Avro 504K - Latin American users, part one

Now it comes the turn for the various latin-American users of this trainer airplane.

• Argentina: The government of the Argentinean president Hipólito Yrigoyen authorised on 31st July 1920 the purchase of various airplanes, among them there were twenty-two Avro 504K powered by a LeRhône 9J engine. They served in the trainer role until 1928 when they were being replaced by the domestically produced FMA version of the 504R Gosport airplane.
• Bolivia: Apparently, Bolivia had some 504 in their Air Corps during the 1920s, however we couldn't find graphical info and the drawing should be considered as speculative.
• Brazil: In 1920 the Brasilian authorities adquired 17 Avro 504k, five of them powered with the Gnome engine and the rest with the LeRhône engine. It was the first airplane adquired by the Brasilian navy destined to operate from land airfields. They were retired in the year 1928 when the government bought the newer N/O version.
• Guatemala: Guatemala funded their Escuela Militar de Aviación (Military Aviation School) back in 1913 and, on 1st May 1920 they renewed their airplane fleet by adquiring some 504Ks.
• Paraguay: There it seems that at least one Avro 504K served with the Paraguayan flying school and some sources claim that it crashed. Anyway we couldn't find any graphical evidence of how it looked like, so the drawing should be considered as speculative.

Sources:

1. http://www.amilarg.com.ar/avro-504.html (translated)

2. https://pt.wikipedia.org/wiki/Avro_504 (translated)

3. https://es.wikipedia.org/wiki/Escuela_Militar_de_Aviación_(Guatemala) (translated)

4. https://en.wikipedia.org/wiki/Avro_504

5. Salamander Books - The Complete Book of Fighters

Avro 504J

The Avro 504J appeared first in autumn 1916 and this new version was powered by a 100hp Gnome Monosoupape engine. The engine cowling was slightly modified in order to make easier to fit other type of engines.
It was usually called Mono-Avro in the RFC, to which it was destined. It had therefore a comma shaped vertical stabilizer and shorter back ailerons.
As the engines were harder to manufacture, the airplanes were completed as those were completed, that's why many of them ended up being completed as the K model.
It was destined from the very beginning to the training role and it was easy to fly and powerful for it's era. That's why it was the basis for a new training method used by the RAF until the end of the World War II. However, at the end of 1916, Avro was commanded to concentrate their manufacturing efforts on the BE.2c instead of the Avro 504. However, a bit later, the 504J was chosen as the standard RFC trainer and the production was resumed.
It wasn't used only by the United Kingdom but also by the American Expeditionary Forces and also by the Chilean army which, fearing a war against it's neighbours Argentina and Bolivia, rearmed themselves.

Sources:
1. https://fr.wikipedia.org/wiki/Avro_504 (translated)
2. Salamander Books - The Complete Book of Fighters

Avro 504 E/F/G/H

We keep going with the Avro 504, this time with more versions.

Avro 504E: As the power of the Gnome engine was insufficient, the RNAS requested from Avro a version with a more powerful engine. Avro fitted a 100hp Gnome engine, which was obviously more powerful than the previous 80hp one plus some more modifications. The engine was fueled with a new vacuum system, and both cockpits had to be moved in order to install a bigger fuel tank. Modification which required the fuselage to be compensated due to the aeronautical offset, from 23 up to 60 centimeters. Due to the modification of the cockpits, the struts had to be reconfigured too.

Avro 504F: Following admiralty orders, Avro modified a 504C version in order to fit a 75hp Rolls-Royce Hawk engine, which was also used in the British airships of the era. Apparently it was very pleasant to fly and 30 airplanes were ordered but only one was manufactured. It seems that only one was on it's way to be refitted and when the order was cancelled, it got back it's regular 80hp Gnome engine. That's why the drawing shown below should be considered as speculative.

Avro 504G: Some 504Bs were modified by the RNAS in order to use them as gunnery/bombing trainers. It seems that a 0.303in Lewis Mk.II machine gun was to be fitted in a scarf ring at the rear cockpit, plus a single second one at the front to fire through the propeller. Apparently it was never completed as the machine guns were never fitted, however some sources lead to the possibility that they were used as night fighters in the Home Defence.

Avro 504H: A single 504C was modified by the pioneer of the naval aviation Squadron Commander E.H. Dunning in order to perform catapult launching trials. In order to perform such achievement, some gear needed to be installed which was designed by R.F. Carey and manufactured by Waygood-Otis. It was reinforced, equipped with catapult launching gear and a special padded seat for the pilot replaced the original one. Dunning died on 7th August 1917 trying to land a Sopwith Pup on the HMS Furious. He was replaced by Flight Commander R.E. Penny who performs the catapult trials without any difficulty or setback at all.

Sources:
1. https://fr.wikipedia.org/wiki/Avro_504 (translated)
2. Salamander Books - The Complete Book of Fighters
3. http://www.historywebsite.co.uk/Museum/Transport/planes/SunbeamAircraft.htm
4. http://1914-1918.invisionzone.com/forums/index.php?/topic/200605-avro-504g/

Avro 504 - A/B/C/D

Today we cover various models of this British pioneer aircraft.

The Avro 504A was the first mass-produced model, from serial 2890 onwards. It held the same 80hp Gnome engine of the previous model but it had the wings ailerons reduced and the bracing struts enlarged. In order to improve the visibility, the lower wing was raised 30cm from the fuselage. The airplanes destined to the RFC were equipped with reconnaissance and observation tools, while those destined to the RNAS were equipped with bombing apparels, however as they soon were outdated for the frontlines, they were relegated to the flying schools. Some of them were converted by Avro with double controls.

The Avro 504B was version specifically designed for the RNAS which appeared first on 1915. It had a distinctive longer vertical stabilizer a bigger wingspan ailerons and some small modifications in order to improve the visibility. Those modifications were adopted by every model destined to the RNAS so the 504B was the first airplane to receive a fixed vertical stabilizer, just like the RAF Be.2c. . Some initial production versions were affected by a light recess but it was quickly corrected. In some later versions, in order to install a scarf ring on the upper wing for the installation of machine-gun, the places of the pilot and the observer were reversed. It still was powered by the 80hp Gnome engine but some later models were powered by a Gnome-Le Rhône delivering also 80hp. Some 504B were employed at the front lines in the Dunkirk area but they retired in the summer of 1916.

Avro 504CAs the range of the 504B wasn't enough for reconnaissance versions or to chase zeppelins, the RNAS ordered a single-seat version and this way the front cockpit was removed and replaced by an addittional fuel tank in order to keep the airplane flying for eight hours. This way the pilot seated in the original rear cockpit encountering the original lateral recess that was present in some original 504Bs. It was powered by the same 80hp Gnome engine and both wings and wingspan were identical to the 504B and, to shot down zeppelins, a single 0.303in Lewis Mk.II was fitted in a 45º angle degree firing through a gap in the upper wing.

The Avro 504D was identical to the 504, designed for the RFC but with the same vertical stabilizer of the A version. It was also powered by the 80hp Gnome engine and the 0.303 Lewis machine-gun was placed on the upper wing mounted in a scarf ring.

Sources:
1. https://fr.wikipedia.org/wiki/Avro_504 (translated)
2. Salamander Books - The Complete Book of Fighters

Avro 504

The Avro 504 was a two-seater biplane that first flown on 18th September 1913 and was powered by an 80hp Gnome Lambda rotary engine.
It was basically a development of the previous Avro 500 model. It was designed for training and private flying purposes made entirely out of wood with two bays and a square fuselage.

Some small numbers were bought by both the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS) before the start of the World War I and, when it started, they were taken to France. It was the first type of British airplane shot down by the Germans on 22nd August 1914 and also the first type of British airplane to perform an air raid when four 504s from a special unit of the RNAS bombed the Zeppelin works at Friedrichshafen, close to the German-Swiss border.
The airplanes departed from the French city of Belfort on 21st November 1914 each of them carrying four 20lbs (9kg) bombs. One aircraft was shot down but the raid was nonetheless a success as several direct hits destroyed the hydrogen generating plants.

It was also the first airplane of the World War I to perform an strafing attack, when on 22nd October 1914, an airplane manned by Strange and Penn-Gaskell fired their crudely fitted Lewis Mk.I machine gun (which in fact was fitted with the tail-boom of a wrecked Farman biplane and a rope) at a train and enemy troops in the French town of Pérenchies.

Sources:
1. https://en.wikipedia.org/wiki/Avro_504
2. Salamander Books - The Complete Book of Fighters

Avis III

The Avis III was developed in parallel to the Avis II and flown for the first time in 1935. It was powered by a 550hp Manfred-Weiss built Gnome-Rhône 9Krsd Mistral engine and was equipped with a three-bladed adjustable-pitch Hamilton standard propeller.

Unlike it's predecessors, which were all of them made entirely out of metal, this one had wooden wings with a combination of plywood and fabric skinning in order to make it lighter. Four prototypes were built and they performed better than the preceding ones, but they lacked the agility of the Italian Fiat Cr.32, which was under evaluation by the Légüyi Hivatal. It was adopted into service but didn't enter into production.
It was armed with two 7,62mm Gebauer machine guns and, apparently one of the prototypes was completed with some minor modifications as the Avis IV. Unfortunately, we couldn't even find textual descriptions of these changes.

Sources:
1. Salamander Books - The Complete Book of Fighters
2. Hikoki Publications - Hungarian Eagles 1920-1945

Avis II

As the Avis I showed poor performance, the designer, prof. Abody-Anderlik were prompted to redesign the aircraft in spite of the decision taken by the Légüyi Hivatal of purchasing 21 Fiat Cr.20bis fighter airplanes from Italy.

The design held to the Jupiter VI engine and, as redesigned it featured a slimmer, slab-sided fuselage as well as redesigned vertical tail surfaces. It also featured narrower interplace bracing struts and an increased gap.
The overall empty weight was reduced by 100kg and, after some initial testing the engine was enclosed within a Townend ring.
It was flight tested in 1935 but it turned to overweight and it wasn't as agile as other contemporary two-winged foreign fighters. It was to be armed with two 7.62mm Gebauer machine guns but the development was abandoned in favour of the Avis III. Unfortunately we haven't found any blueprint or side-drawing of it, so it remains undrawn.

The only known pic of an Avis II fighter

Sources: 
1. Salamander Books - The Complete Book of Fighters