Tag Archives: Pratt & Whitney Twin Wasp S2A5-G

20 December 1934

“This photograph of the Clipper, aloft at the mouth of the Middle River, was taken from another plane by Robert F. Kniesche, Sun staff photographer.” (The Sun (Baltimore), Vol. 196–D, Friday 21 December 1934, Page 30, Columns 3–5 )

20 December 1934: William K. (“Ken”) Ebel lifted off from Middle River, Maryland, taking the Martin M-130 “Clipper” for its first flight. The M-130 was airborne for approximately 1 hours. Flying at 1,200 feet (366 meters), it reached 160 miles per hour (257 kilometers per hour).

Three-view illustration of the Martin M-130. (Flight, The Aircraft Engineer & Airships, Vol. XXVII, No. 1361, 24 January 1935, Page 99)

NC14716, named China Clipper, was the first of three Martin M-130 four-engine flying boats built for Pan American Airways. It was used to inaugurate the first commercial transpacific air service from San Francisco to Manila in November, 1935. Built at a cost of $417,000 by the Glenn L. Martin Company in Baltimore, Maryland, it was delivered to Pan Am on October 9, 1935.

The airplane was operated by a flight crew of 6 to 9, depending on the length of the flight, plus cabin staff, and could carry 18 passengers on overnight flights or a maximum 36 passengers.

Cutaway illustration of Pan American Airways’ Martin M-130 China Clipper. (Detail from larger image. NASM SI-89-1216-A. Full image at: https://airandspace.si.edu/multimedia-gallery/7135hjpg)

The Martin M-130 was 90 feet, 10.5 inches (27.699 meters) long with a wingspan of 130 feet, 0 inches (39.624 meters). It was 24 feet, 7 inches (7.493 meters) high. The total wing area was 2,315 square feet (215 square meters), including the “sea wings”. Its maximum takeoff weight was 52,252 pounds (23,701 kilograms).

Martin M-130 under construction, 24 May 1934. (SFO Museum)

The flying boat was powered by four air-cooled, supercharged Pratt & Whitney Twin Wasp S2A5-G two-row 14-cylinder radial engines with a compression ratio of 6.7:1. They had a normal power rating 830 horsepower at 2,400 r.p.m., and 950 horsepower at 2,550 r.p.m. for takeoff. They drove three-bladed Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The S2A5-G was 3 feet, 11.88 inches (1.216 meters) in diameter, 4 feet, 8.75 inches (1.441 meters) long, and weighed 1,235 pounds (560 kilograms).

The airplane had a cruise speed of 130 miles per hour (209 kilometers per hour) and a maximum speed of 180 miles per hour (290 kilometers per hour). The M-130’s service ceiling was 10,000 feet (3,048 meters). Its range was 3,200 miles (5,150 kilometers).

A Martin M-130, X14714, undergoing ground testing at the Glenn L. Martin Co. plant at Middle River, Maryland, 30 November 1934. (Lockheed Martin)
Martin M-130 X14714, 30 November 1934. (SFO Museum)

William Kenneth Ebel was born at Orangeville, Illinois, 2 January 1899. He was the first of two sons of Willam Henry Ebel, a farmer, and Nora Agnes Rubendall Ebel.

Ken Ebel attended Heidelberg College at Tiffin, Ohio. While at Heidelberg, on 1 October 1918, he enlisted as a private in the Student Army Training Corps (S.A.T.C.). With World War I coming to an end in November, Private Ebel was discharged 20 December 1918. Ebel graduated from Heidelberg in 1921 with a bachelor of arts degree.

Ebel returned to military service, enlisting as a private in the 104th Squadron (Observation), Maryland National Guard, based at Baltimore, Maryland.

Ebel continued his college education at the Case School of Applied Science in Cleveland, Ohio. In 1923, he earned a bachelor of science degree in mechanical engineering (B.S.M.E.)

On 11 September 1923, Private Ebel was appointed an aviation cadet, graduating from primary flying school on 3 June 1924. He received a commission as a 2nd lieutenant, Officers Reserve Corps (O.R.C.), United States Army, on 12 June 1925.

Continuing to serve as a reserve officer, in 1926 Ebel went to work as an engineer for the Glenn L. Martin Company, then located in Cleveland, Ohio. As a test pilot and engineer, Ebel flew the Martin M-130 four-engine flying boar

2nd Lieutenant Ebel,still with the 104th Squadron, Maryland National Guard, was promoted to the rank of 1st lieutenant on 21 December 1928. The U.S. Army advanced his rank to 1st lieutenant, Air Corps, 15 February 1929.

On 21 October 1929, William K. Ebel married Miss Florence E. Sherck at Seneca, Ohio. They would have two children, William Kenneth, Jr., and Lydia Lynn Ebel.

While testing a Martin BM-2 dive bomber, on 11 August 1932, W.K. Ebel “leaped to safety in a parachute Friday when a bombing plane he was testing failed to come out of a spin and crashed at Dahlgren, Virginia. The plane was going through its final tests before being delivered to the navy. It was wrecked in the crash.” Ebel became Member No. 495 of The Caterpillar Club.

On Thursday, 20 December 1934, Chief Pilot Ken Ebel took the new four-engine Martin M-130 flying boat, Pan American Airways System’s Hawaii Clipper, for its first flight from Middle River, Maryland. He also made the first flight of the M-156 “Russian Clipper” in 1935.

Ebel was promoted to captain, Air Corps, on 5 January 1935. On 21 August, he delivered the new Martin Model 146 “mystery bomber” to Wright Field for evaluation by the Bombardment Board.

In 1948, Ken Ebel became director of the Airplane Division of the Curtiss-Wright Corporation in Columbus, Ohio. Soon after, Curtiss-Wright sold its airplane division to North American Aviation. In 1950, the U.S. Navy’s primary submarine builder, the Electric Boat Company, appointed Ebel as Vice Pressident of Engineering for its Canadair Ltd., aircraft manufacturing subsidiary in Montreal, Quebec, Canada. (In 1952, after acquiring Convair, the corporation reorganized as General Dynamics.

William K. Ebel

Ebel returned to the United States in 1961 and served as a consultant for General Dynamics in Washington, D.C. Ebel retired in 1963, purchasing the Mount Pleasant Orchards near Baltimore.

Mrs. Ebel died in 1968. He later married Helene H. Topping.

William Kenneth Ebel, Ph.D., died at the Greater Baltimore Medical Center, 12 July 1972.

© 2019, Bryan R. Swopes

29 July 1938, 04:11 GCT

Pan American Martin M-130 Flying boat, NX14714, 9 September 1935. (Glenn L. Martin Co.)
Pan American Airways’ Martin M-130 flying boat, NX14714, Hawaii Clipper, 9 September 1935. (Lockheed Martin)

29 July 1938: At 12:08 p.m., local time, the Pan American Airways System flying boat Hawaii Clipper lifted off from the waters of Apra Harbor on the west side of Guam, an island in the western Pacific Ocean. The Clipper was on a planned 12½-hour flight to Manila in the Philippine Islands. On board were a crew of nine, with six passengers.

Pan American Airways System brochure, circa 1938. (Smithsonian Institution)

Hawaii Clipper never arrived at its destination. What happened to it and the fifteen persons on board remains one of the enduring mysteries of aviation history.

The flight was designated Trip #229. It had originated at Alameda, on San Francisco Bay, California, and flew to Honolulu in the Hawaiian Islands, then on to Midway Island, Wake Island, and Guam.

The Pan Am crew consisted of Captain Leo Terletzky, First Officer Mark A. Walker, Second Officer George M. Davis, Third Officer Jose M. Sauceda, Fourth Officer John W. Jewett, Engineer Officer Howard l. Cox, Assistant Engineer Officer T.B. Tatum, and Radio Officer William McGarty. The passengers were attended by Flight Steward Ivan Parker.

Captain Terletzky held a Transport Pilot’s License issued by the Aeronautics Branch of the United States Department of Commerce. He had flown more than 9,200 hours, with 1,614 hours in the Martin M-130.

Captain Terletzky's Transport Pilot License, issued 13 February 1930.
Captain Terletzky’s Transport Pilot’s License, issued 13 February 1930. (The Pan Am Historical Foundation)
Leo Terletzky (Davis-Monthan Aviation Field Register)

Captain Terletzky (there are alternate spellings, such as Terletsky, and he was also known as Leo Terlitz) was born 18 January 1894 at Odessa, Imperial Russia (now, Ukraine).

Following the Russian Revolution, he left his native country and traveled to Omsk, Siberia, and then to Yokohama, Japan, where he embarked on S.S. Empress of Japan, on 28 March 1919. The passenger liner arrived at Vancouver, British Columbia, Canada, 6 April. He then traveled on to Seattle, Washington, via the Canadian Pacific Railroad, arriving there on 9 April 1919.

Terletzky became a naturalized citizen of the United States of America, 15 December 1924.

On 1 July 1929, he married Miss Helen Sarepta Bowman ¹ at Miami Beach, Florida.

Canadian Pacific passenger liner S.S. Empress of Japan, passing First Narrows, seen from Brockton Point, looking north. This ship made 315 Pacific crossings. (Major James Skitt Matthews)

The airliner’s six passengers were: Lieutenant Commander Edward E. Wyman, United States Naval Reserve, of Bronxville, New York. Commander Wyman was a former assistant to Juan Trippe, the founder of Pan American Airways. He was now employed by the Curtiss-Wright Corporation. Pan American’s traffic manager, Kenneth A. Kennedy, was also on board.

Two scientists, Colonel Earl E. McKinley, M.D., United States Army Reserve, Dean of Medicine at George Washington University in Washington, D.C., a bacteriologist, and Fred C. Meier, Ph.D., were collecting airborne bacteriological samples to research transocean bacterial transfer.

Wah Sun Choy

Major Howard C. French, Air Corps, United States Army (Reserve), the commanding officer of the 321st Observer Squadron based at Vancouver, Washington, was also on board.

Finally, there was Wah Sun Choy (also known as “Watson Choy”), of New Jersey. Mr. Choy, an American citizen born in San Francisco, California, in 1901, was the owner of a tea room in Manhattan, New York City, New York, and two restaurants in Jersey City, New Jersey. One of them was named “China Clipper.”

Mr. Sun Choy was believed to be transporting $3,000,000 in U.S. Gold Certificates for the Kuomintang, the Nationalist Party of China, which was headed by Chiang Kai-shek.

A United States $10,000 Gold Certificate, Series 1934. (Bureau of Engraving and Printing)

Hawaii Clipper was a Martin M-130, NC14714. It was the first of three of the type built for Pan American Airways. With the experimental registration NX14714, it had made its first flight at Middle River, Maryland, 30 December 1934. When Hawaii Clipper departed Alameda, it had flown 4,751:55 hours, TTAF. When it made its last position report, it had flown another 55 hours, 58 minutes.

The first Martin M-130, NC14714, undergoing ground testing at the Glenn L. Martin Co. plant at Middle River, Maryland, 30 November 1934. (Lockheed Martin)

The Martin M-130 was a large, four-engine flying boat of all-metal construction, designed to carry as many as 36 passengers on transoceanic flights. The M-130 was 90 feet, 10.5 inches (27.699 meters) long with a wingspan of 130 feet, 0 inches (39.624 meters). It was 24 feet, 7 inches (7.493 meters) high. The flying boat had a maximum takeoff weight of 52,252 pounds (23,701 kilograms).

The M-130 was powered by four air-cooled, supercharged Pratt & Whitney Twin Wasp S2A5-G two-row 14-cylinder radial engines with a compression ratio of 6.5:1. The S2A5-G had a Normal Power rating of 830 horsepower at 2,400 r.p.m. to 3,600 feet (1,097 meters), and 950 horsepower at 2,550 r.p.m. for takeoff, using 87-octane gasoline. The engines drove three-bladed Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The S2A5-G was 4 feet, 8.75 inches (1.442 meters) long, 3 feet, 11.88 inches (1.216 meters) in diameter, and weighed 1,235 pounds (560 kilograms).

The airplane had a maximum speed of 180 miles per hour (290 kilometers per hour), and a cruise speed of 130 miles per hour (209 kilometers per hour). The service ceiling was 10,000 feet (3,048 meters). Its range was 3,200 miles (5,150 kilometers).

A pair of Pan American Airways Martin M-130 flying boats at Honolulu, Oahu, Hawaiian Islands. (Hawaii Aviation)
A pair of Pan American Airways Martin M-130 flying boats at Honolulu, Oahu, Hawaiian Islands. (Hawaii Aviation)

Hawaii Clipper departed its mooring at Apra Harbor at 11:39 a.m., local time (3:39 a.m., Manila time) and lifted off 29 minutes later. In addition to its six passengers, the airliner was carrying 1,138 pounds (516 kilograms) of cargo. The duration of the flight was estimated as 12 hours, 30 minutes. The M-130 carried sufficient fuel for 17 hours, 30 minutes of flight. Its gross weight was 49,894 pounds (22,632 kilograms) at takeoff, well under its maximum takeoff weight.

At 04:11 Greenwich Civil Time (12:11 p.m., local time), Radio Officer McGarty sent Hawaii Clipper‘s coded 04:00 Ded Reckoning ² position report. The deciphered message read:

Flying in rough air at 9,100 feet. Temperature 13 °C., wind 19 knots from 247° Position N. 12°27, E 130°40, ground speed made good, 112 knots, desired track 282°. Rain. During past hour conditions varied. 10/10ths sky above covered by strato cumulus clouds, base 9,200 feet. Clouds below 10/10ths sky covered by cumulus clouds whose tops were 9,200 feet. 5/10ths of the hour on instruments. Last DF bearing from Manila 101°

Great Circle line between Apra Harbor, Guam, and Manila, Luzon, Philippine Islands: 1,592 miles (2,562 kilometers). (Google Maps)

This placed the Clipper approximately 582 nautical miles (670 kilometers) east-southeast of Manila. The transmission was acknowledged. When the land-based radio operator tried to make contact one minute later to provide updated weather information, he received no reply. There were no further radio transmissions from Hawaii Clipper.

When Hawaii Clipper did not arrive at Manila, a large ocean search was begun. On 30 July, the Unites States Army transport ship USAT Meigs discovered an oil slick approximately 28 nautical miles (52 kilometers) south-southeast of the flying boat’s last reported position. The slick was described as being approximately 1,500 feet (457 meters) in circumference.

No physical evidence of the Martin M-130 has ever been found. What happened to cause its disappearance is unknown. While it is assumed that the airplane went down at sea, that might not have been the case. A telephone company employee on Lahuy Island (a small island off the coast of Luzon, east-southeast of Manila) reported having heard a large airplane above the clouds at 3 p.m., Manila Time. In 1938, the number of large airplanes operating in the Philippine Islands must have been fairly limited.

As with the disappearance of Amelia Earhart and Fred Noonan the previous year, there was no shortage of “conspiracy theories.” An example is that agents of the Empire of Japan had stowed away aboard Hawaii Clipper, hijacked the airplane and it was flown to Ulithi, an atoll in the Caroline Islands, and then on to Truk. The story goes on that the passengers and crew were murdered and their bodies buried under the foundation of a hospital then under construction.

Kawanishi H6K Type 97 Large Flying Boat.

Another story is that the Clipper was intercepted by a Japanese flying boat, such as the Kawanishi H6K Type 97 Large Flying Boat, which forced it to fly to an unknown destination, similar to the story above.

Only six months earlier, another Pan American flying boat, Samoan Clipper, a Sikorsky S-42B, NC16734, disappeared about two hours out of Pago Pago in the Samoan Islands. The airliner is believed to have exploded in midair. In that case, an oil slick and wreckage were found.

Recommended: Guy Noffsinger’s “The Lost Clipper,” at https://lostclipper.com

¹ Following the United States’ entry into World War II, Captain Terletzky’s widow, Mrs. Sarepta B. Terletzky, (née Helen Sarepta Bowman), a graduate of Smith College, joined the United States Navy. She was commissioned as a Lieutenant, W-VS, United States Naval Reserve, 4 August 1942. On 1 December 1945, she was promoted to the rank of lieutenant commander, and to commander, 1 January 1950. Mrs. Terletzky had been born at New York City, New York, 28 September 1895. She died at Miami, Florida, 4 August 1970.

² Ded Reckoning (Deductive Reckoning), often erroneously referred to as “dead reckoning,” is a method of navigation which uses a previously known position, time of flight, estimated speed and course of the aircraft based on forecast weather conditions, etc., to estimate the current geographical position. It is the standard method of navigation in the absence of radio aids or satellite position.

© 2018, Bryan R. Swopes

28 April 1937

Pan American Airways' Martin M-130, China Clipper, at Macau, 1937.
Pan American Airways’ Martin M-130, China Clipper, at Macau, 1937.

28 April 1937: The first transpacific flight by a commercial passenger airliner is completed when Pan American Airways’ Martin M-130, China Clipper, arrived at Hong Kong. The flight had departed San Francisco Bay, California, on 21 April with 7 revenue passengers and then proceeded across the Pacific Ocean by way of Hawaii, Midway Island, Wake Island, Guam, Manila, Macau, and finally Hong Kong. The Reuters news agency briefly reported the event:

AIR LINK AROUND WORLD FORGED.

China Clipper Lands At Hong Kong.

Hong Kong, April 28.

The Pan-American Airways flying boat China Clipper landed at 11:55 this morning from Manila and Macao. This links the Pan-American and Imperial Airways, completing the commercial air link round the world. —Reuter.

The Straits Times, 28 April 1937, Page 1, Column 4.

Pan American Airways’ China Clipper, a Martin M-130, NC14716, over Oakland, California. (Clyde Herwood Sunderland/Library of Congress 94509042)

The Oakland Tribune reported:

AIR CLIPPER SPANS SEAS TO HONGKONG

U.S. MAIL TO CHINA LANDED IN SIX DAYS

Plane Crew Feted at End Of Historic Hop From U.S. Via Philippines

     HONGKONG, April 28.—(AP)—A 30-year dream of ’round-the-world air service became reality today with the arrival of the Hongkong Clipper from Manila on the first regular flight between the two cities.

     The clipper, bridging the last 700-mile gap in the America-Asia service, placed the final link in an airplane chain whereby it is possible to encircle the world in less than a month, using scheduled commercial planes.

     The craft brought 2500 pounds of American cargo, including 100,000 letters and newspapers from the United States only six days old. The papers left Alameda, Calif., last Thursday aboard China Clipper, being transferred to the Hongkong Clipper at Manila. ¹

     A large crowd welcomed the clipper at Kaitak Airport. Included were Acting Governor N. L. Smith and representatives of all of the colony’s government and commercial activities.

     The clippers’ pilot, A. E. Laporte, and crew were escorted to a dais at the hangar, where the acting governor gave a speech of welcome.

     The plane, on its return flight on Thursday, is expected to carry 2500 pounds of cargo, including 40,000 letters.

     At a reception for the fliers, the acting governor said:

      “We are celebrating the welding of the last link in world air communication. The lessening of the physical gaps is the surest way of ending misunderstandings which have occurred between nations in the past.

“Hongkong offers congratulations, welcomes this American transpacific air service and hopes it will be another bond in the chain of goodwill.”

     Laporte said the Manila-Hongkong flight was “uneventful,” despite poor weather conditions necessitating intermittent blind flying.

Oakland Tribune, Vol. CXXVI, No. 118, Wednesday, 28 April 1937, Page 1, Column 3

The China Clipper, NC14716, was the first of three Martin M-130 four-engine flying boats built for Pan American Airways and was used to inaugurate the first commercial transpacific air service from San Francisco to Manila in November, 1935. Built at a cost of $417,000 by the Glenn L. Martin Company in Baltimore, Maryland, it first flew on 20 December 1934, and was delivered to Pan Am on October 9, 1935.

The airplane was operated by a flight crew of 6 to 9, depending on the length of the flight, plus cabin staff, and could carry 18 passengers on overnight flights or a maximum 36 passengers.

Martin M-130 China Clipper, NC14716, at Honolulu, Ohau, Hawaiian Islands. (Unattributed)
Martin M-130 China Clipper, NC14716, at Honolulu, Oahu, Hawaiian Islands. (Unattributed)

The Martin M-130 was 90 feet, 10.5 inches (27.699 meters) long with a wingspan of 130 feet, 0 inches (39.624 meters). It was 24 feet, 7 inches (7.493 meters) high. Its maximum takeoff weight was 52,252 pounds (23,701 kilograms).

The flying boat was powered by four air-cooled, supercharged, 1,829.389-cubic-inch displacement (29.978 liters) Pratt & Whitney Twin Wasp S2A5-G engines. These were two-row, 14-cylinder radial engines with a compression ratio of 6.7:1. The S2A5-G was rated at 830 horsepower at 2,400 r.p.m., and 950 horsepower at 2,550 r.p.m. for takeoff, burning 87-octane gasoline. They drove three-bladed Hamilton Standard Hydromatic constant-speed propellers through a 3:2 gear reduction. The engine was 3 feet, 11.88 inches (1.216 meters) in diameter and 4 feet, 8.75 inches (1.441 meters) long. It weighed 1,235 pounds (560 kilograms).

The airplane had a maximum speed of 180 miles per hour (290 kilometers per hour), and a cruise speed of 130 miles per hour (209 kilometers per hour). The service ceiling was 10,000 feet (3,048 meters) and its range was 3,200 miles (5,150 kilometers).

Martin M-130, NC14716, China Clipper, moored at some distant exotic locale.
Martin M-130, NC14716, China Clipper, moored at some distant exotic locale. (Unattributed)

¹ There may be confusion as to which airplane was flown from Manila to Hong Kong. Most newspapers identified it as China Clipper, while the Oakland Tribune called it Hongkong Clipper.

Pan American’s Hong Kong Clipper was a Sikorsky S-42, NC823M, which had entered service in December 1934. Many newspapers dated 28 April 1937 showed a photograph of NC832M arriving at Auckland, New Zealand, after a four-day, 7,000-mile survey flight from the United States.

Entering service in 1934, the airline had originally named the NC823M West Indies Clipper. This was changed to Pan American Clipper, and later, Hong Kong Clipper. The airplane crashed on takeoff and sank near Antilla, Cuba, 7 August 1944.

Pan American Airways System’s Sikorsky S-42, NC832M, over San Francisco Bay, 1935. (NASM SI-90-3001)

© 2020, Bryan R. Swopes