Messerschmitt Me.155

In the Spring 1942 a requirement was made by the Reich's Air Ministry (RLM) for a carrier-based single-seat fighter to be based aboard the Graf Zeppelin aircraft carrier whose construction wasn't complete yet. In response, Messerschmitt proposed the Me.155 which, in interest of economy and simplicity, was going to use as many Bf.109G's components as possible, to the point that the project was basically a navalized version of the Bf.109G.
It was to be powered by the Daimler-Benz DB 605A-1 liquid-cooled engine which yielded 1455hp of power. The fuselage was the same as the Bf.109G but it featured an entirely new wing. The undercarriage retracted inwards into wing wells, providing the wider track required for safe carrier landings. It would also feature standard naval equipment such as folding wings, arrester gear and catapult spools. It was going to be armed with one 20mm MG 151 firing through the propeller hub plus two 20mm MG 151s and two 13mm MG 131 in the wings. It was going to have an estimated maximum speed of 649 km/h (403 mph).
Design details were complete by September 1942, however, as the Graf Zeppelin was still far from being completed, Messerschmitt was told to shelve the Me.155 for the indefinite future.
However, in order that all the work on the project would not go to waste, Messerschmitt adapted all the work in November 1942 to match a Luftwaffe's requirement for a fast single-seat bomber which could carry a single 1000 kg (2210 lb) SC1000 bomb. All of the carrier-related equipment was removed from the design and additional fuel tanks were provided. An elongated, non-retractable tailwheel was added to provide clearance for the large bomb and the proposal was named as Me.155A. However, the Luftwaffe rejected it.
By late 1942 the increasing number of USAAF raids, combined with intelligence reports about the threat of a new American bomber (the B-29) that could reach very high altitudes, lead to the Luftwaffe to conduct a research on a new high-altitude interceptor. Messerschmitt adapted the Me.155 design to meet this new requirement. The design was merged with an in-house study originally called Me.409 and later Bf.109ST and the project received the new name of Me.155B. This new project was going to be powered by a Daimler-Benz DB 628 which was basically a DB 605A with a two-stage mechanical supercharger with an induction cooler. A pressurized cabin was going to be provided and the service ceiling was estimated at 14094 m (46250 ft) high.
A modified Bf.109G adapted with the DB 628 engine flew for the first time in May 1942 and reached an altitude of 15500 m (50850 ft) high, however, the Technische Amt (RLM's technical department) concluded that the DB 603A with an exhaust-driven turbosupercharger was more promising as it provided 1610hp for takeoff and 1450hp at 15000 m (49210 ft) high. This engine change required the fuselage to be slightly elongated in order to house the turbosupercharger aft of the pressure cabin. Exhaust gases were carried to the turbosupercharger via external ducts. Air was drawn in via a ventral through aft of the wing. Standard Bf.109G wings were to be fitted outboard of a new long-span, untapered wing center section. Other parts were scavenged from other existing Messerschmitt designs - the vertical tail was from the Me.209 and the horizontal tail and the undercarriage were taken from the Bf.109G.
Apparently, there was a third version projected as well, the Me.155C, which was powered by a Junkers Jumo 213 engine.
In August 1943 the RLM realised that Messerschmitt was over-committed and transferred the design work to Blohm & Voss. The design team there concluded that Messerschmitt's design had too many flaws and therefore, a complete redesign was necessary.

Sources:
1. https://en.wikipedia.org/wiki/Blohm_%26_Voss_BV_155
2. Salamander Books - The Complete Book of Fighters
3. AJ Press - Monografie Lotnicze 44 - Messerchmitt Bf.109 Cz.3 (translated)
4. Midland Publishing - Luftwaffe Secret Projects - Fighters 1939-45

Messerschmitt Me.309

The Messerschmitt Me.309 was a prototype German fighter that was intended as a replacement of the Messerschmitt Bf.109. Although it had many advanced features, its performance wasn't as good as expected and, troublesome as it was, was cancelled with just four prototypes having been built. It was one of the two Messerschmitt's failed attempts to replace the Bf.109, being the other one the Me.209, which we already posted about.
The project began in mid-1940 just when the Bf.109 was being confronted for the first time with the Supermarine Spitfire in the Battle of Britain, being the Spitfire the first aircraft to match the Bf.109 in terms of speed and performance. By that time, Messerschmitt had already anticipated the need for an improved design to replace the Bf.109. However, the Reich Air Ministry (RLM) didn't feel the same urgency and thus, gave the project low priority resulting on the design not being completed until the end of 1941.
The new fighter had many new features like a tricycle landing gear, with a nosegear strut that twisted 90º during retraction to a flat position under the engine, a pressurized cockpit which was intended to give more confortable and higher high-altitude performance. Each of the new features was tested previously on a number of Bf.109Fs airframes, having the Bf.109V23 a ventral radiator, the V31 a radiator and a tricycle landing gear and the V30 a pressurized cockpit.
Due to the lack of interest on the project by the RLM delayed the completion of the prototype until spring 1942 and further trouble with the nosewheel pushed back its maiden flight until July. When it flew, its performance was satisfactory as it was 50 km/h (30 mph) faster than the first versions of the Bf.109G, however it wasn't fast enough to be exemplary. In fact, the Bf.109G could out-turn the Me.309 and, with the addition of armament, the Me.309's speed decreased to unacceptable levels. Given its poor performance and the recent development of the very promising Focke-Wulf Fw.190D, the project was cancelled.
It was powered by a single Daimler-Benz 603G inverted V-12 liquid-cooled piston engine which yielded 1726hp of power and was armed with two 20mm MG 151 cannons and four 13mm MG 131 machine guns placed at wings roots and a single 30mm Mk.108 cannon firing through propeller's hub.

Sources:
1. https://en.wikipedia.org/wiki/Messerschmitt_Me_309
2. https://www.valka.cz/Messerschmitt-Me-309-V1-t179651
3. https://www.valka.cz/Messerschmitt-Me-309-V4-t17618
4. Salamander Books - The Complete Book of fighters
5. AJ Press - Monografie Lotnicze 44 - Messerschmitt Me.109 cz.3 - Translated

Shenyang J-5/F-5.

The Shenyang J-5/F-5 is a Chinese-built single-seat jet fighter interceptor which is a license-built Mikoyan-Gurevich MiG-17. It was exported to many countries under the denomination of Shenyang F-5.
It was originally designated as Dongfeng 101 and also as Type 56 before it was definitely named as J-5 in 1964.
It was built in China from 1956 until the 1960s when production ceased. It's believed that around 767 machines just of the regular version, the copy of the MiG-17F, were manufactured at Songling State-Owned Machinery Factory in the city of Shenyang, located in the province of Liaoning, in Manchuria. Initially, the Chinese obtained a license for the regular version of the MiG-17, which would retroactively be called Shenyang J-4 in the early 1950s. In order to introduce modern production methods to Chinese industry the People's Liberation Army Air Force (PLAAF) obtained plans for the MiG-17F in 1955, along with two completed pattern aircraft, 15 knockdown kits and parts for ten aircraft. The first Shenyang J-5 flew for the first time on 19th July 1956 with test pilot Wu Keming as the pilot.
It was powered by a Wopen WP-5 engine (a copy of the Klimov VK-1) that yielded 25.5 kN (5700 lbf) of thrust and 33.8 kN (7600 lbf) with afterburner. It was armed with a single 37mm Type 37 cannon and two 23mm Type 23-1 cannons placed in the lower part of the nose, just like the regular MiG-17F.
It became the main PLAAF's fighter during the mid-to-late 1950s and even the first part of the 1960s and was also exported to many countries.
It served with the Cambodian Air Force, as ten F-5 were sent to the back then called Royal Khmer Aviation in 1965 as military aid. By 1970 only six of them were operational and those six remaining ones were lost on the ground in 1971 when the North Vietnamese Air Force conducted their "Sapper" attack.
It's also serving with the North Korean Air Force (NKAF). It's believed that at least 107 F-5s are still in active service with the NKAF. However, more than half of them are supposed to not be airworthy as they acquired back in the late 1960s and have been in active since then.

Sources:
1. https://en.wikipedia.org/wiki/Shenyang_J-5
2. https://www.valka.cz/topic/view/80747
3. Salamander Books - The Complete Book of Fighters

Fairey Swordfish, part nine

The Fairey Swordfish saw also action in the Mediterranean front, as well as action in the Indian Ocean in secondary roles. On 14th June 1940 shortly after the Italian declaration of war, nine Swordfish of the 767 Naval Air Squadron (NAS) which were based in Hyeres, Provence-Alpes-Côte d'Azur (South-Eastern France), took off and conducted the first Allied raid on Italian soil of the war. Four days later, on the 18th, they were rebased to Bone, Algeria before splitting the squadron as the training elements went back to Britain and the operational portion was sent to RAF Hal Far, on Malta, where it was renamed as 830 NAS. On 30th June operations resumed as they conducted a night raid against oil tanks in Augusta, Sicily.
On 3rd July 1940 was one of the main weapons employed by the British to attack the French fleet at Mers-el-Kébir, close to Oran, in Algeria to prevent the ships from falling into German hands. Twelve Swordfish from 810 and 820 NAS were launched from the HMS Ark Royal (91) and conducted three sorties against the anchored fleet. In the ensuing torpedo attack the Battleship Dunkerque was crippled and many other ships were severely damaged, proving that capital ships could be seriously damaged while anchored in harbour. It was also the first time that the Royal Navy won a battle without using gunfire.
Shortly after Mers-el-Kébir, a detachment of three Swordfish was sent to support British troops in the Western Desert, responding this way, to a request for torpedo aircraft to destroy hostile naval units operating off the Libyan coast. On 22nd August the three Swordfish destroyed two u-boats, one destroyer and a supply ship present in the Gulf of Bomba, Libya, using just three torpedoes.
On 11th November, Swordfish flying from HMS Illustrious (87) achieved great success at the Raid in Taranto. The main force of the Italian Navy was based at the Italian port of Taranto, located at the South-Eastern tip of the Italian peninsula and, after the success of Mers-el-Kébir, the British admiralty sought another similar victory. The Royal Navy had conducted extensive preparations, with some plans dating back to even 1938, when the war between European powers seemed already unavoidable. Regular reconnaissance aerial missions were flown to gather intelligence about the position of capital ships and Swordfish' crews were trained to conduct nightly operations, because the night raid was seen as the only possible way of overcoming the defences of the well-protected harbour.
The raid on Taranto was originally scheduled for 21st October, however it was delayed to 11th November to allow key reinforcements to arrive and other tasks to be completed. The aerial attack started with a volley of flares dropped by Swordfish aircraft to illuminate the area where the raid would took place, after the which, a formation of Swordfish commenced bombing and torpedo runs. Given the presence of barrage ballons and torpedo nets the number of suitable torpedo-dropping positions was cut so many of the Swordfish were armed with bombs -instead of torpedoes- and conducted a synchronised attack upon the cruisers and destroyers instead. The just three torpedo-armed Swordfish inflicted serious damage on three of the Battleships (Conte di Cavour, Caio Duilio and Littorio) and two cruisers, two destroyers and other vessels were either sunk or damaged. The high manoeuvrability of the Swordfish helped the aircraft to evade the intense anti-aircraft fire and hit the Italian ships. This Battle showed that a single force of torpedo bombers could immobilise an entire fleet and were an effective mean of altering the balance of power. In fact, the Japanese air attaché to Berlin, Takeshi Naito, visited Taranto at the aftermath of the battle in order to, more than one year later, brief the Bombing of Pearl Harbor.
Later, on 28th March 1941 two Swordfish based on Crete contributed to the disabling of the Italian Heavy Cruiser Pola during the Battle of Cape Matapan. In May, six Swordfish based at Shaibah, near Basra, Iraq, took par in suppressing the revolt in the region widely known as the Anglo-Iraqi War as the aircraft conducted bombing missions on Iraqi barracks, fuel depots and bridges.
The Swordfish also flew a high number of anti-shipping missions in the Mediterranean, many of them from Malta. Guided by the aerial reconnaissance of other RAF units, Swordfish would time their attacks to arrive at enemy convoys in the dark to elude German fighters, which were restricted to daytime operations. While there were never more than 27 Swordfish stationed at the island at a time, the Swordfish managed to sink an average of 50.000 tons of enemy shipping per month during a nine-month period. During one record month, 98.000 tons were reported to have been sunk to the island's Swordfish strike force. The recorded lost of Swordfish were low, specially related to the high sortie rate of the aircraft and in light of the fact that many aircraft lacked many blind-flying equipment, making night-flying even more dangerous.
Close to the end of the war, there were still nine front-line squadrons that were equipped with the Swordfish. Overall they counted for 14 u-boats destroyed. The Swordfish was intended to be replaced by the Fairey Albacore, but it outlived its intended successor and was replaced by the Fairey Barracuda. Operational sorties of the Swordfish continued in January 1945 being the last active missions believed to be anti-shipping raids conducted off the Norwegian coast by 835 and 813 NAS, where Swordfish' manoeuvrability was essential. On 21st May 1945 the last operational squadron, 836 NAS, which had been tasked with providing resources for the MAC ships, was disbanded shortly after the end of the war in Europe.
In the summer of 1946 the last training squadron equipped with the type was disbanded, after which only some few aircraft were kept in service to perform sundry duties at few naval air stations.

Sources:
1. https://en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. https://www.navywings.org.uk/aircraft/twin-aircraft/swordfish/
4. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Action

Fairey Swordfish, part eight

During early 1940 Swordfish from 812 Naval Air Squadron, assigned to the RAF Coastal Command performed an aerial attack campaign against continental enemy-hold ports along the English Channel. They were routinely sent to deploy naval mines, task which proved to be hard due to the limitations of the aircraft and the precision navigation skill required. In order to achieve the range needed to reach some naval facilities, additional fuel tanks were installed in the crew area and the third crew member was left behind. In many of these missions the Swordfish were escorted by fighters which also conducted counter-attacks on enemy air bases.
The intensity of the Coastal Command's Swordfish operations was radically increased after the German Invasion of the Low Countries, as they were expanded with four additional Swordfish-equipped squadrons. They were sent to attack strategically important targets off the coasts of Netherlands and Belgium on daylight raids, during which they were subjected to heavy anti-aircraft fire and Luftwaffe fighter interception. Night-time raids were also conducted attacking various types of installations like oil installations, power stations and aerodromes. After the fall of France, Swordfish raids were focused on ports that were seen as useful for a potential invasion of the United Kingdom, which typically meant spotting for naval bombardments on such port facilities as well as conducting security patrols.
In February 1942 the flaws of the Swordfish were demonstrated during a German naval fleet action known as the Channel Dash, when six Swordfish lead by Lt.Cdr. Eugene Esmonde took off from Manston to intercept Battleships Scharnhorst and Gneisenau when they were traversing the English Channel towards Germany. When the Swordfish formation arrived and attack procedure was started, they were intercepted by 15 Messerschmitt Bf.109 resulting in the loss of all the Swordfish without inflicting any damage at all on the ships. Esmonde, who had taken part on the attack on the Bismarck the previous year, was awarded the Victoria Cross posthumously.
The courage of the Swordfish crew was noted on both sides as both German and British commanders wrote favourably about their bravery. As a result of the Channel Dash, the Swordfish was quickly relegated from the torpedo-bomber role and was more often tasked with anti-submarine duties instead where, armed with depth charges and rockets, it soon proved to be a capable submarine-killer.
In that role, it pioneered the usage of air-to-surface vessel (ASV) radar, being the first carrier-borne aircraft to be equipped with it. This, allowed the Swordfish to effectively locate surface ships at night and through clouds. In October 1941 the Swordfish was already flying operational missions with the ASV radar. On 21st December 1941 a Swordfish based in Gibraltar sank an U-Boat. It was the first kill of such type achieved by an aircraft during nighttime. On 23rd May 1943 a rocket-equipped Swordfish attacked and destroyed German submarine U-752 off the coast of Ireland making it the first kill achieved with that weapon.
The Swordfish also saw action during the battle of the Atlantic. In May 1941 it got involved in the pursuit and sinking of the Battleship Bismarck. On 24th May nine Swordfish from the HMS Victorious (R38) made a late night sortie on the Bismarck under bad weather. Thanks to the ASV radar the flight were able to locate and attack the ship resulting in a single torpedo hit that caused minor damage. Later, on 26th May, HMS Ark Royal (91) launched two Swordfish strikes against the Bismarck. The first one failed to locate the ship, while the second manage to strike to hits which jammed the ships' rudders at 12º port helm on position. This attack made the Bismarck unmaneouvrable and unable to escape to port in France. She sank 13 hours later after Royal Navy intense bombardment. The low speed of the attacking aircraft played in their favour as they were too slow for fire control predictors of the Bismarck, whose shells exploded so far in front of the aircraft that the shrapnel damage was greatly diminished. At least one of the Swordfish flew so low on the sea that some of the Bismarck's flak battery couldn't depress enough to aim them.
Throughout 1942 the Swordfish was progressively transferred from Royal Navy's fleet carriers as the Fairey Albacore and the Fairey Barracuda became available. In the submarine hunter role, the Swordfish made significant contributions to both the Battle of the Atlantic, protecting convoys and  in support of the Arctic Convoys between Britain and Russia. In addition to attacking enemy submarines, the Swordfish could also guide destroyers onto their positions to coordinate attacks against u-boats. On one convoy, Swordfish on board escort carrier HMS Striker (D12) and HMS Vindex (D15) flew over 1000 hours performing anti-submarine patrols over a 10-day period.
One of the most innovative implementations of the Swordfish was its usage in combination with the Merchant Aircraft Carriers (MAC) which were 20 civilian cargo or tanker ships modified to carry three or four aircraft each on anti-submarine duties on convoys. Three of these ships were Dutch manned, which we already covered in a previous post and the others were manned by pilots and crew of the 836 Naval Air Squadron which was, at one time, the largest Swordfish operator, being equipped with 91 aircraft.

Sources:
1. https://en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. https://www.navywings.org.uk/aircraft/twin-aircraft/swordfish/
4. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Action

Fairey Swordfish, part seven

During the Norwegian Campaign, the first combat usage of the Swordfish occurred. It was on 11th April 1940 when many Swordfish aircraft were launched from HMS Furious (47) to perform an attack on German vessels that were reported to be in anchor at the port of Trondheim. When the group arrived at Trondheim, they only found two destroyers there. In the ensuing attack only one hit was recorded as being attained, but, that attack holds the record of being the first torpedo-attack of the war to performed by a torpedo-carrying aircraft.
Later, on 13th April, a Swordfish launched from HMS Warspite (03) spotted fall of shot and radioed gunnery corrections back to the ship during the Second Battle of Narvik. The total number of German destroyers sunk or scuttled during that campaign was nine. One of them was damaged by a bomb dropped from a Swordfish belonging to the HMS Warspite, at the cost of zero losses in the British side. The German submarine U-64 was also spotted by a Swordfish, which performed a dive-bombing attack upon it, scoring a direct hit and quickly sinking the submarine, making it the first U-Boat sunk by the Fleet Air Arm (FAA) in the war.
After the Second Battle of Narvik, the Swordfish continually attacked targets in the surroundings for two weeks bombing either ships, land facilities or even enemy parked aircraft. During this time anti-submarine patrols and aerial reconnaissance missions were also flown in spite of the challenge that the challenging terrain and inhospitable weather imposed, which was made worse by its open cockpit.
For many Swordfish crews the Norwegian Campaign were their first active combat missions and often involved many other 'first time tasks' like night-landings upon aircraft carriers.

Sources:
1. https://en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. https://www.navywings.org.uk/aircraft/twin-aircraft/swordfish/
4. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Action

Fairey Swordfish, part six

In July 1936 the Swordfish entered formally in service with the Fleet Air Arm (FAA) which was, back then, part of the Royal Air Force (RAF).
The 825 Naval Air Squadron was the first one to receive the Swordfish that same month. The Swordfish began replacing both the Fairey Seal and the Blackburn Baffin in both spotter-reconnaissance and torpedo-bomber roles competing with the Blackburn Shark in that combined role. Initially it was the Shark which replaced the Seal in the spotter-reconnaissance roles and the Swordfish replaced the Baffin in torpedo-bomber role. Shortly after the Shark was quickly replaced by the Swordfish. For almost two years during the late 1930s the Swordfish was the sole torpedo-bomber aircraft serving with the FAA.
When the World War 2 started in September 1939, the FAA was transferred to Royal Navy control with a total of 13 operational squadrons equipped with the Swordfish Mk.I plus three flights of float-equipped ones for use off-catapult equipped warships. After the outbreak of the World War 2, a total of 26 FAA squadrons would be equipped with the Swordfish and more than 20 second-line squadrons would also operate it in the training role. During the early months of the war, the Swordfish' action was limited to uneventful fleet protection and convoy escort missions.

Sources:
1. https://en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. https://www.navywings.org.uk/aircraft/twin-aircraft/swordfish/
4. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Acti

Fairey Swordfish, part five

The Fairey Swordfish was a medium sized biplane torpedo bomber and reconnaissance aircraft. It employed a metal airframe covered in fabric and featured folding wings to save space inside aircraft carriers and battleships. Once in service, it was nicknamed "The Stringbag" due to the enormous amount of stores and equipment that it could carry. Crews likened the aircraft to a housewife's string shopping bag, which was very usual at the time and could fit contents of any shape and that a Swordfish, like a stringbag, could carry anything.
Its main weapon was the aerial torpedo, but given its low speed and the need for a straight long approach, made it difficult to deliver against well-defended targets. Swordfish' torpedo doctrine recommended an approach at 5000ft (1500m) followed by a dive torpedo release altitude of 18ft (5.5m). The maximum range of British main aerial torpedo at the time, the Mark. XII, was 1500 yards (1400m) at 40 knots (46mph/74km/h) and 3500 yards (3200m) at 27 knots (31mph/50km/h). The torpedo travelled for 200ft (61m) forward from release to water impact, and required further 300 yards (270m) to stabilise at preset depth and arm itself. Ideal release distance was 1000 yards (910m) from target, given that the Swordfish could survive that distance.
The Swordfish was also able of operating as a dive bomber. Just before the war, in 1939, the Swordfish on board HMS Glorious aircraft carrier took part in a series of dive-bombing trials, during which 439 practice bombs were dropped at angles of 60 67 and 70 degrees against the target ship HMS Centurion. Tests against fixed targets showed an average error of 49 yards (45m) from a release height of 1300ft (400m) and a dive angle of 70 degrees. Tests against a manoeuvring target showed and error of 44 yards (40m) on average from a drop height of 1800ft (550m) and a dive angle of 60 degrees.
When more modern torpedo attacks were developed, the Swordfish was successfully relocated to the anti-submarine role, armed with either depth charges or eight "60lb rockets RP-3 rockets and usually it flew from the smaller escort carriers or even the merchant aircraft carriers (MACs), when equipped with the Rocket Assisted Take Off (RATO) system. Given its low stall speed and tough and sturdy design, it was excellent to operate from MAC ships in the harsh mid-Atlantic weather. In fact, its stall speed was so low that, unlike any other carrier-borne torpedo bomber, it did not require the carrier to be steaming into the wind. Sometime, when the wind was right, Swordfish were flown from a carrier at anchor.

Sources:
1. https://en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. https://www.navywings.org.uk/aircraft/twin-aircraft/swordfish/
4. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Action

Fairey Swordfish, part four

In early 1936 an initial production contract for 68 Swordfish was put on at Fairey's as the Swordfish Mk.I. They were manufactured at Fairey's factory in Hayes, West London and the first production batch was completed in early 1936. It entered service with the Fleet Air Arm (FAA) in July 1936.
By early 1940 Fairey was still busy with Swordfish and Albacore's productions so the Admiralty proposed Blackburn Aircraft to build it under license.
In fact, according to production numbers, Fairey manufactured a total of 692 Swordfish Mk.I (the regular first production series with either floats or fixed landing gear) from 1936 until 1940 at Hayes and Blackburn manufactured 300 Mk.I from December 1940 until October 1941. Blackburn was also responsible for manufacturing the subsequent variants like the Mk.II (version with longer wings to fit rockets underneath) which was introduced in 1943 with 1080 machines newly build and/or converted from Mk.I during the period from October 1941 until February 1944 at Blackburn's factory in Sherburn-in-Elmet, in North Yorkshire.
The Mk.III variant (featuring a belly-mounted anti-submarine radar) was introduced also in 1943 but it wasn't produced until February 1944. Three hundred and twenty machines were either converted or built at Sherburn-in-Elmet and production ceased in August 1944 as new more modern types were already rolling out of the factories (namely the Fairey Barracuda and the Grumman Avenger).
During the war, efforts were made to decentralise production and employ the usage of shadow factories to minimise the damage caused by Luftwaffe's bombing raids. Major sub-assemblies were produced by four sub-contractors based in neighbouring Leeds and these were transported by land to Sherburn where they were assembled.
On 18th August 1944, the last Swordfish was manufactured with almost 2400 machines manufactured in every variant.

Sources:
1. en.wikipedia.org/wiki/Fairey_Swordfish
2. https://www.valka.cz/topic/view/6593/Fairey-Swordfish-Mk-I
3. https://www.valka.cz/topic/view/8642/Fairey-Swordfish-Mk-II
4. https://www.valka.cz/topic/view/76663/Fairey-Swordfish-Mk-III
5. Signal Squadron - Aircraft In action 175 - Fairey Swordfish in Action

Fairey Swordfish, part three, origins

As Fairey was a company that had already proven its talent to design and construct naval aircraft, in 1933 they started the design of an entirely new three-seater aircraft intended for the reconnaissance and torpedo-bomber. The project received internally the designation of T.S.R.1 (Torpedo Spotter Reconnaissance) with a biplane configuration and was to be powered by a single Bristol IIM radial engine which could yield 645hp of power. Fairey initially chose to keep the development as purely private while both customers and applicable requirements for the type were sought. The development of the T.S.R.1 was made in parallel to Fairey's activities regarding the Air Ministry Specification S.9/30, for which the company was, at one point, developing a separate but very similar aircraft, powered by a Rolls-Royce Kestrel engine instead and employing also a different fin and rudder configuration.
A respectable amount of contributions for the T.S.R.1 came from Fairey's independent design work on a proposed aircraft for the Greek Naval Air Service which had requested a replacement for the Fairey IIIF and Fairey IIIB, and also came from specifications M.1/30 and S.9/30. Fairey soon informed the Air Ministry about their work for the Greeks, whose interest had eventually waned, and proposed its solution to requirements for a spotter-reconnaissance plane. In 1934, the Air Ministry issued the Specification S.15/33 which added the requirement of the torpedo bomber role.
On 21st March 1933 the first prototype took off to the skies from Great West Aerodrome, in Heathrow at the hands of Fairey's chief test pilot Chris Staniland. It performed various flights which were used to test aircraft's flight characteristics, before being re-engined with with an Armstrong-Siddeley Tiger radial engine and switching back to the Pegasus engine again. On 11th September 1933 the first prototype was lost when it entered in an uncontrollable series of spins that crashed the aircraft with the pilot, fortunately, surviving the accident. Before this, as the prototype had shown favourable handling and flying characteristics, it was decided to proceed with a second prototype (T.S.R.II) which had been designed to fully comply with the Specification S.15/33.
On 17th April 1934 the second prototype flew for the first time, piloted by Staniland. Unlike the previous model, it was equipped with the more advanced version of the Bristol Pegasus Engine, an additional bay within the rear fuselage to counter the spin tendencies and the upper wing was slightly swept back to cope with the increased length of the fuselage together with other aerodynamic-related tweaks to the rear of the aircraft. During the flight test programme T.S.R.II was sent to Fairey's factory in Hamble-le-Rice, Hampshire, where it received a twin float undercarriage instead of its original wheeled one. It flew for the first time in this new floatplane configuration on 10th November 1934 and, after successful water-handling trials, it made a series of catapult launch and recovery tests on board HMS Repulse Battlecruiser. It was restored back to its original wheeled configuration before being handed over to the Royal Aircraft Establishment for an extensive evaluation process at RAF Martlesham Heath.
In 1935, after satisfactory tests were made at Martlesham, the Air Ministry placed a pre-production order for three aircraft. It was then when the T.S.R.II received the nickname of Swordfish. All three of them were powered by Bristol Pegasus IIIM3 engine, but adopoted a three-bladed propeller configuration instead of the two-bladed one employed by the previous two prototypes. On 31st December 1935, the first pre-production Swordfish made its maiden flight and on 19th February 1936, the second one. The third one was completed in floatplane configuration and underwent water-based service trials at the Marine Aircraft Experimental Establishment at Felixstowe, in Suffolk.

Sources:
1. en.wikipedia.org/wiki/Fairey_Swordfish
2. http://www.aviation-history.com/fairey/swordfish.html
3. Hall Park Books - Warpaint 12 - Fairey Swordfish
4. Signal Squadron - Aircraft In action 1175 - Fairey Swordfish in Action

Fairey Swordfish, part two, Commonwealth & Royal Air Force users

As it could've been expected, the Fairey Swordfish was also used by some Commonwealth countries as well as the Royal Air Force. The users covered in this post are:

• Australia: The Royal Australian Air Force got six new Swordfish in 1942 in a rather unexpected way. On 17th March 1942 it was reported that a number of wooden crates had arrived at the Bullsbrook railway siding from Fremantle Port. It was assumed that they contained the expected Curtiss P-40E Kittyhawk fighters that would replace the fighters of the No.77 Squadron RAAF as they were unloaded from an American cargo ship. When it was discovered that they contained Swordfish, it was decided to assemble them. They were operated mainly by No.14 and No.25 Squadrons RAAF as well as some independent HQ flights. 
• The three ones assigned to the No.25 Squadron were used in anti-submarine patrols around Rottnest Island and Gage Roads, off the port of Fremantle. Two more were assigned to the No.14 Squadron which used them in the liaison duty and they flew often between Pearce and Busselton where squadron's detachments were located. The remaining Australian Swordfish served with RAAF Pearce's Station Headquarters in communications flights. 
• Canada: The Swordfish was operated from the Naval Gunnery School at Yarmouth, Nova Scotia and the Royal Navy Station at Dartmouth. In 1946 Fleet Requirement Unit 743 (RCN) was equipped with Swordfish which used them in general purpose duties. When they were finally written off, the Royal Canadian Navy's air arm reserve approved to ferry some of the veteran Swordfish to 11 Naval Reserve Divisions all across Canada for ground crew instructional purposes.
• Royal Air Force: Up to six RAF squadrons were equipped at one point with the Swordfish. Numbers 8, 119, 202, 209 and 613 Squadrons used the Swordfish, apart from two Anti-Aircraft Co-operation units (based in Gibraltar, Malta and Singapore) and one pilot advanced training unit. One of those squadrons, the No.119 was equipped with the Swordfish Mk.III very late in the war, in January 1945 to be more precise. They transitioned to the ASV-equipped variant because they had been rebased to Belgian coast in order to switch to midget submarines as their main targets, for which the ASV-radar proved to be very useful. They flew ASW patrols up to, literally VE-Day, on 8th May 1945 and the squadron was disbanded shortly later, on 25th May. 

Sources:

1. en.wikipedia.org/wiki/Fairey_Swordfish

2. http://www.adf-serials.com.au/swordfish.htm

3. http://silverhawkauthor.com/canadian-warplanes-1-the-biplane-era-fairey-swordfish_697.html

4. https://ingeniumcanada.org/aviation/collection-research/artifact-fairey-swordfish-ii.php

5. https://en.wikipedia.org/wiki/No._119_Squadron_RAF