Vickers Type 161

Vickers Type 161

Company type	Interceptor aircraft
Industry	Aviation, Military aircraft
Founded	1931
Headquarters	United Kingdom
Products	Military aircraft

The Vickers Type 161 was a distinctive pusher biplane interceptor from the 1930s, engineered to engage enemy aircraft by firing a single large-calibre gun angled upwards from below. Although the aircraft demonstrated satisfactory flight characteristics, the concept was ultimately discontinued after producing only one unit.

Development

The Vickers 161 was created in response to Air Ministry specification F.29/27, which demanded an interceptor capable of serving as a stable platform for the Coventry Ordnance Works (COW) 37 mm gun, known for firing shells weighing 23 oz (0.65 kg). The gun was intended to be mounted at an elevation of 45 degrees or more above the horizontal plane, enabling the aircraft to position itself beneath enemy bombers or airships and fire upward into their vulnerable undersides. This tactic bears resemblance to the Luftwaffe's Schräge Musik system used during World War II. Additionally, the specification required a top speed significantly exceeding that of typical bombers' cruising speeds and a strong climb rate.

Vickers appeared to draw inspiration from their First World War experience with the Gunbus series, as the Type 161 shared its single-engine pusher biplane configuration. The design featured unequal-span wings with parallel chords, arranged with pronounced stagger and a substantial gap between them, supported by streamlined I-shaped interplane struts leaning outward in a two-bay arrangement. The tail structure consisted of parallel booms formed by pairs of tubular members on each side, converging from the top and bottom of the inner interplane struts toward the tail assembly. Another set of tubes connected the bottom of the interplane struts to the midpoint of the upper boom. The tailplane extended well beyond the booms, while the vertical stabilizer and rudder were conventional in shape, reinforced with lighter bracing attached midway along the booms. All flying surfaces were covered in fabric.

The cockpit and gun were housed within a metal monocoque nacelle fixed beneath the upper wing, leaving an open space below. The pilot's seat was offset to port side, with the gun positioned to his right, allowing easy access to its breech. Power came from a Bristol Jupiter VIIF engine mounted so that its cylinders aligned with the trailing edge of the upper wing, supported by two pairs of struts connecting to the lower wing spars and driving a four-blade propeller. This propeller featured a unique rotating ring fairing that matched the diameter of the engine cowling. Extending aft without interruption was a fuselage-like fairing tapering toward the tail, stabilized on each side by pairs of struts linking it to both upper and lower booms. The landing gear employed a split-axle design with legs attached to both the nacelle and forward wing spar, reinforced by a strut connecting their upper joints.

The Type 161 took to the air for its maiden flight on 21 January 1931. Subsequent test flights led to modifications aimed at enhancing yaw stability; these included enlarging and rounding off the rudder's top section and adding small fins above and below the tailplane at its boom attachment points. Adjustments were also made to the elevator trim tabs' geometry and control gearing—some suggest this may have been among the earliest instances of inflight adjustable elevator trims. In September 1931, it underwent trials at RAF Martlesham Heath where it performed reliably and pilots reported favorable handling characteristics. Tests involving firing the gun showed no adverse effects on structural integrity or flight performance. Despite these positive outcomes, neither this aircraft nor its competitor—the Westland C.O.W. Gun Fighter—received production orders, leading to the discontinuation of aerial deployment for the COW gun concept.

References

• Andrews, C. F.; Morgan, E. B. (1988). Vickers Aircraft since 1908 (2nd ed.). London: Putnam. ISBN 0-85177-815-1.