Shin Meiwa US-1A

The Shin Meiwa PS-1 and US-1A are large STOL aircraft designed for anti-submarine warfare (ASW) and air-sea rescue (SAR) work respectively by Japanese aircraft manufacturer Shin Meiwa. The PS-1 anti-submarine warfare (ASW) variant is a flying boat which carried its own beaching gear on board, while the search-and-rescue (SAR) orientated US-1A is a true amphibian.

Development of the PS-1 has its origins in flying boat research performed by the Shin Meiwa in the 1950s. The company, believing that their design was capable of regular use upon the open sea, petitioned the Japanese military to acquire the type as a maritime patrol aircraft (MPA). Following the demonstration of a converted Grumman HU-16 Albatross testbed aircraft, referred to as the UF-XS, the Japan Maritime Self-Defense Force (JMSDF) awarded Shin Meiwa a contract in 1966 to further develop its design via two further prototypes, which were designated PS-X. In 1969, the JMSDF placed the first order for an eventual fleet of 21 ASW aircraft, designated PS-1. Orders for the SAR variant, designated US-1A, were issued in the 1970s.

Shin Meiwa were keen to develop additional variants and derivative aircraft, including substantially larger designs which they had studied, but many of these ambitions remained as paper projects only. In the 1980s, the JMSDF adopted land-based Lockheed P-3 Orions, displacing the PS-1s from the ASW role and leading to the variant's retirement in 1989. Following the withdrawal of the last active US-1A in 2017, the type has been replaced by the ShinMaywa US-2, a newer design.

Design and development

Background

Following the end of the Second World War and the start of the Occupation of Japan, a ban on aircraft manufacturing imposed in December 1945 required Japan's aircraft industry to find other work. In the late 1940s, Japanese aircraft manufacturer Kawanishi Aircraft Company reorganised itself, becoming ShinMeiwa Industries. In the 1950s, the emergence of the Cold War between the United States and the Soviet Union led to the aircraft construction ban being rescinded. The UF-XS also featured a new T-tail arrangement which resembled that of the advanced variant of the Martin P5M-2 Marlin.

From 1962 onwards, the UF-XS performed numerous test flights, demonstrating the improved features which enabled a flying boat to both land and take-off from the open ocean. These tests were closely followed and critiqued by the Japanese military.

Operational history

thumb|A pair of US-1As led by a [[ShinMaywa US-2|US-2 performing an aerial demonstration above MCAS Iwakuni, Yamaguchi Prefecture, Japan, 2011]]

Between 1971 and 1978, 21 PS-1 flying boats entered service with the JMSDF. Starting in 1973, they were operated as Fleet Air Wing 31. On a typical ASW mission, a PS-1 would range over hundreds of square miles of ocean, landing between 12 and 16 times to dip its sonar. In the 1980s, the JMSDF decided to replace the PS-1 in the ASW role with land-based Lockheed P-3 Orions. The last examples of the ASW variant were phased out of service in 1989. It was outlived by the Search-and-Rescue oriented US-1A fleet, which continued to be used into the 21st century. Between 1976 and 1999, Japan's US-1A fleet participated in over 500 rescues and were responsible for the saving of 550 lives. The US-1A was retired in December 2017. According to aviation periodical Air International, 827 people have been rescued by US-1s since the type entered service during 1976. It has been succeeded in its role by the modernised US-2.

|prime units?=met

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General characteristics

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|crew=4 flight crew, 1 auxiliary crew seat and 2 observers

|capacity=20 seated passengers / 12 stretchers

|length m=33.46

|length note=

|span m=33.15

|span note=

|height m=9.95

|height note=

|wing area sqm=135.82

|wing area note=

|aspect ratio=8.1

|airfoil=

|empty weight kg=23300

|empty weight note=

|gross weight kg=36000

|gross weight note=

|max takeoff weight kg=43000

|max takeoff weight note=from water

:::: from land

|fuel capacity= usable fuel in five wing tanks + usable fuel in two fuselage tanks

|more general=

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Powerplant

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|eng1 number=4

|eng1 name=Ishikawajima-Harima / General Electric T64-IHI-10J

|eng1 type=turboprop engines

|eng1 kw=2605

|eng2 number=1

|eng2 name=Ishikawajima-Harima / General Electric T58-IHI-10-M2

|eng2 type=turboshaft

|eng2 kw=

|eng2 hp=

|eng2 shp=

|eng2 kn=

|eng2 lbf=

|eng2 note=Compressed air generator driving a C-2 compressor

|prop blade number=3

|prop name=Sumitomo built Hamilton Standard 63E60-27

|prop dia m=4.42

|prop dia note=fully-feathering reversible constant-speed propellers

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Performance

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|max speed kmh=511

|max speed note=<br/>

:::: at

|cruise speed kmh=426

|cruise speed note= at

|stall speed kmh=

|stall speed note=

|never exceed speed kmh=

|never exceed speed note=

|minimum control speed kmh=

|minimum control speed note=

|range km=3817

|range note=at at

|combat range km=

|combat range note=

|ferry range km=

|ferry range note=

|endurance=

|ceiling m=7195

|ceiling note=at MTOW

:::: at

|g limits=

|roll rate=

|climb rate ms=8.133

|climb rate note=at MTOW

:::: at

|time to altitude=

|wing loading kg/m2=331.4

|wing loading note=

|fuel consumption kg/km=

|power/mass=

|more performance=<br/>

Take-off distance to : 30° flap, BLC on, on land
Landing distance from : 40° flap, BLC on, on land
Take-off distance: at 40° flap, BLC on, on water
Landing distance: at 60° flap, BLC on, on water

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Armament

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|avionics=

:* APS-80N Ocean search radar

References

Citations

Bibliography

External links

ShinMaywa aircraft page
Footage of US-1A operations - YouTube.com
The Shin Meiwa PS-1 / US-1 & Harbin SH-5 Flying Boats - airvectors.net

Design and development

Background

Operational history

See also

References

Citations

Bibliography

External links