Avro 684
| Industry | Aerospace, Defense |
|---|---|
| Founded | 1910 in United Kingdom |
| Founder | Alliott Verdon Roe |
| Headquarters | United Kingdom |
| Products | Aircraft, including Avro 684 (conceptual bomber) |
The Avro 684 was a conceptual British high-altitude heavy bomber project during the Second World War, derived from the well-known Avro Lancaster design.[1]
Design
As heavy bombers of the era became increasingly susceptible to anti-aircraft artillery and fighter attacks, operating at greater altitudes emerged as a critical strategy for survival. To meet this demand, Avro initiated development of a high-altitude bomber, culminating in the Avro 684 Stratosphere Bomber brochure completed in August 1941. Roy Chadwick envisioned a bomber that eliminated defensive weaponry, instead relying on superior altitude and velocity to avoid enemy threats. Essentially, this design was a Lancaster modified with a pressure-sealed nose section—drawing inspiration from the pressure cabin used in the Vickers Wellington B Mark XTemplate:Fix/category[citation needed]—and equipped with a prominent chin-mounted air intake and heat exchanger systemTemplate:Fix/category[citation needed]. Cabin pressure was to be sustained by a Rotol blower set to maintain an internal environment equivalent to 10,000 ft (3,000 m) while flying at an altitude of 40,000 ft (12,000 m).[1]
To deliver the required performance, Chadwick employed a 'Master-Slave' engine configuration. Four wing-mounted Rolls-Royce Merlin XX engines, each turning four-bladed 13 ft (4.0 m) Rotol propellers, were supercharged by an additional fuselage-mounted 'slave' Rolls-Royce Merlin 45 engine. This slave engine powered a large supercharger that provided compressed air through an intercooler, enhancing engine efficiency. The slave engine’s output was regulated to maintain air pressure equivalent to 20,000 ft (6,100 m) between flight altitudes of 20,000 ft (6,100 m) and 40,000 ft (12,000 m).[1]
With an estimated maximum takeoff weight of 60,000 lb, the Avro 684 was projected to achieve a service ceiling of 42,000 ft and could reach up to 49,600 ft during its return leg.[1]
However, ongoing modifications to the Lancaster and concurrent design efforts on its transport variant, the Avro York, led to the suspension of the Avro 684 project.[1]
Specifications (estimated)
References
Bibliography
- Buttler, Tony (2004). British Secret Projects. Fighters & Bombers 1935 - 1950. Hinckley: Midland Publishing. ISBN 1-85780-179-2..
- Holmes, Harry. Avro Lancaster. The Definitive Record 2nd Edition. Shrewsbury, UK: Airlife Publishing Ltd, 2001. ISBN 1-84037-288-5.