Supermarine Spitfire. At Royal Air Force's service. Part three. The Spitfire in the Battle of France.

 

The Spitfire Mk. III, pictured below, was an attempt to improve the basic Spitfire design. It was powered by a Rolls-Royce RM 2SM, which was later known as the Merlin XX and yielded 1,390 hp of power, thanks to its two-speed supercharger and reduced wingspan. In order to increase ground stability, the undercarriage was raked forward, and had flaps to completely enclose the wheels when retracted. The tailwheel was fully retractable too. 
The windscreen was remodelled, with a built-in internal bulletproof glass panel, and was armed with the "c-type" wing, which could host four 20 mm cannons, eight 0.303 in machine guns or two cannons and four machine guns. Maximum speed was increased to 385 mph (620 km/h).
The first prototype, registered as N3297 flew for the first time on 16th March 1940 and was thoroughly tested and, although the Mk. III was ordered for mass production, it was soon cancelled as the Merlin XX engine was in short supply and was needed for the Hawker Hurricane Mk. II, which was the workhorse of the Royal Air Force. In the meantime Rolls-Royce developed the Merlin 45, a similar engine in terms of performance, which could be fitted in the fuselage of a Spitfire Mk. I or a Mk. II. The Mk. III was abandoned in favour of the Mk. V, although the improvements first seen in the Mk. III were incorporated in later marks of the Spitfire. The airframe of the Mk. III was used to test the Merlin 61 engine, which later powered the marks VII, VIII and IX, making the Mk. III the true ancestor of those marks.

Some other Spitfires were also altered, one of those was R6722,  which, when the Germans invaded Norway in April 1940, the RAF showed interest in the concept of floatplane fighters, which could be useful in those areas were airfields were not immediately available, so R6722 was taken from the Woolston factory, to be fitted with floats taken from a Blackburn Roc naval fighter. The conversion was made by No. 12 Maintenance Unit at RAF Kirkbride in Cumbria and later, tank tests were carried out at Farnborough, employing a scale model, finding that the concept was solid even if some changes were to be made, such as enlarging vertical tail surfaces to counter-balance the side area of the floats. The "Narvik Nightmare", that's how this Spitfire was commonly known, was reverted back to a regular Mk. I when the Battle of Norway ended and, eventually, it was upgraded to a Mk. V. 

The Spitfire was first used at an operational level over western Europe on 13th May 1940, during the German invasion of the Netherlands. Since three days earlier, German paratroopers were pinned down by the Dutch Army in the Battle of Hague, so the Royal Air Force sent No. 66 Squadron, equipped with Spitfires to escort No. 264 Squadron, equipped with Boulton Paul Defiants, to provide ground support for the Dutch army. The Spitfires encountered German Junkers Ju.87 Stukas belonging to IV (St.)./Lehrgeschwader 1 and shot down four of them. However, they were soon intercepted by Bf.109 from 5./Jagdgeschwader 26 that shot down five Defiants and one Spitfire, for the loss of just one Bf.109.On 23rd May 1940 other German Bf.109s were shot down by Spitfires of No. 54 Squadron over Calais Marck airfield, on the northern shore of France.
During the Battle of France a total of 67 Spitfires were lost on French soil, most of them during attempts to prevent the Luftwaffe from bombing the evacuation beaches at Dunkirk. During this period, every Spitfire unit was based in Great Britain, as Air Vice Marshal Hugh Dowding ordered, however, from late 1939 some Spitfire PR.I, specially modified for photo reconnaissance duties, belonging to No. 2 Camouflage Unit, were operating from Seclin, northern France, close to the border with Belgium, performing photo-intelligence gathering of German defences and cities. 

The Battle of Britain began on 10th July 1940 and became the first major test for both the Spitfire and the RAF Fighter Command. During this time, very important lessons were learned about Spitfire's capabilities and setbacks, but that's for another post.

Sources:
1st https://en.wikipedia.org/wiki/Supermarine_Spitfire_operational_history
2nd https://en.wikipedia.org/wiki/Supermarine_Spitfire_(early_Merlin-powered_variants)
3rd https://www.historyofwar.org/articles/weapons_spitfire_mkIII.html
4th https://en.wikipedia.org/wiki/Supermarine_Spitfire_(late_Merlin-powered_variants)
5th https://www.solentsky.org/post/secret-files-the-spitfire-floatplanes
6th https://allspitfirepilots.org/aircraft/R6722

Supermarine Spitfire. At Royal Air Force's service. Part two. Prototypes and early Spitfires.

 

After the disappointment of the Type 224, Mitchell and his design staff, began to draw cleaner designs using the experience with the Schneider Trophy seaplanes as a departing point. This, eventually led to the Type 300, which featured retractable undercarriage and a reduced wingspan. This original design was submitted to the Air Ministry but it was rejected, so it had to undergo a series of changes such as an enclosed cockpit, oxygen-breathing gear, smaller and slimer wings, and it was to be powered by the, back then, cutting edge Rolls-Royce PV XII V-12 engine, which was later commonly known as the Rolls-Royce Merlin. 
In November 1934, Mitchell was given permission from Vickers-Armstrong (Supermarine's parent company) to develop and reife the Type 300 and on 1st December he was given £ 10,000 from the Air Ministry for the construction of the Type 300, under contract AM 361140/34. 
On 5th March 1936 the first prototype, registered as K5054, took-off for the first time at Eastleigh Aerodrome, Hampshire. At the controls was Cpt. Joseph "Mutt" Summers, chief test pilot for Vickers, who praised the design. 
The initial prototype was later fitted with a new propeller and it was flown again on 10th March 1936, where the undercarriage was retracted for the first time and, after a fourth flight, a new engine was fitted. After overcoming many small failures and improving the design, it was flown again to RAF Martlesham Heath where it was handed to Squadron Leader Anderson of the Aeroplane & Armament Experimental Establishment (A&AEE) to be delivered to the Royal Air Force (RAF). Soon after the Air Ministry placed a production order for 310 Spitfires.
Although it was presented to the public on 27th June 1936, numerous problems hindered the mass production of the Spitfire and the first production aircraft wasn't completed until mid-1938 and it was delivered to No. 19 Squadron at RAF Duxford on 4th August 1938 and during the next weeks No. 66 Squadron also received the type, albeit at a slower pace. The next unit to receive the Spitfire was No. 41 Squadron at RAF Catterick and the first public sight of the Spitfire in RAF's colours and markings took place on Empire Air Day, on 20th May 1939. Later, more squadrons were gradually equipped with the type.
When World War 2 began, there were a total of 306 Spitfires in service with the RAF, seventy-one of them in reserve and 2.000 under manufacture with 36 written off due to accidents.
On 6th September 1939, shortly after the outbreak of the war, a friendly-fire incident known as the Battle of Barking Creek took place where two Hawker Hurricanes of 56 Squadron were shot down by Spitfires of 74 Squadron over the river Medway, Kent. One of the victims of this incident, P/O Montague Leslie Hulton-Harrop, was the first British pilot fatality of the World War II. This incident placed the manufacture of IFF (Identification Friend or Foe) equipment as a top priority.
On 16th October 1939 the Spitfire clashed against the German Luftwaffe for the first time when three aircraft from 602 and 603 Squadrons intercepted three Junkers Ju.88 belonging to 1./KG.30 over Rosyth (Fife, Scotland) trying to attack the cruiser HMS Southampton and HMS Edinburgh on the Firth of Forth. Two of the Ju.88 were shot down and another one was heavily damaged.

The PR (Photo-Reconnaissance) variants of the Spitfire, was a sub-variant dedicated for photo-reconnaissance missions. Before the war, military aerial doctrine dictated that the best option for long-range reconnaissance duties was to employ converted bombers, as they had defensive armament, however, it was soon discovered that Bristol Blenheims and Westland Lysanders were easy targets for German fighters so, following a memorandum made back in August 1939 by Flying Officer Maurice Longbottom, two Spitfires, N3069 and N3071 were released from RAF Fighter Command and sent to the Heston flight, a secret reconnaissance unit. 
Those two Spitfires were stripped from their armament and radio gear, two F24 ventral cameras were installed, heating equipment was added to prevent photographic cameras from freezing and the lenses from frosting. These Spitfires were later known as Spitfire Mk. I PR Type A and achieved a high speed of 390 mph (627 km/h) and were employed for the first in late 1939 to perform photographic reconnaissance flights over western Germany.

The Speed Spitfire was an racer-built variant which was built in late 1938 to achieve world speed records, mainly against German aircraft such as the Messerschmitt Bf.109 V13, Heinkel He.100 V2 and the Messerschmitt M.209 V1, which eventually got the prize achieving a top speed of 755.14 km/h (469.22 mph) on 26th April 1939.
It featured many design changes to make the type more aerodynamic and lacked radio equipment and armament to make it lighter. The Speed Spitfire was eventually handed to the RAF at the beginning of World War 2 where it was suited for photographic reconnaissance, given its high top speed. 

Sources:
1st https://en.wikipedia.org/wiki/Supermarine_Spitfire
2nd https://en.wikipedia.org/wiki/Supermarine_Spitfire_operational_history
3rd https://en.wikipedia.org/wiki/Supermarine_Speed_Spitfire
4th https://en.wikipedia.org/wiki/Supermarine_Spitfire_variants:_specifications,_performance_and_armament
5th https://en.wikipedia.org/wiki/Supermarine_Spitfire_(early_Merlin-powered_variants)

Supermarine Spitfire. At Royal Air Force's service. Part one. The Type 224 Spitfire.

 

The Supermarine Spitfire was a British fighter of the World War II era. It is regarded as one of the best fighters of the war. It has its origins in an Air Ministry Specification; F.7/30 from October 1931 which sought an all-metal day and night fighter armed with four machine guns, a good cockpit visibility, decent high maximum speed and good rate of climb to replace the ageing Gloster Gauntlet. 
The Air Ministry favoured the usage of the Rolls-Royce Goshawk engine, although it wasn't exclusive, so any kind of engine could be employed. 
Bristol, Hawker, Westland, Blackburn and Supermarine submitted proposals, but only three were selected for prototype production: Supermarine Type 224, Blackburn F.3 and Westland F.7/30, with designs from both Bristol and Hawker being rejected. 
Given Supermarine's success in the Schneider Trophy contests, R.J. Mitchell (Supermarine's chief design), was confident in designing a high-speed fighter, so four months after receiving the specification, a monoplane design was submitted, the Type 224.

The Type 224 featured an inverted gull-wing, had a fixed landing gear encased in large fairings and the fuselage was of monocoque construction. It was armed with four Vickers Mk. IV machine guns, two in either side of the open cockpit and the whole fighter was powered by a Rolls-Royce Goshawk II piston engine rated at 600 hp of power.
After wind tunnel tests, Supermarine submitted theoretical performance data to the Air Ministry , suggesting that the aircraft would enjoy good enough performance, so the Air Ministry granted Supermarine a prototype contract. 
On 19th February 1934, the Type 224 took off for the first time, at the hands of Joseph "Mutt" Summers, chief test pilot of Supermarine. Its performance was, however, disappointing, with lateral stability problems caused by the wing design, so a series of redesigns were carried out to the model, among them, an enlarged fin. 
Mitchell proposed a series of improvements to the Type 224, such a new wing, tailplane and a new engine, which would increase performance, but the Air Ministry decided in favour of a new fighter aircraft, instead of a modification of the Type 224. In January 1935 further production was cancelled. 
On 25th May 1937 the only Type 224 was transferred to the Aeroplane and Armament Experimental Establishment at RAF Martlesham Heath, Suffolk to be used during the summer for target practice at Orford Ness, Suffolk.

Although the Type 224 was a failure, Mitchell pushed on and kept designing a fighter, with a complete redesign feature a new straight wing and a thinner airfoil shape. 
The new redesign quickly caught Air Ministry's attention, so in January 1935, shortly after cancelling production on the Type 224, they issued Specification F.37/34 for the sole purpose of covering a new design by Supermarine. This specification mentioned purposely Supermarines specification 425a drawing and, eventually, led to the design of the Supermarine Spitfire.
Supermarine asked the Air Ministry to reserve the name 'Spitfire' to be reserved for the Type 224 and it was adopted, however Mitchell disliked it, so it was later dropped.

Sources:
1st https://en.wikipedia.org/wiki/Supermarine_Type_224
2nd Putnam Books - Supermarine Aircraft since 1914

Nieuport 11 & 16, part six. In French service.

 

The Nieuport 11, nicknamed 'Bébé' (Baby) was built upon the previous Nieuport 10, as it was a smaller and lighter version of it. Designed specifically to be a single-seat fighter, it was, like the "10", a sesquiplane, a biplane with full-sized top wing with two spars and a lower narrower wing and a single spar. Both wings were connected by "Vee" shaped interplane struts. 
The sesquiplane configuration reduced drag and improved the rate of climb and offered a better view from the cockpit than either a conventional biplane or even a monoplane, while being substantially stronger than other fighter from that era. The narrow lower-wing could lead to some aeroelastic flutter at speeds that the Nieuport 11 couldn't achieve, so it wasn't much of a problem. 
The Nieuport 11 was, in many ways a modern fighter, however its armament wasn't. As the Frenchs didn't possess a synchronization gear when the 'Bébé' was designed, a single Hotchkiss or a Lewis gun was fixed to the top wing along the center line which fired above the propeller's arc. The gun was fitted with a circular ammunition drum which contained 97 cartridges and was mounted on a hinged platform, so the pilot could tip it backward to reload the gun. Some machines were field-modified to have twin-Lewis guns and others were also fitted with some rudimentary synchronization devices. 
On the field, some Nieuport 11 were also fitted with the more powerful 110hp Le-Rhône  engine. The pilots of the Nieuport 11 often also carried a pistol of their own.
The Nieuport 11 was powered by either a 50, 60 or 80 hp Gnome or Le-Rhône 9C rotary engine, which yielded impressive performance ratios. However the aircraft was dangerous in a lateral skid. Many pilots, who learnt how to fly in the stable Caudron G.3 and Blériot XI, found the 'Bébé' to be unforgiving to handle and accidents were very frequent.

One Nieuport 11 was fitted with a 150 hp Hispano-Suiza engine and flown by pilot Albert Etéve, to test that new engine. The engine was a success, but it was decided to employ on the new SPAD S.VII fighter, so the Nieuports kept their rotary engines.

The first Nieuport 11 arrived at the frontlines on 5th January 1916 and by February there were 90 in service with Aviation Militaire (French Army's Air Wing). The aircraft allowed the French escadrilles to regain aerial superiority from the Germans , who flew the fearsome Fokker E.III. While the Nieuport 11 was hard to control and to manoeuvre, it could also be very effective at the hands of a skilled pilot. However, aiming was difficult, given the position of the gun, placed high above the pilot's head, which required to angle the aircraft to ensure the bullets struck their target. Still, many French's aces, achieved their ace status while flying a 'Bébé'.
By early 1916, records from escadrille N 38 showed that the Nieuport units still were forced to employ the Nieuport 10 as a fighter, simply because there were not enough Nieuport 11 available. This was the reason why the Nieuport 11 was only supplied to the unit's most experienced pilots which, considering how difficult it was to handle, was a fortunate decision. By the time of the Battle of the Somme, N 38 had only five Nieuport 11 available, while N 49 just seven in March 1916 and N 31 had just three by October 1916.

The Nieuport 11 was gradually supplied to the following escadrilles:

N 3, N 12, N 15, N 23, N26, N 31, N 37, N 38, N 48, N 49, N 57, N 65, N 67, N 68, N 69, N 73, N 102, N 103, N 112, N 124, plus one special escadrille, Escadrille 92.
The Armée Française d'Orient (A.F.O. - French Army of the East, the French Army serving in the Macedonian front) also had two escadrilles under its command, N 387 and N 391. 
During the famous Battle of Verdun, which began on 21st February 1916, nine Nieuport 11 escadrilles were sent to that sector to achieve aerial supremacy. Initially those units were under direct control of various Groupes d'Armée (Army Groups), meaning that they employed most of the time escorting reconnaissance and bomber units assigned to the same Groupe d'Armée, while the Nieuport units themselves were also required to perform reconnaissance missions, leaflet drops and even spy deliveries behind enemy lines. Those duties were in addition to the usual fighter patrols and attacking enemy balloons. 
However, the French realized that it was more effective to concentrate fighter units in a single group and employ them to gain air superiority over sectors of the front. 
In preparation for the incoming Battle of the Somme one new group, Groupement de Combat de la Somme (Somme's Combat Group) containing seven escadrilles was formed in April 1916. This group was tasked with the inhibition of German reconnaissance aircraft and balloons from detecting French movement of troops and supplies to the front before tha battle began in late June.
By mid-1916 the Nieuport 11 was being replaced by the Nieuport 16 and by late 1916 almost every Nieuport 11 was already withdrawn from frontline service. 
After being withdrawn from the frontlines, the Nieuport 11 were assigned to training units. 

The Nieuport 11 gave France its first modern fighter and allowed Aviation Militaire to keep supremacy over the Fokker E.III, while, as stated, at Verdun and the Somme the Nieuport 11 controlled the skies over the battlefield.

The Nieuport 16, on the other hand, was an improved variant of the Nieuport 11. It was developed in 1916 with a strengthened airframe and powered by a more powerful 110 hp Le-Rhône 9J rotary engine. Visually it was similar to the "11" but it could be distinguished for having a headrest for the pilot and a larger aperture in front of the "horseshoe" cowling. The "16" was seen as an interim type, while the better Nieuport 17 became available. Just like the Nieuport 11, the "16" lacked a synchronization gear, so it was armed with either a Hotchkiss or a Lewis machine gun, mounted over the top wing, firing over the propeller's arch. Some Nieuport 16 were also fitted with Le Prieur rockets, from the struts to attack German observation Kite balloons. 

Unlike the Nieuport 11, the Nieuport 16 wasn't employed in large quantities, as it was seen as an interim type, while the Nieuport 17 arrived. Some of the escadrilles to have employed the Nieuport 16 were: N 3, N 12, N 15, N 23, N 26, N 31, N 37, N 48, N 49, N 57, N 62, N 65, N 67, N 68, N 69, N 73, N 75, N 77, N 102, N 103, N 112 and N 124.
The Nieuport 16-equipped escadrilles were active at the Somme Front. The Groupement de Combat de la Somme was formed in April to achieve local aerial supremacy over the front, while the Groupement de Chasse Cachy (Cachy's Fighter Group) also employed the type. 

Groupe de Combat de la Somme was tasked with supporting the 6th Armée during the battle. When the Somme offensive began, the group acted in the infantry support role, performing ground attacks while attempting to control the skies over the battlefield. When the Germans sent additional aircraft to the Somme, the Aviation Militaire sent seven escadrilles from Groupement Cachy to keep the aerial supremacy. Groupement Cachy's main mission was to provide aerial cover for the reconnaissance and bombing units in the Somme.
Anyway, the Nieuport 16s were soon replaced by the better and more effective Nieuport 17, with some few escadrilles kept the "16" until early 1917. It seems likely that by late 1916 most units had already replaced the Nieuport 18 entirely.

Sources:
1st Flying Machines Press - French Aircraft of the First World War
2nd https://en.wikipedia.org/wiki/Nieuport_11
3rd https://en.wikipedia.org/wiki/Nieuport_16

Nieuport 11 & 16, part five. The 'Bébé' in Italy.

 

Italy employed the Nieuport 11 in large quantities to supplement and replace the outdated Nieuport 10. Italian aircraft manufacturer Macchi, which initially was a subsidiary of Nieuport,  built the Nieuport 11 locally. In fact, a total of 450 'Bébés' were manufactured in Italy, plus additional 93, out of 200 originally ordered, by the Officine Elettro-Ferroviarie in Milan. 
The Nieuport 11 was initially employed in Italy in 1916 by 70a Squadriglia (a squadron-sized unit), based at Santa Caterina, north-eastern Italy. The unit was rebased to Udine, where the supreme command was located. When destined in this area, 70a Squadriglia performed offensive patrols over the frontlines. By December 1916 the majority of the 56 enemy airplanes downed by Italian fighters were dispatched by Nieuport 11s. By this time, Italian pilots complained about the Lewis gun, which was difficult to reload while in flight, and the Nieuport 11 could just carry a small number of additional magazines. By late 1916 some few 'Bébés' were equipped with the Le Prieur rocket system to attack enemy balloons.
During 1916 there were four squadriglias employing the Nieuport 11; 70, 71, 75 and 76a.
By early 1917 there were six additional squadrons: 77, 78, 79, 80, 81 and 82a, plus 83a Squadriglia based at Kremain, Macedonia, 85a Squadriglia at Piskupi, Albania and the Sezione (Section - a flight-sized unit) Nieuport at Belluno. These two last squadriglias were, in spite of their name, also flight-sized.
During 1916 and 1917 Macchi was able to produce between 35 and 45 aircraft per month, being Nieuport 11 most of them. However, by early 1917 they were being replaced by the Nieuport 17 in production lines, so by October 1917 only nine squadriglias still had the Nieuport 11 in active service: 70, 71, 72, 75, 76,  78, 79, 82 and 85, this last one still operating from Piskupi, in Albania. 
By late 1917 the number of Nieuport 11-equipped squadriglias was reduced to six: 71, 72, 75, 76, 82 and 91. 
The Nieuport 11 was, by 1918, outdated and being replaced by the better Nieuport 17 as it became available, so the Nieuport 11 was reassigned to training units. By February 1918 there were just 22 Nieuport 11 in service, with 85a Squadriglia, in Albania, being the last operator of the type as they kept it until 4th November 1918.

Sources:
1st Flying Machines Press - French Aircraft of the First World War
2nd https://it.wikipedia.org/wiki/Nieuport_11 (translated)
3rd https://it.wikipedia.org/wiki/70ª_Squadriglia_caccia (translated)
4th https://it.wikipedia.org/wiki/71ª_Squadriglia_caccia (translated)
and so on for every squadriglia.

Nieuport 11 & 16, part four. The 'Bébé' in service with Russia and the USSR.

 

During World War I, the Imperial Russian Air Service (IRAS) found that the Nieuport 10 (a versatile sesquiplane, forerunner of the Nieuport 11 which could fill a wide variety of roles, among them, the fighter one) was barely effective as a fighter and saw the Nieuport 11 as an important improvement. Initially, some few French machines were imported but a license production contract was granted soon to Dux factory, in Moscow. 
An early order of 200 Nieuport 11s was soon placed with Dux in 1916. Dux-built machines differed from the original French machines. For instance, Russian-built machines were made out of pine, instead of spruce and flax was employed for covering in lieu of silk, due to the scarcity of materials in Tsarist Russia. Those changes in construction materials made the Dux-Nieuport 11s to be 30 kg heavier than its French counterparts and their quality overall was very poor. Quoting a commander of the 8th Fighter Unit, the Dux Nieuports "... could not be assembled because the parts did not fit and... the bolts fixing the struts with the spars broke into pieces." The 'Bébé' was later built under license by Mosca-Bystritsky (Moscow), Anatra (Odessa) and Shchetinin (St. Petersburg), making a total of just seventy machines being manufactured in 1916.
The initial imported Nieuport 11s were unarmed, so many pilots of the front-line squadrons had to supply their own weapons, like pistols and rifles. Luckily for them, V.V. Jordan designed a machine gun mount that allowed a weapon to be carried, although it had to be angled in order to fire over the propeller, the mount enable it rotate vertically. 
The Nieuport 16, on the other hand, was mainly imported to Russia with some few examples being built by Dux. The purchased Nieuport 16s were powered by the 110 hp. Le Rhône 9J engine with one Nieuport 16 being powered by a de-rated 80 hp Le Rhône, which was employed as a trainer.

Anyway, both Nieuport 11 and Nieuport 16s were supplied to frontline squadrons and by 1st March 1917 there were ten serving in the northern front, five serving in the western front, sixteen in the south-western front, five in the Romanian front and one in the Caucasus front, making a total of 37 machines.
One month later, there were a total of 70 Nieuport 11s in active service and by June 1917 there were twelve at the northern front, four at the western front, twenty-five at the southwestern/Romanian fronts and seven at the Caucasus front.
The Nieuport 11 proved to be a huge improvement, specially when compared to the Nieuport 10, however, it was soon replaced by the Nieuport 17, when it became available. 
The Nieuport 11 was employed also during the subsequent Russian Civil War, by both Bolsheviks and Whites, mainly as trainers. In fact, when the Civil War was almost over, in December 1921, there were a total of 18 Nieuport 11 in service as trainers serving with the 2nd Military School of Pilots and the 1st Higher School of Military Pilots in June 1923, with the last one being written off charge in 1924.

Sources:
1st Flying Machines Press - French Aircraft of the First World War
2nd https://ru.wikipedia.org/wiki/Nieuport_11
3rd https://ava.org.ru/ww1.html (translated)

Nieuport 11 & 16, part three, various users

 

The Nieuport 11, nicknamed 'Bébé' (baby) in French was a French sesquiplane fighter of the World War I era that enjoyed good reputation as a combat plane and was exported (or was captured by) to various countries around the world, among its users stand the following ones:

• Austro-Hungarian Empire: At least one Macchi-built Nieuport 11 was captured by Austrian troops in north-eastern Italy and was sent to Vienna for evaluation and propaganda. It was painted in Austro-Hungarian KUK markings and received a new Austrian registration, 00.27. Its fate is unknown.
  
  
• German Empire: During 1916 the German Army managed to capture many Nieuport 11 & 16, these being employed by some German pilots who achieved ace status in those machines. They were Oblt. Kurt Student and Lt. Gustav Leffers.
  
  
• Netherlands: During the war, on 2nd February 1917, one Nieuport 11 with 3981 as serial number and belonging to 'A' Squadron, No.1 Wing Royal Naval Air Service (according to other sources it belonged to No. 6 Squadron) made a forced landing at the village of Cadzand, western Netherlands. Dutch authorities purchased the plane from the British and registered it as 'LA-40', with subsequent changes being made to the serial number, to N 213 and then N 230.
  The Royal Netherlands Army evaluated the aircraft and, based on its results, they ordered twenty additional machines to be built by the NV Dutch Motor Car and Airplane Factory at Trompenburg, Rotterdam under license. This factory was commonly known as Spyker (or Spykjer). However, given the war necessities, the needed parts and other materials were not delivered until 1918, so the first twelve aircraft lacked wheels and other important parts, however, as five Nieuport 11 were delivered shortly later and, as the war ended, the flow of spare parts and materials was resumed and the original twelve incomplete machines were, eventually completed.
  It seems that, according to an official report, the Dutch Nieuports were kept out of use between November 1919 and March 1920 after some accidents took place due to the poor quality of the machines. Some other sources claim they were never flown.
  Anyway, it also seems that in 1925 the Dutch Nieuports were still employed.
  
  
• Romania: Given the urgent for armament of the Royal Romanian Army in 1916, a total of twenty-eight Nieuport 11s were sent from the Royal Naval Air Service to Romania. Of those eight were assigned to Grupul 3 (Grupul is the Romanian word for 'Squadron') as the 'Escadrilla Nieuport (Franco/Romana). The deliveries of Nieuports were steady and eventually four fighter units saw service with the Corpul de Aviatie (Aviation Corps - the aviation branch of the Royal Romanian Army back then). 
  Those units were Grupul 1 & 2, attached to 1st Romanian Army and Grupul 1 & 3 attached to 2nd Romanian Army. 
  The Nieuports were used, under French supervisors, to provide aerial defence for Bucharest and the Russian army at Braila, northern Romania. The Grupuls saw extensive action over the fronts and by 15th December 1916 there were less than half of the original 28 Nieuports in service as only 12 were still in service, with six being kept under maintenance and additional eight no longer airworthy. The Nieuport 11s were replaced by the better Nieuport 17 as the year 1917 progressed.

Sources:

1st Flying Machines Press - French Aircraft of the First World War
2nd https://kw.jonkerweb.net/index.php/en/aircraft-factory-lists/aircrafts-n/nieuport-11-c1-bb-uk?showall=1
3rd Signal Squadron - Aircraft In action 167 - Nieuport Fighters in Action
4th https://en.wikipedia.org/wiki/Nieuport_11