Vickers Vellox

Vickers

Industry	Aerospace
Founded	1911
Headquarters	United Kingdom
Products	Aircraft

The Vickers Vellore was a sizeable biplane crafted primarily for carrying mail and freight, available in both single-engine and twin-engine configurations. It experienced limited deployment as a cargo transporter and as a platform for extended-range experimental flights. The final iteration, featuring a wider fuselage, was designated the Vellox and completed as a passenger airliner.

Development

Named after the Indian city of Vellore, the Vickers Vellore was developed in response to Air Ministry specification 34/24, which sought a civil aircraft capable of transporting mail and cargo. This large single-engine biplane had two bays, constructed with a metal frame covered in fabric. Its wings were equal in span, exhibiting slight stagger and sweep, supported by parallel interplane struts. Balanced ailerons were installed on both the upper and lower wings. The fuselage featured gaps above and below, with its diameter expanding aft of the radial engine. The open cockpit accommodated the crew seated side by side just ahead of the wings, providing excellent visibility. Behind the cockpit lay the cargo compartment, tapering toward the biplane tailplane equipped with balanced elevators. Four slender rudders without fins were spaced evenly between the two tailplanes. The landing gear consisted of a fixed split-axle setup complemented by a sprung tailskid.

The initial model, Vellore I, powered by a 515 hp (384 kW) Bristol Jupiter IX engine, took flight on 17 May 1928. It was showcased at the RAF Hendon exhibition in June of that year before undergoing trials at RAF Martlesham Heath in October. These evaluations were successful, with performance surpassing expectations and demonstrating reliable operation. Early in 1929, modifications included fitting an Armstrong Siddeley Jaguar VI engine and installing additional fuel tanks within the cargo area to prepare for an Australian flight attempt. Departing from Lympne on 18 March 1929 carrying a full 5,000 lb (2,300 kg) payload including extra fuel, the Vellore II (also known as Jaguar-Vellore) progressed in stages to Benghazi, where engine problems forced an unscheduled landing. After receiving replacement parts, the journey resumed until another engine failure occurred over the Timor Sea, resulting in a crash within trees near Cape Don lighthouse at the western tip of the Cobourg Peninsula on mainland Australia. Both Australian crew members escaped unharmed.

File:Vickers Vellox Annuaire de L'Aéronautique 1931.jpg

The twin-engine Vickers Vellore III, from Annuaire de L'Aéronautique 1931

The twin-engine variant, designated Vellore III, was equipped with two 525 hp (391 kW) Jupiter XIF engines fitted with Townend ring cowlings mounted in nacelles positioned midway between the wings.

To accommodate this configuration, the lower wing’s span was slightly reduced so that the outer interplane struts angled outward. Another modification involved repositioning the main landing gear beneath the engines to provide a wider track. Additionally, the Vellore III could be converted into a seaplane by replacing wheels with single-step floats. A second twin-engine version was produced with marginally higher compression Jupiter IX engines; this model became known as the Vellore IV. It remained operational until early 1935, primarily ferrying troops and supplies between Martlesham and nearby Orfordness.

File:Vickers 212 Vellox on ground.jpg

Vellox on the ground

File:Vickers 212 Vellox in flight.jpg

Vellox in flight

The final aircraft in this series was developed from an incomplete third twin-engine Vellore frame but featured a redesigned fuselage that was broader and included an enclosed cockpit along with cabin windows for passengers. This version utilized 600 hp (450 kW) Bristol Pegasus IM3 radial engines and was rebranded as the Vickers Vellox. Its maiden flight occurred on 23 January 1934 under pilot Mutt Summers.

Operational history

Vickers originally intended the Vellox to serve as a ten-passenger airliner, featuring a redesigned fuselage with five windows on each side positioned ahead of large cargo doors on the starboard side at the wing's trailing edge. However, the only unit produced was operated by Imperial Airways primarily as a freighter, mail carrier, and for trials involving the Lorenz blind landing system. The aircraft suffered a fatal accident shortly after departing Croydon Airport in August 1936, attributed to an engine power loss likely caused by fuel-related issues. Tragically, the two pilots and two wireless operators onboard lost their lives in the crash.

Variants

Vellore I (Type 134)

Single-engine freighter powered by a Jupiter engine; one example constructed.

Vellore II/Jaguar-Vellore (Type 166)

Single-engine freighter driven by a Jaguar IV engine, designed for flights to Australia; one built.

Vellore III (Type 172)

Twin-engine freighter equipped with Jupiter XIF engines; one unit produced.

Vellore IV (Type 173)

Twin-engine mailplane powered by Jupiter XIF engines; single aircraft manufactured.

Vellox (Type 212)

Twin-engine airliner powered by Pegasus engines; only one model completed.

Specifications (Vellore III)

File:Vickers Vellore 3-view NACA Aircraft Circular No.83.jpg

Three-view illustration of the Vickers Vellore from NACA Aircraft Circular No.83

References

Bibliography

• Andrews, C.F.; Morgan, E.B. Vickers Aircraft since 1908, 2nd edition, Putnam, London, 1988, ISBN 0851778151.
• "The Vickers 'Vellore'", Flight, 6 September 1928.
• "To Australia in a fortnight", Flight archive.