The Martin 156, referred to in the press variously as the "Russian Clipper", "Moscow Clipper", or "Soviet Clipper" was a very large
flying boat
A flying boat is a type of seaplane with a hull, allowing it to land on water. It differs from a floatplane in having a fuselage that is purpose-designed for flotation, while floatplanes rely on fuselage-mounted floats for buoyancy.
Though ...
aircraft intended for trans-Pacific service. The single example of the M-156 was designed and built in response to a request from
Pan American Airways
Pan American World Airways, originally founded as Pan American Airways and more commonly known as Pan Am, was an airline that was the principal and largest international air carrier and unofficial overseas flag carrier of the United States for ...
to provide a longer-range replacement for the
Martin M-130
The Martin M-130 was a commercial flying boat designed and built in 1935 by the Glenn L. Martin Company in Baltimore, Maryland, for Pan American Airways. Three were built: the ''China Clipper'', the ''Pan Am Flight 1104, Philippine Clipper'' and ...
.
Design and development
Martin Martin may refer to:
Places Antarctica
* Martin Peninsula, Marie Byrd Land
* Port Martin, Adelie Land
* Point Martin, South Orkney Islands
Europe
* Martin, Croatia, a village
* Martin, Slovakia, a city
* Martín del Río, Aragón, Spain
* M ...
delivered three Martin Ocean Transport Model-130s (M-130) to Pan Am in 1935 which were flown as the ''
China Clipper
''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 airmail service from San Francisco to Manila on November 22, 193 ...
'', ''
Philippine Clipper'' and ''
Hawaii Clipper
Pan Am Flight 229 was a regularly scheduled passenger flight operated by Pan Am's Martin M-130 flying boats from San Francisco to Manila, which on July 28 1938, disappeared after flying over the Pacific Ocean. The flight was operated by ''Hawaii ...
''. Pan Am rejected the M-156 in preference to the
Boeing 314
The Boeing 314 Clipper was an American long-range flying boat produced by Boeing from 1938 to 1941. One of the largest aircraft of its time, it had the range to cross the Atlantic and Pacific oceans. For its wing, Boeing re-used the design fro ...
for its replacement.
Pan Am was seeking to expand its trans-Pacific air service between
San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...
and
Hong Kong
Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...
in
1937
Events
January
* January 1 – Anastasio Somoza García becomes President of Nicaragua.
* January 5 – Water levels begin to rise in the Ohio River in the United States, leading to the Ohio River flood of 1937, which continues into Feb ...
. This route had been pioneered by the Martin M-130 and Pan Am was in need of a larger aircraft. The San Francisco to Hawaii flight was and took 18 to 20 hours. Pan Am would have configured the M-156 as a 26-berth sleeper. The trans-Pacific flights flying Hawaii -
Midway Islands
Midway Atoll (colloquial: Midway Islands; ; ) is a atoll in the North Pacific Ocean. Midway Atoll is an insular area of the United States and is an unorganized and unincorporated territory. The largest island is Sand Island, which has housi ...
-
Wake Island
Wake Island (), also known as Wake Atoll, is a coral atoll in the Micronesia subregion of the Pacific Ocean. The atoll is composed of three islets – Wake, Wilkes, and Peale Islands – surrounding a lagoon encircled by a coral reef. The neare ...
-
Guam
Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...
-
Manila
Manila, officially the City of Manila, is the Capital of the Philippines, capital and second-most populous city of the Philippines after Quezon City, with a population of 1,846,513 people in 2020. Located on the eastern shore of Manila Bay on ...
- Hong Kong were less than half the California-to-Hawaii leg. With a lower fuel load requirement, the M-156 could carry additional passengers. The M-156 would have been converted to a 33- to 56-seat day-trip configuration. Pan Am and Matson Liners advertised an "Air-Sea Cruise" where Matson Liners carried passengers from San Francisco to Honolulu. Passengers would then transfer to Pan Am Clippers for westward flights to China and the Orient.
After Pan Am selected the Boeing 314, Martin negotiated a deal with the Soviet Union for this aircraft and the M-156 was never put into regular trans-Pacific service. The M-156 was sold to the Soviets and operated by
Aeroflot
PJSC AeroflotRussian Airlines (, ), commonly known as Aeroflot ( or ; , , ), is the flag carrier and the largest airline of Russia. Aeroflot is headquartered in the Central Administrative Okrug, Moscow, with its hub being Sheremetyevo Interna ...
on the Soviet Union's far-east routes under the designation PS-30.
Like the M-130, the M-156 was a four-engined,
parasol wing
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings.
A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...
design. While the M-156 retained the same length as its predecessor, its wingspan was increased by more than with the addition of
flap
Flap may refer to:
Arts, entertainment, and media
* ''Flap'' (film), a 1970 American film
* Flap, a boss character in the arcade game '' Gaiapolis''
* Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland''
Biology and h ...
s for increased control. The M-156 also differed from the M-130 by having a horizontal stabilizer mounted atop a pylon at the rear of the hull, with twin vertical stabilizers and twin rudders located atop the horizontal stabilizer.
Along with the increase in wing size, fuel capacity was expanded from the M-130's 3,165 gal (11,981 L) to a total of 4,260 gal (16,126 L) in the M-156/PS-30. Power for each of the four engines increased from to utilizing the more powerful
Wright Cyclone
Wright Cyclone was the name given to a family of air-cooled radial piston engines designed by the Wright Aeronautical Corporation and used in numerous American aircraft in the 1930s, 1940s and 1950s.
Background
The Wright Aeronautical Corporatio ...
G2 radials.

The Soviet government purchased the M-156 from Martin in 1937. The sale included a set of production plans, engineering specifications and manufacturing licenses as the Soviets intended to mass-produce this aircraft. The German invasion of the Soviet Union in 1941 negated these plans.
The single M-156/PS-30 was put into regular service in 1940 by Aeroflot and was utilized in the Soviet Far East along the Pacific coast. In this role, Aeroflot configured the aircraft to carry up to 70 passengers. It was flown by Aeroflot until 1944, at which time it was scrapped.
Specifications (Martin 156C)
See also
References
External links
{{Soviet transport designations
1930s United States airliners
Flying boats
156
Year 156 ( CLVI) was a leap year starting on Wednesday of the Julian calendar. At the time, it was known as the Year of the Consulship of Silvanus and Augurinus (or, less frequently, year 909 ''Ab urbe condita''). The denomination 156 for thi ...
Four-engined tractor aircraft
High-wing aircraft
Four-engined piston aircraft
Twin-tail aircraft