World War I: RAF S.E.5

RAF SE5a fighters
S.E.5a aircraft of No. 32 Squadron RAF. Public Domain

One of the most successful aircraft used by the British in World War I (1814-1918), the Royal Aircraft Factory S.E.5 entered service in early 1917. A reliable, stable gun platform, the type soon became the favored aircraft of many notable British aces. The S.E.5a remained in use through the end of the conflict and was retained by some air forces into the 1920s.

Design

In 1916, the Royal Flying Corps issued a call to the British aircraft industry to produce a fighter that was superior in all respects to any aircraft currently in use by the enemy. Answering this request were the Royal Aircraft Factory at Farnborough and Sopwith Aviation. While discussions began at Sopwith which led to the legendary Camel, R.A.F.'s Henry P. Folland, John Kenworthy, and Major Frank W. Goodden began working on a design of their own.

Dubbed the Scout Experimental 5, the new design utilized a new water-cooled 150-hp Hispano-Suiza engine. In devising the rest of the aircraft, the team at Farnborough crafted a tough, square-rigged, single seat fighter capable of enduring high speeds during dives. Increased durability was achieved through the use of a narrow, wire braced, box-girder fuselage which improved pilot vision while also ensuring a higher rate of survivability in crashes. The new type was initially powered by a Hispano-Suiza 150 HP V8 engine. Construction of three prototypes began in the fall of 1916, and one flew for the first time on November 22. During testing, two of the three prototypes crashed, the first killing Major Goodden on January 28, 1917.

Development

As the aircraft was refined, it proved to possess high speed and maneuverability, but also had excellent lateral control at lower speeds due to its square wingtips. As with previous R.A.F. designed aircraft, such as the B.E. 2, F.E. 2, and R.E. 8, the S.E. 5 was inherently stable making it an ideal gun platform. To arm the aircraft, the designers mounted a synchronized Vickers machine gun to fire through the propeller. This was partnered with a top wing-mounted Lewis gun which was attached with a Foster mounting. The use of the Foster mount permitted pilots to attack enemies from below by angling the Lewis gun upwards and simplified the process of reloading and clearing jams from the gun.

Royal Aircraft Factory S.E.5 - Specifications

General:

  • Length: 20 ft. 11 in.
  • Wingspan: 26 ft. 7 in.
  • Height: 9 ft. 6 in.
  • Wing Area: 244 sq. ft.
  • Empty Weight: 1,410 lbs
  • Loaded Weight: 1,935 lbs.
  • Crew: 1

Performance:

  • Power Plant: 1 x Hispano-Suiza, 8 cylinders V, 200 HP
  • Range: 300 miles
  • Max Speed: 138 mph
  • Ceiling: 17,000 ft.

Armament:

  • 1 x 0.303 in. (7.7 mm) forward-firing Vickers machine gun
  • 1x .303 in. (7.7 mm) Lewis gun
  • 4x 18 kg Cooper bombs

Operational History

The S.E.5 began service with No. 56 Squadron in March 1917, and deployed to France the following month. Arriving during "Bloody April," a month that saw Manfred von Richthofen claim 21 kills himself, the S.E.5 was one of the aircraft that aided in reclaiming the skies from the Germans. During its early career, pilots found that the S.E.5 was under-powered and voiced their complaints. Famed ace Albert Ball stated that the "S.E.5 has turned out a dud." Quickly moving to address this issue, R.A.F. rolled out the S.E.5a in June 1917. Possessing a 200-hp Hispano-Suiza engine, the S.E.5a became the standard version of the aircraft with 5,265 produced.

The improved version of the aircraft became a favorite of British pilots as it provided excellent high-altitude performance, good visibility, and was much easier to fly than the Sopwith Camel. Despite this, production of the S.E.5a lagged behind that of the Camel due to production difficulties with the Hispano-Suiza engine. These were not resolved until the introduction of the 200-hp Wolseley Viper (a high-compression version of the Hispano-Suiza) engine in late 1917. As a result, many squadrons slated to receive the new aircraft were forced to soldier on with older types.'

A Favorite of the Aces

Large numbers of the S.E.5a did not reach the front until early 1918. At full deployment, the aircraft equipped 21 British and 2 American squadrons. The S.E.5a was the aircraft of choice of several famed aces such as Albert Ball, Billy Bishop, Edward Mannock, and James McCudden. Speaking of the S.E.5a's impressive speed, McCudden noted that "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." Serving until the end of the war, it was superior to the German Albatros series of fighters and was one of the few Allied aircraft that was not outclassed by the new Fokker D.VII in May 1918.

Other Uses

With the end of the war that fall, some S.E.5as were briefly retained by the Royal Air Force while the type continued to be used by Australia and Canada into the 1920s. Others found second lives in the commercial sector. In the 1920s and 1930s, Major Jack Savage retained a group of S.E.5as which were used to pioneer the concept of skywriting.  Others were modified and improved for use in air racing during the 1920s.

Variants & Production:

During World War I, the S.E.5 was produced by Austin Motors (1,650), Air Navigation and Engineering Company (560), Martinsyde (258), the Royal Aircraft Factory (200), Vickers (2,164) and Wolseley Motor Company (431). All told, 5,265 S.E.5s were built, with all but 77 in the S.E.5a configuration. A contract for 1,000 S.E.5as was issued to the Curtiss Aeroplane and Motor Company in the United States, however only one was completed before the end of hostilities.

As the conflict progressed, R.A.F. continued development of the type and unveiled the S.E.5b in April 1918.  The variant possessed a streamlined nose and spinner on the propeller as well as a retractable radiator. Other alterations included the use of single bay wings of unequal cord and span and a more streamlined fuselage. Retaining the armament of the S.E.5a, the new variant did not show significantly improved performance over the S.E.5a and was not selected for production. Testing later found that drag caused by the large upper wing offset the gains made by the sleeker fuselage.