No. 48 Squadron was the first unit to take the Bristol Fighter to France, and its introduction to combat came in the worst month the Royal Flying Corps ever endured. On 5 April 1917 a patrol of six aircraft led by Captain William Leefe Robinson — the airman who had won the Victoria Cross for destroying a German airship over England in 1916 — ran into the Albatros scouts of Jasta 11, led by Manfred von Richthofen. Flying in the tight defensive formation appropriate to older two-seaters, the Bristols were unable to use their real strengths. Four of the six were shot down, and Leefe Robinson was forced down and taken prisoner. To observers it looked as though the new “fighter” was no better than the machines it replaced. The truth was almost the opposite: the aircraft was superb, but the tactics were wrong, and the price of learning that was paid in the first days of April 1917.

Within weeks of the disaster, pilots began to work out what the Bristol Fighter really was. It was strong, it was fast, and with the Falcon it climbed and manoeuvred like a scout. The men who survived started to fly it as one: turning to bring the fixed Vickers to bear, diving and zooming aggressively, treating the observer’s gun as insurance against attack from behind rather than as the primary weapon. The change in results was dramatic. Squadrons that had dreaded the type began to rack up victories, and German pilots — who had briefly thought the Bristol easy prey — learned to be extremely wary of it. It is one of the clearest examples in air warfare of a weapon whose potential was unlocked not by engineering but by doctrine.

The most successful Bristol Fighter pilot of the war was the Canadian Andrew Edward McKeever of No. 11 Squadron, credited with roughly 31 aerial victories — an extraordinary total for a two-seater and more than many single-seat aces achieved. McKeever fought his Bristol exactly as the type demanded: offensively, using the front gun as his main weapon and coordinating with his observers, among them Leslie Powell, to deal with anything that got behind. On one celebrated occasion the pair took on a much larger formation of German aircraft and fought their way clear. McKeever’s record was the emphatic answer to Bloody April: in the right hands, the Bristol Fighter was one of the deadliest aircraft in the sky.

Attacking German pilots developed a healthy respect for the Bristol Fighter’s rear cockpit. The observer sat behind the pilot with one or two Lewis guns mounted on a Scarff ring — a spring-balanced rotating mount that let him swing his fire quickly through a wide arc and elevate it to cover the whole rear hemisphere. A scout diving on what looked like a slow two-seater could find itself flying straight into a stream of .303 fire from an alert observer while the pilot hauled the nose round to add the fixed Vickers. Good crews worked as a team, the observer calling threats and clearing the tail while the pilot pressed the attack. It was this cooperation, more than any single feature, that gave the aeroplane its lethal reputation.

Everything good about the Bristol Fighter began with its engine. The Rolls-Royce Falcon was a compact liquid-cooled V12, a smaller relative of the Eagle, giving about 275 horsepower in its Falcon III form. It was smooth, reliable and powerful enough to make a two-seater fight like a scout. But Rolls-Royce built engines slowly and to exacting standards, and Falcon output never matched the number of airframes coming off the lines. That shortage forced the fitting of inferior substitute engines to many aircraft and was, by common agreement, the single greatest limitation on the type — a limitation of industry, not of design.

To keep production moving in the face of the Falcon shortage, many Bristol Fighters were completed with the Sunbeam Arab, an engine of nominally around 200 horsepower, or with Hispano-Suiza units. The Arab was persistently troubled by vibration and reliability problems that were never really solved, and aircraft fitted with it were markedly inferior to the Falcon-engined machines: slower, less pleasant to fly and less trusted by their crews. These under-powered examples unfairly coloured some early judgements of the design. The consistent verdict of historians is to judge the Bristol Fighter by its Falcon form — the substitutes were a wartime compromise, not the aircraft Barnwell built.

The Bristol Fighter did not only serve over the trenches. Home Defence squadrons in Britain used it against the German bombing raids of 1917–18, when Gotha and Giant aircraft — and, earlier, airships — attacked London and the south-east. Its combination of a good climb, endurance and two guns made it a useful night and day interceptor at a time when catching a fast bomber over a blacked-out country was desperately hard. The type’s association with home defence was fitting: its most famous early pilot, Leefe Robinson, had won his Victoria Cross shooting down an airship over England before he ever flew a Bristol.

Far from the mud of Flanders, Bristol Fighters served in the Middle East, where No. 1 Squadron of the Australian Flying Corps flew them in support of the advance through Sinai and Palestine in 1918. The dry, open theatre suited the aeroplane’s range and ruggedness. Among the pilots was Ross Smith, later to become famous for the first flight from England to Australia; photographs by the war photographer Frank Hurley captured him and his Bristol against the desert landscape. In this theatre the type ranged widely on reconnaissance, escort and ground-attack work, harrying retreating columns and helping to establish the air superiority that contributed to the collapse of the Ottoman armies.

After the war the RAF adopted a policy of “air control” — using aircraft to police remote and rebellious territories cheaply. The Bristol Fighter, rugged and easy to maintain, became the standard army-cooperation aircraft for this work. It flew from dusty strips in Iraq, over the mountains of India’s North-West Frontier and across the Middle East, carrying out reconnaissance, message-dropping, light bombing and support of ground columns. The role was often grim and politically controversial, but it kept the type in demanding front-line service for well over a decade — a longevity almost unheard of for an aeroplane designed in 1916. It is a large part of why so many Bristol Fighters were built.

The Bristol Aeroplane Company’s works at Filton, near Bristol, were the heart of production, but demand far outstripped what one firm could supply and a network of sub-contractors built airframes as well. Estimates of the total vary — figures from about 5,300 upward are commonly quoted — and production continued after the Armistice to meet the needs of the peacetime RAF and export customers, which is one reason the totals are hard to pin down. Whatever the exact number, the Bristol Fighter was built in quantities that put it among the most numerous British aircraft of its generation, and enough survived in service and in store to keep the type flying for many years.

Of the thousands built, one genuine Bristol Fighter is kept in flying condition today: D8096, an F.2B operated by the Shuttleworth Collection at Old Warden in Bedfordshire. Restored to fly with a Rolls-Royce Falcon engine, it is one of the very few airworthy aircraft of its type and era anywhere in the world, and it appears at Shuttleworth’s flying displays where the public can watch and hear a real First World War Bristol Fighter in the air. It is important to be clear about what this is and is not: D8096 is a priceless historic aircraft flown by its custodians for display, not a machine you can book a ride in. Seeing it fly is the closest anyone can come to the real thing.

Very few aircraft designed in 1916 were still doing useful front-line work in 1932, but the Bristol Fighter was. Its secret was a combination of virtues: a strong, repairable airframe; the fine Rolls-Royce Falcon engine; genuine fighter performance; and honest, forgiving handling that suited both a raw wartime pilot and a peacetime frontier squadron. It could fight, reconnoitre, escort, bomb lightly and police a colonial territory, and it could be kept flying with the tools and skills of a modest field workshop. That versatility, more than any single record, is the measure of the design — and the reason the “Brisfit” is remembered as one of the great aeroplanes of the First World War.