liberty L12 engine.
Major Henry H. Arnold standing beside the first Liberty 12 aircraft engine turned out for war use. “Hap” Arnold would later hold the 5-star rank of General of the Army and General of the Air Force. (U.S. Air Force)
The Liberty L12 aircraft engine was designed by Jesse G. Vincent of the Packard Motor Car Company and Elbert J. Hall of the Hall-Scott Motor Company. It was a water-cooled, normally-aspirated, 1,649.336-cubic-inch-displacement (27.028 liter) Liberty L-12 single overhead cam (SOHC) 45° V-12 engine with a compression ratio of 5.4:1. The Liberty produced 408 horsepower at 1,800 r.p.m. The L-12 as a right-hand tractor, direct-drive engine and it turned turned a two-bladed fixed-pitch wooden propeller. The Liberty 12 was 5 feet, 7.375 inches (1.711 meters) long, 2 feet, 3.0 inches (0.686 meters) wide, and 3 feet, 5.5 inches (1.054 meters) high. It weighed 844 pounds (383 kilograms). This engine was produced by Ford Motor Company, as well as the Buick and Cadillac Divisions of General Motors, The Lincoln Motor Company (which was formed by Henry Leland, the former manager of Cadillac, specifically to manufacture these aircraft engines), Marmon Motor Car Company and Packard. Hall-Scott was too small to produce engines in the numbers required.
Following World War I, many DH-4s were rebuilt by Boeing and Atlantic Aircraft. An improved version, the DH-4M, used a tubular steel framework instead of the usual wood construction. DH-4s remained in service with the United States Army as late as 1932.
De Havilland XDH-4L, U.S. Army Air Service serial number A.S. 64593, was used for engineering tests at McCook Field. It carried project number P193 painted on its rudder. At the time of the world speed records, it was powered by a Hall-Scott Liberty 375, a 375 horsepower version of the Liberty V-12 engine. The rear cockpit was faired over and a 185 gallon (700.3 liter) fuel tank installed for long range flights.
Lieutenants Oakland G. Kelly and John A. Macready with the fuel drums for their duration flight in front of the Fokker T-2, A.S. 64233. (U.S. Air Force)
16–17 April 1923: At Wilbur Wright Field, Dayton, Ohio, U.S. Army Air Service pilots Lieutenant Oakland George Kelly and Lieutenant John Arthur Macready set six Fédération Aéronautique Internationale (FAI) World Records for speed, distance and duration, flying the Nederlandse Vliegtuigenfabriek Fokker T-2, serial number A.S. 64233, which they planned to fly non-stop across the United States of America.
They flew 2,500 kilometers (1,553.428 miles) at an average speed of 115.60 kilometers per hour (51.83 miles per hour);¹ 3,000 kilometers (1,864.114 miles) at 115.27 kilometers per hour (71.63 miles per hour);² 3,500 kilometers (2,174.799 miles) at 114.82 kilometers per hour (71.35 miles per hour);³ 4,000 kilometers (2,485.485 miles) at 113.93 kilometers per hour (70.79 miles per hour);⁴ flew a total distance of 4,050 kilometers (2,517 miles);⁵ and stayed aloft for 36 hours, 4 minutes, 34 seconds.⁶ Their overall average speed was 112.26 kilometers per hour (69.76 miles per hour).
Lieutenant Oakley George Kelly, U.S. Army Air Service. (FAI)Lieutenant John A. Macready, U.S. Army Air Service
The Fokker F.IV was built by Anthony Fokker’s Nederlandse Vliegtuigenfabriek at Veere, Netherlands in 1921. The Air Service purchased two and designated the type T-2, with serial numbers A.S. 64233 and A.S. 64234.
Several modifications were made to prepare for the transcontinental flight. Normally flown by a single pilot in an open cockpit, a second set of controls was installed so that the airplane could be controlled from inside while the two pilots changed positions. On this flight, it carried 735 gallons (2,782 liters) of gasoline in three fuel tanks.
For its time, the Fokker was a large airplane: 49 feet (14.9 meters) long, with a wing span of 82 feet (25 meters). The high-wing monoplane was powered by a 1,649.3-cubic-inch-displacement (27.028 liter) liquid-cooled Liberty L12 single overhead cam (SOHC) 45° V-12 engine producing 420 horsepower. The airplane was designed to carry 8–10 passengers in an enclosed cabin.
The second Fokker T-2, A.S. 64234, also designated A-2 (ambulance). (U.S. Air Force)
From 2–3 May 1923, MacReady and Kelly succeeded in their non-stop transcontinental flight, flying from Roosevelt-Hazelhurst Field, Long Island, New York, to Rockwell Field (now, NAS North Island), San Diego, California, 2,470 miles (3,975 kilometers) in 26 hours, 50 minutes, 38.8 seconds, for an average speed of 92 miles per hour (148 kilometers per hour).
The U.S. Army Air Service transferred A.S. 64223 to the Smithsonian Institution in January 1924. It is on display at the National Air and Space Museum.
17 April 1913: Pioneer British aviator Gustav Wilhelm Hamel flew from Dover, England, across the English Channel and on to Cologne, Germany. Also on board his airplane was Frank Dupree,¹ a reporter for the London Standard. His airplane was a Blériot XI. ² The duration of the flight was 4 hours, 18 minutes.
FLIGHT reported:
HAMEL FLIES FROM DOVER TO COLOGNE.
AMONG the many extraordinary flights which have been accomplished, certainly not the least epoch-making, inasmuch as it was the first flight from England to Germany, was that made by Mr. Gustav Hamel last week, with a passenger, from Dover to Cologne. Starting from Dover Aerodrome (accompanied by Mr. F. Dupree, of the staff of the Standard, by whom arrangements for the flight had been made), he left Dover as 12.40 p.m. Making his way across the Channel, the French coast was picked up just south of Dunkirk, and then a course was set by the aid of the compass for Mechlin. Across Belgium and Holland the military Blériot sped its way, but the storms which had to be passed through put the pilot out a little in his reckoning, and when the Rhine was sighted it was at a point about 60 miles north of Cologne. This deviation lengthened the journey considerably, but Cologne was safely reached at 4.58 p.m., and on alighting the English travellers were courteously received by the German officers. The duration of the flight was 4 hrs. 18 mins., and the distance as the crow flies from point to point is 245 miles. In view of the deviation, Mr. Hamel estimates the distance covered at 320 miles. Altogether, Mr. Hamel passed over five countries.
The Blériot monoplane which was used was fitted with an 80 h.p. Gnome motor, which, by the way, was equipped with the famous F. and S. ball-bearings. ³ The fuel used was Shell spirit, of which forty gallons were carried, and there was sufficient left at the journey’s end to cover another 100 miles, a distance which would have taken the aviator well out of the German Empire. For lubrication purposes Wakefield “Castrol” was used.
The Machine for New Zealand.
Hamel’s great flight from Dover to Cologne was arranged by the Standard in conjunction with the Imperial Air Fleet Committee, of which Lord Desborough is President, and on conclusion of the flight the aeroplane was offered to and accepted by the New Zealand Government. A fund has now been opened with the object of paying for the machine, the cost of which has been in the meantime guaranteed by the Standard and Messrs. Wm. Coward and Co., Ltd.
—FLIGHT, No. 226 (No. 17, Vol. V.), 26 April 1913, at Page 466
A short film of preparations for the flight is available from British PATHÉ at:
Gustav Hamel was born in Germany, but he and his family emigrated to England in 1910, becoming subjects of the Crown. In 1911 he attended the Blériot flying school at Pau, France, and earned Aéro-Club de France‘s aviator certificate number 358, and the Royal Aero Club (R.Ae.C.) certificate number 64. He completed many “firsts” in aviation, including delivering the first official air mail. Hamel disappeared on another flight across the English Channel, 23 May 1914.
The Blériot XI was a single-seat, single-engine monoplane, designed by Raymond Saulnier and built by Louis Charles Joseph Blériot. It was 24 feet, 11 inches (7.595 meters) long with a wingspan of 27 feet, 11 inches (8.509 meters) and overall height of 8 feet, 10 inches (2.692 meters). The wings had a chord of 6 feet (1.829 meters). The airplane had an empty weight of 507 pounds (229.9 kilograms).
In its original configuration, the airplane was powered by an air-cooled, 3.774 liter (230.273 cubic inches) R.E.P. two-row, seven-cylinder fan engine (or “semi-radial”) which produced 30 horsepower at 1,500 r.p.m., driving a four-bladed paddle-type propeller. The R.E.P. engine weighed 54 kilograms (119 pounds). This engine was unreliable and was soon replaced by an air-cooled 3.534 liter (215.676 cubic inch) Alessandro Anzani & Co., 60° (some sources state 55°) three-cylinder “fan”-type radial engine (or W-3) and a highly-efficient Hélice Intégrale Chauvière two-bladed fixed-pitch propeller, which had a diameter of 6 feet, 8 inches (2.032 meters). The Anzani W-3 was a direct-drive, right-hand tractor engine which produced 25 horsepower at 1,400 r.p.m. It was 1.130 meters (3 feet 8.49 inches) long, 1.500 meters (4 feet, 11.01 inches) high, and 0.720 meters (2 feet, 4.35 inches) wide. The engine weighed 66 kilograms (145.5 pounds).
Blériot Type XI, front view.Blériot Type XI, side view.Blériot Type XI, top view.
The Anzani-powered Blériot XI had a maximum speed of 76 kilometers per hour (47 miles per hour) and its service ceiling was 1,000 meters (3,281 feet).
Gustav Hamel and his Blériot XI at Radnorshire, Knighton, England, 29th August 1913.
¹ Also reported in contemporary newspaper articles as “Frank Dupre,” and frequently described as “an American.”
² Although not specifically identified in contemporary newspaper articles, the airplane flown by Hamel on this date was a Blériot XI-2 Génie, a two-place variant which was powered by a Gnome Lambda 7-cylinder rotary engine. The weights, dimensions and performance very likely varied from those described above. It was accepted by New Zealand on 4 March 1913, and was shipped aboard the White Star Line passenger ship, S.S. Athenic. It arrived at Auckland on 29 September 1913. The airplane was named Britannia.
According the Air Force Museum of New Zealand:
The first flight was not undertaken until January 1914, when Joe Hammond, a New Zealander and Second Lieutenant in the Royal Flying Corps, was engaged to demonstrate the machine. After several test flights from the Epsom Showgrounds, he was ready to take up his first passenger. Rather than select one of the many dignitaries present, he took aloft an actress, Miss Esme McLennan of the Royal Pantomime Company. Hammond was released from duty for his lapse in protocol, and the aircraft put into storage in New Zealand. The New Zealand Government offered it for service in World War One, and it returned to the UK in October 1914.
The New Zealand Monoplane Britannia over the Auckland Exhibition Grounds, January 1914. (Air Force Museum of New Zealand)
