Tag Archives: Pratt & Whitney Hornet S1E-G

11 January 1938

January 11, 2024AviationAircraft Accident, Edwin Charles Musick, Fédération Aéronautique Internationale, Flying Boat, NC16734, Pan American Airways, Pratt & Whitney Hornet S1E-G, Samoan Clipper, Sikorsky S-42B, Transoceanic Flight, USS Avocet (AVP-4), Vought-Sikorsky Aircraft DivisionBryan Swopes

11 January 1938: Pan American Airways’ Sikorsky S-42B NC16734, Samoan Clipper, took off from Pago Pago, American Samoa, enroute Auckland, New Zealand. The airplane had a crew of seven, commanded by Captain Edwin C. Musick, the airline’s senior pilot, and a cargo of mail.

About two hours out, the number four engine began leaking oil. Captain Musick ordered the engine shut down. The flight radioed that they were returning to Pago Pago. They never arrived. Wreckage, a large oil slick, various documents and articles of the crew’s clothing were found by the U.S. Navy seaplane tender USS Avocet (AVP-4), 14 miles (22.5 kilometers) west of the island. It was apparent that the S-42 had exploded in mid-air.

The cause of the explosion is not known with certainty but based on Captain Musick’s handling of a similar problem with one of Samoan Clipper‘s engines on an earlier flight, a possible cause can be suggested.

Sikorsky S42B NC16734, Samoan Clipper, taxiiing on water. Right front quarter. (Hawaii Aviation) — Pan American Airways’ Samoan Clipper. (Hawaii Aviation)

On the earlier flight, the number four engine had begun seriously overheating and Musick ordered the flight engineer to shut it down. Because of the decreased power with only three engines, Captain Musick ordered the crew to begin dumping fuel to decrease the weight of the airplane before landing.

Pan American had tested the fuel dumping characteristics of the Sikorsky S-42 using dye, and had learned that because of the air flow patterns around the wings, the fluid tended to accumulate around the trailing edge of the wings and that it could actually be sucked into the wings themselves.

As fuel was being dumped on the previous flight, fuel vapors were present in the cabin, requiring all electrical systems to be shut off—even though it was night. Liquid gasoline was also dripping into the cockpit from the wing above.

Sikorsky S-42B NC16734, Samoan Clipper, at Pago Pago, American Samoa, 24 December 1937. — Pan American Airways’ Sikorsky S-42B NC16734 at Pago Pago, 24 December 1937. (Unattributed)

Samoan Clipper had been very heavy with fuel when it departed for the long transoceanic flight to Auckland. Presuming that Captain Musick once again ordered fuel to be dumped prior to landing back at Pago Pago, and that the vapors collected around the wings, the fuel could have been detonated by the electrical motors which were used to lower the flaps for flight at slower speed, or by coming into contact with the hot exhaust of the engines.

Two independent investigations were carried out by Pan American and by the United States Navy, and both came to this conclusion.

Musick, Edwin Charles, Chief Pilot, Pan American Airways. — Captain Edwin Charles Musick, Chief Pilot, Pan American Airways. (1894–1938)

There were no survivors of the explosion. Killed along with Captain Musick were Captain Cecil G. Sellers, Second Officer P.S. Brunk, Navigator F.J. MacLean, Flight Engineer J.W. Stickrod, Flight Mechanic J.A. Brooks and Radio Operator T.D. Findley.

The Sikorsky S-42B 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 68 feet (20.726 meters) long with a wingspan of 118 feet, 2 inches (36.017 meters). The S-42 had an empty weight of 19,764 pounds ( kilograms) and gross weight of 38,000 pounds ( kilograms). It could carry up to 37 passengers.

The S-42B 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-42B has 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), and it could maintain 7,500 feet (2,286 meters) with three engines. Its range was 1,930 miles (3,106 kilometers).

Sergievsky, Boris Vasilievich — Boris Vasilievich Sergievsky. (Test & Research Pilots, Flight Test Engineers)

During flight testing of the S-42, Sikorsky test pilot Boris Vasilievich Sergievsky, with co-pilot Raymond B. Quick, set three Fédération Aéronautique Internationale world records for payload and altitude.¹ Later, Captain Musick, with Sergievsky and world-famous aviator Charles A. Lindbergh, flew the S-42 to set eight Fédération Aéronautique Internationale world records for speed.²

Ten Sikorsky S-42, S-42A and S-42B flying boats were built for Pan Am. None remain in existence.

Pan American Airways' Sikorsky S-42B NC16734, Samoan Clipper, moored at mechanic's Bay, Auckland, New Zealand, December 1937. The flying boat in the background is a Short S.23 Empire, G-ADUT, named Centaurus. (Turnbull Library) — Pan American Airways’ Sikorsky S-42B NC16734, Samoan Clipper, moored at Mechanic’s Bay, Auckland, New Zealand, December 1937. The flying boat in the background is a Short S.23 Empire, G-ADUT, named Centaurus. (Turnbull Library)

¹ 26 April 1934 FAI Record File Numbers: 11583: Greatest load to 2,000 meters (6,562 feet): 7,533 kilograms (16,652 pounds). 17 May 1934: 11582 and 11978: Altitude with a 5,000 Kilogram (11,023 pounds) Load, 6,220 meters (20,407 feet).

² 1 April 1934 FAI Record File Numbers: 11517: Speed over a closed circuit of 1,000 Kilometers (621.3 statute miles), 253,60 km/h (157.58 m.p.h.); 11518: . . . with a 500 Kilogram (1,102 pounds) Payload, 253,60 km/h (157.58 m.p.h.); 11519: . . . with a 1,000 Kilogram (2,205 pounds) Payload, 253,60 km/h (157.58 m.p.h.); 11520: . . . with a 2,000 kilogram (4,409 pounds) Payload, 253,60 km/h (157.58 m.p.h.); 11521: Speed over a closed circuit of 2,000 Kilometers (1,242.7 statute miles), 253,18 km/h (157.32 m.p.h); 11522: . . . with a 500 Kilogram Payload, 253,18 km/h (157.32 m.p.h.); 11523: . . . with a 1,000 Kilogram Payload, 253,18 km/h (157.32 m.p.h.); 11524: . . . with a 2,000 Kilogram Payload, 253,18 km/h (157.32 m.p.h.).

28 July 1935

July 28, 2023AviationBoeing Airplane Company, Boeing B-17 Flying Fortress, Boeing Field, Boeing Model 299, Boeing XB-17, Bomber, Browning Aircraft Machine Gun Caliber .30 M2, First Flight, Heavy Bomber, Hornet, Les Tower, Leslie Ralph Tower, Louis Waite, Pratt & Whitney Hornet S1E-G, Prototype, Test Pilot, X13372Bryan Swopes

Boeing test pilot Les Tower. (Boeing) — Boeing’s Chief Test Pilot Leslie R. Tower.

28 July 1935, At Boeing Field, Seattle, Chief Test Pilot Leslie Ralph (“Les”) Tower and Louis Waite took off on the maiden flight of the Boeing Model 299, X13372,¹ a prototype four-engine long range heavy bomber. For approximately one-and-a-half hours, Tower flew back and forth between Tacoma and Fort Lewis. When he landed, he said, “It handles just like a little ship—a little bigger, of course.”

The Boeing Model 299 was a four-engine bomber operated by a crew of eight. It was designed to meet a U.S. Army Air Corps proposal for a multi-engine bomber that could carry a 2,000 pound (907 kilogram) bomb load a distance of 2,000 miles (3,219 kilometers) at a speed greater than 200 miles per hour (322 kilometers per hour). Design of the prototype began in June 1934 and construction was started 16 August 1934. The Air Corps designated it B-299, and later, XB-17. It did not carry a military serial number, being marked with civil experimental registration X13372.

The Boeing Model 299 with Mount Rainier. (U.S. Air Force)

The Model 299 was 68 feet, 9 inches (20.955 meters) long with a wingspan of 103 feet, 9–3/8 inches (31.633 meters) and height of 14 feet, 11–5/16 inches (4.554 meters). Its empty weight was 21,657 pounds (9,823 kilograms). The maximum gross weight was 38,053 pounds (17,261 kilograms).

The prototype was powered by four air-cooled, supercharged, 1,690.537-cubic-inch-displacement (27.703 liter) Pratt & Whitney Hornet S1E-G nine-cylinder radial engines with a compression ratio of 6.5:1. The S1E-G was rated at 750 horsepower at 2,250 r.p.m., and 875 horsepower at 2,300 r.p.m. for takeoff, using 87-octane gasoline. They turned 11 foot, 6 inch (3.505 meters) diameter, three-bladed, Hamilton Standard Hydromatic 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)

Boeing Model 299 (United States Air Force 050406-F-1234P-028) — Boeing Model 299. (U.S. Air Force)

In flight testing, the Model 299 had a cruise speed of 204 miles per hour (328 kilometers per hour) and a maximum speed of 236 miles per hour (380 kilometers per hour) at 10,000 feet (3,048 meters). The service ceiling was 24,620 feet (7,504.2 meters). Its maximum range was 3,101 miles (4,991 kilometers). Carrying a 2,573 pounds (1,167 kilograms) load of bombs, the range was 2,040 miles (3,283 kilometers).

Boeing 299 NX13372, all engines running. — Boeing 299 X13372, all engines running.

The XB-17 could carry eight 500 pound (226.8 kilogram) bombs in an internal bomb bay. Defensive armament consisted of five air-cooled Browning .30-caliber machine guns.

Nose turret of the Boeing Model 299, photographed 24 July 1935. (U.S. Air Force) — Nose turret of the Boeing Model 299, photographed 24 July 1935. (The Boeing Company)

X13372 was destroyed when it crashed on takeoff at Wright Field, Dayton, Ohio, 30 October 1935. An Army Air Corps pilot making his first familiarization flight neglected to remove the control locks. This incident led directly to the creation of the ”check list” which is used by all aircraft crew members.

Waist gun position of the Boeing 299. (U.S. Air force) — Waist gun position of the Boeing 299. (The Boeing Company)

Designated XB-17 by the Army Air Corps, this airplane and the YB-17 pre-production models that followed would undergo several years of testing and improvement before entering production as the B-17 Flying Fortress, a legendary airplane of World War II. By the end of the war 12,731 B-17s had been built by Boeing, Douglas and Lockheed Vega.

Boeing Model 299 X13372, designated XB-17, at Wright Field, Ohio, 1935. (U.S. Air Force)

Leslie Ralph Tower was born at Sisseton, South Dakota, 21 January 1903. He was the first of three children of Ralph R. Tower, a farmer who would later serve as a state senator for Montana, and Mayme Amanda Johnson Tower, a Swedish immigrant.

Les Tower attended high school at Polson, Montana, graduating in 1922. He then attended the University of Washington, where he studied engineering. He was a member of the Radio Club.

Tower enlisted in the United States Army as an aviation cadet, training at Brooks and Kelly airfields in Texas. He then served with the 2nd Bombardment Squadron at Langley Field, Virginia.

In 1925 Tower started working for Boeing as a draftsman, but soon began test flying new airplanes, which included the B-9 bomber and the Model 247 commercial airliner. He also demonstrated and delivered Boeing airplanes around the world.

On 20 August 1935, Tower and Louis Wait flew the Model 299 from Seattle to Dayton, approximately 2,100 miles, in 9 hours, 3 minutes, averaging 233 miles per hour (375 kilometers per hour).

Les Tower was aboard the XB-17 as an observer during the 30 October flight. He saw that the control locks had not been released and tried to reach them, but was unable. In the fire that followed the crash, Tower suffered severe burns to his face, right arm and both legs.

Leslie Ralph Tower died of his injuries 19 November 1935 at Miami Valley Hospital in Dayton. His remains were transported by train, escorted by Army airplanes, and were buried at Lakeview Cemetery, Polson, Montana.

¹ At that time, experimental and restricted category aircraft were prohibited from displaying the letter “N” at the beginning of their registration mark.

16 July 1935

July 16, 2023AviationBoeing Airplane Company, Boeing B-17 Flying Fortress, Boeing Field, Boeing Model 299, Boeing XB-17, Bomber, Browning Machine Gun Caliber .30 M2, Browning Machine Gun Caliber .50 AN-M2, c/n 1963, Model 299, Pratt & Whitney Hornet S1E-G, Prototype, Rollout, World War II, X13372Bryan Swopes

16 July 1935: Just over a year after design began, the Boeing Model 299, X13372,¹ a prototype four engine long range heavy bomber, was rolled out of its hangar at Boeing Field, Seattle, Washington for the first time. The largest land airplane built up to that time, it seemed to have defensive machine guns aimed in every direction. A Seattle Times reporter, Roland Smith, wrote that it was a “flying fortress.” Boeing quickly copyrighted the name.

After several years of testing, the Model 299 went into production as the B-17 Flying Fortress. By the end of World War II, 12,731 B-17 Flying Fortresses had been built by Boeing, Douglas and Lockheed Vega.

Rollout of teh Boeing Model 299, NX13372, prototype XB-17. (Museum of Science and Industry) — Rollout of the Boeing Model 299, X13372, prototype XB-17. (Museum of Science and Industry via *Seattle Post-Intelligencer*)

The prototype was powered by four air-cooled, supercharged, 1,690.537-cubic-inch-displacement (27.703 liter) Pratt & Whitney Hornet S1E-G nine-cylinder radial engines with a compression ratio of 6.5:1. The S1E-G was rated at 750 horsepower at 2,250 r.p.m., and 875 horsepower at 2,300 r.p.m. for takeoff, using 87-octane gasoline. They turned 11 foot, 6 inch (3.505 meters) diameter, three-bladed Hamilton Standard Hydromatic 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)

Cockpit of the Boeing Model 299. (U.S. Air Force) — Cockpit of the Boeing Model 299. (Boeing)

In flight testing, the Model 299 had a cruise speed of 204 miles per hour (328 kilometers per hour) and a maximum speed of 236 miles per hour (380 kilometers per hour) at 10,000 feet (3,048 meters). The service ceiling was 24,620 feet (7,504.2 meters). The maximum range was 3,101 miles (4,991 kilometers). Carrying a 2,573 pounds (1,167 kilograms) load of bombs, the range was 2,040 miles (3,283 kilometers).

Boeing XB-17 (Model 299) bombers and front gunners compartment. (U.S. Air Force photo) 060706-F-1234S-007

Nose turret of the Boeing Model 299, with .50-caliber machine gun, photographed 24 July 1935. (Boeing 8195)

Bomb sight position., 9 August 1935. (Boeing 8227-B)

The XB-17 could carry eight 500 pound (227 kilogram) bombs in an internal bomb bay. Defensive armament consisted of five air-cooled .30-caliber or .50-caliber Browning machine guns.

Starboard waist gunnner’s position of the Boeing 299. (Boeing)

Starboard waist gunners position, with Browning M2 .50-caliber machine gun and ammunition canisters. (Boeing)

NX13372 was destroyed when it crashed on takeoff at Wright Field, Dayton, Ohio, 30 October 1935. An Army Air Corps pilot making his first familiarization flight neglected to remove the control locks. This incident led directly to the creation of the “check list” which today is used by all aircraft crew members.

Boeing Model 299, left quarter, at Boeing Field, south of Seattle, Washington,August 1935. (Boeing)

Boeing Model 299, NXxxx72, the prototype XB-17. (U.S. Air Force) — Boeing Model 299, X13372, the prototype XB-17, at Wright Field, Ohio. (U.S. Air Force)

Boeing Model 299, left profile, at Boeing Field, 13 August 1935. (Boeing 8234-B)