Forgotten Aircraft: Avro’s First Bombers (Part 3)

<Avro’s First Bombers (Part 1)
<Avro’s First Bombers (Part 2)

The Avro 557 AvaAvro 557 Ava N171

World War I had completely changed the world’s perspective on the aeroplane as a weapon of war. Whereas before it was seen as little more than a tool for reconnaissance, now it was directly challenging age-old beliefs about the superiority of armies and navies. Nevertheless, the Royal Air Force (RAF) was still fighting for its continued existence and in order to prove its worth it had to show that it had the potential to truly affect the future battlefield. For Chief of the Air Staff, Lord Hugh Trenchard this was no easy feat as the RAF was constantly strapped for cash in the face of peacetime cuts.

Both the Army and Navy lobbied for abolishment of the RAF now that the war was over and to have their respective air arms reinstated but Trenchard and his political supporters put up a staunch defence. In order to prove the RAF’s worth, Trenchard was careful but ambitious about his service’s reequipment program in the 1920s hoping to make the most out of what little he had. One such role he envisioned the RAF undertaking was the defence of Britain against surface warships using air launched torpedoes. During the war, Britain had suffered humiliating attacks by German battleships which shelled coastal towns like Scarborough, Hartlepool and Whitby and those who supported the RAF believed that aircraft could prevent further attacks using both speed and firepower to intercept the raiders out at sea. Trenchard went further adding that in his opinion, combat aircraft had the potential to render the battleship entirely obsolete.

In 1922, the Air Ministry issued specification 16/22 aimed at acquiring an aircraft to fulfil the challenging role. Like the specification that produced the Avro Aldershot which was at that time undergoing flight testing, it was conceived around a possible war breaking out with France which was now the only real European superpower able to threaten Britain with Germany being crushed by the Treaty of Versailles and Austro-Hungary having broken up. The specification called for an aircraft capable of carrying a 21-inch (533mm) torpedo to a target around 500 miles from its base allowing it to attack shipping as far as Denmark and the entrance to the Baltic Sea. This was no easy feat since the 21-inch torpedo was over 3,000lbs in weight but Trenchard believed this weapon was the bare minimum needed to sink a battleship. To increase the type’s usefulness, the specification also stipulated that the aircraft was to be used as a bomber and carry the equivalent weight in bombs.

Avro and Blackburn Aircraft were both shortlisted to produce prototypes for testing with Avro’s project being led by the talented Roy Chadwick. Both companies had to work under a strict veil of secrecy however since at that time there were calls for world-wide disarmament and it was believed by some that an aircraft capable of sinking a battleship might be perceived as contrary to this. Initially, Chadwick opted for a single engined design centred around the 1,000hp Napier Cub engine which Avro had been testing on the original Avro Aldershot prototype. Blackburn adopted the same engine for their design but eventually Chadwick dropped it in favour of producing a twin engined design equipped with individually less powerful engines that combined produced even more power; something the Air Ministry was looking more favourably upon.

Chadwick’s design was for a three-bay biplane of wooden construction with a biplane tail that had a triple rudder arrangement. The two uncowled engines were mounted close to the fuselage but forward of the main wing resting on pylons that extended down to their relative undercarriage. Chadwick settled on the Rolls Royce Condor III V12 engine which churned out 650hp to power the type. The aircraft was to have a crew of five with two pilots sat in an open cockpit located at the top of the forward fuselage slightly ahead of the propellers. The navigator/bomb aimer worked in the enclosed cabin during the flight but could occupy a “dustbin” gun turret that retracted down from beneath the aircraft when it was under attack. The aircraft also had two dedicated gunners with one located in the extreme nose and the other in a dorsal position behind the wings. Each gunner was equipped with a single .303in Lewis machine gun.  The main offensive armament was carried on racks underneath the fuselage between the two innermost undercarriage wheels.

Avro 557 Ava (1)

The first prototype of the new aircraft was completed in 1924 and given the in-house number 557 and the serial number N171 before the name “Ava” was assigned to it. The origin of the name is unclear but it is likely a derivative of the Latin word “Avis” which means “bird”. Avro test pilot Bert Winkler was at the controls during the type’s first flight and being a man of rather short stature, he had to be propped up in the seat with a few cushions to allow him to see forward over the nose. Not long in to the test program, the central rudder was removed as it was deemed unnecessary. Work also began on a second prototype, N172, which was to be of all-metal construction reflecting this growing trend amongst aircraft manufacturers.

Meanwhile, Blackburn Aircraft had begun test flying their own aircraft to meet the Air Ministry’s specifications known as the Cubaroo – a name likely inspired by its powerful Napier Cub engine. Despite the Air Ministry emphasizing a preference for a twin-engined design, Blackburn submitted their single-engined Cubaroo which was at that time the largest single-engined military aircraft in the world. Despite this fact, flight trials showed that it had good flight characteristics although Blackburn would suffer a temporary setback when the prototype crash landed in January 1925.

As work on both aircraft continued, the grey clouds of cancellation began to form over their respective aerodromes. Naval observers of the project argued that these relatively large and lumbering aircraft would offer an easy target to the newer anti-aircraft guns being fielded aboard surface warships around the world. They also argued that they would be vulnerable to interception by modern carrier aircraft equivalent to the Royal Navy’s Fairey Flycatcher which was significantly faster than either the Ava or the Cubaroo when carrying their torpedo.

Avro 557 Ava N172In 1924, the Fleet Air Arm was formed within the RAF to handle shipboard operations and this new branch argued for smaller torpedo-carrying carrier aircraft to fulfil essentially the same role as was envisioned for the Ava and Cubaroo. These aircraft would be equipped with the 1,800lb Mark.VIII torpedo so could be smaller, faster and tougher to shoot down with defensive fire. The Air Ministry agreed and had rescinded specification 16/22 by 1926 rendering both the Ava and the Cubaroo surplus to requirements. With the veil of secrecy having been lifted, Avro demonstrated N171 during the 1926 Hendon Air Pageant while at the same time continued work on the second prototype which would not be completed until 1927, flying for the first time on April 22nd. In terms of design, the only difference between the two prototypes was that the second prototype had more rectangular shaped wing tips than the first prototype.

Avro quickly began scouring the Air Ministry’s order books for a requirement that the all-metal Ava could possibly fulfil and settled on the recently issued B19/27 which was designed to produce a replacement for the Vickers Virginia and Handley Page Hinaidi bombers. With some more development, the Ava could just about squeeze in to this requirement which demanded a night bomber capable of carrying a 1,500lb bombload, 920 miles from its base at an average speed of 115mph. However, Avro faced stiff competition from Bristol, Fairey, Handley Page and Vickers all of whom were working on newer designs with Fairey even offering up a new monoplane design in the shape of the Fairey Hendon. The Air Ministry weren’t interested and the Ava joined the list of Avro’s failed attempts to produce an operational bomber.

SPECIFICATIONS

Crew: 5
Length: 58 ft 3 in (17.75 m)
Wingspan: 96 ft 10 in (29.51 m)
Height: 19 ft 7¾ in (5.99 m)
Empty weight: 12,760 lb (5,788 kg)
Max. takeoff weight: 19,920 lb (9,036 kg)
Powerplant: 2 × Rolls-Royce Condor III water cooled V-12, 650 hp (485 kW) each
Maximum speed: 115 mph [3] (100 kn, 185 km/h)
Armament;
3 × 0.303 in (7.7 mm) Lewis Guns (Nose, dorsal and retractable ventral positions)
1 × 21 in (553 mm) torpedo or 4 × 550 lb (250 kg) bombs

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Gloster Goral

Born in war, the immediate post-war period was both a time of optimism and frustration for the new born Royal Air Force. On the one hand, military aviation had been firmly established as an indispensable tool of war but the concept of an air arm independent of both army and navy was seen as an unnecessary expense in peacetime. Coupled with the tightening of the national purse, it meant that after 1918 the RAF had to fight for every penny from the government and make the most of everything they had not only keep the service viable but alive.

Airco DH.9AThroughout 1918, numerous companies were developing new and more advanced aircraft ready for the front in 1919 but the armistice on November 11th 1918 saw many of these projects curtailed. The RAF were thus left to operate the best picks of their wartime inventory from 1918 among them of which was the Airco DH.9A. The DH.9A was an excellent light bomber and reconnaissance aircraft and when its performance is compared to the Avro 504s and Royal Aircraft Factory BE.2s that the Royal Flying Corps went to war with in 1914 it becomes strikingly clear how quickly military aviation advanced in just four years of fighting.

Peace in Europe however did not translate in to world peace and the RAF went back to war almost immediately supporting the anti-Bolshevik “White” Russians in the Russian Civil War. The RAF also flew intensive operations policing the British Empire which now included former Ottoman Empire territories that were resentful of their new British masters. The DH.9A proved adept in these theatres being rugged and reliable but over time it became clear that they needed replacing and in the mid-1920s the RAF began to seriously look at its options. Under Air Specification 26/27, the RAF told Britain’s aircraft manufacturers that in order to reduce costs the winning design would have to make the maximum use of DH.9A parts that were readily available. Emphasis would also have to be placed on suitability for policing the Empire with all the harsh and primitive operational environments that entailed. With the relative drying up of government orders in the 1920s, the aircraft manufacturers were quick to respond to the specification. Eight companies drew up plans for an aircraft to meet the RAF’s requirements including Bristol, de Havilland, Fairey Aviation, Gloster, Vickers and Westland.

The Gloster submission was headed up by two well respected aircraft designers namely Captain S. J. Waters who had previously worked for Fairey and H. P. Folland who had worked for the Sopwith company during the war. The resulting design was essentially the mating of a new oval-shaped, all-metal frame, fabric-covered fuselage with the wings from a DH.9A. Careful consideration was given to the need to make repairs in the field and so the aircraft was designed to allow key metal components to be replaced with wooden ones should the need arise. In theory, the aircraft could have been manufactured with an all-wooden frame and this was offered as an option to potential export customers. The fuselage was essentially built in three whole main sections that could be quickly separated if the aircraft needed to be transported by sea or rail and then reassembled relatively quickly. With humidity being a constant problem in parts of the Empire such as India a great deal of rust proofing was incorporated in to the frame.

Gloster Goral J8673 Bristol Jupiter

The aircraft had a crew of two with the pilot sat under the wing trailing edge with a cutout above his head for vertical visibility. The gunner/observer sat behind him in a position raised several inches higher and had a single 0.303 in (7.7 mm) Lewis machine gun mounted on a ring to provide defensive firepower and to complement the pilot’s own 0.303 Vickers machine that was synchronised to fire through the propeller arc. The aircraft had provision for carrying a variety of light bomb configurations up to 460lbs total.

The Air Ministry specification had originally highlighted the Napier Lion 12-cylinder ‘broad arrow’ W12 engine as the preferred choice to power the winning design because it was readily available. Developed for military purposes in 1917, it was the most powerful Allied aeroengine when it entered service and had seen considerable use in civilian and racing circles. However, Gloster defied this requirement and went with the newer and more advanced Bristol Jupiter series of radial engines. They had briefly considered the even more complex Siddeley Jaguar 14-cylinder, two-row radial engine but this was seen as too risky to propose to the conservative RAF. The Jupiter was a nine-cylinder, single-row, air-cooled radial engine that despite having a lengthy development period that even saw its original manufacturer, Cosmos Engineering, go bankrupt had developed in to a fine powerplant that was seeing increasing use in both military and civilian aircraft. Gloster was not alone in this choice with Bristol themselves and more notably Westland selecting this engine for their own similar aircraft.

As construction of the first prototype was nearing completion it was fitted with the Jupiter VIA which developed 425hp and drove a two-bladed propeller 12ft in diameter. The prototype was given the serial J-8673 and was christened the Goral after a type of mountain goat found in northern India which reflected its planned use to police the Empire. The prototype took to the air for the first time on February 8th 1927 and once it was proven airworthy it was handed over to the Aeroplane and Armament Experimental Establishment (A&AEE) at Martlesham Heath for evaluation. Over the coming months, it was joined by other contenders for Air Specification 26/27 including Westland’s design which had been christened the Wapiti. The prototype was returned to Gloster at least twice to have the design tweaked and the engine replaced with the more powerful Jupiter VIIIF that churned out 480hp but it was to no avail and the Wapiti was declared the winner.

Gloster Goral J8673 Bristol Jupiter A&amp;AEE

Compared to the Wapiti the Goral was faster, had a greater service ceiling and a longer range while the Wapiti had a marginally higher bomb load. However, where the Wapiti won was that it shared a much higher degree of commonality with the DH.9A which was one of the key points of the Air Ministry’s specification in the first place. Westland had a distinct advantage over the competition in that they had produced DH.9As under license and were far more familiar with it. In October 1927, the Air Ministry placed an initial order for 25 Wapitis confirming that the Goral had no future with the RAF but Gloster kept the aircraft on the books hoping to attract foreign interest.

Despite some passing enquiries, nothing really materialised until 1931 when an Argentinian purchasing commission which had set up an office in Brussels sent a request for information on the aircraft to Gloster. The commission confirmed their interest but expressed concerns that the aircraft was unsafe and believed this was why the Air Ministry had rejected it. The Air Ministry responded by sending the Argentinians a detailed letter outlining that the aircraft was not only safe but well suited to the Argentinian requirements. Unfortunately, the Argentinians didn’t resply to the letter and a short while later they placed an order with France for the Breguet Br.19; an aircraft of similar performance and configuration.

Thus the Goral was lost to history.

SPECIFICATION

Gloster Goral

  • Role: Two seat light bomber and reconnaissance aircraft
  • Crew: 2
  • Length: 31ft 6in (9.4m)
  • Wingspan: 46ft 7in (14.19m)
  • Height: 11ft 4in (3.3m)
  • Empty weight: 2,796lbs (1,268kg)
  • Gross weight: 4,441lbs (2,014 kg)
  • Powerplant(s):
    (i) 1 × Bristol Jupiter VIA 9-cylinder radial (425hp)
    (ii) 1 x Bristol Jupiter VIIIF 9-cylinder radial (480hp)
  • Maximum speed: at 5,000ft (1,524 m) 136mph (218km/h)
  • Maximum Range: 750 miles (1,207 km)
  • Service ceiling: 21,500ft (6,552m)
  • Armament:
    1× synchronised forward firing 0.303 in (7.7 mm) Vickers machine gun
    1× 0.303 in (7.7 mm) Lewis gun mounted on ring in gunner’s cockpit
    Up to 460lbs of bombs

Royal Aircraft Factory S.E.5a F5475 at the Brooklands Museum

A collection of pictures of a replica Royal Aircraft Factory S.E.5a marked as F5475 on display at the Brooklands Museum in Surrey.

All photos were taken on April 5th 2016
Photos: Tony Wilkins


The fuselage section was built on site at Brooklands and wears “1st Battalion Honourable Artillery company”. titles. Unfortunately, the tight confines of the Wellington Aircraft Hangar where the fuselage is stored do not allow for great photo angles but it was still exciting to view this piece of history.

For more images of British military equipment and museums please visit the Galleries section or follow Defence of the Realm on Instagram

If you have photographs or articles you wish to contribute to Defence of the Realm than you can email them to defencerealmyt@gmail.com. If successful you will of course be given full credit for your contribution and can even promote your own website/blog/social media account.

Sopwith Pup N6452 replica at Yeovilton Fleet Air Arm Museum

History: Fleet Air Arm Museum
Photos: Tony Wilkins

The Sopwith Pup was a single-seater biplane fighter built by the Sopwith Aviation Company. It entered service with the Royal Flying Corps and the Royal Naval Air Service in the autumn of 1916 and served on the Western Front until the end of 1917 by which time it was outclassed by some of the latest German fighting scouts.

The aircraft displayed at Yeovilton is a replica built in the 1980s.

12/04/1983 – first flight at Old Warden as G-BIAU
07/1983 – noted at Cranfield Airshow
01/08/1983 – by now at the Whitehall Theatre of War
10/06/1985 – arrived at FAAM after being bought at auction
13/09/1989 – Certificate of Airworthiness expired


 

 

The First Sortie

BE2 RFC

Royal Flying Corps BE2 (RAF Museum)

In 2015 the British government voted to extend the Royal Air Force’s campaign against the so-called Islamic State terrorist group by bombing targets in Syria. The pilots of the Panavia Tornado GR.4s and Eurofighter Typhoon FGR.4s probably had little thought to the fact that in doing so they were continuing a 101 year-long story of British forces using aeroplanes to conduct a war.

The story begins – as do so many stories of modern, mechanised warfare – in the First World War. On August 4th 1914 Great Britain declared war on Germany following the violation of Belgium neutrality by German troops in their attack on France. To help repel the Germans the British Expeditionary Force (BEF) was raised which included four squadrons of the British Army’s Royal Flying Corps (RFC) operating an assortment of aeroplanes. Three of the squadrons comprising around 60 aircraft crossed the English Channel on August 13th 1914; an impressive feat when you consider that it had barely been five years since Louis Blériot had made the first crossing by a heavier-than-air flying machine.

RFC Bleriot XI

RFC Bleriot Monoplanes (1418now)

Even before they left Britain the RFC was reminded how dangerous flying was in itself during those very early days to say nothing of encountering the enemy. An aircraft flying to Dover to join the rest of the RFC before attempting the crossing crashed killing both its pilot Lt. Robert R. Skene and Air Mechanic Ray Barlow. As the BEF began their march towards Maubeuge in north east France the RFC took off and arrived there almost two full days before the first British troops arrived. Their journey had been anything but uninteresting however as the French infantry in the area proved somewhat trigger-happy taking pot-shots at the unmarked British aircraft. Their lesson learned, the RFC squadrons quickly took to painting crude Union Jack flags on the underside of their wings which went some way to reducing the risk but didn’t eliminate it (it would be another year before roundels appeared on aircraft).

Despite the hazards posed by both hostile and friendly fire the RFC was set to fly its first operational sortie of the war on August 19th 1914. The mission had two separate objectives and would be flown by two aircraft departing together and then going about their own tasks upon reaching Nievelles. From No.3 Squadron RFC, Captain  would fly his Blériot Monoplane to Nievelles-Gnappe to report on the condition and disposition of Belgian forces in the area. In the early days of the war there was little information feeding back to the BEF in France about how well the Belgians were repelling the Germans. The second aircraft, a Royal Aircraft Factory BE2 flown by Lieutenant Gilbert Mappleback of No.4 Squadron RFC, was tasked to confirm the suspicion that German cavalry were operating in the vicinity of Gembloux in central Belgium.

Given the need to save weight and thus reduce the fuel consumption to increase range the decision was taken that both pilots should fly without observers; a rather contentious decision at the time within the squadrons. At 0930hrs the two aircraft bounced their way in to unfriendly looking skies that was blanketed with thick clouds. The two aircraft chugged their way through the skies together on their way to Nievelles where the plan was for them to separate on to their individual tasks. The reason for flying part of the mission together was so if one aircraft crashed or was shot down then the remaining pilot could report his position.

Lieutenant Gilbert  Mapplebeck

Lieutenant Gilbert Mappleback DSO

It was not to be however. The low cloud enveloped the two aircraft several times and before long the two RFC pilots realised that they had lost sight of one another. Nevertheless, they pressed on but keeping the BE2 flying and navigating by himself, Lieutenant Mappleback soon became lost and found himself flying over a very large town. He didn’t know it at the time but the town was actually Brussels. Tootling along for a short while longer he eventually found enough landmarks to ascertain his position and proceeded to his objective at Gembloux. Shortly after beginning his reconnoitre of the area he spotted a small pocket of enemy cavalry and recorded their position noting that they were moving south-east away from the allied lines; they were possibly returning from their own more traditional horseback reconnaissance mission.

Mappleback then turned his aircraft for Maubeuge but the cloud was getting lower and lower forcing him to eventually drop down to just 300ft in order to keep sight of his navigational markers. Eventually he reached the town of Namur and took to following the La Sambre river back to Maubeuge. He would become so intent on following the river that he actually flew passed Maubeuge and on to Le Cateau where he put the aircraft down in order to get his bearings fixed before attempting to fly back to Maubeurge. He arrived back at his base at close to midday to report the position of the enemy cavalry. His report was not the news the General staff were hoping for but his mission was at least a success.

While Mappleback was hunting German cavalry at Gembloux, Joubert in his Blériot Monoplane was having an extremely difficult time navigating to Nievelles-Gnappe. With such heavy cloud constantly causing him to lose sight of the ground Joubert found his position on the map through a break in the cloud and resorted to flying primarily by his compass. The lightweight frame of the Blériot saw Joubert being blown off course and after two hours of wandering around the Belgian countryside he eventually landed near the Belgian Army barracks at Tournai. The Commandant of the barracks, fascinated with the English flier, proceeded to invite him to dine with his men where they made polite conversation but Joubert learned little of the Belgian disposition from him as was his objective.

Having finished dining, Joubert took off at around midday and once again got lost. After another two hours of trying to find his way in the low cloud and poor weather he spotted the medieval Belgian city of Courtrai where he again landed hoping to secure some petrol for his Blériot. The local Gendarmerie (police) were suspicious of the flier however and attempted to arrest him until he was able to convince them he was an RFC pilot. The local population helped with gathering enough fuel for his aircraft to take off again and the Gendarmerie pointed him in the direction of the Belgian Flying Corps headquarters at Louvain, east of Brussels. This was too far away for him to contemplate flying and therefore he elected to return to Maubeuge via La Cateau. He and his aircraft arrived rather sullenly at 1730hrs.

It was hardly a successful first day. Nevertheless, it laid the groundwork for more successful future operations and before long the aircraft would become an integral part of the battlefield adding a third dimension to military planning. The importance of the aircraft would finally be fully recognised on April 1st 1918 when the RFC became absorbed in to the Royal Air Force, the world’s first air arm independent of both Army and Royal Navy.

Philip Joubert de la Ferté would survive the war and remain in the RAF eventually rising to the rank of Air Marshall leading Coastal Command during World War II and receiving a knighthood. Lieutenant Gilbert Mappleback would later be awarded the Distinguished Service Order (DSO) for carrying out an attack on a German convoy of vehicles by hurling small hand held bombs on top of them. He returned to Britain in April 1915 and assisted in testing at Farnborough. On August 25th 1915 he was killed when the Morane Saulinier Type N “Bullet” he was flying crashed.

 

Airco DH.2 vs. Fokker Eindecker III

Airco DH.2 Fokker Eindecker III

A myth about the type of war the Royal Flying Corps (RFC) was involved in developed quickly in the First World War. Serving as a distraction from the gory and unpleasant scenes of the trenches below them the men of the RFC and their wonderful flying machines were seen as having the most glamorous and exciting job in the war sipping French wine and eating fine food in between brief joyrides over the lines. In reality while their accommodation may have been better than a trench the RFC fought just as deadly and brutal a war as the men in the infantry. In fact it would be no exaggeration to say that the average life expectancy of an ordinary soldier in the trenches was longer than that of a pilot or observer in the RFC because as well as the enemy he had to contend with what was still a new and quite dangerous military occupation partially as a result of very primitive machines and partially because of appallingly insufficient training procedures.

Nevertheless in the traditional British make-do attitude the men of the RFC persisted in their reconnaissance and artillery spotter roles both of which they became quite proficient in. So proficient in fact that soon the Germans knew that bringing down the spotter planes of the RFC like B.E.2c and Avro 504 would have to become a priority. Initially pilots of both sides who encountered an enemy plane would take a few pot-shots at it with a pistol or a rifle carried by the observer. The results were very poor and the encounters often ended with the two pilots exchanging waves or salutes before breaking off reiterating the belief that there was still a code of honour amongst airmen.

This code of the air would have a short lifespan however as on both sides more and more effort was put in to bringing down enemy planes. Putting guns in single engine aircraft on trainable mounts was difficult, cumbersome and produced little-to-no results thanks to the difficulty of being able to train the gun on the enemy plane. The key was to instead use the aircraft itself to aim a fixed gun but this too had its problems. Mounting guns on the wing of early fighters was out of the question because the wings were so flimsy that they couldn’t support the weight while putting guns on the forward fuselage would risk damaging the propeller. The only saving grace for the RFC was that the Germans too had to contend with the same problems.

Fokker EindeckerThen in mid-1915 RFC pilots reported the occasional sighting of what appeared to be French Morane-Saulnier H monoplanes in areas they shouldn’t have been in. At around the same time RFC losses began to skyrocket and it was not long before the RFC realised that rather than being French aircraft they were in fact German single seater fighting scouts – aircraft designed to shoot down other aircraft and the forerunner of today’s air superiority fighters. The Germans had built a machine based loosely on the French aircraft called the Fokker Eindecker but more importantly they had developed synchronisation gear for its single machine gun allowing the pilot to fire his weapon through the propeller arc in between the turning of the blades. Now all the pilot had to do was point his aircraft at the target and squeeze the trigger. It was the beginning of the Fokker Scourge; a nine month period where the RFC was effectively at the mercy of the Eindecker.

Vickers FB5 GunbusThe RFC had its own dedicated fighting scouts. The Vickers F.B.5 “Gunbus” (right) was the first aircraft to be designed from the ground up as a fighter aircraft and as such when No.6 Squadron equipped with the type in November 1914 it was able to claim the distinction of being the world’s first fighter squadron. The F.B.5 was a pusher aircraft (the propeller was at the rear of the aircraft) and had a crew of two with the observer seated at the front with a single .303 machine gun. However against the Eindecker it was hopelessly outclassed being too slow to pursue or escape the German monoplane and too cumbersome to outfight it even with a trainable machine gun in the nose.

Airco DH.2In Britain the need for a new fighting scout to combat the Eindecker became a top priority for Britain’s aircraft manufacturers. One of them, Airco, had already built the DH.1 an aircraft designed by Geoffrey De Havilland that was remarkably similar to the F.B.5 and thus just as obsolete. With British engineers as yet still unable to produce their own synchronisation gear the pusher configuration remained the only way to mount a fixed machine gun on the front of an aircraft and use it in the same way as the Eindecker. De Havilland went to work on an improved version of the DH.1 which dispensed with the observer leaving the pilot to be solely responsible for his aircraft in combat. This freed up a lot of weight and with a more powerful engine the new aircraft offered greatly improved performance over the other fighting scout pushers. With its fixed machine gun unhindered by a propeller the DH.2 (above left) was able to take the fight to the Eindecker on almost equal terms and it helped bring an end to the Fokker Scourge.

Throughout aviation history there have been cases of two distinct aircraft types that have wrestled with one another for control of the skies but this was the one of the very first. Along with the two-seat Royal Aircraft Factory F.E.2b pusher and the French Nieuport II the DH.2 helped restore parity in the air until the arrival of the famed Fokker Albatross tipped it back in the German’s favor.

So just how well matched was the DH.2 against the Fokker Eindecker? For this comparison we will be comparing the Airco DH.2 against the Fokker Eindecker III which was the main production version of the German aircraft.


Configuration Considerations

Airco DH.2 2

The DH.2 was an equal span biplane with a pusher configuration and a single tail unit joined to the main fuselage by an unskinned frame. The pusher design meant that the pilot had an excellent forward field of view compared to tractor aircraft as well as adding a degree of safety if the engine caught fire since the pilot wasn’t getting blasted with flames or doused in leaking oil and petrol. However, like all pusher aircraft the DH.2 was easier to stall since the propeller was mounted behind the wings meaning there was no propwash over them that would increase lift as in tractor aircraft. The propeller was also less effective behind the fuselage (see below). Additionally having the engine mounted in the aircraft’s centre of gravity helped with agility in all three planes of flight but additionally made the aircraft more of a handful to inexperienced pilots. Given the especially poor training in the RFC this meant that accidents were high and later in its career the DH.2 would serve as a trainer to ensure pilots became more accustomed to this type of flying. The pilot sat in the main fuselage in a bath-tub style compartment that also housed the engine and fuel tank.

To modern eyes, at first glance the monoplane design of the Eindecker III coupled with its reputation as a destroyer of lumbering British biplanes seems quite sophisticated for the time. In fact the opposite was true with it being quite primitive. The aircraft can trace its origins to a touring aircraft built before the war and retained much of the aerodynamic technology including a lack of ailerons in the wings as in the DH.2. Instead the aircraft was controlled by using pulleys to flex the wings similar to how one controls a kite. This resulted in a rather poor roll rate as compared to many other aircraft of the era including the DH.2 and F.B.5. The aircraft was skinned in fabric around a wooden frame and featured an all moving rudder and taileron arrangement which gave good pitch and yaw performance but made level flight something of a dicey affair for new pilots due to their sensitivity in the controls. The mid mounted wings were situated in-line with the pilot which dramatically reduced his all-round vision especially to the port and starboard low areas.

Powerplant

Airco DH.2 4

The DH.2 was powered by a license-built version of the French Gnôme Monosoupape 9 B-1 nine cylinder rotary engine that developed 100hp. This was translated in to forward motion via a four bladed wooden propeller. The effectiveness of this propeller was reduced somewhat by the pusher arrangement as airflow was often disturbed by the passing over of the forward fuselage before reaching the blades. Like many early engines it was controlled by restricting its ability to function which in the DH.2 was done with the fitting of a blip switch on the control column which cut out the engine’s ignition causing it to lose power and thus slow down. The engine was air cooled and lubrication was on the total-loss principle meaning that it would burn or discharge all its lubricant by the end of the flight.

Fokker Eindecker III 2

The Eindecker III was powered by a single Oberursel U.I nine cylinder air-cooled rotary piston engine which also produced 100hp but had a lighter airframe to contend with than the DH.2’s Monosaupape engine. This drove a two-bladed propeller mounted in the tractor position in the nose of the aircraft and early fears that synchronising the gun to the engine would inhibit performance proved unfounded. The pilot of the Eindecker had to pump additional fuel in to the engine around eight times an hour to keep fuel running in to a small tank that gravity-fed the engine. It was not uncommon for the engine to cut out as a German pilot neared the enemy and his mind became distracted from this task.

Performance

Airco DH.2 3

The pilot’s handbook for the DH.2 put its top speed at sea level in the region of 81mph however many pilots claimed it could go faster with speeds of around 90mph being achievable in the right atmospheric conditions. Some adventurous pilots dived their aircraft to gain even more speed with reports of 120mph or more but this was discouraged by commanding officers except in the most dire of conditions such as escaping a superior enemy for fear of structurally overstressing the aircraft. As altitude increased the speed invariably dropped off with speeds nearing 60mph at its service ceiling of nearly 14,000ft. In order to attain this height the unfortunate pilot would find himself climbing for nearly three quarters of an hour! Endurance was in the 2 ½ hour region while range was around 250 miles.

Fokker Eindecker III 3

When it first appeared in mid-1915 the Eindecker III’s top speed of 87mph was enough for it to run circles around the RFC’s existing types including the Vickers F.B.5 “Gunbus” which was almost 20mph slower at sea level. Another great advantage the Eindecker had over RFC types including the DH.2 was its ability to climb relatively quickly for although it had a similarly powerful engine the aircraft was nearly a 100lbs lighter. This also improved agility but as has been previously mentioned this made it less stable and more unforgiving to new pilots. The Eindecker III took just 5 minutes to reach 3,281ft while the DH.2 took closer to 7 minutes. However as the altimeter reached 10,000ft DH.2 began to catch up as the Eindecker’s engine began to lose steam the nearer to its 11,000ft service ceiling it got. In a continuous climb both aircraft could reach this altitude in around half an hour before in the final few hundred feet of climb the DH.2 would leap ahead. Endurance for the Eindecker III was a full hour less than the DH.2 but since the aircraft operated in defence for much of the time this was less of a concern.

Armament

Airco DH.2 5

The DH.2 was equipped with the tried and tested .303 in (7.7 mm) Lewis machine gun fitted with a 47-round drum magazine that the pilot had to reach over and replace once its rounds were exhausted. This weapon had the capability to fire up to 600 rounds a minute at a velocity of 2,440ft/sec. The effective firing range of the Lewis gun was 800m although combat rarely approached anywhere near that figure.

Fokker Eindecker III 4

The Eindecker III was fitted with a synchronised 7.92 mm (0.312 in) lMG 08 Spandau machine gun positioned just offset to starboard to improve forward visibility when training the weapon on to a target. This had an exceptionally high rate of fire being in the range of 900rds/min but synchronising the weapon to the propeller did lower this figure slightly. This high rate of fire was not achieved without problems however with the early weapons being prone to stoppages. The synchronisation gear developed by Anthony Fokker was also prone to breaking down and several pilots found themselves shooting up their own propeller when firing their guns. If the propeller wasn’t destroyed then the unfortunate airman had to fly an increasingly unstable aircraft away from battle. A major advantage on the battlefield over the Lewis gun was that it had almost double the range but again combat rarely if ever occurred at those kinds of ranges.

Conclusion

The DH.2 had high altitude performance on its side which meant that the higher the arena the greater his aircraft would perform compared to the Fokker. The Eindecker enjoyed a higher degree of agility however particularly in the longitudinal plane where the rudder of the DH.2 had to work harder to keep up thanks to the heavier airframe it was turning. With most engagements taking place at lower levels the Eindecker could also outclimb the DH.2 in this arena and inflict greater damage with its heavier armament. While it could dish out plenty of punishment the Eindecker certainly couldn’t take it in return proving a much more flimsy machine. In truth the DH.2 was not exactly bulletproof either and it only took a few bullets in either aircraft’s engine to render it inoperable.

Overall the DH.2 has a slight edge over the Eindecker III except when below 4,000ft but as in most cases the outcome of an air-to-air combat would be determined primarily on the pilot playing his aircraft to its own strengths. More than anything it would be determined by who spotted who first as that pilot would have the immediate advantage of being able to tailor that all important first attack that would initiate combat. Using superior speed at altitude the DH.2 pilot has a higher chance of making that killer first attack by diving down on to the enemy but if he was to fail in bringing down the Eindecker in this initial first attack then the German aircraft would give a good account of itself in the hands of an experienced pilot.

Between 1915-16 the DH.2 didn’t help win the battle for the skies but it did restore parity thus helping to significantly reduce the danger to the RFC’s reconnaissance operations. Such was the speed of development in wartime that by mid-1916 both these aircraft were already outclassed by even newer types after just a year in action.

Boulton Paul P.29 Sidestrand & P.75 Overstrand

boulton paul sidestrand overstrand

While perhaps occupying a less prestigious place in history than Supermarine or Avro, Boulton Paul Aircraft Ltd nevertheless helped forge British military aviation. The company’s name, Boulton Paul, has a rich heritage as ironmongers stretching as far back as 1797. Prospering in the Industrial Revolution of Victorian Britain the firm evolved to become a general manufacturer by the start of the 20th century before founding an engineering division in 1905. It would be this engineering division that would lay the foundation for Boulton Paul Aircraft Ltd and this was thanks to the outbreak of World War I.

Despite a somewhat muddled start aircraft were now proving indispensable over the Western Front and the Royal Flying Corps was going through a rapid expansion. In order to meet the demand for its F.E.2b combat aircraft the Royal Aircraft Factory approached Boulton Paul to manufacture 550 airframes and thus Boulton Paul became an aircraft manufacturer albeit building other company’s products. During the course of the war a number of companies sub-contracted Boulton Paul to build their designs and this gave the company’s engineers a wealth of experience to the extent that the company then decided to attempt to design and manufacture aircraft themselves.

P.3 Bobolink (Aviastar.org)

P.3 Bobolink (Aviastar.org)

To help them in this bold endeavour in 1917 they brought in John Dudley North an established engineer who had worked on aircraft designs for the Austin Motor Company. The fruits of this new department could be seen in the company’s first aircraft the P.3 Bobolink, a prototype for a new fighter to replace the Sopwith Camel which the company had intimate knowledge of thanks to a sub-contract to build it from Sopwith. This knowledge was obvious in Boulton Paul’s aircraft as in many ways it resembled the previous Sopwith design. Boulton Paul’s aircraft was rejected in favour of the Sopwith Snipe and it would be only the first of a series of promising but ultimately disappointing attempts to design and build their own aircraft for the newly established Royal Air Force.

With the end of the war Boulton Paul Aircraft Ltd needed to establish itself quickly in the British aviation scene if it was to survive and that was no easy feat. Several of the main manufacturers of aircraft during the war collapsed within two years of the armistice the biggest shock being Sopwith who’s Camel and Snipe had been credited with winning back air superiority over the Western Front. In 1918 the RAF was already looking for a new bomber to replace its wartime Handley Page O-series aircraft and Boulton Paul saw this as an opportunity to show that it was capable of competing with the best.

John Dudley North began work on the P.7 Bourges to meet the RAF’s specification. North adopted the tried and tested design of a large biplane design with a gunner/bomb aimer in the exposed nose of the aircraft and the pilot seated behind. Despite good flying qualities the aircraft was ultimately never acquired by the RAF and after four years of redesigns in an effort to entice interest in the aircraft it was finally dropped in 1924 when the RAF rescinded and revised the original requirement. North tried to redesign the aircraft in to a transatlantic airliner but this failed also.

Boulton Paul P.7 Bourges (Aviastar.org)

Boulton Paul P.7 Bourges (Aviastar.org)

North and Boulton Paul Aircraft Ltd remained undeterred however and produced a series of one-off prototypes building on the Bourges. While none of these were successful the company was continuing to gain experience and Boulton Paul as a whole was getting enough work to keep North’s division open. The company’s efforts had not gone entirely unnoticed however and other companies began to view Boulton Paul as a serious competitor for contracts. Finally in 1924 the Air Ministry issued a specification for a three/four seat medium day bomber to replace their wartime fleet of aircraft. North took all he had learned from his previous prototypes and put that knowledge in to a single design which was given the in-house designation P.29.

The P.29 had an overall similar configuration to his previous designs stretching back to the Bourges but was more bloated in appearance as North designed the aircraft with sweeping lines for increased aerodynamic efficiency. The aircraft was of mixed metal and traditional wood/canvas construction with thin steel skin covering the main frame around the cockpit. Identifying the vulnerability of the wartime bombers to enemy fighters the P.29 was designed to be heavily armed for its day with three gunner positions in total – one in the nose, one behind the pilot and one in the lower half of the fuselage facing backwards. Each gunner was armed with a single manually trainable .303 (7.7mm) Lewis machine gun while the aircraft was designed to carry an offensive load of 1,000lbs of bombs.

Boulton Paul Sidestrand I (airwar.ru)

Boulton Paul Sidestrand (airwar.ru)

Power for the aircraft was to come from a pair of Bristol Jupiter VIIF 9-cylinder air-cooled radial engines. These were geared to produce 460hp each and were mounted in streamlined nacelles on the lower wing. Originally North wanted to power the aircraft with Napier Lion inline engines and the shape of the nacelles retained a look more akin to an inline engine at the rear. The Jupiter was a sound alternative choice by North as the engine was a well-established and proven powerplant. Many aircraft designers in the 1920s remembered the “Dragonfly debacle” – the decision by the Air Ministry in 1918 to standardize the RAF’s aircraft on the ABC Dragonfly engine. The engine was so problematic and repeatedly delayed that many advanced aircraft projects stalled and were then cancelled as a result such as the Avro 533 Manchester bomber and Sopwith’s last fighter design the Snark.

The Air Ministry was suitably impressed with the design on paper to authorise the construction of two prototypes for flight testing in early 1925 with the first prototype, J7938, being completed in March the following year. It fell down to Boulton Paul’s first full-time test pilot, Flight Lieutenant Cecil Arthur Rea, to take the aircraft aloft for the first time. After initial flight testing was completed the company handed the aircraft over to the RAF for service trials at Martlesham Heath. A second prototype, J7939, was under construction at the same time and would be demonstrated at the 1927 Hendon air display under the rather clinical name of “Hendon Display New Type No. 8.” Testing at Martlesham Heath with J7938 revealed that the bomber had quite lively performance for an aircraft of its size but in a time before power assisted controls throwing it around the sky was a laborious affair leaving the pilot quite exhausted if done for extended periods. The RAF pilots also complained that the aircraft suffered from quite severe vibration when running the engines at high power. This was seen as of little importance however since it was not expected to be flown like a fighter and so the RAF turned their interest in to an acquisition. After showing so much promise John North and Boulton Paul finally got one of their aircraft in to frontline service.

The name “Sidestrand” was chosen by the Secretary of State for Air in 1927, Samuel Hoare, in honour of his home town of Sidestrand, Norfolk. The two prototypes therefore became known as Sidestrand Mk.Is but some minor redesign was requested by the RAF to help alleviate the vibration problems following the trials at Martlesham Heath. This resulted in the Sidestrand II the first six of which were powered by the same Jupiter VIIF engines as the prototype before production switched to the Jupiter VIIIF after six airframes were completed. The Jupiter VIIIF equipped versions subsequently adopted the designation Sidestrand III and all six Mk.IIs were upgraded to this standard.


Sidestrand III Specifications

Role: Medium Day Bomber
Maximum speed: 139mph
Range: 520 miles (approx operational range)
Powerplant: 2x Bristol Jupiter VIIIF 9-cylinder air-cooled radial engine (460hp each)
Service ceiling: 20,800ft
Length: 46ft 0in
Wingspan: 71ft 11in
Height: 14ft 9in
Defensive Armament: 3x .303in (7.7 mm) Lewis guns (nose, dorsal and ventral positions)
Offensive Armament: 1,040lbs of bombs


Boulton Paul Sidestrand (Aiwar.ru)

Boulton Paul Sidestrand (Aiwar.ru)

After full service acceptance No.101 Squadron was selected as the first Sidestrand unit replacing their increasingly ageing De Havilland DH.9As. However the RAF’s interest in the type was suddenly waning as it became clear that despite it being a new design it offered performance that was little better than some of the twin engine bombers it was expected to replace and with new types like the Fairey Hendon monoplane under development it was clear the Sidestrand was obsolete technology. In the end only twenty aircraft would be built and No.101 Squadron would be the only frontline unit to equip with the type.

All was not lost for Boulton Paul however. They did at least have their foot in the RAF’s door with an aircraft that sported their logo and realising their concerns they began work on a further improved version in 1932. The Jupiter VIIIFs were dropped in place of far more powerful Bristol Pegasus II.M3 9-cylinder radial engines which each churned out 580hp.

Boulton Paul Overstrand gun turret (historyofwar.org)

Boulton Paul Overstrand gun turret (historyofwar.org)

This increased the aircraft’s speed but this in turn presented another problem as a result of the open cockpit and gun positions. For the forward gunner aiming the .303 Lewis gun was extremely difficult thanks to the increased headwind while the pilot found his face being blasted with air throughout the flight. At about the same time Boulton Paul was experimenting in developing powered gun turrets and they decided to put this in to practice by scabbing a powered gun turret on to the nose of the Sidestrand. It was heavily glazed and offered a greater forward field of vision to the gunner who at the same time felt a little more vulnerable even though he was no safer in the older model. The turret was rotated by pneumatic motors while elevation and depression of the single Lewis gun was achieved by hydraulic rams. The cockpit was also given a glazed canopy and the new Sidestrand Mk.V was considered so different to its predecessor that the RAF decided to rename the aircraft as the Overstrand after another village in Norfolk.

First flying in 1933 the Overstrand could fly faster, higher and carry a heavier bomb load than the Sidestrand III. The first examples were converted from Sidestrand IIIs before production examples entered service again with the RAF’s No.101 Squadron to replace the earlier machines in 1934 (the last Sidestrand IIIs were retired in 1936). Nevertheless despite these advances it was clear that the new aircraft was only a stop gap until the newer monoplanes became ready. An Overstrand II was proposed with a retractable undercarriage and this later became known as the Superstrand but it never left John North’s drawing board. Only 28 Overstrands were eventually built including the original conversions and they served with No.101 Squadron until 1938 when they were replaced by Bristol Blenheims. A number of Overstrands were operated by the newly reformed No.144 Squadron in 1937 to keep the pilots current until a number of Avro Ansons arrived allowing them to return the aircraft to No.101 Squadron.

Boulton Paul Overstrand (commons.wikimedia)

Boulton Paul Overstrand (commons.wikimedia)

After No.101 Squadron relinquished their Overstrands in 1938 the aircraft were divided up amongst gunnery training schools. A number of aircraft also served with the RAF’s Balloon Development Unit designing new barrage balloons. The RAF had little interest in keeping their aircraft in service for any extended period of time and so effectively worked them all to death. In 1941 the last aircraft was withdrawn from a gunnery training school.

Although the Overstrand’s career could be considered unspectacular it does hold two accolades to its name. It was the aircraft that introduced the powered turret to regular RAF service and the experience both the RAF and Boulton Paul gained from it went in to developing more powerful and successful gun turret/aircraft combinations. It was also the last biplane bomber to serve in the RAF thus closing the opening chapter of Bomber Command’s technical history. Only two Overstrands were ever lost in accidents both of which proved fatal but percentage-wise this was a small figure compared to other types then in service.

Boulton Paul Aircraft Ltd would never make a massive impression on British aviation like Avro, Hawker or Supermarine but they did have one final “ace” to produce before they ended their efforts to build their own aircraft. The Boulton Paul Defiant combined their expertise in building aircraft with their growing expertise in gun turret technology. Early success with the RAF over France was overshadowed by a sudden rise in losses as Luftwaffe pilots developed tactics to counter the aircraft. Nevertheless the Defiant helped form an effective early part of the RAF’s nightfighter force and it was thanks largely to the story of Boulton Paul’s forgotten bombers.


Overstrand I Specifications

Crew: 4
Role: Medium Day Bomber
Maximum speed: 148mph
Range: 545 miles (approx operational range)
Powerplant: 2 × Bristol Pegasus II.M3 9 cylinder radial engine (580hp each)
Service ceiling: 21,300ft
Length: 46ft 0in
Wingspan: 72ft 0in
Height: 15ft 6in
Defensive Armament: 3x .303in (7.7 mm) Lewis guns (nose, dorsal and ventral positions)
Offensive Armament: 1,500lbs of bombs