Royal Aircraft Factory S.E.5

The Royal Aircraft Factory S.E.5 was a British biplane fighter aircraft of the First World War.

The first examples reached the Western Front before the Sopwith Camel. Although it had a much better overall performance than the Camel, problems with its Hispano-Suiza engine, particularly the geared-output H-S 8B-powered early versions, meant that there was a chronic shortage of S.E.5s until well into 1918 and fewer squadrons were equipped with the S.E.5 than with the Sopwith fighter. Together with the Camel, the S.E.5 was instrumental in regaining allied air superiority in mid-1917 and maintaining it for the rest of the war, ensuring there was no repetition of "Bloody April" 1917 when losses in the Royal Flying Corps were much heavier than in the Luftstreitkräfte.

Royal Aircraft Factory S.E.5
Class Aircraft
Type Fighter
Manufacturer Royal Aircraft Establishment
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1916
Country Name Operational Year Retirement Year
Argentina View
Australia View
Canada View
Chile View
Ireland View
Poland View
South Africa View
United Kingdom - UK (Great Britain) 1917 1919 View
United States of America View
ManufacturerName Production From Production To Quantity
Royal Aircraft Establishment 5265 View

The S.E.5 (Scout Experimental 5) was designed by Henry Folland, John Kenworthy and Major Frank Goodden of the Royal Aircraft Factory in Farnborough. It was built around the new 150 hp (112 kW) Hispano-Suiza 8 a V8 engine that, while providing excellent performance, was initially underdeveloped and unreliable. The first of three prototypes flew on 22 November 1916. The first two prototypes were lost in crashes (the first killing the chief test pilot at the Royal Aircraft Factory, Major F. W. Goodden on 28 January 1917) due to a weakness in their wing design. The third prototype underwent modification before production commenced; the S.E.5 was known in service as an exceptionally strong aircraft which could be dived at very high speed – the squarer wings also gave much improved lateral control at low airspeeds.

Like the other significant Royal Aircraft Factory aircraft of the war (B.E.2, F.E.2 and R.E.8) the S.E.5 was inherently stable, making it an excellent gunnery platform, but it was also quite manoeverable. It was one of the fastest aircraft of the war at 138 mph (222 km/h), equal at least in speed to the SPAD S.XIII and faster than any standard German type of the period.

While the S.E.5 was not as agile and effective in a tight dogfight as the Camel it was much easier and safer to fly, particularly for novice pilots. The S.E.5 had one synchronised .303-inch Vickers machine gun to the Camel's two, but it also had a wing-mounted Lewis gun on a Foster mounting, which enabled the pilot to fire at an enemy aircraft from below as well as providing two guns firing forward. This was much appreciated by the pilots of the first S.E.5 squadrons as the new hydraulic-link "C.C." synchronising gear for the Vickers was unreliable at first. The Vickers gun was mounted on the forward left dorsal surface of the fuselage with the breech inside the cockpit, at a slight upwards angle. The cockpit was set amidships, making it difficult to see over the long front fuselage, but otherwise visibility was good. Perhaps its greatest advantage over the Camel was its superior performance at altitude, making it a much better match for the Fokker D.VII when that fighter arrived at the front.

S.E.5a

Only 77 original S.E.5 aircraft were built before production settled on the improved S.E.5a. The initial models of the S.E.5a differed from late production examples of the S.E.5 only in the type of engine installed – a geared 200 hp Hispano-Suiza 8b, often turning a large clockwise-rotation four-bladed propeller, replacing the 150 hp H.S. 8A model. In total 5,265 S.E.5s were built by six manufacturers: Austin Motors (1,650), Air Navigation and Engineering Company (560), Curtiss (1), Martinsyde (258), the Royal Aircraft Factory (200), Vickers (2,164) and Wolseley Motors Limited (431). A few were converted to two-seat trainers and there were plans for Curtiss to build 1,000 S.E.5s in the United States but only one was completed before the end of the war. At first, airframe construction outstripped the very limited supply of French-built Hispano-Suiza engines and squadrons earmarked to receive the new fighter had to soldier on with Airco DH 5s and Nieuport 24s until early 1918. The troublesome geared "-8b" model was prone to have serious gear reduction system problems, sometimes with the propeller (and even the entire gearbox on a very few occasions) separating from the engine and airframe in flight, a problem shared with the similarly-powered Sopwith Dolphin.

The introduction of the 200 hp (149 kW) Wolseley Viper, a high-compression, direct-drive version of the Hispano-Suiza 8a made under licence by Wolseley Motors Limited, solved the S.E.5a's engine problems and was adopted as the standard powerplant.

About 38 of the late-production Austin-built S.E.5as were assigned to the American Expeditionary Force, with the 25th Aero Squadron getting its aircraft (mostly armed only with the fuselage-mounted Vickers gun) at the very end of the war.

S.E.5b

The S.E.5b was a variant of the S.E.5 with a streamlined nose and upper and lower wings of different span and chord. The single example, a converted S.E.5a, first flew in early April 1918. It had a spinner on the propeller and a retractable under-slung radiator. The S.E.5b was not a true sesquiplane – as the lower wing had two spars. Its performance was little better than the S.E.5a – the increased drag from the large upper wing seems to have cancelled out any benefit from the better streamlined nose. The S.E.5b was not considered for production; probably it was always intended mainly as a research aeroplane. In January 1919 it was tested with standard S.E.5a wings and in this form survived as a research aircraft into the early twenties.

Variants

S.E.5 : First production version. Single-seat fighter biplane, powered by a 150 hp (112 kW) Hispano-Suiza 8a piston engine.

S.E.5a : Improved production version, powered by a 200 hp (149 kW) Hispano-Suiza 8b V-8 or 200 hp (149 kW) Wolseley Viper piston engine.

S.E.5b : Experimental prototype, with semi-sequiplane wings, streamlined nose and retractable radiator.

Eberhart S.E.5e : S.E.5a assembled from spare parts by American company Eberhart Aeroplane, 180 hp Wright-Hispano E engine and plywood-covered fuselages, about 60 built. 


The S.E.5 entered service with No. 56 Squadron RFC in March 1917, although the squadron did not deploy to the Western Front until the following month. Everyone was suspicious of the large "greenhouse" windscreens fitted to the first production models. These were designed to protect the pilot in his unusually high seating position, which was in turn intended to improve vision over the upper wing. The squadron did not fly its first patrol with the S.E.5 until 22 April, by which time, on the insistence of Major Blomfield, 56 squadron's commanding officer, all aircraft had been fitted with small rectangular screens of conventional design. The problem of the high seating position was solved by simply lowering it, pilots in any case preferring a more conventional (and comfortable) seating position. No complaints seem to have been made about the view from the cockpit, in fact this was often cited as one of the strong points of the type.

While pilots, some of whom were initially disappointed with the S.E.5, quickly came to appreciate its strength and fine flying qualities, it was universally held to be underpowered, and the more powerful S.E.5a began to replace the S.E.5 in June.

At this time 56 Squadron was still the only unit flying the new fighter; in fact it was the only operational unit to be fully equipped with the initial 150 hp S.E.5 – all other S.E.5 squadrons officially used the 200 hp S.E.5a from the outset – although a few S.E.5s were issued to other squadrons due to an acute shortage of the S.E.5a. This shortage resulted in a very slow initial buildup of new S.E.5a squadrons, and lasted well into 1918. Once the Wolseley Viper-powered model became plentiful many more units re-equipped, until by the end of the war the type was employed by 21 British Empire squadrons as well as two U.S. units. Many of the top Allied aces flew this fighter, including Billy Bishop, Andrew Beauchamp-Proctor, Edward Mannock and James McCudden. Legendary British ace Albert Ball was initially disparaging of the S.E.5, but in the end claimed 11 of his 44 victories flying it. McCudden wrote of the S.E.5 "It was very fine to be in a machine that was faster than the Huns, and to know that one could run away just as things got too hot."

Sholto Douglas who commanded No. 84 Squadron RFC which was initially equipped with the S.E.5a, listed the type's qualities as:

  •     Comfortable, with a good all-round view
  •     Retaining its performance and manoeuvrability at high level
  •     Steady and quick to gather speed in the dive
  •     Capable of a very fine zoom
  •     Useful in both offence and defence
  •     Strong in design and construction
  •     Possessing a reliable engine

Some S.E.5s remained in RAF service after the Armistice, but began to be withdrawn soon afterwards. The type continued in service for a time in Australia and Canada, and in 1921 a Viper-engined S.E.5a was taken to Japan by the British Aviation Mission to the Imperial Japanese Navy.

A number of machines found roles in civilian flying after the war. The first use of skywriting for advertising was on 30 May 1922, when Cyril Turner, a former RAF officer, spelt out "London Daily Mail" in black smoke from an S.E.5a at the Epsom Derby.[7] Others were used for air racing; an example won the Morris Cup race in 1927.

Role Single-seat fighter
Manufacturer various (see text)
Designer Henry Folland / John Kenworthy
First flight 22 November 1916
Introduction March 1917
Primary users Royal Flying Corps
United States Army Air Service
Royal Australian Air Force
Royal Canadian Air Force
Number built 5,205


General characteristics

  • Crew: One
  • Length: 20 ft 11 in (6.38 m)
  • Wingspan: 26 ft 7 in (8.11 m)
  • Height: 9 ft 6 in (2.89 m)
  • Wing area: 244 ft (22.67 m)
  • Empty weight: 1,410 lb (639 kg)
  • Loaded weight: 1,935 lb (880 kg)
  • Max takeoff weight: 1,988 lb (902 kg)

Performance

  • Maximum speed: 138 mph (222 km/h)
  • Range: 300 miles (483 km)
  • Service ceiling 17,000 ft (5,185 m)
  • Wing loading: lb/ft (kg/m)

Armament

  • 1x 0.303 in (7.7 mm) forward-firing Vickers machine gun with Constantinesco interrupter gear
  • 1x .303 in (7.7 mm) Lewis gun on Foster mounting on upper wing
  • 4x 18kg Cooper bombs, two under each lower wing, to be dropped in 2, 3, 4, 1 order.

End notes