The PZL TS-11 Iskra (English: Spark) is a Polish jet trainer, developed and manufactured by aircraft company PZL-Mielec. It was used by the air forces of Poland and India. It is notable as being the first domestically-developed jet aircraft to be produced by Poland, its service for over 50 years as the principal training aircraft of the Polish Air Force, and at the time of its retirement was the oldest jet-propelled aircraft still in service in Poland.

As a part of efforts to preserve Poland's ability to independently develop aircraft in an era of political and economic subservience to the neighbouring Soviet Union, during the 1950s, Polish engineers at the Poland's Aviation Institute (IL) commenced early work upon the design of what would become the first jet aircraft to be developed in Poland. Following the death of Joseph Stalin, work on the initiative could be performed more openly and government officials became supportive of such a venture. The fledgling design was heavily influenced by the requirements specified by the Polish Air Force, who had formalised a requirement for a jet-propelled aircraft for training purposes. On 5 February 1960, the first prototype conducted its maiden flight, powered by an imported British Armstrong Siddeley Viper turbojet engine.

During 1963, deliveries of the first production model of the type, designated as the TS-11 Iskra bis A, commenced to the Polish Air Force. During the 1960s, the Iskra competed to be selected as the standard jet trainer throughout the Warsaw Pact. However, it was not selected to fulfil this significant role, the rival Czechoslovakian Aero L-29 Delfín having been chosen instead, which went on to be built in greater numbers for a wide number of export customers. Production of the TS-11 came to an end during 1987, however the type remained in service with the Polish Air Force and the Indian Air Force into the 21st century. From 1969 onwards, a handful of TS-11s have been used by the Polish Air Force's Biało-Czerwone Iskry aerobatics display team, who performed their last display on 22 August 2021. It has also been used for aerial reconnaissance purposes. During the aircraft's later years of service, several examples have been sold onto private owners.

The PZL TS-11 Iskra is an all-metal jet-propelled trainer aircraft. It is relatively conventional in layout, featuring a trapezoid-shaped mid-wing arrangement. These wings, which only had a gentle angle of sweep along the leading edge, feature air intakes embedded into the wing root. The TS-11's single turbojet engine is accommodated within the main fuselage, its exhaust is located beneath the boom-mounted tail fin, which provides the aircraft with a fairly unusual silhouette. Both of the crew, typically being the student in the front and instructor in the back, are provided with ejector seats for emergency egress.

Some models of the TS-11 can be armed; armaments have consisted of a single nose-mounted Nudelman-Rikhter NR-23 cannon with 80 rounds, along with a total of four underwing hardpoints that were compatible with a variety of different weapons, including bombs and rockets. Most models of the aircraft lack a radar set; however, the specialised TS-11R reconnaissance variant is provided with such equipment. The TS-11 can also be outfitted with various cameras for the purpose of performing aerial photography missions. 

There are four Iskra registered in Australia.

For more information on development, operational history and variants, click here.

The Reggiane Re.2000 Falco I was an Italian all metal, low-wing monoplane developed and manufactured by aircraft company Reggiane. The type was used by the Regia Aeronautica (Italian Air Force) and the Swedish Air Force during the first part of the Second World War.

The Re 2000 was developed by a team headed by aircraft designers Roberto Longhi and Antonio Alessio to be a lightly-built and highly maneuverable interceptor/fighter aircraft. The emergent design, which had been designated as the Re 2000 Falco I, was equipped with a Curtiss-Wright-style retractable undercarriage, bore substantial similarities to the American-built Seversky P-35. On 24 May 1939, the prototype performed its maiden flight. Flight testing of the prototype revealed it to be able to outfight several significant combat aircraft of the time, including even the more modern Macchi C 200 and the German Messerschmitt Bf 109E fighters. During the run up to and following the outbreak of the Second World War, the aircraft was ordered by several nations, including the Hungarian, Swedish, British and Italian governments.

Upon entering squadron service, the Re 2000 soon proved to be a technically advanced aircraft, being well balanced and extremely aerodynamic during flight, but was not without its faults. Although the aircraft was potentially superior to Italian contemporary fighters (Fiat G 50 and Macchi C 200), the Re 2000 was not considered to be satisfactory by Italian military authorities. Consequently, the manufacturer built the type for export and almost all of the first production served with the Swedish Air Force and Hungarian Air Force, rather than in the Regia Aeronautica. The Re.2000 served as the starting point for several derivatives, including the MÁVAG Héja, Reggiane Re.2001, Re.2002, Re.2003, Re.2004, Re.2005, Re.2006 and Re.2007 combat aircraft.

The Reggiane Re.2000 is an Italian all metal, low-wing monoplane fighter aircraft. It is the first aircraft to be designed by Reggiane to employ aluminum stressed skin construction, as opposed to the wooden or mixed wood and metal structures that had been traditionally used in contemporary Italian aircraft such as the Savoia-Marchetti SM.79 (which had been previously produced by Reggiane under license). The stressed skin fuselage was highly streamlined, save for the protrusions of the hard-rivetted finish. The majority of the aircraft's exterior, including the tail, was metal-skinned; however, the control surfaces had fabric coverings.

The aircraft was furnished with an elliptical wing, the internal structure of which comprised a multi-cell configuration using a total of five spars, stress-skin covering, and integral fuel tanks within the center section. The wing made use of a modified N.38 airfoil section and was outfitted with Frise-type ailerons complete with static and aerodynamic balance, along with a split-continuous flap.[6] The cockpit of the Re.2000 featured a large backwards-sliding canopy; it is claimed that this canopy provided "almost unrestricted all-round visibility".

For more extensive details of development, design, operational history and variants, click here. There were five Italian variants with a total of 186 built, and three variants built under licence in Hungary under the name Mavag Héja of which 204 were built.

The Republic F-84 Thunderjet was an American turbojet fighter-bomber aircraft. Originating as a 1944 United States Army Air Forces (USAAF) proposal for a "day fighter", the F-84 first flew in 1946. Although it entered service in 1947, the Thunderjet was plagued by so many structural and engine problems that a 1948 U.S. Air Force review declared it unable to execute any aspect of its intended mission and considered canceling the program. The aircraft was not considered fully operational until the 1949 F-84D model and the design matured only with the definitive F-84G introduced in 1951. In 1954, the straight-wing Thunderjet was joined by the swept-wing F-84F Thunderstreak fighter and RF-84F Thunderflash photo reconnaissance aircraft.

The Thunderjet became the USAF's primary strike aircraft during the Korean War, flying 86,408 sorties and destroying 60% of all ground targets in the war as well as eight Soviet-built MiG fighters. Over half of the 7,524 F-84s produced served with NATO nations, and it was the first aircraft to fly with the U.S. Air Force Thunderbirds demonstration team. The USAF Strategic Air Command had F-84 Thunderjets in service from 1948 through 1957.

The F-84 was the first production fighter aircraft to utilize inflight refueling and the first fighter capable of carrying a nuclear weapon, the Mark 7 nuclear bomb. Modified F-84s were used in several unusual projects, including the FICON and Tom-Tom dockings to the B-29 Superfortress and B-36 bomber motherships, and the experimental XF-84H Thunderscreech turboprop.

The F-84 nomenclature can be somewhat confusing. The straight-wing F-84A to F-84E and F-84G models were called the Thunderjet. The F-84F Thunderstreak and RF-84F Thunderflash were different airplanes with swept wings. The XF-84H Thunderscreech (not its official name) was an experimental turboprop version of the F-84F. The F-84F swept wing version was intended to be a small variation of the normal Thunderjet with only a few different parts, so it kept the basic F-84 number. Production delays on the F-84F resulted in another order of the straight-wing version; this was the F-84G.

For details of development and design, operational history and long list of variants, click here.

The Republic P-43 Lancer was a single-engine, all-metal, low-wing monoplane fighter aircraft built by Republic, first delivered to the United States Army Air Corps in 1940.[1] A proposed development was the P-44 Rocket. While not a particularly outstanding fighter, the P-43A had a very good high-altitude performance coupled with an effective oxygen system. Fast and well-armed with excellent long-range capabilities, until the arrival of the Lockheed P-38 Lightning, the Lancer was the only American fighter capable of catching a Japanese Mitsubishi Ki-46 "Dinah" reconnaissance plane at the speeds and heights at which they flew. In addition, the P-43 flew many long-range, high-altitude photo recon missions until replaced by F-4/F-5 Lightnings (P-38 variants) in both the USAAF and RAAF.

The Seversky Aircraft Company, which in 1939 changed its name to Republic, constructed a range of private venture, one-off variants of its P-35 design, featuring different powerplants and enhancements, designated AP-2, AP-7, AP-4 (which flew after the AP-7), AP-9, and XP-41. The series included a carrier-based version designated the NF-1 (Naval Fighter 1) that was also built. The most significant of these was the AP-4, which served as the basis for future Seversky/Republic aircraft. It featured fully retractable landing gear, flush riveting, and most significantly a Pratt & Whitney R-1830-SC2G engine with a belly-mounted turbo-supercharger, producing 1,200 hp (890 kW) and good high-altitude performance. The turbo-supercharger had been refined by Boeing as part of the development program for the B-17 Flying Fortress, and the improved performance it offered was of great interest to other aircraft manufacturers.

The XP-41 and sole AP-4 were nearly identical, although the AP-4 was initially fitted with a large prop spinner and a tight-fitting engine cowling, as a testbed to evaluate means of improving the aerodynamics of radial-engined fighters, following similar experiments with the first production P-35. The AP-4's big spinner was later removed and a new tight cowling fitted. Unsurprisingly, these measures led to overheating problems. On 22 March 1939, the engine caught fire in flight, the pilot had to bail out, and the AP-4 was lost. Despite the loss of the prototype, the USAAC liked the turbo-supercharged AP-4 demonstrator enough to order 13 more in May 1939, designating them YP-43.

For more information on the YP-43 prototype, Operational history and variants, click here, and for information on the Lancer's service in the RAAF, click here.

Republic P-43-1 Lancer A56-6, 1 A.P.U., Laverton, Sept 1943.

The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American aerospace company Republic Aviation from 1941 through 1945. Its primary armament was eight .50-caliber machine guns, and in the fighter-bomber ground-attack role it could carry five-inch rockets or a bomb load of 2,500 lb (1,100 kg). When fully loaded, the P-47 weighed up to eight tons, making it one of the heaviest fighters of the war.

The Thunderbolt was effective as a short-to medium-range escort fighter in high-altitude air-to-air combat and ground attack in both the European and Pacific theaters. The P-47 was designed around the powerful Pratt & Whitney R-2800 Double Wasp 18-cylinder radial engine which also powered two U.S. Navy/U.S. Marine Corps fighters, the Grumman F6F Hellcat and the Vought F4U Corsair. An advanced turbo-supercharger system ensured the aircraft's eventual dominance at high-altitude, while also influencing its size and design.

The P-47 was one of the main United States Army Air Forces (USAAF) fighters of World War II, and also served with other Allied air forces, including those of France, the United Kingdom, and the Soviet Union. Mexican and Brazilian squadrons fighting alongside the USAAF also flew the P-47.

The armored cockpit was relatively roomy and comfortable and the bubble canopy introduced on the P-47D offered good visibility. Nicknamed the "Jug" owing to its appearance if stood on its nose, the P-47 was noted for its firepower, as well as its ability to resist battle damage and remain airworthy. A present-day U.S. ground-attack aircraft, the Fairchild Republic A-10 Thunderbolt II, takes its name from the P-47.

For details of development and operational history, click here.

There are so many variants, they have a section of their own. Click here.

The Ryan FR Fireball was an American mixed-power (piston and jet-powered) fighter aircraft designed by Ryan Aeronautical for the United States Navy during World War II. It was the Navy's first aircraft with a jet engine. Only 66 aircraft were built before Japan surrendered in August 1945. The FR-1 Fireball equipped a single squadron before the war's end, but did not see combat. The aircraft ultimately proved to lack the structural strength required for operations aboard aircraft carriers and was withdrawn in mid-1947.

Design of the FR-1 began in 1943 to a proposal instigated by Admiral John S. McCain Sr. for a mixed-powered fighter because early jet engines had sluggish acceleration that was considered unsafe and unsuitable for carrier operations. Ryan received a contract for three XFR-1 prototypes and one static test airframe on 11 February 1943 with the first two prototypes delivered in 14 months. Another contract was placed for 100 aircraft on 2 December 1943 and a later contract on 31 January 1945 increased the total of FR-1s on order to 700.

The XFR-1 was a single-seat, low-wing monoplane with tricycle landing gear. A 1,350-horsepower (1,010 kW) Wright R-1820-72W Cyclone radial engine was mounted in the fighter's nose while a 1,600 lbf (7,100 N) General Electric I-16 (later redesignated as the J-31) turbojet was mounted in the rear fuselage. It was fed by ducts in each wing root which meant that the wing had to be relatively thick to house the ducts and the outward-retracting main landing gear. To simplify the fuel system, both engines used the same grade of avgas. Two self-sealing fuel tanks were housed in the fuselage, one of 130 US gallons (490 L; 110 imp gal) and the other of 50 US gallons (190 L; 42 imp gal). The cockpit was positioned just forward of the leading edge of the wing and the pilot was provided with a bubble canopy which gave him excellent visibility. The XFR-1 had the first laminar flow airfoil in a navy carrier aircraft.

The Fireball was armed with four .50 in (12.7 mm) M2 Browning machine guns with 300 rounds per gun. They were mounted in the center section of the wing, immediately outboard of the air intakes for the jet engine. Four 5-inch (127 mm) rockets could be carried under each outer wing panel and two hardpoints were provided under the center section for 1,000 lb (454 kg) bombs or 100 US gal (380 L; 83 imp gal) drop tanks. Armor plates were provided in front and behind the pilot's seat and for the oil cooler.

For more details of design, development and operational history, click here.

Variants

XFR-1
Military designation of the prototype Model 28 aircraft, three built.
FR-1 Fireball
Single-seat fighter aircraft, 66 built. (Specifications below)
FR-2
Conversion with a Wright R-1820-74W replacing earlier piston engine, one aircraft modified.
FR-3
Proposed variant with a General Electric I-20 replacing earlier jet engine; never built.
XFR-4
Variant with Westinghouse J34; one built.[7]J34-WE-12.

The Ryan STs were 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 trainers by flying schools and the militaries of several countries.

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[1] (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),[2] the first design of the company, in 1933.

The ST featured two open cockpits in tandem in a 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 wing spars and six more alclad frames; and alclad skin. 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. 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.

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 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.

After the 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. 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.

For more information on the development, operational history and numreous variants, click here.

The Saab 17 is a Swedish single-engine monoplane reconnaissance dive-bomber aircraft of the 1940s originally developed by ASJA prior to its merger into Saab. It was the first all-metal stressed skin aircraft developed in Sweden.

The project was initiated in response to a 1938 request from the Flygvapnet (Swedish Air Force) for a reconnaissance aircraft to replace the obsolete Fokker S 6 (C.Ve) sesquiplane. Design work began at the end of the 1930s as the L 10 by ASJA, but once accepted by the Flygvapnet it was assigned the designations B 17 and S 17 for the bomber and reconnaissance versions respectively, and it became better known as the Saab 17.

The design chosen was a conventional mid-wing cantilever monoplane with a long greenhouse canopy and a single radial engine in the nose. Control surfaces were covered in fabric but the remainder was stressed-skin duraluminum. It could be fitted with wheels or skiis, both of which retracted straight to the rear along the underside of the wing, leaving prominent fairings, and when fitted with wheels the undercarriage doors could be used as dive brakes. A retractable tailwheel was provided. A floatplane version was built in small numbers for coastal reconnaissance to replace the obsolete Svenska S 5, with massive fairings joining the floats to the wings where the wheels would have been. To maintain stability small vertical fins were added to the horizontal stabilizer. The wings were reinforced so that it could be used as a dive bomber and bomb racks were provided under the wings, along with a small bomb bay below the cockpit, although some examples used a conventional rack on the centreline, while on the bomber versions, a crutch was fitted to swing the bomb clear of the aircraft in vertical diving attacks, when the bomb could otherwise have passed through the propeller. The reconnaissance versions lacked the crutch. Split flaps broken into four segments were fitted to the underside trailing edge of the wing.

Two L 10 prototypes were ordered, the first being powered by a 880 hp (660 kW) Bristol Mercury XII radial engine built by Nohab in Sweden, and the second with an imported 1,065 hp (794 kW) Pratt & Whitney R-1830 Twin Wasp C radial.

Supplies of suitable engines remained a major problem, and resulted in the aircraft being built in three versions with different engines. The definitive B 17A used the Swedish-built STWC-3 (Swedish Twin Wasp C-3), an unlicenced copy of the R-1830. The B 17B used a Bristol Mercury XXIV built by Svenska Flygmotor AB (SFA) in Sweden, and the B 17C used an imported 1,060 hp (790 kW) Piaggio P.XI radial from Italy. The United States government denied a request to purchase a licence to build the Twin Wasp, so an unlicensed, reverse engineered copy was built instead as the STWC-3 (Swedish Twin Wasp C-3) to supplement and replace the lower powered Mercury radials already being built under licence. Until production caught up to demand, the earliest aircraft being delivered were flown to their destinations, the engines were removed and shipped back, to be used on the next aircraft to be delivered.Number built    326 (including 2 prototypes)

Variants

Company designations
L 10
internal ASJA/Saab designation; two produced

Saab S 17BS mounted on floats
L 10A
internal ASJA/Saab designation for 17A, B, and C
L 10BL
internal ASJA/Saab designation for S17BL
L 10BS
internal ASJA/Saab designation for S17BS
Flygvapnet designations
P 7

     L 10 development prototypes
B 8
Preliminary designation for bomber version of L 10, not used

B 17A
Bomber with 1,065 hp (794 kW) Svenska Flygmotor Aktiebolaget (SFA)-built STWC-3 (Pratt & Whitney R-1830-S1C3G Twin Wasp) radial engine; 132 built
B 17B
Bomber with 980 hp (730 kW) SFA-built Bristol Mercury XXIV radial engine; 55 built
B 17C
Bomber with 1,060 hp (790 kW) Piaggio P.XIbis R.C.40D radial engine; 77 built
S 15
Preliminary designation for reconnaissance version of the L 10, not used
S 17BL
Reconnaissance version of B 17B with wheeled or ski landing gear; 21 built
S 17BS
Reconnaissance version of B 17B with floats, powered by a Bristol Mercury XXIV engine; 38 built

The Saab 21R was a Swedish fighter/attack aircraft developed and produced by Svenska Aeroplan AB (SAAB). It was a jet-powered development of the piston-engined SAAB 21 and was the first jet aircraft to be produced by Saab. The R-suffix stands for reaktion (reaction), referencing reaktionsdrift (jet power) or reaktionsmotor (jet engine). Along with the Soviet Yakovlev Yak-15, the 21R was one of only two jet fighters to have been successfully converted from piston-powered aircraft.

Sweden was under threat during the Second World War, and ordered SAAB to develop an advanced fighter. The result was an unorthodox twin-boom pusher, with a low wing, tricycle landing gear, and a heavy forward-firing armament. Several options were then explored to improve its performance, leading to a jet-powered version.

During 1947, SAAB began converting the piston-engined J 21s to jet propulsion, which required extensive modifications. 124 aircraft were planned, however this was reduced to 64 and they were instead mainly used as fighter-bombers. It saw service in the late 1940s and early 1950s before it was replaced by a new generation of fighters designed from the onset with jet propulsion, such as the de Havilland Vampire and the Saab 29 Tunnan.

During the early stages of the Second World War, Sweden was concerned that its neutrality and its independence could be threatened by one of the belligerent powers, and so enacted a series of emergency measures to increase its military's preparedness and deterrence value against potential aggressors. Between 1939 and 1941, the Swedish Air Force committed itself to a major expansion programme, which included the procurement of large numbers of foreign and locally developed fighters. As a consequence of the conflict, few nations possessed available production capacity or a willingness to supply modern fighters to Sweden, being a relatively small neutral country. While Sweden's own domestic production capability would be insufficient until at least 1943, Sweden would have to develop its own first-rate designs to meet its needs.

In 1941, in response to Swedish Air Force requirements, the Swedish aviation company SAAB commenced work on a radical new fighter.The company envisioned an unorthodox twin-boom pusher configuration fighter aircraft, featuring a low wing, a tricycle landing gear, and with a heavy forward-firing armament. It was powered by a licensed version of the new German Daimler-Benz DB 605B inline piston engine, which was refined and built by Svenska Flygmotor AB. The Swedish Air Force designated it the J 21, and a prototype was flown on 30 July 1943.

By 1945, options were being explored to improve its performance. Many of these involved the substitution of the 605B engine with a more powerful powerplant. During the first half of the year, a variant was planned with a 2,000 hp (1,500 kW) Rolls-Royce Griffon engine which would have raised the top speed to 416 mph (669 km/h). Other projects, such as the SAAB 27, were intended to use the Griffon as well, but by the end of the year, all work on the piston-engine design was abandoned.

In parallel with the piston-engine studies, SAAB and other Swedish companies had been evaluating a new type of engine - the jet engine. Two early studies, RX 1 and RX 2, had been studied, both of which being twin-boom aircraft similar to the 21. Recognising the Swedish Air Force's enthusiasm for a jet-powered aircraft for late 1945, SAAB decided to produce a version of the 21 harnessing jet propulsion. A design study was initiated for converting the J 21A to jet power. It was recognized that Sweden would otherwise be left behind while nations such as the United Kingdom already had the Gloster Meteor and de Havilland Vampire in production.

The design study was proceeding in late 1945 despite no specific engine having been chosen, but the opportunity came up to purchase a license to manufacture the "Goblin 2" turbojet engine in Sweden. This was the first jet engine to be used by the Swedish Air Force, who designated it as the RM1. The first flight of Saab's first jet aircraft, a converted J 21, was on 10 March 1947, powered with a single Goblin 2 engine. The results of the flight test programme were largely satisfactory.

During 1947, SAAB began to receive piston-engined J 21s to convert them to jet propulsion. This requiring each aircraft to be extensively modified. In all, in over 50 per cent of the airframe, tailplane and wing was changed and, each of them was equipped with a single British-sourced de Havilland Goblin turbojet engine, which replaced the DB 605B and propeller unit. It became the Swedish Air Force's first jet aircraft. In light of the extensive changes, rebuilt 21s were redesignated J 21R.

Variants

J 21RA – First production series, intended as fighters, powered by British-built de Havilland Goblin II engines, 34 built in 1950 (including four prototypes)

• A 21RA – J 21RA redesignated as attackers in 1951 and modified to carry external attack ordnance, retired in 1953

J 21RB – Second production series, intended as fighters, powered by Swedish-built de Havilland Goblin III engines, 30 built between 1950 and 1952

• A 21RB – J 21RB redesignated as attackers in 1951 and modified to carry external attack ordnance, retired in 1956

For more details of development and operational history, click here.

Based on the SAI KZ III air ambulance, the KZ VII was a strut-braced, high-wing monoplane of conventional design with an enclosed cabin for four seats. Fifty-six aircraft were built, and another 22 partially completed aircraft were destroyed in a factory fire in 1947. The Danish Air Force operated 10 of the type as trainers between 1950 and 1977.

The Savoia-Marchetti SM.79 Sparviero (Italian for sparrowhawk) is a three-engined medium bomber developed and manufactured by the Italian aviation company Savoia-Marchetti. It may be the best-known Italian aeroplane of the Second World War. The SM.79 was easily recognizable due to its fuselage's distinctive dorsal "hump", and was reportedly well liked by its crews. It was nicknamed il gobbo maledetto ("damned hunchback").

The SM.79 was developed in the early 1930s. It is a cantilever low-wing monoplane of combined wood and metal construction, designed with the intention of producing a swift eight-passenger transport aircraft capable of outperforming the fastest of its contemporaries, but its potential as a combat aircraft quickly attracted the attention of the Italian government. It made its first flight on 28 September 1934 and early examples of the type established 26 separate world records between 1937 and 1939, qualifying it for some time as the fastest medium bomber in the world.[4] As such, the SM.79 quickly came to be regarded as an item of national prestige in Fascist Italy, attracting significant government support and often being deployed as an element of state propaganda. Early on, the aircraft was routinely entered in competitive fly-offs and air races, seeking to capitalise on its advantages, and often emerged victorious in such contests.

The SM.79 first saw combat during the Spanish Civil War. In this theatre it normally operated without fighter escort, relying on its high speed to evade interception. The SM.79's performance during the Spanish deployment was successful and stimulated demand for the type, including a decision to adopt it as the backbone of Italy's bomber units. Both Yugoslavia and Romania opted to procure the type for their own air services, while large numbers were also procured for the Regia Aeronautica. Almost 600 SM.79-I and –II aircraft were in service when Italy entered the Second World War in May 1940; thereafter, they were deployed in every theatre of war in which the Italians fought.

The SM.79 was operated in various capacities during the Second World War, initially being used mainly as a transport aircraft and medium bomber. Following pioneering work by the "Special Aerotorpedoes Unit", Italy put the type to work as a torpedo bomber; in this role, the SM.79 achieved notable successes against Allied shipping in the Mediterranean theatre of the war. A specialised drone version of the aircraft flown by remote control was also developed, although the Armistice with Italy was enacted prior to any operational deployment. It was the most numerous Italian bomber of the Second World War, with about 1,300 built. The type would remain in Italian service until 1952.

The SM.79 was a cantilever low-wing monoplane trimotor, with a retractable taildragger undercarriage. The fuselage had a welded tubular steel framework covered with duralumin on the forward section, a mixture of duralumin and plywood across the upper fuselage surface, and fabric for all of the other exterior surfaces. The wings were of all-wood construction, with trailing edge flaps and leading edge slats (Handley Page style) to offset their relatively small size. The structure consisted of three spruce and plywood spars, linked with plywood ribs, with a skin of plywood. The wing had a dihedral of 2° 15'. The ailerons were capable of rotating through +13/-26°, and were used together with the flaps in low-speed flight and in takeoff. The aircraft's capabilities were significantly greater than its predecessor, the SM.75, with over 1,715 kW (2,300 hp) available and a high wing loading that gave it characteristics not dissimilar to a large fighter.

For more details of development, design, operational history and 10 variants, click here.

The Seversky SEV-3 was an American three-seat amphibian monoplane, the first aircraft designed and built by the Seversky Aircraft Corporation.

The SEV-3 was an all-metal cantilever low-wing monoplane powered by a nose-mounted 420 hp (313 kW) Wright J-6 Whirlwind radial engine. It had two cockpits in tandem, a forward cockpit for the pilot and a rear cockpit for two passengers, both with sliding canopies. It could either be fitted with twin amphibious floats which had main wheels fitted in the floats to allow it to operate from land, or with a fixed tailwheel undercarriage with the mainwheels enclosed in large fairings.

The SEV-3 first flew as a floatplane in June 1933, demonstrating excellent performance as both an amphibian and a landplane. It was built in small numbers mainly for export.

An SEV-3 established a world speed record for piston-engined amphibians in 1933, and on 15 September 1935, a Wright Cyclone-powered SEV-3 set a record of 230 mph (370.8 km/h) which stood for 49 years. A landplane version was also developed with conventional landing gear.

The design influenced a long line of Seversky and later Republic aircraft, eventually leading to the development of the P-47 Thunderbolt. A landplane version was used by the United States Army Air Corps as a basic trainer with the designation BT-8, 30 of which were ordered in 1935. This proved grossly underpowered and was quickly replaced by the North American BT-9.

One BT-8 was delivered to Bolling Field, on 11 June 1936, for use by Chief of the Air Corps Major General Oscar Westover, and assigned to the 14th Bombardment Squadron, GHQ Air Force. It replaced an O-38F, which was reassigned to the 21st Observation Squadron, GHQ Air Force, for general flying.

Variants

SEV-3XAR
Landplane trainer

SEV-3XLR
Landplane
SEV-3M-WW
Amphibian for the Colombian Air Force, six built (only delivered four to Colombia), with Wright Whirlwind engines.
BT-8            (Specifications below)
Landplane basic-trainer for the United States Army Air Corps, developed from SEV-3XAR. 30 built.
SEV-X-BT
multi-discipline trainer version of the BT-8 with retractable undercarriage. The sole SEV-X-BT lost in competition to the North American BT-9 and was reportedly scrapped for spares to service the Seversky 2PA.

Not to be confused with the 1928 Supermarine Seamew or 1940 Curtiss SO3C Seamew.

The Short SB.6 Seamew was a British aircraft designed in 1951 by David Keith-Lucas of Shorts as a lightweight anti-submarine platform to replace the Royal Navy Fleet Air Arm (FAA)'s Grumman Avenger AS 4 with the Reserve branch of the service. It first flew on 23 August 1953, but, due to poor performance coupled with shifting defence doctrine, it never reached service and only 24 production aircraft had flown before the project was cancelled. It has been described as a "camel amongst race-horses".

The Short Seamew was selected to fulfill Admiralty Specification M.123D for a simple, lightweight anti-submarine aircraft capable of unassisted operation from any of the Royal Navy's aircraft carriers in all but the worst of conditions, in particular escort carriers which the UK still had in considerable numbers from the Second World War. Although specifically designed for naval operations, the Seamew was also intended for land-based use by the RAF. It was to be suitable for mass production and operation by the Air Branch of the Royal Naval Volunteer Reserve (RNVR). This specification was in response to the alarming increase in capabilities of the Soviet submarine forces following the Second World War.

Three prototypes were ordered in April 1952 and the first flight (XA209), piloted by test pilot Sqn. Ldr. Walter J. "Wally" Runciman, took place on 23 August 1953. This same aircraft, also piloted by Runciman, took part in the 1953 Farnborough Airshow three weeks later. In 1954 both XA209 and the second prototype XA213 took part at Farnborough, where the following year both prototypes and two production AS Mk 1 models (XE171 and XE172) gave a formation display.

The pilot and observer were located in tandem cockpits located high up in the front of the deep, narrow fuselage, creating a decidedly "curious" profile. They sat atop the Armstrong Siddeley Mamba turboprop in front and the weapons bay to the rear of them. The design had originally called for the tried and tested Rolls-Royce Merlin piston engine but the Royal Navy had made it policy to phase out piston engines, in order that supplies of highly flammable high octane aviation fuel need not be carried in large quantities on ships. The turboprop engine also caused less airframe vibration so that the pilot could be sat directly over it with the absence of a piston engine ignition system which would have interfered with the radar scanner mounted below the engine housing.

For simplicity, and so that a nosewheel would not obscure the forward field of the radar scanner, a fixed tailwheel undercarriage was used. The long stroke necessary on the main undercarriage to allow for heavy deck landings while giving the radar scanner and propeller adequate clearance from the ground resulted in an alarming attitude on the ground and the cockpits mounted at a seemingly perilous height. For landing the tailwheel extended so it could land at a more level attitude.

The pilot and observer sat very far forward in order for the pilot to have a reasonable field of downward vision for takeoff and landing and so that both he and the observer had a good field of view for spotting surface vessels even when in level flight. A total of 26 Seamew were produced.

Variants.

SB.6 Seamew
Three prototype anti-submarine aircraft, one completed as a structural test rig.
SB.6 Seamew AS.1   (Specifications below)
Production anti-submarine aircraft for the Royal Navy, 60 aircraft ordered later amended to 30 but only 24 completed.
SC.2 Seamew MR.2
Production aircraft for the Royal Air Force Coastal Command, larger wheels with low-pressure tyres, manual wing-folding and no deck handling gear, 30 aircraft ordered but only 4-built that were converted or completed to AS.1 standard.

It has the distinction of being the first four-engined bomber to be introduced into service with the Royal Air Force (RAF).

The Stirling was designed during the late 1930s by Short Brothers to conform with the requirements laid out in Air Ministry Specification B.12/36. Prior to this, the RAF had been primarily interested in developing increasingly capable twin-engined bombers but had been persuaded to investigate a prospective four-engined bomber as a result of promising foreign developments in the field. Out of the submissions made to the specification Supermarine proposed the Type 317, which was viewed as the favourite, whereas Short's submission, named the S.29, was selected as an alternative. When the preferred Type 317 had to be abandoned the S.29, which later received the name Stirling, proceeded to production.

The Short Stirling was a four-engined monoplane heavy bomber designed to provide a previously unmatched level of strategic bombing capability to the Royal Air Force (RAF). It was powered by four Bristol Hercules radial engines which were spaced across its mid-mounted wing. The Stirling has the distinction of being the only British bomber of the period to see service that had been designed from the start with four engines - the Avro Lancaster was a re-engined, stretched-wingspan Avro Manchester while the Halifax was planned to be powered by twin Rolls-Royce Vulture engines but was similarly re-designed to use an arrangement of four Merlin engines in 1937.

Although smaller than both of the pre-war American "XBLR"-designation designs (the 149-foot wingspan, 35-ton Boeing XB-15 and the 212-foot wingspan, 79-ton Douglas XB-19) and nearly as large Soviet experimental heavy bomber designs, the Stirling had considerably more power and far better payload/range than anything then flying from any British-based aviation firm. The massive 14,000 lb (6.25 long tons, 6,340 kg) bomb load put it in a class of its own, double that of any other bomber. It was longer and taller than the Handley Page Halifax and the Avro Lancaster which replaced it but both of these were originally designed to have twin engines.

For more details of the development, design, operational history and six variants, click here.

The Short Sturgeon was a planned British carrier-borne reconnaissance bomber whose development began during Second World War with the S.6/43 requirement for a high-performance torpedo bomber, which was later refined into the S.11/43 requirement which was won by the Sturgeon. With the end of the war in the Pacific production of the aircraft carriers from which the Sturgeon was intended to operate was suspended and the original reconnaissance bomber specification was cancelled.

The Sturgeon was then redesigned as a target tug which saw service with the fleet for a number of years. Later, the basic Sturgeon design was reworked as a prototype anti-submarine aircraft. The many modifications that resulted turned the promising design into a "hapless and grotesque-looking hybrid."

The development process leading to the S.38 Sturgeon began with the 1943 S.6/43 requirement for a high-performance torpedo bomber with a bomb bay that could accommodate six 500-pound (230 kg) bombs or any of the current standard aerial torpedoes, operating from Audacious and Centaur-class aircraft carriers. A maximum all-up-weight of 24,000 lb (11,000 kg) was specified. Short Brothers were not invited to respond to S.6/43, but the preliminary responses from the other participating manufacturers indicated that a twin-engined design meeting all requirements was likely to weigh in excess of 24,000 lbs, while a single-engined design was unlikely to exceed the performance of in-service aircraft.

S.6/43 was allowed to proceed, and there are indications that Shorts submitted two uninvited tenders, a single-engined Bristol Centaurus design and a twin-Rolls-Royce Merlin design. However, none of the original S.6/43 submissions was adopted and no reference to the Shorts submissions has been located in the official documentation. Focus instead shifted to splitting the requirements, with the torpedo bomber requirement becoming O.5/43, eventually leading to the Fairey Spearfish, while S.11/43 was written for a reconnaissance aircraft able to operate as a bomber.

Specification S.11/43 called for the design and construction of a twin-engine naval reconnaissance aircraft for visual and photographic reconnaissance and shadowing, by day or night, and also able to operate as a bomber. The specification included a maximum all-up weight of 24,000 lb, height (stowed) of 17 ft (5.2 m), length of 45 ft (13.7 m) and a wingspan of 60 ft (18.3 m) (spread) / 20 ft (6.1 m) (folded). Powered wing-folding was also required.

Shorts submitted the twin-Merlin S.38 Sturgeon as their tender to S.11/43, while Armstrong Whitworth proposed the twin-Merlin powered AW.54. After the AW.54 was criticized for lack of power, the AW.54A with two MetroVick F.3 turbojets was submitted. Submissions were also made by Blackburn and Fairey (also with twin-Merlin designs) and by Westland with a mixed-power design comprising a Pratt & Whitney R-4360 Wasp Major radial in the nose and a Halford H.1 turbojet in the tail. On 19 October 1943, Shorts received the "Instruction to Proceed" and an order for three prototypes designated Sturgeon S.1, with military serials RK787, RK791 and RK794 assigned. The final tailored S.11/43 requirements followed in February 1944.

The pilot's cockpit was a sub-assembly bolted to the front of the spar, placing him level with the leading edge of the wing, the navigator was behind the centre section of the wing and the radio operator — separated from the navigator by his equipment — behind him. The navigator and radio operator entered through a door, which acted as a ladder when opened, in the starboard side with their seats being offset to port. The cameras were installed in the fuselage behind the radio operator. One of the Sturgeon's unfortunate failings was in placement of controls. The fire extinguisher switch was located next to the cockpit switches required for firing the engine starter cartridges, resulting in some inadvertent mishaps and some unintended hilarity for ground crews.

For more information on design and development, operational history, and variants, click here.

The SNCAC Martinet was a German-designed but French-built twin-engined military trainer and light transport monoplane. It was operated by the French military and in small numbers by French airlines from the late 1940s.

To aide the German war effort the SNCAC factory at Bourges was ordered to produce 455 Siebel Si 204s light transports for the Luftwaffe. Production started in 1942 and 168 had been delivered before the Liberation stopped production. The French decided to continue producing the aircraft and designated the aircraft NC.700. Only a prototype NC.700 was built powered by Renault 12S-00 engines (derived from the German AS-411) although the designation was also used for a small number of aircraft originally intended for the Luftwaffe and diverted to the French Air Force.

The company then produced two variants; the NC.701 Martinet based on the Si 204D with a glazed unstepped nose and powered by two Renault 12S engines, and the NC.702 Martinet with a conventional stepped windscreen nose based on the Si 204A.

The Martinet was used by both the French Air Force and Navy and the final example did not retire until 1963. A small number were used by commercial operators including Air France but were soon replaced by larger aircraft like the Douglas DC-3. A number were used by the French Postal Service but they were grounded following an accident to F-BBFA is July 1946. The aircraft was used by the IGN for photo-survey work and a few aircraft were also exported to Poland and Sweden for use on photo-mapping duties.

Variants

NC.700
A Renault 12S powered Si-204, one prototype.
NC.701  (Specifications below)
Trainer version with dual controls and transparent nose based on the Si-204D. Room for five students as a radio trainer.
NC.702
Eight-seat transport version based on the Si-204A.

NC701

NC702

The Soko G2 Galeb (English: Seagull) is a Yugoslav single engine, two-seater jet trainer and light ground-attack aircraft. The G2 was developed during the 1950s by the Aeronautical Technical Institute at Žarkovo as a replacement for the Lockheed T-33 in service with the Yugoslav Air Force (Serbo-Croatian Latin: Ratno vazduhoplovstvo i protivvazdušna odbrana – RV i PVO). Production started in 1965 at the Soko aircraft factory in Mostar, and ended in 1985 with 248 aircraft delivered. The G2 had the distinction of being the first mass-produced jet aircraft in socialist Yugoslavia. It also served as a basis for the single-seat ground-attack J-21 Jastreb.

The RV i PVO took delivery of 128 aircraft that were used by the Air Force Academy for training new pilots. The second largest operator of the Galeb was Libya, which acquired over 100 aircraft during the 1970s. A small number were also acquired by Zaire, Zambia and Indonesia. During the breakup of Yugoslavia, the Galebs were used for ground attack sorties throughout Croatia and Bosnia and Herzegovina. By 1992, RV i PVO G-2s relocated to Serbia and Montenegro where they operated with the Air Force of the new FR Yugoslavia. The aircraft remained in service until 1999 when the majority of them were destroyed on ground during the NATO bombing of Yugoslavia.

The Libyan Air Force's G2s were used during the Libyan Civil War by Gaddafi forces, with an unknown number surviving the war and being reported in service as late as 2013. A single aircraft remains in service with the Technical Test Center of the Serbian Armed Forces. A number of aircraft are still flown by civilians as warbirds, including the private aerobatic team "Stars" from Novi Sad.

John Travolta is listed as a private owner, and the hangar photo below (177) was taken at Lilydale in 2011.

For details of development, design, operational history and variants, click here.

The Soko J-20 Kraguj (from Serbian: крагуј, lit. 'sparrowhawk') is a light military, single-engine, low-wing single-seat aircraft with a metal airframe, capable of performing close air support, counterinsurgency (COIN), and reconnaissance missions, that was designed by VTI and manufactured by SOKO of Yugoslavia, first flown in 1962.

It is of classic semi-monocoque, metal structure with a slightly tapered wing. The pilot is accommodated in an enclosed, heated and ventilated cockpit with adjustable seats. The cockpit canopy slides backwards to open. The landing gear is non-retractable with a tail wheel. Rubber dampers provide shock absorption, and hydraulic brakes are used for wheel braking.

The power plant comprises one 340 hp Textron Lycoming GSO-480-B1J6 piston engine and Hartzell HC-B3Z20-1/10151C-5 three-blade metal variable-pitch propeller. The engine cooling airflow is intensified by means of two specially designed ejectors. 36 US Gal of fuel contained in two rubber tanks enables a flight range of 350 NM for the fully armed configuration of the aircraft. 28 V DC electric power is supplied from a 1,5 kW generator and a storage battery. De-fogging and de-icing of the windshield is done by blowing of hot air.

The aircraft was specially designed for low-altitude missions against day and night visible ground targets in a broad area. It was readily available to be loaded with weapons and supplied through a flexible system of auxiliary airfields that required no special preparations, especially in mountainous regions. Yugoslav military planners assumed that potential aggressor will first disable airfields. Therefore, J-20 Kraguj was designed to take-off from short unprepared runways, even ones covered in deep snow when fitted with skis. It was also called a "Partisan aircraft".

The Kraguj P-2 was intended for close ground force support, and could be used for training of pilots in visual day/night flights, aiming, missile firing and bombing of ground targets.

The Sud-Ouest Aviation (SNCASO) S.O. 4050 Vautour II (French for vulture) was a French jet-powered bomber, interceptor, and attack aircraft developed and manufactured by aircraft company Sud Aviation.

The Vautour was operated by France's Armée de l'Air, having been originally developed by Sud Aviation in response to a French requirement for a jet aircraft for bombing, low-level attack and all-weather interception operations. The Vautour was used in the Force de frappe under the Commandement des Forces Aériennes Stratégiques; each aircraft was suitable for the carriage of a nuclear weapon. The shortcomings of the type as a bomber, such as its lack of radar or other advanced navigation/attack systems, led to the type being replaced by the more capable Dassault Mirage IV. The Vautour never saw combat use with the French Air Force.

The only other customer for the Vautour was Israel. During its service with the Israeli Air Force (IAF), the type undertook various mission and roles and was quickly used in combat. Vautours were used during the wars between Israel and its neighbors, including the Six-Day War and the War of Attrition. Only one air-to-air kill was recorded by a Vautour; the type was used more for bombing and ground strafing and was reportedly considered by Israel to be comparable to the Soviet-built Ilyushin Il-28 medium bombers used by its regional adversaries. During the early 1970s, the Vautour was replaced by the American Douglas A-4 Skyhawk.

The Sud Aviation Vautour was a jet-propelled mid-sized combat aircraft, typically employed as a bomber and attack aircraft, as well as having some usage as an interceptor. In terms of its basic configuration, it had a shoulder-wing monoplane configuration, furnished with a 35° swept wing and a "flying" tail. Power was provided by a pair of SNECMA Atar 101 turbojet engines, which were carried in pods located underneath the wings. The Vautour was equipped with a bicycle-type landing gear configuration in which the main units were located upon the underside of the fore and aft fuselage, these were augmented by smaller stabilizing gear set into bottom of the engine pods. The internal space of the central fuselage was largely dedicated to a large 5.0 meter (16 ft 5 in) weapons bay, along with substantial internal fuel tankage. 149 units were produced.

For more details on development, design, operational history and variants, click here.

The Supermarine Seagull III was a British designed and built amphibian bi-plane.  The prototype, the Seagull I, was developed in 1921 and this led to improvements for the construction of 25 Seagull II, in 1922, for use by the Royal Navy and Royal Air Force.  Further improvements resulted in the Seagull III, fitted with a Napier Lion V engine, becoming available in 1925.   The Royal Australian Air Force (RAAF) ordered six of these aircraft in 1925 to replace its Fairey IIID seaplanes at a cost of £ 8,000 each.  The aircraft were freighted to Australia arriving in mid-1926 with the first test flight conducted in June of that  year.  A further three aircraft were ordered in 1927.

The  Seagull was constructed from timber and canvas and the Australian version had a radiator modified for tropical usage. The lower wing was set in the shoulder position and the engine was mounted in a nacelle slung from the upper wing; powering a four-blade propeller in ‘tractor’ configuration.  The aircraft carried a crew of three with the pilot being a RAAF officer, the observer (navigator) a naval officer and the telegraphist air gunner a naval rating. The Seagulls were allocated to 101 Flight RAAF and three aircraft took part in the Great Barrier Reef Survey during 1926-27 and were based at Bowen in far north Queensland.  Due to their size and the logistics / engineering needs the aircraft were based ashore and carried out regular flights over the reef to conduct photographic surveys in support of survey work being conducted by HMA Ships Geranium and  Moresby.

The Seagulls were normally located at RAAF Base Point Cook, Victoria but following the commissioning of the sea plane carrier HMAS Albatross, in January 1929, they were embarked regularly for training exercises; where the aircraft proved very useful in spotting, and signalling corrections, for the fall of shot during gunnery practice firings.  The Seagulls were also employed on reconnaissance flights where they were also adept in locating other vessels and signalling, via wireless telegraphy, the location of the ships. The range of the wireless telegraphy equipment was however only 30 kilometres in good weather conditions. 

Number ordered - 9.

For further information on the Seagull III, click here.

Many variants of the Spitfire were built, using several wing configurations, and it was produced in greater numbers than any other British aircraft. It was also the only British fighter produced continuously throughout the war. The Spitfire continues to be popular among enthusiasts; nearly 60 remain airworthy, and many more are static exhibits in aviation museums throughout the world.

The Spitfire was designed as a short-range, high-performance interceptor aircraft by R. J. Mitchell, chief designer at Supermarine Aviation Works, which operated as a subsidiary of Vickers-Armstrong from 1928. Mitchell pushed the Spitfire's distinctive elliptical wing with cutting-edge sunken rivets (designed by Beverley Shenstone) to have the thinnest possible cross-section, helping give the aircraft a higher top speed than several contemporary fighters, including the Hawker Hurricane. Mitchell continued to refine the design until his death in 1937, whereupon his colleague Joseph Smith took over as chief designer, overseeing the Spitfire's development throughout its multitude of variants.

For details of the development and producton, design, testing, operational history of the Spitfire, click here. This link provides further links the large number of variants over the lengthy life of the Spitfire.

Specifications below are for the Spitfire Mk VB.

The Supermarine Walrus (originally known as the Supermarine Seagull V) was a British single-engine amphibious biplane reconnaissance aircraft designed by R. J. Mitchell and manufactured by the British aircraft company Supermarine.

The Walrus made its maiden flight in 1933, the design effort having commenced as a private venture four years earlier. It shared its general configuration with that of the earlier Supermarine Seagull. Having been designed to serve as a fleet spotter for catapult launching from cruisers or battleships, the aircraft was largely employed in other roles, notably as a maritime patrol aircraft and as a rescue aircraft for ditched aircrew. The Walrus featured numerous innovations for the period, being the first British squadron-service aircraft to incorporate in one airframe a fully retractable main undercarriage, completely enclosed crew accommodation and an all-metal fuselage. Early-build aircraft featured the original metal hull design for its greater longevity in tropical conditions, while later-build examples instead used a wooden counterpart to conserve the use of light metal alloys.

The first examples of the Seagull entered service with the Royal Australian Air Force (RAAF) in 1935. The type was subsequently adopted in quantity by the Fleet Air Arm (FAA), Royal Air Force (RAF), Royal New Zealand Navy (RNZN) and Royal New Zealand Air Force (RNZAF). Hundreds of Walruses were in operational service throughout the Second World War, where it was prolifically operated against Axis submarines. It was also adopted by the RAF Search and Rescue Force for recovering downed personnel. An intended replacement, the Supermarine Sea Otter, which possessed considerably more power, was introduced during the conflict but never fully displaced the Walrus. The Walrus continued to serve in a limited capacity with several militaries around the world during the postwar era, while some aircraft were also operated in a civil capacity in regions such as Australia and the Antarctic. It was largely succeeded by the first generation of rescue helicopters.

The Supermarine Walrus was a single-engine amphibious biplane principally designed to conduct the maritime observation mission. The single-step hull was constructed from aluminium alloy, with stainless-steel forgings for the catapult spools and mountings. Metal construction was used because experience had shown that wooden structures deteriorated rapidly under tropical conditions. The fabric-covered wings were slightly swept back and had stainless–steel spars and wooden ribs. The lower wings were set in the shoulder position with a stabilising float mounted under each. The elevators were high on the tail-fin and braced on either side by 'N' struts. The wings could be folded, giving a stowage width of 17 ft 6 in (5.33 m). The single 620 hp (460 kW) Pegasus II M2 radial engine was housed at the rear of a nacelle mounted on four struts above the lower wing and braced by four shorter struts to the centre-section of the upper wing. This powered a four-bladed wooden pusher propeller. 

For more information on the development, design, operational history, civil use, and variants, click here.

The Tachikawa Ki-9 (九五式一型練習機, Kyūgo-shiki ichigata renshuki) was an intermediate training aircraft of the Imperial Japanese Army Air Force built by Tachikawa Aircraft Company Ltd in the 1930s. It was known to the Allies under the nickname of "Spruce" during World War II. This aircraft was mistakenly identified as a Tatchikawa by the British.

The Ki-9 was a two-seat, unequal wingspan biplane design. Tachikawa originally planned to use the same basic airframe for both basic training and intermediate training, differentiating the two models by the use of different engines.

The prototype Ki-9 flew on 7 January 1935, powered by a 261 kW (350 hp) nine-cylinder Hitachi Ha-13a radial engine. The second prototype was identical, and the third prototype was powered by a 112 hp (80 kW) Nakajima NZ seven-cylinder radial engine. The third prototype exhibited stability problems due to a center of gravity issue, and, as a result, the primary trainer model was abandoned and the Ki-9 was developed only for the intermediate trainer. Tachikawa subsequently developed the Ki-17 for the primary trainer role. The first production aircraft were delivered in 1935.

The Ki-9 was introduced to service as the Army Type 95-1 Medium Grade Trainer Model A under the former aircraft naming nomenclature system. The first version had a complex, split-axle landing gear with fairings over the top of the wheels. In 1939, this was modified and simplified, the fuselage slightly shortened, and the total weight reduced. The resulting Army Type 95-1 Model B or Ki-9-kai had improved maneuverability and flight characteristics. This version was quickly superseded by the Army Type 95-1 Model C, or Ki-9-otsu, in full production.

Both versions were used widely for blind-flying training with a folding hood over the rear cockpit, and several were modified with a glazed canopy over the rear cockpit for use as a staff officer transport plane.

Some were pressed into service for use as "special attack" (kamikaze in American terminology) aircraft in the closing days of the war, fitted with either a 100 kg anti-ship bomb, an oil drum filled with explosives, or fuel in the rear cockpit.

Production by Tachikawa totaled 2,395 aircraft, ending in 1942. At least another 220 Ki-9s were constructed by Tokyo Gasu Denki (also known as Gasuden) from 1943 to 1945.

The Ki-9 was also flown in wartime by Japanese satellite countries and postwar by the fledgling government of Indonesia and captured units by the Republic of China.

Variants

Ki-9 (Army Type 95-1 Medium Grade Trainer Model A): Initial version two-seat intermediate trainer aircraft.
Ki-9-ko (Army Type 95-1 Medium Grade Trainer Model B): Improved version.
Ki-9-otsu (Army Type 95-1 Medium Grade Trainer Model C): Standard production version.

The Tachikawa KKY, full name Tachikawa Army Small and Light Ambulance Aircraft, was designed to rescue injured or sick patients from places without established airfields. Following two earlier prototypes, twenty-one production examples were built between 1936 and 1940 and served in the Second Sino-Japanese War.

In August 1932, the Japanese Army placed an order for a small ambulance aircraft, capable of using rough airstrips and holding two stretcher cases and a medical attendant, with what was then the Aeroplane Factory of Ishikawajima Shipbuilding Company. Though the prototype was completed in December 1933, its development was protracted, and it was not ready for production until 1936. By then, the Ishikawajima Company had become the Tachikawa Aeroplane Co.

It was a single bay cabin biplane with wings attached to the upper and lower longerons and braced on each side with near-parallel interplane struts. The wings had wooden structures and were fabric-covered.

The KKY was powered by a 120–130 hp (89–97 kW) Cirrus Hermes IV four cylinder air-cooled, inverted inline engine and the later KKY-2 by a 150 hp (110 kW) Gasuden Jimpu seven cylinder radial engine. The fuselage had a welded steel tube structure, flat-sided behind the engine, with a windowed cabin that included the pilot's seat just ahead of the wing leading edge with the patients and attendant under the wing. The tail, with an aluminium structure and fabric-covered, was conventional with a tailplane on top of the fuselage and braced to it from below. The vertical tail had a strongly-blunted triangular profile.

As its purpose was to rescue patients from rough airfields or unmade airstrips, the ambulance needed a robust undercarriage. This had split axles mounted on a short, central, V-strut from the fuselage underside. Both short, faired shock absorber legs and their rearward drag struts were mounted on the lower fuselage longerons. Wheels with wide, low-pressure tires were available for missions to unmade strips.

Twenty-one Aikoku-go (privately funded) production KKYs were built between 1936 and 1940. They were active in the Second Sino-Japanese War, which began in 1937 and became part of World War II, when China entered on the Allies' side shortly after the attack on Pearl Harbor.