View source for Ryan ST

{{Short description|American light airplane}}
{{Use mdy dates|date=January 2022}}
{{Use American English|date=January 2022}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Infobox aircraft
  |name= Ryan ST series
  |image=File:Ryan ST-A ‘S11’ (N7779).jpg
  |caption= A restored Ryan ST-A Special
  |type= Monoplane Trainer
  |manufacturer= [[Ryan Aeronautical Company]]
  |designer= [[T. Claude Ryan]]
  |first_flight= 8 June 1934
  |introduction= 1934
  |retired=
  |number_built=1,568
  |status= Production completed
  |primary_user= [[United States Army Air Forces]]
  |more_users= Netherlands East Indies Army and Navy <br> [[Royal Australian Air Force]]
  |developed_from=
  |variants=[[Ryan PT-22 Recruit]]
}}
[[File:Ryan PT22 at Old Warden.jpg|thumb|right|Ryan PT-22 Recruit at Old Warden 2009]]
[[File:Ryan NR-1 NAS Jax 1942.jpg|thumb|A U.S. Navy Ryan NR-1 at [[Naval Air Station Jacksonville|NAS Jacksonville]], 1942.]]
[[File:Ryan ST-3 in San Diego Bay Circa 1940.jpg|thumb|Ryan ST-3 floatplane in [[San Diego Bay]], circa 1950.]]

The '''Ryan ST'''s are a series of two seat, low-wing [[monoplane]] aircraft built in the United States by the [[Ryan Aeronautical Company]]. They were used as sport aircraft, as well as [[trainer (aircraft)|trainers]] by flying schools and the militaries of several countries.

==Design and development==
[[T. Claude Ryan]] was the founder of the Ryan Aeronautical Company, the second incarnation of a company with this name, and the fourth company with which he had been involved to bear his name<ref name=NZ>Russell, Stuart. [http://nzwarbirds.org.nz/gallery/warbirds-family-album/Ryan+STM+S-2.html "Ryan Stm-S2."] ''New Zealand Warbirds,'' 2002, 2014. Retrieved: 6 March 2015.</ref> (the first, Ryan Airlines, was the manufacturer of the Ryan NYP, more famously known as the ''[[Spirit of St. Louis]]''). He began the development of the '''ST''' (for "Sport Trainer", and also known as S-T),<ref>{{cite magazine |title=Operator's Profits Soar with Ryan S-T* |magazine=Aero Digest |date=June 1937 |publisher=Aeronautical Digest Publishing Corporation |volume=30 |issue=6 |page=53 |url=https://archive.org/details/aerodigest3019unse/page/53 |accessdate=21 July 2021}}</ref> the first design of the company, in 1933.<ref>Gunston, Bill. ''Jane's Fighting Aircraft of World War II''. London: Bracken Books, 1989. {{ISBN|1-85170-199-0}}.</ref>

The ST featured two open [[cockpit]]s in [[tandem]] in a [[Monocoque|semi-monocoque]] metal [[fuselage]] of two main frames – one steel, the other half of steel and half of aluminium alloy ([[alclad]]) – to take the loads from the [[Spar (aviation)|wing spars]] and six more alclad frames; and alclad skin.<ref name=RC/> It had wings in three sections of hybrid construction; the center section integral with the fuselage had tubular steel spars, the front spar a simple tube with an external brace to the upper fuselage, and the rear spar in the form of a parallel chord [[truss]].<ref name=RC/> The two outer wing panels had wooden spars and alclad ribs, with diagonal rods bracing the wings internally. Alclad sheet was used to form the leading edges, and fabric covered the whole structure. When attached, the outer wings were braced with [[flying wires]] to the fixed [[conventional landing gear]] and landing wires to the upper fuselage.<ref name=RC>Holcomb, Kevin.[http://www.airminded.net/st/const/st_const1.html#wing "Ryan ST Construction description."] ''Holcomb's Aerodrome''. Retrieved: 23 January 2008.</ref>

The fuselage only required eight [[bulkhead (partition)|bulkheads]], and no longerons or stringers were required. According to Cassagneres, "The stressed skin, of heavy 18 and 20 gauge 24ST Alclad, was riveted to the [[Drop hammer|drop-hammer]] formed [[duralumin|dural]] bulkhead rings." The main fuselage bulkhead, "was of built-up welded sheet steel and carried the important spar fittings as well as attachment points for the diagonal wing bracing strut, the upper landing wires, and lower flying wires."  Cassagneres goes on to state, "The wings were constructed of solid spruce spars, stamped aluminum alloy ribs, and steel compression members, and were fabric covered. Ailerons and flaps were steel and aluminum structure with fabric covering. All tail surfaces were constructed entirely of tubular aluminum alloy with stamped ribs, and fabric covered."<ref name="ec">{{cite book |last1=Cassagneres |first1=Ev |title=The Spirit of Ryan |date=1982 |publisher=TAB BOOKS Inc. |location=Blue Ridge Summit |pages=145–146, 158–160}}</ref>

Five STs were built, each powered with a 95HP Menasco B4 engine <ref name=JE>Taylor, M. J. H. ed. ''Jane's Encyclopedia of Aviation.'' London: Studio Editions Ltd., 1989. {{ISBN|1-85170-324-1}}.</ref> before the follow-on '''ST-A''' (A for [[aerobatics|''A''erobatic]]) was developed with a more powerful 125HP Menasco C4 engine. A single '''ST-B''' was produced, this being an ST-A with only one seat and an extra fuel tank where the front cockpit normally was; this aircraft was subsequently converted back to ST-A standard.<ref name=AF>[http://www.aerofiles.com/_ryan.html "Ryan."] ''Aerofiles.com,'' 13 March 2009. Retrieved: 23 January 2008.</ref> The ST-A was further developed as the '''ST-A Special''', with a super-charged 150HP Menasco C4-S engine of increased power.

In 1937 the ST-A Special was developed into a military version, the '''STM''' (also ST-M) series. The first STMs were virtually identical to the STA-Special. The STM-2 was derived from the STM with changes including wider cockpits to enable military pilots to enter and exit while wearing [[parachute]]s, external stringers, and provision for a machine gun on some examples.<ref name=JE/> The military also required a turnover brace and a hand-cranked intertia engine starter. Variants, designated the PT-16s and PT-20s, also had their wheel pants, fairings and tail cones removed.<ref name=ec/> Variants in the series included the STM-2P single-seat version armed with a [[machine gun]] delivered to [[Kuomintang|Nationalist China]]; and the STM-S2, which could be fitted with landing gear or with [[EDO Corporation|EDO Model 1965]] [[floatplane|floats]].<ref name=RC/><ref name="CW">Orphan, Graham M. "The Ryan ''ST'' in Australia (and the survivors of the breed)". ''Classic Wings Downunder'' magazine, Volume 7, No. 4, September/October 2000, pp. 26–29. ISSN 1172-9643.</ref>

After the ST-M came the '''ST-3''', a substantial redesign in 1941 partly brought about by the unreliability of the [[Menasco]] engines fitted to STs to that point. The [[United States Army Air Corps]] (USAAC) had purchased several dozen ST-M variants under various designations and had Ryan Aeronautical re-engine most with [[Kinner B-5|Kinner R-440]] radial engines.<ref name=JE/><ref name=PP/> The USAAC found the modification to be beneficial and asked Ryan Aeronautical to design a variant with this engine as standard, and with airframe modifications considered desirable from in-service experience. The ST-3 that resulted featured a longer and more circular wider fuselage, this being suggested by the circular radial engine. Other changes included a revised rudder, balanced ailerons and elevators, and strengthened main landing gear with the legs spaced further apart. The streamlining spats covering the mainwheels, found on ST series aircraft to that point, were deleted as well.<ref name=NZ/> The ST-3 served as the basis for military versions ordered by the USAAC and the [[United States Navy]] (USN).<ref name=JE/><ref>Mondey 2006, pp. 224–225.</ref>

The ST-3 gave rise to another model developed in 1941 and early 1942, this was the '''ST-3KR''' (for ''K''inner ''R''adial). The ST-3KR had a more powerful [[Kinner R-5]] engine fitted and became the definitive model; more than 1,000 military versions were built during [[World War II]] as '''[[Ryan PT-22 Recruit|PT-22 Recruits]]'''.<ref name=JE/> According to Cassagneres, "The only noticeable difference between the PT-21 and PT-22 was the metal landing gear fairings which covered the main gear structure, leaving the wheels exposed. Otherwise the airframe and its parts and components were interchangeable with the PT-22. One other difference from the later 22 model is in the aileron balance ring. On the 21 it is mounted below the aileron and on the 22 it's on top."<ref name=ec/>{{rp|196–197}} The final variant was the '''ST-4''', which was a version of the ST-3 with a wooden fuselage, developed in case a shortage of "[[strategic material]]s" (i.e. of metal) developed. Such a shortage did not eventuate and the ST-4 was not put into mass-production.<ref name=JE/>

Some U.S. Navy versions of the ST-3, the NR-1, were converted to specialized ground trainers to teach cadets how to taxi aircraft when on the ground or after landing, and especially in crosswinds. The main wing was clipped back to the landing gear; a small nose wheel added to prevent ground loops; a roll cage between cockpits to protect the pilot and cadet; and the throttle modified so the engine could not go over a certain RPM.<ref>[https://books.google.com/books?id=gN8DAAAAMBAJ&dq=Popular+Mechanics+Science+installing+linoleum&pg=PA32 "Navy Planes altered to protect cadet fliers."] ''Popular Mechanics'', December 1944, p. 32.</ref>

The first Ryan ST flew for the first time on 8 June 1934<ref name=NZ/> and production began the following year, when nine aircraft were delivered.<ref name=PP/> Except for 1937 (when 46 aircraft were built), production rates remained low for several years, at about one aircraft every two weeks. This changed in 1940 when deliveries to military forces began in earnest; production that year was just under three aircraft per week.<ref name=PP/> Total production of civil and military aircraft prior to the entry of the United States into [[World War II]] amounted to 315.<ref name=PP/><ref name=AFP>[http://www.aerofiles.com/ryanST-regs.html "Ryan ST serial number list."] ''Aerofiles,'' 13 March 2009. Retrieved: 23 January 2008.</ref> Another 1,253 military versions were produced in 1942 and 1943, for a total of 1,568 aircraft of all models.<ref>Donald 1997, pp. 792–793.</ref>

==Operational history==
Most civil aircraft in the ST series were delivered in the United States, although a few were exported to South Africa, Australia and various countries in Latin America. An example of the ST-A was procured by the USAAC in 1939 for evaluation as the '''XPT-16'''. This was followed by 15 YPT-16s, the first time the USAAC had ordered a monoplane trainer. These were the first of more than 1,000 Ryan STs to serve the USAAC, its successor, the [[United States Army Air Forces]] (USAAF) and the USN.<ref name=JG>Holmes, Tony. ''Jane's Historic Military Aircraft Recognition Guide''. London: HarperCollins, 1998. {{ISBN|0-00-472147-0}}.</ref><ref>[https://web.archive.org/web/20130404182201/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=350 "YPT-16."] National Museum of the United States Air Force. Retrieved: 16 July 2017.</ref>

A large number of STMs were exported in the 1930s and early 1940s (prior to the entry of the United States into World War II) to various air forces, with the biggest customer being the military of the [[Dutch East Indies|Netherlands East Indies]], now [[Indonesia]]. The Netherlands East Indies Army and Navy took delivery of 84 STM-2s and 24 STM-S2s in 1940 and early 1941.<ref name=NZ/><ref name=PP>[http://www.airminded.net/st/stprod.html "Ryan ST series pre-war production figures."] ''airminded.net.'' Retrieved: 15 January 2008.</ref><ref name=AFP/>{{#tag:ref|Orphan is in disagreement with the other sources. In the article, "The Ryan ''ST'' in Australia", he quotes different numbers to each arm and a different mix of the two types (60 STM-2s to the NEI Army and 48 STM-S2s to the NEI Navy) but the same overall number of deliveries.<ref name="CW"/>|group=N}} Another 50 STM-2Es and STM-2Ps were exported to [[Nationalist government|Nationalist China]], while a number of STMs were exported to [[Bolivia]], [[Ecuador]], [[Guatemala]], [[Honduras]], [[Mexico]] and [[Nicaragua]].<ref name=JE/> The STM was chosen by the South American Air-forces because of the superior performance of the super-charged Menasco engine at the high altitude airports encountered.

After the [[Netherlands East Indies campaign|Japanese invasion of the Netherlands East Indies]] many Ryans in that country were pressed into combat, especially in [[reconnaissance]] roles, and large numbers were shot down or destroyed on the ground.<ref>[http://www.aviationmuseum.com.au/aircraft_colection/ryan/index.html "Ryan STM-S2."] ''Temora Aviation Museum.'' Retrieved: 4 August 2013.</ref> Surviving STM-2s and STM-S2s that were not captured by the Japanese were shipped to Australia, where 34 entered service in the [[Royal Australian Air Force]] as trainers. Many of those that survived until the end of World War II were then placed on the civil register in Australia and elsewhere, and some are still flying more than 70 years after they were built.<ref name=CW/><ref>[http://www.adf-serials.com/2a50.shtml "Ryan serials."] {{Webarchive|url=https://web.archive.org/web/20181215121407/http://www.adf-serials.com/2a50.shtml |date=2018-12-15 }} ''ADF Serials''. Retrieved: 23 January 2008.</ref><ref>Heyman, Jos. [http://nei.adf-serials.com/nei-aust.pdf "NEI Aircraft in Australia".] {{webarchive|url=https://web.archive.org/web/20071023074416/http://nei.adf-serials.com/nei-aust.pdf |date=2007-10-23 }} ''ADF serials'', pp. 11–13. Retrieved: 23 January 2008.</ref>

==Variants==
===Manufacturer designations===
[[File:SAM 1881.JPG|thumb|right|Ryan STM-S2 with Netherlands East Indies markings during [[AirVenture]] 2011]]
[[File:Temora Aviation Museum (VH-RSY) Ryan ST-M S2 at Temora.jpg|thumb|A surviving Ryan STM-S2 in Australia, showing the larger cockpit openings and external stringers unique to the STM-2]]
;ST: Prototype and first model, fitted with a [[Menasco B4]] engine of 95&nbsp;hp; five built.
;ST-A: Improved ST designed for aerobatics, fitted with a [[Menasco C4]] engine of 125&nbsp;hp;<ref>[http://rgl.faa.gov/regulatory_and_guidance_Library%5CrgMakeModel.nsf/0/11B9AFD592AD64328525673D006300A3/$FILE/TC571.pdf "Ryan ST-A Type Certificate."] ''FAA''. Retrieved: 23 January 2008.</ref> 73 built. 
;ST-A Special: Improved ST-A, fitted with a super-charged [[Menasco C4|Menasco C4S]] engine of 150&nbsp;hp;<ref>[http://rgl.faa.gov/regulatory_and_guidance_Library%5CrgMakeModel.nsf/0/A3D2DDFA25C59B048525673D00631233/$FILE/ATC681.pdf "Ryan ST-A Special Type Certificate."] ''FAA''. Retrieved: 23 January 2008.</ref> 10 built.
;ST-B: Single-seat variant of ST-A with extra fuel tank in place of front cockpit; one built, later converted to ST-A.
;STM: Military version of ST-A Special, some with provision for a machine gun; 22 built for various South American air-forces.
;STM-2: Variant of STM for Netherlands East Indies Army and Navy; 95 built.
;STM-2E: Variant of STM delivered to China, fitted with a [[Menasco C4|Menasco C4S2]] engine of 165&nbsp;hp; 48 built.
;STM-2P: Single-seat variant of the STM-2E with provision for a machine gun, also delivered to China; 2 built.
;STM-S2: Variant of STM-2 with interchangeable wheel landing gear or floats for Netherlands East Indies Navy; 13 built.
;ST-W: Experimental conversions, with a [[Warner Scarab]] radial engine; one converted from USAAC YPT-16 with Scarab of 125&nbsp;hp; one converted from USAAC PT-20A with Super Scarab of 160&nbsp;hp.<ref name=AF/><ref name=PP/>
;ST-3: Variant with new fuselage shape and a [[Kinner B-5]] radial engine of 125&nbsp;hp; one built.
;ST-3KR: Variant of ST-3 with a [[Kinner R-5]] radial engine of 160&nbsp;hp, one built.
;ST-4: Variant of ST-3 manufactured with wooden fuselage; one built.

===US military designations===
====USAAC/USAAF====
[[File:Ryan YPT-16 USAF.jpg|thumb|Ryan YPT-16]]
[[File:Ryan PT-22 Recruit USAF.jpg|thumb|Ryan PT-22 Recruit]]

'''PT-16'''
* '''XPT-16:''' A single ST-A bought by the USAAC for evaluation.
* '''XPT-16A:''' XPT-16 re-engined with [[Kinner B-5|Kinner R-440]] radial engine of 125&nbsp;hp.
* '''YPT-16:''' A total of 15 aircraft similar to the ST-M ordered for service trials.
* '''PT-16A:''' 14 YPT-16s re-engined with Kinner R-440 engine.
;PT-20: Production version of PT-16; 30 built.<ref name=PP/><ref name=JG/>
* '''PT-20A:''' Designation of PT-20s that were re-engined with Kinner R-440 engines.
;PT-21: Military production version of ST-3; 100 built.
;[[Ryan PT-22 Recruit|PT-22 Recruit]]: Military production version of ST-3KR with [[Kinner R-5|Kinner R-540-1]] engine; 1,048 built, including PT-22As.<ref name=JE/><ref>[http://rgl.faa.gov/regulatory_and_guidance_Library%5CrgMakeModel.nsf/0/49ED4BC31C7BD8CF8525670C00699B49/$FILE/TC153.pdf "Ryan ST-3KR Type Certificate."] ''FAA.'' Retrieved: 23 January 2008.</ref>
* '''PT-22A:''' Designation for 25 examples of ST-3KR built for the [[Royal Netherlands Air Force]] but not delivered, aircraft subsequently taken by the USAAF.<ref name=NZ/>
* '''PT-22C:''' Aircraft re-engined with [[Kinner R-5|Kinner R-540-3]] engines, 250 aircraft modified.<ref name=NZ/><ref>Baugher, Joe. [http://cgibin.rcn.com/jeremy.k/cgi-bin/gzUsafSearch.pl?target=&content=PT-22C "USAAF PT-22C Serial Number list."] ''USAAF Serial Number lists,'' 26 January 2013. Retrieved: 23 January 2008.</ref>
;YPT-25: Military version of ST-4, ordered for evaluation; five built.<ref name=AF/><ref>[http://cgibin.rcn.com/jeremy.k/cgi-bin/gzUsafSearch.pl?target=&content=YPT-25 "USAAF YPT-25 Serial Number list."] ''USAAF Serial Number lists,'' 26 January 2013. Retrieved: 23 January 2008.</ref>

====USN====
;NR-1: Naval production version of ST-3; 100 built.<ref name=JE/>

==Operators==
Numbers used from ''World Air Forces''<ref>[http://www.worldairforces.com/Countries/countriesindex.html "Countries Index."] {{webarchive|url=https://web.archive.org/web/20120716224643/http://www.worldairforces.com/Countries/countriesindex.html |date=2012-07-16 }} ''World Air Forces''. Retrieved: 4 August 2013.</ref>
[[File:Ryan STM-S2 YMPC Creek.jpg|thumb|Surviving STM-S2 in Australia (2006).]]
;Australia
* [[Royal Australian Air Force]] operated 34 ex-Netherlands examples that had escaped capture by the Japanese from 1942 to 1945
;Bolivia
* [[Bolivian Air Force]] operated one from 1939 to 1944
;China
* [[Republic of China Air Force]] operated 120 from 1940 to 1942
;Ecuador
* [[Ecuadorian Air Force]] operated 10 from 1941
;Guatemala
* [[Guatemalan Air Force]] operated 12 STA specials from 1938 to 1958
;Honduras
* [[Honduran Air Force]] operated three STA specials from 1938 to 1943
;Japan
* [[Imperial Japanese Army Air Service]] operated an unknown number captured from the Netherlands
;Mexico
* [[Mexican Air Force]] operated six STA specials from 1937 to 1947
;Netherlands East Indies
*[[Royal Netherlands East Indies Army Air Force]] operated 60 STM-2/STM-S2 from 1940 to 1942
*[[Royal Netherlands Navy]] operated 48 STM-2/STM-S2s from 1941 to 1942
;Nicaragua
* [[Nicaraguan Air Force]] operated one STA special during 1938
;South Africa
* [[South African Air Force]] operated three from 1939
;United States
*[[United States Army Air Corps]] and [[United States Army Air Forces]] operated 1,224 of all versions from 1939 until 1946
*[[United States Navy]] operated 100 NR-1s (PT-22) from 1940 until 1944

==Surviving aircraft==
[[File:RyanStaSpecial173ConcreteWa.jpg|thumb|An example of a restored Ryan STA-Special]]

There are a number of surviving Ryan ST series aircraft remaining.<ref>{{Cite web|url=http://www.flytoanothertime.com/ryanst.html|title = Ryan ST}}</ref> The survivors range from project aircraft in various stages of completion to restored flying examples. There are remaining examples of the ST, STA, STA-Special, STM, STM-2 and PT20. Many of these restored examples have had their Menasco C4 engines replaced with Menasco D4-87 engines.<ref>{{Cite web|url=http://www.pilotweb.aero/features/flight-tests/flight-test-ryan-st-a-the-thirties-sportster-1-4641951|title = Flight Test: Ryan ST-A – the Thirties Sportster|date = 2 August 2016}}</ref> This change was often because of the shortage of parts available for the C4 engine.{{citation needed|date=May 2018}}

==Specifications (ST-A)==
{{multiple image
 |total_width = 500
 | image1 = Ryan ST-A 3-view line drawing.png
 | alt1 = 3-view line drawing of the Ryan ST-A
 | caption1 = 3-view line drawing of the Ryan ST-A
 | image2 = Ryan PT-20A 3-view line drawing.png
 | alt2 = 3-view line drawing of the Ryan PT-20A
 | caption2 = 3-view line drawing of the Ryan PT-20A
}}

{{Aircraft specs
|ref=Profile Number 158: The Ryan PT/ST Series<ref name="Prof158 p10,2">Mayborn 1967, pp. 10, 12</ref>
|prime units?=imp

|crew= one
|capacity=one passenger
|length m=
|length ft=21
|length in=5
|span m=
|span ft=29
|span in=11
|height m=
|height ft=6
|height in=11
|wing area sqm=
|wing area sqft=124
|empty weight kg=
|empty weight lb=1023
|gross weight kg=
|gross weight lb=1575
|fuel capacity={{convert|24|USgal|impgal L|abbr=on}}
<!--
        Powerplant
-->
|eng1 number=1
|eng1 name=[[Menasco C4]]
|eng1 type=inverted four-cylinder air-cooled inline-engine
|eng1 kw=<!-- prop engines -->
|eng1 hp=125<!-- prop engines -->

|prop blade number=<!-- propeller aircraft -->
|prop name=
|prop dia m=<!-- propeller aircraft -->
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->

<!--
        Performance
-->
|perfhide=

|max speed kmh=
|max speed mph=150
|max speed kts=
|max speed mach=<!-- supersonic aircraft -->
|cruise speed kmh=<!-- if max speed unknown -->
|cruise speed mph=127<!-- if max speed unknown -->
|cruise speed kts=
|stall speed mph=42
|stall speed note=(with flaps)
|range km=
|range miles=350
|range nmi=
|ceiling m=
|ceiling ft=17500
|climb rate ms=
|climb rate ftmin=1200
|more performance=

|avionics=
}}

==See also==
{{aircontent
|related=
|similar aircraft=
* [[de Havilland Moth Minor]]
* [[Fairchild PT-19]]
* [[Miles Magister]]
* [[Yakovlev UT-2]]
|lists=
|see also=
*[[Historical Ryan STA]], homebuilt replica of the Ryan design
}}

==References==

===Notes===
{{Reflist|group=N}}

===Citations===
{{Reflist|30em}}

===Bibliography===
* Cassagneres, Ev. ''The New Ryan: Development and History of the Ryan ST and SC.'' Eagan, Minnesota: Flying Books, 1995. {{ISBN|978-0-91113-920-4}}.
* Donald, David, ed. ''Encyclopedia of World Aircraft''. Etobicoke, Ontario, Canada: Prospero Books, 1997. {{ISBN|1-85605-375-X}}. 
*{{cite journal |last1=Ledet|first1=Michel|title=Des avions alliés aux couleurs japonais |journal=Avions: Toute l'Aéronautique et son histoire |date=April 2002 |issue=109 |pages=17–21 |trans-title=Allied Aircraft in Japanese Colors|language=fr |issn=1243-8650}}
*{{cite journal |last1=Ledet|first1=Michel|title=Des avions alliés aux couleurs japonais |journal= Avions: Toute l'Aéronautique et son histoire |date=May 2002 |issue=110 |pages=16–23|language=fr |issn=1243-8650}}
*{{cite journal |last1=Ledet|first1=Michel|title=Des Ryan aux triangles oranges |journal=Avions: Toute l'Aéronautique et son histoire |date=October 2000|issue=91 |pages=31–38 |trans-title=The Ryans With Orange Triangles|language=fr |issn=1243-8650}}
*{{cite journal |last1=Ledet|first1=Michel|title=Des Ryan aux triangles oranges |journal=Avions: Toute l'Aéronautique et son histoire |date=November 2000|issue=92 |pages=39–46|language=fr |issn=1243-8650}}
* Mayborn, Mitch. ''Profile Number 158: The Ryan PT/ST Series''. Leatherhead, UK: Profile Publications, 1967.
* Mondey, David. ''American Aircraft of World War II ''(Hamlyn Concise Guide). London: Bounty Books, 2006. {{ISBN|978-0-7537-1461-4}}.
* ''Pilots Flight Operating Instructions for Army Model PT-22 Airplanes, T.O. NO. 01-100GC-1.'' Wright-Patterson AFB, Ohio: U.S. Army Air Forces, 1943.
* ''United States Air Force Museum Guidebook.'' Wright-Patterson AFB, Ohio: Air Force Museum Foundation, 1975.

==External links==
{{Commons category}}
* [http://www.airminded.net/st/st.html The Ryan ST page]
* [https://books.google.com/books?id=xdYDAAAAMBAJ&dq=Popular+Mechanics+February+1943+New+Magic+From+Test+Tubes&pg=PA33 ''Popular Mechanics'', February 1943, '' "Plywood Trainer Saves Metal for Warplanes" ''] shows ST-4 wooden construction

{{Ryan aircraft}}
{{USAF trainer aircraft}}
{{USN trainer aircraft}}
{{ADF aircraft designations}}

{{DEFAULTSORT:Ryan St}}
[[Category:1930s United States sport aircraft]]
[[Category:Ryan aircraft|ST]]
[[Category:Aerobatic aircraft]]
[[Category:Low-wing aircraft]]
[[Category:Single-engined tractor aircraft]]
[[Category:Aircraft first flown in 1934]]
[[Category:Aircraft with fixed conventional landing gear]]
[[Category:Single-engined piston aircraft]]