Pan American Airways’ Martin M-130 flying boat, China Clipper (NC14716), leaving the Golden Gate enroute to Honolulu, 22 November 1935. Photographed by Clyde Herwood Sunderland, Jr. (1900–1989).
22 November 1935: The Pan American Airways flying boat, China Clipper, a Martin M-130, NC14716, departed Alameda, California (an island in San Francisco Bay) at 3:46 p.m., Friday, and arrived at Honolulu at 10:39 a.m., Saturday, completing the first leg of a five-day trans-Pacific flight to Manila in the Philippine Islands.
The aircraft commander was Captain Edwin Charles Musick, with First Officer Robert Oliver Daniel (“Rod”) Sullivan. The navigator was Frederick Joseph Noonan, who would later accompany Amelia Earhart on her around-the-world flight attempt. There were also a Second Officer and two Flight Engineers. The cargo consisted of 110,000 pieces of U.S. Mail.
Captain Edwin Musick and R.O.D. Sullivan, at the center of the image, next to the China Clipper before leaving San Francisco Bay with the first transpacific airmail, 22 November 1935. The three men at the right of the image are (left to right) Postmaster General James Farley; Assistant Postmaster General Harllee Branch; and Pan American Airways’ President Juan Trippe.
Pan Am personnel called the Clipper “Sweet Sixteen,” referring to its Civil Aeronautics Board registration number, NC14716. The airplane and Humphrey Bogart starred in a 1936 First National Pictures movie, “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 was delivered to Pan Am on October 9, 1935. The airplane’s serial number was 558.
The M-130 was operated by a flight crew of 6–9, 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. (National Air and Space Museum SI-89-1216-A)Martin M-130 3-view drawing. (Flight)
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).
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).
Martin M-130 NC14716, right rear quarter view.
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).
Martin M-130, NC14716, China Clipper, moored at some distant exotic locale. (Unattributed)
Boeing 314, California Clipper, NC18602, over Oakland, California, 1937. Photographed for Pan Am by Clyde Herwood Sunderland, Jr. (1900–1989).(Clyde Sunderland Photograph Collection, Library, University of California Berkeley)
3–4 November 1945: On the evening of Saturday, 3 November 1945, the Boeing 314 Honolulu Clipper, NC18601, departed Honolulu, Oahu, Territory of Hawaii, enroute to San Francisco, California. The flying boat was under the command of Captain Sanis E. (“Robby”) Robbins, Pan American Airways, with First Officer Wally Reed, Second Officer Dunbar Carpenter, Radio Officer Jack B. Crawford, First Engineer Dan W. Broadwater, Second Engineer Robert J. Dernberger. There were 13 passengers and 10 crew members on board. The flight to San Francisco was expected to take 11 hours.
Approximately 5 hours into the flight, the number 3 engine (starboard wing, inboard) began to backfire. It was shut down and the propeller feathered. Captain Robbins decided to return to Hawaii. A short while later, the number 4 engine (starboard wing, outboard) also started to malfunction. It continued to run but eventually it was also shut down.
With two engines inoperative, the airplane was unable to maintain altitude. At 11:07 p.m. local, Captain Robbins, in total darkness, brought the flying boat to a “masterful” landing on the relatively calm surface of the Pacific Ocean. There were no injuries. The airplane suffered minor damage to the port sea wing, and started taking on water.
California Clipper, NC18602, another Boeing 314, also enroute to San Francisco, orbited Honolulu Clipper‘s position to guide rescue ships to scene. The following message was broadcast from Pearl Harbor:
PAN AMERICAN CLIPPER DOWN AT SEA AT 040935Z POSITION 2749N 14802W. PLANE IN GOOD CONDITION. IS ABLE TO COMMUNICATE ON [frequency deleted] KCS VOICECALL C18601 ON [frequency deleted] KCS. INVESTIGATE SIGHTINGS REPORT PERTINENT INFO TO ORIGINATOR.
Freighter S.S. John Henry Payne sighted flares fired from the flying boat and quickly arrived on scene. The ship took all of the passengers on board. Ten crew stayed aboard flying boat.
USS Manila Bay (CVE 61), a Casablanca-class escort aircraft carrier under the command of Captain Leon Johnson, was approximately 60 miles (97 kilometers) away, and had been ordered to take charge of efforts to salvage the airplane.
On arrival, a whale boat was sent to remove the remaining crew members from the flying boat. Wind and waves had increased and it was feared that the boat might damage the hull of the flying boat, so a rubber life raft was used to transfer the Clipper‘s crew to the whale boat. Aircraft mechanics were sent from Manila Bay to attempt to repair the airplane, but were not successful.
A whale boat from USS Manila Bay approaches Honolulu Clipper, 4 November 1945. (U.S. Navy)
Plans were made to rig the airplane for towing. 200 fathoms (1,200 feet/366 meters) of 6-inch (15.2 centimeter) diameter hawser was rigged from the aircraft carrier to the nose of the flying boat. Stabilizing lines were tied to the propeller hubs of the outboard engines. Manila Bay began towing the Honolulu Clipper and was gradually able to increase speed to 6 knots (7 miles per hour/11 kilometers per hour). About an hour after sunset, at about 7:30 p.m., the tow line parted.
Darkness and rising seas made it impossible to rig a new tow. Manila Bay stood by awaiting arrival of USS San Pablo (AVP-30) (Commander Charles Robert Eisenbach), a Barnegat-class seaplane tender, on Tuesday, 6 January, then departed for Pearl Harbor.
Seaplane tender USS San Pablo (AVP-30) standing by Honolulu Clipper. (U.S. Navy)USS San Pablo approaches the undamaged Honolulu Clipper. (U.S. Navy)
During the several days that Honolulu Clipper was afloat in the open ocean, weather increased to the point that it was considered too hazardous to approach it in a small boat, so the aviation tender closed on the airplane directly to try to take it on tow. Unfortunately, San Pablo hit the clipper and caused significant damage.
Hawaii Clipper from the bridge of USS San Pablo. The starboard wing is damaged and the Number 4 engine is missing. (U.S. Navy)
With salvage impossible, the derelict Honolulu Clipper was now considered a hazard to navigation. It was sunk by 20 mm gun fire from San Pablo.
Honolulu Clipper was the prototype for the Boeing Model 314 series flyjng boat. It had been designed to carry a maximum of 76 passengers and a crew of 10 a distance of 5,200 miles at 184 miles per hour. The design used the wings and engine nacelles of Boeing’s experimental Model 294 (XB-15) very long-range heavy bomber.
The Boeing Model 314 was a large four-engine, high-wing monoplane flying boat designed and built by the Boeing Airplane Company to take off and land on water. It was 106 feet (32.309 meters) long with a wingspan of 152 feet (46.330 meters). It had a maximum take off weight of 82,500 pounds (37,421 kilograms).
Boeing 314 prototype NX18601 in original configuration. (Boeing Airplane Company)
The airplane was built at Boeing’s Plant 1, then transported by Barge to Elliot Bay. It carried experimental registration NX18601. Test pilot Edmund Turney (“Eddie”) Allen made the first flight of the prototype on 7 June 1938. He reported that the flying boat had insufficient rudder control and that he had to vary engine power to turn it. The prototype was modified to a twin-tail configuration.
Boeing Model 314 NX18601 flying over Elliot Bay. Note the twin-tail configuration. (Boeing Airplane Company)
With two vertical fins and rudders, control was improved, but was still insufficient. A third, center, fin was added and this became the production configuration.
Prototype Boeing 314 NX18601 in triple-tail configuration, 24 November 1938. (U.S. Air Force/San Diego Air and Space Museum)
The Boeing 314 was powered by four air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.668 liter) Wright Aeronautical Division Cyclone 14 GR2600A2, two-row, 14-cylinder radial engines with a compression ratio of 7.1:1. They were rated at 1,200 horsepower at 2,100 r.p.m., and 1,550 horsepower at 2,400 r.p.m. for takeoff, burning 91/96 octane gasoline. These engines (also commonly called “Twin Cyclone”) drove three-bladed Hamilton Standard Hydromatic full-feathering constant-speed propellers with a diameter of 14 feet (4.267 meters) through a 16:9 gear reduction. The GR2600A2 was 5 feet, 2.06 inches (1.576 meters) long and 4 feet, 7 inches (1.387 meters) in diameter. It weighed 1,935 pounds (878 kilograms). The engines could be serviced in flight, with access through the wings.
The Boeing 314 had a maximum speed of 199 miles per hour (320 kilometers per hour), with a range of 3,685 miles (5,930 kilometers) at its normal cruising speed of 183 miles per hour (295 kilometers per hour). Its service ceiling was 13,400 feet (4,084 meters). The fuel capacity was 4,246 gallons (16,073 liters).
Boeing built six Model 314 and another six 314A flying boats for Pan American Airways and British Overseas Airways Corporation. Pan Am paid $549,846.55 for each 314, about $9,545,726.07 in 2017 dollars, and Boeing lost money on every one sold.
Honolulu Clipper was leased to the United States Navy by Pan American Airways, 17 December 1942, and assigned Bureau of Aeronautics serial number (“Bu. No.”) 48227. The airplane continued to be operated by Pan Am crews.
A Pan American Airways Boeing 314 at Hawaii. (San Diego Air and Space Museum)
Sanis E. (“Robby”) Robbins was born at Matthews, Indiana, 17 September 1898. He was the sixth of seven children of William S. Robbins, a real estate agent, and Sarah Ellen Brokaw Robbins.
Robbins enlisted as a Private, United States Army, at Camp Dodge, Iowa, 26 June 1916. He was promoted to Private First Class on 1 August 1916, and to Corporal, 18 December 1916. Corporal Robbins was hospitalized at Brownsville, Texas, 4–23 January 1917. He was released from military service at Fort Des Moines, Iowa, 20 February 1917, shortly before the United States entered World War I. A 1920 Air Service Information Circular listed Second Lieutenant Sanis E. Robbins as a pursuit pilot, residing at Cassia, Florida.
Robby Robbins married Miss Virginia J. Bing. They would have three children.
Robbins was commissioned as a Lieutenant Commander, United States Naval Reserve, 15 September 1940. He held this rank until at least 1955.
Captain Sanis E. Robbins died at Palo Alto, California, 8 August 1961, at the age of 62 years. He was buried at the Golden Gate National Cemetery, San Bruno, California.
Pan American Airways Boeing 314 NC18604, Atlantic Clipper, taking off. (NASM)
“Nov. 2, 1947: The Hughes Aircraft H-4 Hercules “Spruce Goose” during short flight in the Long Beach-Los Angeles Harbor. This photo was published in the Nov. 3, 1947 L.A. Times.” (Los Angeles Times)
2 November 1947: Howard Hughes’ Hughes Aircraft Company H-4 Hercules flying boat, NX37602, made its first and only flight at the harbor of Los Angeles, California. The new media called it “The Spruce Goose” due to its strong but lightweight wooden construction. As with the famous de Havilland DH.98 Mosquito fighter-bomber, the use of wood freed up valuable metal alloys during World War II.
Conceived by Henry J. Kaiser, the airplane was initially called the HK-1. It was designed to carry as many as 750 fully-equipped soldiers on transoceanic flights.
Hughes H-4 Hercules NX37602 in San Pedro Bay, 2 November 1947. Two U.S. Navy heavy cruisers and a fleet oiler are in the background. On the horizon is Santa Catalina Island. (LIFE Magazine)
The H-4 is 218 feet, 8 inches (66.650 meters) long with a wingspan of 320 feet, 11 inches (97.815 meters). Its height is 79 feet, 4 inches (24.181 meters). The Hercules’ designed loaded weight is 400,000 pounds (181,437 kilograms).
The flying boat was powered by eight air-cooled, supercharged 4,362.49-cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major VSB11-G (R-4360-4A) four-row 28-cylinder radial engines with a compression ratio of 7:1. The R-4360-4A had a Normal Power rating of 2,500 horsepower at 2,550 r.p.m. to 5,000 feet (1,524 meters), 2,200 horsepower at 2,550 r.p.m. to 14,500 feet (4,420 meters), and a Takeoff rating of 3,000 horsepower at 2,700 r.p.m. The Military Power rating was also 3,000 horsepower at 2,700 r.p.m., to an altitude of 1,500 feet (457 meters), then decreased to 2,400 horsepower at 2,700 r.p.m. to 13,500 feet (4,115 meters). The engines turned four-bladed Hamilton Standard propellers with a diameters of 17 feet, 2 inches (5.232 meters) through a 0.425:1 gear reduction. The R-4360-4A was 8 feet, 0.75 inches (2.457 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,390 pounds (1,538 kilograms).
On its only flight, the H-4 Hercules traveled approximately one mile (1.6 kilometers) at 135 miles per hour (217 kilometers per hour), remaining in ground effect. It never flew again, and its estimated performance was never verified through flight testing.
Howard Robard Hughes, Jr., in the cockpit of the H-4 Hercules, 6 November 1947. (J.R. Eyerman/LIFE Magazine)
The airplane is on display at the Evergreen Aviation and Space Museum, McMinnville, Oregon.
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’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)
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.
Martin XPB2M-1 Mars, Bu. No. 1520. (Hans Groenhoff Photographic Collection, Smithsonian Institution National Air and Space Museum NASM-HGC-1059)
3 July 1942: Chief Test Pilot William Kenneth Ebel, Ph.D., Vice President of Engineering for the Glenn L. Martin Company, took the Martin Model 170, s/n 877, for its first flight, lifting off from the waters of Chesapeake Bay. Dr. Ebel’s co-pilot was Ellis Dent Shannon, who would later become the chief test pilot for Convair.
Designated XPB2M-1 Mars, Bureau of Aeronautics serial number (“Bu. No.”) 1520, by the United States Navy, the flying boat was a prototype for a long-range patrol bomber. The first rivets had been driven for the airplane’s keel 22 August 1940, and the Mars was launched 8 November 1941. During a test in December 1941, the prototype had been damaged when a runaway propeller tore away from the No. 3 engine.
The Martin Mars prototype was launched 8 November 1941. (Charles M. Daniels Collection, San Diego Air & Space Museum Archives, Catalog #: 15_001975)
The U.S. Navy’s experiences early in World War II led it to adopt the Consolidated B-24 Liberator as its long range bomber (PB4Y-1 and PB4Y-2 Privateer). The XPB2M-1 was converted to a transport configuration, the XPB2M-1R, in 1943. The Navy ordered twenty transport versions, designated JRM-1. By the end of the war, only six had been built and the remaining order was cancelled.
Martin Model 170 Mars (XPB2M-1 Bu. No. 1520) at the Glenn L. Martin Co. ramp, near Baltimore, Maryland, 13 May 1942 (United States Navy, National Naval Aviation Museum, NMNA 1985.0481.003)
Crew: 11
The Martin XPB2M-1 was 118 feet, 9 inches (36.195 meters) long with a wing span of 200 feet, 0 inches (60.96 meters), and height of 37 feet, 4 inches (11.379 meters). The hull had a maximum width (“beam”) of 13 feet, 6 inches (4.115 meters). The total wing area was 3,683 square feet (342.2 square meters). The flying boat had an empty weight 75,573 pounds (34,279 kilograms), and gross weight of 140,000 pounds (63,503 kilograms).
The XPB2M-1 prototype was powered by four air-cooled, supercharged, cubic-inch-displacement Wright R-3350-4 engines with a compression ratio of 6.85:1. Burning 100-octane aviation gasoline, these engines had a normal power rating of 1,700 horsepower at 2,300 r.p.m., and 2,000 horsepower at 2,400 r.p.m., at Sea Level for Takeoff. They drove three-bladed 16 foot, 6 inch (5.029 meters) diameter Curtiss Electric constant-speed propellers through a 16:7 gear reduction. The R3350-4 was 5 feet, 11.5 inches (1.816 meters) long, 4 feet, 7.12 inches (1.400 meters) in diameter, and weighed 2,450 pounds (1,111 kilograms).
The prototype Mars had a maximum speed of 221 miles per hour (356 kilometers per hour) at 4,500 feet (1,372 meters). It took 27.1 minutes to climb to 10,000 feet (,048 meters), and its service ceiling was 14,600 feet (4,450 meters). The flying boat’s fuel capacity was 10,410 gallons (39,406 liters), with 664 gallons (2,514 liters) of lubricating oil. This gave it a maximum range of 4,945 statute miles (7,958 kilometers)at 135 miles per hour (217 kilometers per hour). The maximum endurance was 37.1 hours at 131 miles per hour (211 kilometers per hour).
In the patrol bomber configuration, the XPB2M-1 could carry bombs or torpedoes. It was armed with machine guns for defense.
Assigned to VR-8, Pax River, 27 Nov 1943; later to VR-2, NAS Alameda. withdrawn from service March 1945, and beached at Alameda. April 1945 returned to Martin Co. for JRM-1 crew training.. Maint trainer til ’49. Broken up
PAX to Natal 4,375 mi w 13,000#
JRM: 0 -lift over drag coefficient 0.0233, max lift over drag 16.4
Martin Mars taxi test (Charles M. Daniels Collection, San Diego Air & Space Museum Archives, Catalog #: 15_001976)Martin Model 170 in flight. (Charles M. Daniels Collection, San Diego Air & Space Museum Archives, Catalog #: 15_001977)
Not So Graceful
It was not so graceful as it was towed from the Martin plant into the misty bay by small auxiliary craft.
Through the mists from following craft it looked like as large gray whale.
It was moved slowly by the power boats down Dark Head Creek from the plant and into the channel of the bay, 15 miles north of the mouth of the Patapsco River.
At the controls was William K. Ebel, chief test pilot and vice-president in charge of engineering at the Martin Company.
Maneuvered Slowly
He maneuvered the Mars slowly. When the towing boats cast off and while fireboats stood by, he started each engine separately.
It was at this point last December, during a water test, that the No. 3 propeller tore away.
No such mishap occurred yesterday. As the motors warmed, Ebel took the flying boat in half circles, first right, then left.
Then he “gunned” her and the Mars sailed through the water down the bay to meet boats carrying naval officials, executives of the Martin Company and Washington officials.
Twenty-Man Crew
With the twenty-man crew headed by Pilot Ebel, Co-Pilot Ellis E. Shannon, Capt. Harold Gray of Pan American Airways and Flight Engineer Benjamin Zelubowski, the ship warmed up for thirty minutes.
Brig. Gen. James H. Doolittle sat with Glenn L. Martin in the observer’s boat.
Out of the sky came a not-so-small navy amphibian plane. It paced the huge flying boat down the Chesapeake and hung over its right wing as the four largest propellers in the world lifted the ship from the water.
Together, the two planes disappeared toward the southwest. Within thirty minutes the Mars was back. It “bumped” easily four times and sat down just as easily in the water.
Martin Jubilant
Within a few minutes it was off again. This time it met the water evenly as it landed, then was immediately taken off again.
Its manufacturer, Glenn L. Martin, was jubilant over the flying boat’s maiden performance.
—The Sun, Baltimore, Maryland, Vol. 211, No. 42, Saturday, 4 July 1942, Page 18, Columns 3 and 4, and continued on Page 4, Column 6
Martin XPB2M-1 Mars with a 1941 Piper J3C-65 Cub, NC40743. (Hans Groenhoff Photographic Collection, Smithsonian Institution National Air and Space Museum NASM-HGC-1073)
William Kenneth Ebel was born at Orangeville, Illinois, 2 January 1899. He was teh son of Willam Henry Ebel, a farmer, and Nora Agnes Rubendall Ebel.
One 1 October 1918, Ebel was enlisted as a private in the Student Army Training Corps (SATC). He was trained at Heidelberg College, Tiffin, Ohio. With the end of the War, Private Ebel was discharged 20 Dec 1918.
Ebel continued his education at Heidelberg, graduating with a Bachelor of Arts (B.A.) degree in 1921, and in 1923, he completed a Bachelor of Science in Mechanical Engineering (B.S.M.E.) at the Case School of Applied Science, Cleveland, Ohio.
Also in 1921, Ken Ebel joined the 104th Observation Squadron, Maryland National Guard, based at Baltimore. He was assigned as an aviation cadet from 11 September 1923 to 3 June 1924. He was trained as a pilot at the National Guard Primary Flying School.
On 12 January 1925, William K. Ebel was commissioned as a second lieutenant, Air Service, Officers Reserve Corps. He was promoted to first lieutenant, Air Corps, 21 December 1926. He continued to serve with the Maryland National Guard
Also in 1926, Lieutenant Ebel began his career as an engineer and test pilot for the Glenn L. Martin Company.
Effective 15 February 1929, Ebel’s reserve officer’s commission was converted to first lieutenant, Air Corps.
On 21 October 1929, William Kenneth Ebel married Miss Florence E. Sherck at Seneca, Ohio. The would have two children.
Ebel was promoted to captain, Air Corps, 5 January 1935.
The first Martin Marauder, B-26-MA 40-1361, takes off for the first time at Middle River, Maryland, 25 November 1940. (U.S. Air Force)
On 25 November 19840, Ken Abel made the first flight of the Martin B-26 Marauder twin-engine medium bomber.
Ebel earned a doctorate degree in engineering (Ph.D.) from Case.
After the War, Ebel left Martin. In 1948, he became the director of the airplane division Curtiss Wright Corporation at Columbus, Ohio. In 1950 he was appointed vice president of engineering for Canadair Ltd., a Canadian aircraft manufacturer owned by the General Dynamics Corporation. After serving as a consultant for General Dynamics in Washington, D.C., Ken Ebel retired.
Mrs. Ebel died in 1968. He later married Ms. Helene H. Topping
Walter Kenneth Ebel died at the Greater Baltimore Medical Center, Baltimnore, 12 July 1972.
22 November 1935: The Pan American Airways flying boat, China Clipper, a Martin M-130, NC14716, departed Alameda, California (an island in San Francisco Bay) at 3:46 p.m., Friday, and arrived at Honolulu at 10:39 a.m., Saturday, completing the first leg of a five-day trans-Pacific flight to Manila in the Philippine Islands.
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 was delivered to Pan Am on October 9, 1935. The airplane’s serial number was 558.
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).
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