A hundred years ago the armistice of November 11th 1918 ended the fighting on the Western Front and largely brought to a close four years of continuous frenetic aviation development. Had the fighting continued into 1919 these are the types that would have been in the front line; Snarks and Rumplers would have been as well known today as Camels and Fokkers. 

This group represents the ultimate development in Great War fighter aircraft yet despite their potential, none of these aircraft saw operational service before the end of hostilities and chances are you’ve never heard of any of them (unless you’re over 100 years old and happened to be employed in the aviation sector in the early interwar period).

In 1918 aircraft designs were churned out at an astounding rate, for example the Fokker V20 of early 1918 was allegedly designed and built in six and a half days. As a result the aircraft below are limited to single seat, single engine aircraft only to limit the potential entries and help maintain the sanity of the compiler.

Honourable Mention: Orenco-Curtiss Model D

Despite being the first nation to actually fly an aeroplane, US aviation lagged behind the European powers when they entered the conflict in 1917. All the combat aircraft operated by the American Expeditionary Force over the Western front were either French or British. In 1919 however the first indigenous American fighter design to enter production (though still equipped with a French engine) took to the air in the form of the Orenco Model D.

The aircraft was apparently excellent, test pilot Clarence Coombs (who gained second place in the inaugural Pulitzer Trophy the following year in the Curtiss Kitten) reporting “This aircraft performs better than the Sopwith Camel and Snipe, the Thomas-Morse, the Nieuport and Morane Parasol, the Spad and S.V.A.” which was praise indeed, and thus the Army ordered a batch of fifty production aircraft. So why is Orenco virtually unknown today? Well it turned out that the US Army had bought the rights to the design from Orenco and then offered a tender to companies to actually build the production aircraft. In a cruel twist, the winning (i.e. cheapest) bid came not from Orenco themselves but from the aviation giant Curtiss. Curtiss tinkered with the design a little and duly manufactured the fifty fighters.

Orenco meanwhile folded shortly afterwards and became largely forgotten by history. 

10. Sopwith Snark

Similarly forward-looking was its construction, the Snark featured a wooden monocoque fuselage that conferred high strength for low weight. It would be the last RAF fighter, experimental or otherwise, to fly with such a fuselage until the prototype Mosquito fighter W4052 of 1941. The Snark appeared in public on just one occasion and it was noted that it ‘chucked stunts’ and seemed ‘uncommonly fast’. Upon landing out popped test pilot Harry Hawker, who was flying without a coat, though ‘everybody else was cold enough though well wrapped up.” 

Massive cuts to the armed forces at the end of the war meant that there would be no production order for the forward-looking, stunt-chucking and demonstrably warm Snark, thus depriving aviation writers the opportunity to use the phrase ‘The Hunting of the Snark’ in articles and features for evermore. A cruel blow.

Despite a nearly-successful entry into the motorcycle manufacturing business (Under the name ABC motors), Sopwith was saddled with insurmountable tax debts from its massive wartime production and was wound up in 1920. Though Tom Sopwith, Harry Hawker and three others immediately bought the assets of Sopwith as the H.G. Hawker Engineering company which would ultimately become a giant of the British aviation industry. 

9. Zeppelin D.I

Designed by Claude Dornier, the Zeppelin D.I was one of very few truly revolutionary aircraft in aviation history. The first aircraft to be built and flown with a stressed-skin metal construction throughout, the Zeppelin was the progenitor of virtually all modern fixed wing aircraft but never entered service and today is obscure in the extreme. 

Zeppelin’s name is inextricably linked with airships but the company were (and indeed still are) specialists in more general aluminium engineering so it was hardly surprising that they would seek to apply this material to aircraft construction. In the case of the D.I, construction was of duralumin (an alloy of aluminium and copper) throughout. This alloy would later be used to build the ill-fated Hindenburg passenger airship. 

Zeppelin’s D.I was present, though not an official entry, at the second fighter competition at Adlershof but was struck by incredible ill-fortune. Despite being grounded at the factory’s behest pending fitment of the correct wing attachment, the Zeppelin was flown anyway and fatally crashed when the upper wing departed from the aircraft, killing ace Wilhelm Reinhard. Curiously The D.I had been flown minutes earlier by Herman Goering and one wonders how history would have changed had he been the victim rather than the luckless Reinhard. This accident, though seemingly the result of ill-luck rather than any flaw in the aircraft inevitably coloured opinions. Whether or not this had an effect when the Zeppelin appeared at the next fighter contest is open to question but despite its promise the metal aircraft did not put up a particularly good showing, even when fitted with Germany’s best inline engine, the 185 hp BMW. “Does not possess characteristics of a modern fighter. Ailerons too heavy.” noted  Heinrich Bongartz, commander of the Aircraft Test Centre at Aldershof in a remarkably succinct but damning report. Had fighting continued it is likely that a developed version would have addressed the shortcomings this aircraft possessed.

8. Pfalz D.XV

Recipient of a major production order exactly one week before the end of hostilities, the Pfalz D.XV bid fair to reverse the prevailing attitude that Pfalz fighters were invariably inferior to their Fokker rivals. An unusual design, the fuselage of the Pfalz was placed halfway between upper and lower wing and attached to both by complex struts, resulting in a distinctly ungainly look. The D.XV was notable also for its complete absence of bracing wires as both wings were cantilever units. Despite its clumsy appearance, the new Pfalz was an impressive performer. When both were fitted with the same BMW engine, it was slightly faster than the Fokker D.VII and the new Pfalz matched its rival for rate of climb.

Entered into the third fighter trial at Adlershof, the performance of the D.XV was sufficient to warrant an order despite issues of tail-heaviness (which should have been relatively easy to cure) and being difficult to land – neither seen as particularly serious when weighed against the aircraft’s excellent performance. It was also noted that Pfalz’s production capacity was superior to Fokker and for this reason alone, the new fighter, at least as good as the D.VII but available quickly in great numbers made the Pfalz an extremely attractive machine to the Inspektion der Fliegertruppen (Idflieg).

The D.XV immediately entered production but time was not on Pfalz’s side and not a single example of the D.XV was to reach the front. It is not definitely known how many complete aircraft were built, probably no more than four, but in 1919, when Allied officials inspected Pfalz’s Speyer factory, they found 74 complete fuselages on the production line. Curiously, two D.XVs were exported to Italy for evaluation as late as 1920, presumably licence production there was being considered. The ultimate fate of both these aircraft sadly remains unknown.

Despite never again building a complete aircraft, Pfalz Flugzeugwerke still exists today, as a component subcontractor to both Airbus and Boeing amongst others.

7. Nieuport Nighthawk / Gloster Mars

Had the war continued into 1919 the British would have had a serious problem as virtually all their future aircraft types were designed around the ABC Dragonfly, a radial engine that promised much but delivered little. One such was the outstanding Nieuport Nighthawk, the design of which would set the standard for British fighters for the next twenty years. Despite its name, the Nieuport and General Company, often referred to as ‘British Nieuport’, was a completely separate entity to Nieuport in France. It had been set up to construct Nieuport aircraft under licence, hence the name, but by 1918 was building Sopwith Camels and eventually set up its own design office under Henry Folland, who had earlier designed the superlative SE5a. 

When the Dragonfly engine was running properly, the Nighthawk demonstrated superior characteristics to the Sopwith Snipe, and was the first of an array of radial-engined biplane fighters that formed the backbone of the RAF and Fleet Air Arm’s fighter force until the arrival of the Hurricane and Spitfire in the late 1930s. Despite being the ancestor of virtually all British inter-war fighters, the Nighthawk itself was plagued by the hopelessness of its engine. The Dragonfly never developed its advertised power, was prone to colossal overheating – Nighthawks under test were recorded landing with charred propellor hubs – and most seriously of all the engine had been inadvertently designed to run at its own resonance frequency, meaning that simply switching the engine on caused it to shake itself apart. 

The Nieuport and General Company closed down in 1920 but all was not lost for their seemingly unlucky aircraft. The Nighthawk was known to be an excellent design let down solely by its unreliable engine and production was continued by the Gloucestershire Aircraft company (later to be known as Gloster) who snapped up both development rights and designer Folland. At Gloster the Nighthawk was renamed the Mars, re-engined with a selection of motors that actually worked, and then developed into a confusing swathe of broadly similar types that served with distinction in many air arms across the globe. Examples included the Gloster Nightjar, essentially a Nighthawk with a Bentley rotary, which served operationally as a carrier fighter, and the similar Gloster Sparrowhawk, the first fighter operated by the Japanese Navy. Meanwhile on land a Nighthawk had been fitted with a Napier Lion and shorter wings, inexplicably named the Bamel, and became for a brief period the fastest aircraft in the world. Folland’s designs at Gloster progressed by a process of evolution by way of the Grebe, Gamecock and Gauntlet, to the famous Gladiator, the last fighter biplane of the RAF and a direct descendant of the Nighthawk.

6. Fokker V29

Fokker built the best fighting monoplane and biplane to serve the Central powers in significant numbers during the war, the V.29 prototype sought to combine the best of both worlds by marrying the fuselage of the biplane D.VII to the cantilever parasol wing of the D.VIII. This simple scheme resulted in an excellent aircraft that shared top place at the third Adlershof fighter competition in 1918 with the Rumpler D.I (of which more later). Pilots universally adjudged the V29 to have the best handling of all aircraft at the competition. If the war had continued the new fighter would have entered service as the Fokker D.IX and would likely have proved formidable. As it was, the amazing and continuing success of Fokker’s D.VII meant that there was no great rush to put the new monoplane into production and only the prototype was ever built. Some years later Fokker, by now operating once more in his native country of the Netherlands, built eleven of the D.X, a Hispano-Suiza powered development of the D.VIII which saw service in Spain and Finland and bore more than a passing resemblance to the earlier V29.

Unlike nearly every other manufacturer on this list, Fokker enjoyed great success producing both civil and military aircraft for many years until finally ceasing aircraft manufacture in 1996.

5. Rumpler D.I

The height at which aircraft were compelled to operate had inexorably risen throughout the war and the tubby Rumpler D.I possessed unmatched high altitude performance. Described as ‘perhaps the best fighter Germany never had in 1918’, the D.I appeared in ever more developed form at three of the Adlershof fighter competitions and was declared joint winner of the third in concert with the lash-up Fokker V29.

Rumpler Flugzeugwerke was liquidated in 1920, though Edmund Rumpler went on to design the remarkable Rumplertropfen car which was a technical triumph but a commercial failure. Only 100 were built of which two survive today. Rumpler himself, being Jewish, had his career ruined after the Nazis gained power and was briefly imprisoned. He died in 1940.

4. Gordou-Leseurre Type B (later GL-2)

Probably the best aircraft designed and built by brothers-in-law, the Gordou-Leseurre Type B was just beginning deliveries when the conflict ceased. The French were less monoplane-averse than their British allies and the Type B was the best of the numerous ‘parasol’ types built by the French during the war. As you may have guessed, the Type B was preceded by the Type A which was very fast indeed (in tests it was nudging 250 km/h which made it unofficially the fastest aircraft in the world) but doubts over the structural integrity of the wing mounting led to a modest redesign with a generally lightened structure and heavily reinforced wing. This process delayed service entry of the new aircraft, now named Type B, and as a result this extremely promising high speed monoplane missed the war, a mere 20 examples being manufactured of the initial 1918 version. 

This was not the end of the story as developed versions saw limited production for the Aeronavale first as a fighter and then as an advanced trainer. This latter version conducted carrier trials aboard France’s first aircraft carrier Bearn and was adapted for use as a carrier reconnaissance aircraft.

Handfuls were produced for the air arms of Yugoslavia, Latvia, Estonia, Czechoslovakia and Finland and ultimately around 130 aircraft were built. The final three off the production line were civilian versions constructed in the early 1930s for use in competition aerobatics.

As is invariably the case with in-laws, relations between Gordou and Leseurre became strained and after producing a few modestly successful designs the company closed down in 1934.

3. Siemens-Schuckert D.VI

As everyone knows, the First World War ended in 1918. Except, of course, that it didn’t. It is true that the fighting ceased (mostly) in November 1918 but that was only an armistice. The war was actually brought to a close on the 28th June 1919 with the signing of the Treaty of Versailles. In the intervening seven months, the German military had somewhat cheekily, but undeniably prudently, maintained aviation development work and even held a competition for new fighter aircraft at Adlershof between February and March 1919. Likewise Siemens-Schuckert flew the D.VI, their final aircraft design, in 1919.

Essentially a monoplane version of the earlier Siemens-Schuckert D.IV, the D.VI retained the exceptional rate of climb that had made its progenitor probably the best interceptor of the war and conferred upon it a useful increase in speed. The D.VI is also notable for being the only aircraft on this list powered by a rotary engine. Rotaries had been dominant as fighter powerplants in the mid-war period but had reached the limits of their development potential by 1919. The eleven cylinder Siemens-Halske Sh.III fitted to the D.VI represented the zenith of this engine type and its choice was no doubt influenced by its being built by the same parent company that made the airframe. By dint of an ingenious crank and gearing system, the torque that proved so deadly on other rotary powered aircraft such as the Sopwith Camel had been virtually eliminated and the high compression ratio meant that the Sh.III maintained an impressively high power output at altitude. As a straightforward development of a proven and formidable aircraft there is every chance the D.VI would have made for a potent fighter. As it turned out one of the prototypes was lost during testing and the other was unceremoniously burned to avoid it falling into Allied hands.

Germany had been notably more interested in the safety of their pilots than any of the other fighting powers – German fighter pilots were unique by the end of the war in that they were provided with parachutes. The D.VI continued this trend, its fuel tank was mounted externally and could be jettisoned if set on fire, giving the pilot a fighting chance to bring the aircraft safely down. Meanwhile pilots of all other nationalities could expect to burn to death in the event of their aircraft catching fire.  

2. Martinsyde F.4 Buzzard

The best British fighter aircraft of the war was doomed by bad timing to remain little more than a footnote in aviation history. Its success seemed assured with an order for 1450 from the RAF and several thousand more planned to be obtained or licence built by the US and France. A development of the earlier F.3, which despite excellent performance had been cursed by the non-availability of its preferred Rolls-Royce Falcon engine (which was required for the highly successful two-seat Bristol F.2b), the F.4 featured a modest redesign and mounted a more powerful Hispano-Suiza 8 delivering 300 hp. Thoroughly conventional, the Buzzard was well designed and sturdily built and its principle advantages lay in its colossal speed and exceptional rate of climb, both superior to any other British fighter.    

Delays in engine availability resulted in a mere 48 (or 57, depending on which source you believe) being delivered by the armistice, none of which made it to an operational squadron, though a handful were used by the Central Flying School. With the incredibly savage cutbacks to the RAF in the immediate postwar period, the Sopwith Snipe, an inferior aircraft in nearly every measurable performance parameter was selected as the RAF’s standard fighter, mainly because it was cheaper but also because it wasn’t powered by a foreign engine. Although, given the horrific debacle of the ABC Dragonfly, the fact that it was powered by a Hispano-Suiza rather than the benighted British radial would have counted massively in the Martinsyde’s favour if operational flying had continued into 1919. However all was not totally lost for Martinsyde, as the Buzzard enjoyed modest export success, ultimately flying in small numbers with the air forces of thirteen nations. Major users included Finland, Spain and the Soviet Union and eventually the creditable total of about 370 aircraft was built. 

Despite never serving its home nation operationally, it did see action with pro-treaty Free State forces during the Irish Civil war and despite being completely outdated performed limited operations during 1936 with the Republic Air force in the early stages of the Spanish Civil war. Amazingly Buzzards were used for training by Finland as late as 1940. Belgium was another potential export customer, the Belgian Air Force extensively tested an F.4 Buzzard as part of a competition to select a fighter to supplement their Fokker D.VIIs. The Buzzard lost out to the aircraft detailed below.

Like Sopwith, Martinsyde attempted to stave off postwar bankruptcy by manufacturing motorcycles. The motorcycles were excellent and quite successful but a factory fire in 1922 forced the company into liquidation. 

1. Nieuport 29 (later Nieuport-Delage Nid.29)

Winner of an exhaustive competition to select a replacement for the outstanding SPAD XIII, the Nieuport-Delage NiD-29 would have been built in enormous numbers had war continued. Even with the outbreak of peace over 1500 of these excellent machines were built, roughly half by Nieuport, 600 of them under licence by Nakajima in Japan with SABCA in Belgium and Macchi and Caproni in Italy building a few hundred more.

Nieuport’s chief designer Gustave Delage was the fighter king in 1916 and 17, with thousands of his diminutive sesquiplane fighters swarming through the skies. Nieuports were operated by all the Allied nations and built under licence in most of them. Captured examples even served the Central powers in significant numbers. By 1918 however SPAD had stolen the top spot; in November 1918 literally every operational single-seat fighter in the French air force was a SPAD. The competing Nieuport 28 had to suffer the ignominy of being rejected for service by its home nation and palmed off on the Americans. Delage and Nieuport had to come up with something special to regain their ascendency and the magnificent Nieuport 29, an aircraft that would prove to be the fastest and highest flying in the world, was the result. 

By the spring of 1918 Monsieur Delage had been tinkering with a succession of prototype fighters to replace the Nieuport 28 on the production line. When specifications were announced for a new fighter by the Section Technique de l’aéronautique (STAé) Delage took what the best of these prototypes and modified it further. First flown in mid-1918 (sources differ on the date) the Nieuport 29 competed with the SPAD XXI, the Martinsyde Buzzard, and the Sopwith Dolphin (in its Mk II form developed and built by SACA in France) to fulfil the new fighter requirement. All four aircraft were equipped with the same Hispano-Suiza 8fb 300 hp engine and all were impressive performers. At this stage the 29 proved the fastest of the competitors but the Buzzard demonstrated the best rate of climb. The Nieuport also failed to attain the altitude required in the original specification. Delage quickly increased the span of the new fighter and lightened the structure resulting in a significant increase in both ceiling and climb rate and in this form the Nieuport 29 was considered the best of the competing types.

Prudently the French ordered large production of all the entries except the poorest performer, the SPAD XXI. However the continuing success of the earlier SPAD XIII in service lent no great urgency to the development of the new aircraft types. Concurrent delays in production of the all-important Hispano-Suiza 8fb engine meant that by the armistice not a single Martinsyde nor Nieuport 29 had been delivered to the Armee de l’air Français, and only 20 or so Dolphins had been completed by SACA. The coming of peace led to an immediate wind-down of French aircraft requirements, orders for the British designed Buzzard and Dolphin were cancelled and development of the new Nieuport proceeded at a more leisurely pace.

And so the best French fighter to fly during the Great war finally entered service in 1922 as the Nieuport-Delage NiD-29, the change of name being considered necessary to distinguish the French company from its British offshoot Nieuport and General. It was the fastest fighter aircraft in service anywhere in the world.

In the intervening three years Nieuport-Delage had been far from idle, developing versions of the NiD.29 for both speed and altitude. The NiD.29V was the high-speed variant and was distinguishable from the standard NiD29 by its shortened wings. It set the first post-war official speed record with pilot  Joseph Sadi-Lecointe on February 7 1920 and later became the first aircraft to exceed 300 km/h in level flight. NiD.29Vs also won both the Coupe Deutsch de la Meurthe and Gordon Bennett cup air races in 1920. Meanwhile the NiD.40R, an extended span version with a Rateau turbocharger was piloted by Sadi-Lecointe to ever-greater heights culminating in a record of 11,145 m (36,565 ft) on October 30 1923. 

The military NiD.29s gave excellent, reliable service in France throughout the 1920s, equipping some 25 squadrons of the French air force, and three examples were used in combat during the Rif war in Morocco in 1925. The only other nation to use the NiD.29 operationally was Japan. Despite beginning withdrawal of their licence built version (the Nakajima Ko.4) in 1933, many were still in service when the Sino-Japanese conflict erupted in 1937 and saw brief service over Shanghai and Manchuria. A remarkable longevity of front-line service for a 1918 design.

Nieuport dropped the Delage name in 1932 after Gustave Delage’s retirement when it merged with the Loire aircraft company. Loire-Nieuport became a component part of the nationalised SNCAO concern in 1936.

Afterword:

If you want to see any of these aircraft in real life your best bet at present is to go to the Finnish Air Force Museum (Suomen Ilmavoimamuseo). There the sole remaining examples of the Martinsyde Buzzard and Gordou-Leseurre Type B are exhibited not just in the same location but the same room. The last surviving Nieuport-Delage NiD-29 is in the collection of the Musée de l’air in Paris but is not apparently on display at the moment. Sadly, not a single example of any of the other aircraft in this fascinating list has survived to the present day.