In the interwar period, and indeed during WW2 itself, numerous attempts were made at
designing an aircraft that could attack a formation of bombers from below.
Of these attempts, the Vickers Type 161 – also known as the COW Gunfighter, was perhaps one
of the weirdest.
In the late 1920s members of the British Air Ministry were divided on the topic of bomber
formations, specifically how to attack them.
One group was of the firm belief that large formations of bombers would always need escort
fighters, the other believed that bomber defences were becoming sufficient enough that large,
organised formations could provide enough defensive fire between them.
Understandably, the Air Ministry assumed that the same kinds of arguments were likely happening
across the Channel in France and Germany.
This in turn meant that they had to plan for the possibility of engaging large, unescorted
formations of bombers in a hypothetical war in the future.
As these hypothetical bomber formations would be unescorted, they could afford to develop
an interceptor with a focus on outright firepower rather manoeuvrability.
This resulted in the issuing of specification F.29/27, which called for an interceptor capable
of carrying the 37mm Coventry Ordnance Works cannon – often known simply as the cow gun.
Along with being able to carry said gun, the aircraft also needed to be able to rapidly
overtake an enemy aircraft flying at 150mph at 20,000ft in the shortest possible time,
and maintain enough stability to serve as a gun platform.
This stability was especially important as the gun would be in a fixed position, firing
up at an elevation of at least 45 degrees.
To reduce complexity, reloading would not be necessary as the gun would be fed by a
loading system that held 50 shells.
Tenders for this specification were issued to several aircraft manufacturers, one of
them being Vickers.
Their design, dubbed the type 161, was one of the most unorthodox and was a call back
to the early single-seat pusher fighters of the first world war.
Though that might make their design sound archaic, it was in many ways ahead of its
time.
Broadly speaking, this sort of design would feel a lot more at home during the Jet era
- discounting the fact that it was a biplane.
What Vickers had designed was a plane that had a nose-mounted cannon, a pilot positioned
far forward, a central engine within the confines of the fuselage (more or less), and one that
provided its thrust in a pusher configuration.
Its uniqueness certainly caught the attention of the air ministry, who eventually rejected
four of the seven proposals they received.
They took great interest in the structural design of Vickers new plane, which among other
innovations included concealed control wires that were carried inside the tubular tail
booms for added protection.
As a result, a contract for the production of a prototype model was granted, and it was
completed at the end of 1930.
It was built as an unequal span biplane.
The wings were arranged with a heavy stagger, had a tubular support structure and were clad
in duraluminium.
Support with the fuselage was provided by single tube K-struts in a two-bay arrangement,
and the wings themselves were connected by two pairs of I-struts.
To produce the high amount of climb required they were built with a high aspect ratio,
and to prevent this causing interference between the upper and lower wings, the gap between
them was kept as wide as possible.
As the upper wing also had to be kept relatively low on account of the cannon, the type 161s
wing configuration looked especially weird upon its completion.
The central fuselage behind the engine…was not really a fuselage.
It was in fact a large fuselage-like fairing, with the actual tail support being provided
by the twin tail booms.
To improve aerodynamics and streamlining, the propellers were mounted in a sort of spinner-fairing
that matched the slope profile of the fairing that connected to the tail.
This would prove to be a good move, as eventual tests with the National Physical Laboratory
showed that it added a few mph to the planes top speed.
The pilot and gun were housed in a metal monocoque nacelle, this had a smooth outer skin with
a corrugated inner skin riveted directly to it.
This was to withstand the severe shocks expected from the big gun, which for the time was certainly
on the larger side of things for this sort of aircraft.
The combat strategy for using said gun was to fly up and under a formation of bombers,
hope that they don’t notice the interceptor and scatter, and then unload high explosive
shells into their weak undersides.
An optimistic strategy perhaps, but one that was being pursued nonetheless.
In January 1931 the aircraft flew for the first time.
On the whole it went well, but some modifications were made to improve its elevator and yaw
stability.
Around this time, it was fitted with elevator trim tabs that could be adjusted in flight,
which would mark one of the first appearances of such a device.
Further flight trials resulted in other modifications, which included a broader-chord rudder, a new
tailskid shoe, alterations to the geometry and gearing of the trim tabs, and the addition
of small fins near the extremities of the tailplane.
Eventually the aircraft was sent to Martlesham heath for evaluation trials in September.
Apart from a couple of incidents, such as a loose propeller fairing and broken wires
in the tail-boom caused by loose stones thrown up by the propeller, the trials were without
incident and Vickers aircraft was reviewed favourably by its pilots.
The gun was fired in armament trials without much noticeable effect on the airframe and
flying performance.
However, the gunnery trials did reveal that the overall workload on the single crew member
was a bit…well, it was a bit much.
The gun/plane combination was sighted to its target using a periscope sight, this sight
was mounted on the left side of the centre control panel.
The gun itself kept the pilot company on the starboard side of the cockpit, complete with
its huge, automatically fed ammunition clips which were stored in racks.
This meant the cockpit was very cramped, and bailing out safely under certain circumstances
may have proven to be an issue.
This meant that not only did the pilot have to navigate the plane underneath a formation
of bombers…all the while hoping that they don’t take notice, but he would then have
to keep it steady whilst simultaneously having his right eardrum blown out by a bovine-themed
cannon attempting the aerial equivalent of a raking fire.
This migraine-inducing complexity was probably the main reason why further development of
the type 161 was stopped.
However, the concept of an interceptor mounting upward firing guns would live on, though the
COW gun would never be implemented in such a configuration.
With hindsight, and considering the later development of proximity fuses, its argued
that night-fighters with that sort of armament could have delivered some heavy blows during
the Battle of Britain…but that will always remain a speculative ‘what if?’.
Despite its failure, the short-lived development of the type 161 would set the Air Ministry
down the path towards another weird, but more iconic, interceptor: the Boulton-Paul Defiant.
But that…isn’t a story for another day as I’ve already covered it!
However stay tuned for more weird and wonderful planes in the future.
As always thank you all so much for watching, and I’ll catch you all next time.
Goodbye.