Monday, July 11, 2011

Britain - 1915 Vickers F.B.5 Gunbus

The World's First Operational Fighter

Purpose built fighters entered production in 1915. Although this type of aircraft was still referred to as light scouts they were intended for air to air combat. Compared to later planes they were slow, fragile, and had their share of faults. However for their day they were state of the art and lethal in combat. The twin gun version of the Fokker Eindecker spelled the end of the Gunbus as a front-line fighter, relegating it to the ranks of training aircraft.

The Vickers F.B.5 (Fighting Biplane 5) was the first aircraft specifically designed for air-to-air combat to see service as a fighter for the Royal Flying Corps, making it the world's first operational fighter aircraft. With its engine mounted behind the cockpit, it the first pusher to enter service during World War I. Commonly referred to as the "Gunbus," it was armed with a moveable, forward firing 0.303 in (7.7 mm) Lewis Gun operated by the observer in the front of the nacelle. Vulnerable to attack from the rear, the Gunbus was soon replaced by more advanced single-seat fighter aircraft. Lionel Rees scored more victories with this aircraft than any other ace. In 1915, he and his gunner downed six enemy planes while flying the F.B.5.

Vickers began experimenting with the concept of an armed warplane designed to destroy other aircraft in 1912. The first resulting aircraft was the Type 18 "Destroyer" (Vickers E.F.B.1) which had been demonstrated in 1913. This aircraft was of the "Farman" pusher layout, to avoid the problem of firing through a tractor propeller, and was armed with a single belt-fed Maxim gun. The belt feed proved problematic for a flexible machine gun, and the weapon installed was changed to the lighter, handier, drum-fed 0.303 in (7.7 mm) Lewis gun. The E.F.B.1 was the first in a line of Vickers' "Experimental Fighting Biplanes", of which the F.B.5 was the most famous - and the first to be built in quantity.

The F.B.5 first flew on 17 July 1914. It was powered by a single 100 hp (75 kW) Gnome Monosoupape 9-cylinder rotary engine driving a two-bladed propeller, and was of simple, clean, and conventional design compared with its predecessors. In total, 224 F.B.5s were produced, 119 in Britain by Vickers, 99 in France and 6 in Denmark.

The first F.B.5 was delivered to No. 6 Squadron of the Royal Flying Corps (RFC) at Netheravon in November 1914. On 25 December 1914, the first use of the F.B.5 in action took place, when a F.B.5 took off from Joyce Green airfield to engage a German Taube monoplane, hitting the Taube (and possibly causing its loss) with incendiary bullets from a carbine after the Lewis gun jammed.

The F.B.5 began to be seen on the Western Front when the first examples reached No.2 Squadron RFC on 5 February 1915. The type served in ones and twos with several other units before No. 11 Squadron RFC became the world's first fighter squadron when, fully equipped with the F.B.5, it deployed to Villers-Bretonneux, France on 25 July 1915. Second Lieutenant G.S.M. Insall of 11 Squadron won the Victoria Cross for an action on 7 November 1915 in which he destroyed a German aircraft while flying a Gunbus. No. 18 Squadron RFC, which deployed to France in November 1915, also operated the F.B.5 exclusively.

The F.B.5's performance proved to be inadequate for its intended role; although its forward-firing machine gun was a great advantage, the fighter did not have the speed or rate of climb to pursue its quarry. By the end of 1915, it was outclassed by the Fokker Eindecker. Some examples of the improved Vickers F.B.9 were sent to France, pending sufficient supplies of the Royal Aircraft Factory F.E.2b, but the active career of the Gunbus was soon over. The remaining examples were mostly used as trainers.

The Vickers company persisted with an active experimental program during the First World War period, including a line of single-seat pusher fighters, but the F.B.5 remained their only significant production aircraft until the Vickers Vimy bomber, which entered service too late to have an impact on the war.

Despite its moderate effectiveness, the Vickers F.B.5 did have a lasting legacy as German pilots continued to refer to British pusher aircraft as "Vickers-types". Many victories over D.H.2 or F.E.2b pushers were reported as destruction of a "Vickers".


  1. From Wikipedia Vickers F.B.5, ""
  2. Andrews, C.F. and Morgan, "E.B. Vickers Aircraft since 1908". London:Putnam, 1988. ISBN 0 85177 815 1.
  3. Bruce, J.M. "Vickers' First Fighters". Air Enthusiast No 12, April -July 1980. pp.54-70. ISSN 0143-5450.
  4. Gutmann, Jon and Dempsey, Harry. "Pusher Aces of World War 1". Osprey Pub Co, 2009. ISBN 1846034175, 9781846034176.


Jon Yuengling said...

It might just be me, but, why have a second crew member when you could lose him and add a second fixed machine gun?

Unknown said...

Part of the reason may be that it would change the aircraft's geometry, the design was configured for a longer 2 seat arrangement. changing the mix might have changed the balance.

Another possible reason is the Lewis gun was mounted on a pivoting gun mount and they did not think the pilot would be able to fly the aircraft, aim and fire, reload the ammunition canisters and clear any jams at the same time.

Another reason might have been because of the weight of the extra ammunition which would have been needed. Not only do you need to lift the extra gun, you had to lift twice the ammunition load. Given the lack of power of engines of the day it might just not have been practical. Since most rounds were expended without hitting anything. adding an extra gun would have meant you would use twice the ammunition without gaining much more lethality.

We are looking at a period when very little was known about combat tactics and aircraft design.

Add the fact that the they needed aircraft immediately and redesigns would postpone deliveries you fought with what you had not what you wished you did.

This is just my opinion, but it seems to be based on the state of the art in aviation. However I may be wrong.