Sopwith Snark

Sopwith Snark showing off its triplane configuration (flyingmachines.ru)

Sopwith Snark showing off its triplane configuration (flyingmachines.ru)

Sopwith’s Last Fighter

The famed blood-red triplane design of the Red Baron Manfred Von Richthofen’s Fokker Dr.I became the iconic image of the air war over the Western Front of World War I. Richthofen’s Dr.I became an indispensable tool for the German propaganda machine and in an age of countless biplane designs there was a feeling in the general public that this “extra wing” was what made Richthofen so unbeatable in the air.

In reality the triplane design was something of fad in aviation design that was quickly falling out of favour. Triplanes had the advantage of being able to use shorter span wings with the same or even greater levels of agility than an equivalent biplane which made them smaller targets in the air than an equivalent De Havilland DH.4. The trade-off however was that triplanes were often heavier than their biplane counterparts and incurred far more drag. They were also prone to cross wind interference which was especially dangerous on landing. As the air war dragged on over the trenches it became increasingly obvious that speed was going to be the deciding factor and the newer biplanes were able to surpass even the feared the Dr.I in this respect.

1917 Sopwith Triplane (Commons.wikimedia)

1917 Sopwith Triplane (Commons.wikimedia)

Nevertheless some aircraft designers persevered with the configuration believing they could find a balance between the agility a triplane offered and the speed of the latest biplanes. One such company was Sopwith of Great Britain who had produced the near legendary Sopwith Camel, Snipe and Pup fighters. Sopwith had long been a proponent of triplane designs and in early 1917 their appropriately named Sopwith Triplane fighter entered very limited service with the Royal Naval Air Service.

Spurred on by this brief success Sopwith decided to return to the triplane configuration when in early 1918 the Air Ministry requested proposals for a replacement for the Snipe. Sopwith knew that the triplane was falling out of favour and took no chances designing a common fuselage and tail section that could be fitted with either a biplane or triplane configuration. This produced two aircraft the Snapper (biplane) and the Snark (triplane). As designed the Snark had a wooden monocoque fuselage with equal span single-bay wings each fitted with ailerons for a high degree of agility. The wings were unequally spaced and staggered with the gap between the mid and upper wings being less than that between the lower and mid wings.

Included in the specification was the requirement for the aircraft to be powered by the ABC Motors Ltd Dragonfly I 320hp engine then under development. The Dragonfly was an air cooled radial engine which promised very high performance and based on this promise the Air Ministry decided it was to become the main engine for the next series of combat aircraft for the newly formed Royal Air Force. For the aircraft manufacturers this would prove to be a frustrating and costly decision for the aeroengine proved extremely problematic and ABC constantly had to push back its service entry. This delayed numerous aircraft projects such as the promising Avro 533 Manchester bomber and Sopwith’s Snark.

Snark prototype (Aviastar.org)

Snark prototype (Aviastar.org)

Despite the problems with the engine the Air Ministry was sufficiently interested in Sopwith’s Snark to order three prototypes for testing on May 14th 1918. One of the aircraft’s main selling points was that for its day it had an exceptionally heavy armament. Nearly all British aircraft of the period had the proven configuration of two .303 (7.7mm) Lewis machine guns mounted forward of the pilot synchronized with the propeller and indeed the Snark did feature two such weapons. Additionally however the aircraft featured four more Lewis guns under the lower wing firing outside of the propeller arc; a configuration more akin to World War Two fighters. Despite the fact that the pilot couldn’t reach these weapons in-flight to reload them or correct a jam it did mean that the Snark had huge potential as a bomber destroyer although the weapons did add even more weight to the aircraft.

Sopwith’s engineers worked steadily to produce the three prototype airframes by October 1918 but the Dragonfly I engine was nowhere to be seen and so the three prototypes sat grounded until finally the first Dragonfly I aeroengine was delivered in early 1919 well after the armistice ended the war it was designed to fight in. The aircraft finally took flight sometime in July 1919 (exact date is unknown) and the first flying prototype arrived at Martlesham Heath for official trials on the 12th of November 1919. The other two prototypes still had to wait for their engines to be delivered and the second prototype didn’t reach Martlesham until March 17th 1920 while the third prototype, which was fitted with a 360hp Dragonfly la engine, didn’t arrive until much later in the year.

Testing must have been a sullen experience for those involved from Sopwith. The company was in trouble and a lot was riding on the Snark’s success. Testing of the first two prototypes revealed that it had fine handling qualities being quite responsive although not as nimble as previous triplanes. It achieved a top speed of 130mph, 9mph faster than the Snipe it was to replace, but this came at a price. The loathsome Dragonfly engine was not yet finished ruining the Snark’s prospects and proved horribly unreliable being prone to overheating in flight. Testing continued at a relaxed pace in to 1921 but by then the requirement for a Snipe replacement was brought in to question as the RAF found itself watching every single penny almost lecherously. The detection of deterioration in the fuselage structure sounded the death knell for the Snark and all three were written off by the end of the year.

It was a sad end to the great Sopwith Company who had been at the forefront of British fighter technology throughout the war. Even before the Snark project ended the company had gone in to liquidation it being unable to survive in the harsh post war climate where its expertise in fighter design was no longer wanted.


SPECIFICATIONS 

  • ENGINE: 1 x 320hp ABC Dragonfly radial engine
  • MAX SPEED: 130 mph
  • WINGSPAN: 8.08m (27ft 6in)
  • LENGTH: 6.25m (21ft 6in)
  • HEIGHT: 3.30m (11ft 10in)
  • WING AREA: 29.91 m2 (321.95 sq ft)
  • ARMAMENT: 6x .303 (7.7mm) Lewis Mchine guns
Advertisements

Gloster Gamecock J7904 at the Jet Age Museum

The Gloster Gamecock first flew in 1925 and was the RAF’s last wooden fighter. No complete Gamecock survives but the Jet Age Museum’s reproduction Gamecock I is nearing completion. Work has been carried out on the reproduction at the Tithe Barn Centre in Brockworth, not far from the site of the former Gloster Aircraft Company’s factory-airfield. Rear fuselage sections of two Finnish-built Gamecocks survive in museums in Finland, but apart from a handful of components that is all.

A few compromises have been made – the rigging wires are circular rather than streamline section due to cost, and plywood is used instead of asbestos for the firewall – but otherwise it is pretty much spot on. The engine is on loan from the RAF Museum and was reconditioned by Rolls-Royce Heritage Trust. The propeller is original, as are one interplane strut and two inter-aileron struts, one of them restored after it had been sharpened as a fence post.

The Gamecock reproduction is being finished as J7904 of 43 Squadron as flown by the squadron commander, complete with black and white chequers on the rear fuselage spine.

History: The Jet Age Museum
Photos: Tony Wilkins


The Capture of Fiat CR.42 “MM5701/95-13”

The legend of the Battle of Britain tells the story of a handful of RAF pilots battling swarms of German aircraft and fighters. A little known part of the story however is that Mussolini’s air force also contributed aircraft to the campaign albeit briefly and with limited success.

On the 11th November 1940, Fiat CR.42 “MM5701/95-13” flown by Sergente Pietro Salvadori of 95a Squadriglia force-landed near the Orfordness lighthouse after he developed engine troubles. He was subsequently captured by the local Home Guard and interrogated by British intelligence. The interrogation revealed some startling facts about the Italian pilots operating in the Battle of Britain from bases in Belgium. There seemed to be very little will to fight amongst their ranks with Salvadori apparently pleased he had been taken prisoner. He also revealed that there was a strong dissatisfaction among the lower officer ranks with the Italian officer-elite and a strong dislike for the Germans.

This aircraft was made serviceable by the RAF and flown on evaluation trails as BT474 and is now on exhibition in the Battle of Britain Museum, Hendon.

Forgotten Aircraft: Avro’s First Bombers (Part 1)

Avro

The name “Avro” is synonymous in aviation circles with excellence in bomber design thanks to two very special aircraft; the World War II-era Lancaster and the Cold War-era Vulcan. Both aircraft captured the public’s imagination and their hearts and both enjoy a strong enthusiast’s following today. While these aircraft are among the greats of military aviation it’s easy to forget that it took Avro a long time to finally get a bomber in to service. In order to reach that goal there were a series of prototypes and experimental warplanes which although showed promise never made it beyond the prototype stage.

Vulcan & Lancaster

One of the world’s first aircraft manufacturers, A.V. Roe and Company was established at Brownsfield Mill, Great Ancoats Street, Manchester, by Alliott Verdon Roe and his brother Humphrey Verdon Roe on January 1st 1910. The great aeronautical mind behind the company was Alliot’s and Humphrey’s contribution was primarily financial and organizational. Alliot had already constructed a successful aircraft the Roe I Triplane but now with the help of his brother he could push forward with his designs. Between 1910 and 1916 the company primarily produced “flying machines” i.e. aircraft for the sake of flying and had no real specified role.

Avro 504Then in 1913 the company took a more serious tone and produced the Avro 504 biplane. Intended as a combat aircraft it was quickly rendered obsolete as the pace of aviation development rocketed but not before three would make history when they set out from Belfort in north-eastern France on 21st November 1914 armed with four 20 lb bombs each. Their target was the Zeppelin works at Friedrichshafen and the aircraft successfully scored several hits inflicting heavy damage by hitting the hydrogen production facility. The raid suffered the loss of one aircraft to ground fire but it was the first time in history that an Avro aircraft was used in an offensive role.

The 504’s useful life as a combat aircraft was short lived although it did see sporadic combat throughout the war but it would be as a trainer that the aircraft would see its greatest use and throughout the 1920s and early 1930s every RAF pilot gained his wings on the 504K trainer. In this role it was a true success story and gained A.V.Roe enough respect to be taken seriously by the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). So when in 1916 the RNAS demanded a long range multi-role combat aircraft to act as a flying escort to its fleet A.V.Roe went to work on his own design to meet the requirement.


Avro 523 Pike

Avro 523

Avro 523 Pike

The resulting design was the Avro 523 Pike, a large twin engined biplane with a crew of three that was powered by two Sunbeam Nubian engines rated at 162 hp each that were arranged in a pusher configuration (facing the tail). The aircraft was expected to provide fighter escort for the fleet against Zeppelin airship attacks, provide reconnaissance for the fleet and offer a true offensive capability with a bombload of 225lbs (just 15lbs less than the entire complement of bombs dropped by the Avro 504s in 1914). This was a tall order for any aircraft manufacturer whose trade was barely in its teen years.

The design of the aircraft was very contemporary. It was a rather large biplane design with its engines mounted on spars between the upper and lower wings. The crew of three were seated in three open cockpits with the pilot in the centre flanked by a bomb aimer/gunner in the nose and a defensive gunner just behind in the dorsal position. The fully skinned fuselage was rectangular in shape but blended rather attractively throughout its entire length.

Unfortunately results showed that while the aircraft had excellent endurance, around seven hours when flown economically, the rest of the aircraft’s performance was disappointing. The Admiralty assessment said that the aircraft would soon be surpassed by the newer aircraft then in development which offered superior performance. A second prototype was completed with Green E.6 engines and was given the in-house number 523A but the engines offered even lower performance and no production order was placed. The two prototypes would continue on as test aircraft with Avro however.

SPECIFICATIONS (Avro 523)

  • ENGINE: 2 x 160hp Sunbeam Nubian in-line
  • MAX SPEED: 97 mph
  • WINGSPAN: 18.29 m (60 ft 0 in)
  • LENGTH: 11.91 m (39 ft 1 in)
  • HEIGHT: 3.55 m (12 ft 8 in)
  • WING AREA: 75.71 m2 (814.93 sq ft)
  • TAKE-OFF WEIGHT: 2751 kg (6065 lb)
  • EMPTY WEIGHT: 1814 kg (3999 lb)
  • ARMAMENT: 2x .303 Lewis Mchine guns
    225lbs of bombs

Avro 529

Avro 529

The RFC had shown interest in the 523 but like the Admiralty were too concerned with its impending obsolescence in the face of other newer types then in development to place an order. A.V.Roe was undeterred however and he believed that with some development work the 523 could become a war winning aircraft. After the Admiralty declined to order the 523, Roe managed to convince them to fund two prototypes of an improved version.

The resulting Avro 529 was a generally enlarged version of the 523 Pike but incorporated several noteworthy improvements. The most obvious change was the switch to tractor propellers as opposed to pushers as on the 523. These were turned by far more powerful Rolls-Royce Falcon engines that produced 190hp each however this was not enough to counteract the greater weight of this larger aircraft and the result was that the 529 had performance generally inferior to its predecessor. This forced A.V. Roe to promptly finish work on a second prototype powered by 230hp Galloway engines and this improved all round performance. A less obvious change was that the tail on the 529 had also been moderately redesigned.

Other innovations that came with the aircraft was the ability to fold the wings back from a point just beyond the engine mounts indicating that it could be used in some shipboard capacity if the Admiralty renewed their interest. A.V. Roe and his team displayed their genius with the 529 by taking far more consideration of how the three man crew would function under battlefield conditions; something that was barely given a second thought in other designs of the period. The bomb aimer who sat up front was provided with a Gosport tube communication device allowing him to yell instructions back to the pilot so as to help with aiming. The rear gunner was also given duplicate controls so if the pilot became incapacitated the plane would not necessarily be lost.

The 529 displayed good flight characteristics in all areas except the longitudinal plane. This could have been easily rectified with yet another redesign of the tail section but the Admiralty was growing impatient and refused to commit themselves any further. As though history repeated itself, the 529 shared an almost replicated life of its 523 forebear there being two prototypes both of which were powered by different engines and both of which ended their days as trial aircraft.

SPECIFICATIONS (Avro 529)

  • ENGINE: 2 x 190hp Rolls-Royce Falcon
  • MAX SPEED: 93 mph
  • WINGSPAN: 19.20 m (63 ft 0 in)
  • LENGTH: 12.09 m (39 ft 8 in)
  • HEIGHT: 3.96 m (13 ft 0 in)
  • WING AREA: 85.70 m2 (922.50 sq ft)
  • TAKE-OFF WEIGHT: 2862 kg (8309 lb)
  • EMPTY WEIGHT: 2148 kg (4736 lb)
  • ARMAMENT: 2x .303 Lewis Mchine guns
    1000lbs of bombs

Avro 533 Manchester

avro 533 Manchester

The Avro 533 Manchester was the ultimate expression of Avro’s World War I bomber concept. This was yet a further development of the 529 incorporating all that aircraft’s improvements over the 523 and then expanding on them. Design work began in 1917 and originally the aircraft was to be given the number 529B but the changes proved so extensive that it warranted its own number becoming the 533 before adopting the name Manchester (not to be confused with the later Avro Manchester, the Lancaster’s forebear). The 533 Manchester was similar to the 529 but with some subtle changes. Overall the aircraft was marginally smaller and featured a raised centre fuselage roof, a glass window for the bomb aimer and attractive smoothed over engine cowls.

At the time a number British aircraft manufacturers were instructed to design their planes around the Dragonfly radial engine then in development which promised 320hp; nearly twice the power of the 529’s Falcon engines. The Dragonfly ultimately proved to be quite the developmental nightmare and this stalled many of the aircraft under development that was relying on it. With time pressing on and afraid of losing out yet again, Avro installed the 300hp Siddeley Puma engine in the first 533 Manchester prototype as a stop-gap and to allow flight testing to begin but the Dragonfly’s delay had hurt the program badly and by the time the Puma engined aircraft was ready the war was over.

Orders for any aircraft then under development were cut back dramatically and Avro was not promised any firm order for the Manchester. A.V.Roe optimistically pressed ahead with development hoping that the newly established Royal Air Force would see its potential and want to build its post war bomber force on the type but despite the arrival of the long overdue Dragonfly engines in 1919 the program was effectively dead as far as RAF procurement was concerned. A.V. Roe put forward plans for a passenger version but these too were shelved.

It was a sad end to a promising design lineage.

SPECIFICATIONS (Avro 533 Manchester)

  • ENGINE: 2 x 320hp ABC Dragonfly radial engines
  • MAX SPEED: 115 mph
  • WINGSPAN: 18.29 m (60 ft 0 in)
  • LENGTH: 11.28 m (37 ft 0 in)
  • HEIGHT: 3.81 m (12 ft 6 in)
  • WING AREA: 75.90 m2 (817.00 sq ft)
  • TAKE-OFF WEIGHT: 3352 kg (7390 lb)
  • EMPTY WEIGHT: 2217 kg (4887 lb)
  • ARMAMENT: 2x .303 Lewis Mchine guns
    880lbs of bombs