The Aquila was a nine-cylinder single-row radial

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years ma ...

Bristol Engine Company The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aircraft engines. Notable a ...

starting in 1934. A

sleeve valve The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truc ...

engine, its basic design was developed from the

Bristol Perseus The Bristol Perseus was a British nine-cylinder, single-row, air-cooled radial aircraft engine produced by the Bristol Engine Company starting in 1932. It was the first production sleeve valve aero engine. Design and development In late 192 ...

. The Aquila was never used in production, but further developments led to the

Bristol Hercules The Bristol Hercules is a 14-cylinder two-row radial aircraft engine designed by Sir Roy Fedden and produced by the Bristol Engine Company starting in 1939. It was the most numerous of their single sleeve valve ( Burt-McCollum, or Argyll, typ ...

, Bristol Taurus, and

Bristol Centaurus The Centaurus was the final development of the Bristol Engine Company's series of sleeve valve radial aircraft engines. The Centaurus is an 18-cylinder, two-row design that eventually delivered over . The engine was introduced into service l ...

Design and development

The Aquila was developed two years after the somewhat larger

Perseus In Greek mythology, Perseus ( /ˈpɜːrsiəs, -sjuːs/; Greek: Περσεύς, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer ...

, both being

designs. The primary difference was in size, the Perseus being based on the cylinder used in the Mercury engine, while the Aquila used a new and smaller sized cylinder. The result was a reduction in displacement from 1520 to 950 cubic inches (24.9 to 15.6 L). The first Aquila engine delivered a modest , which was unspectacular for an engine of this size. It soon developed into more powerful versions as improvements were worked into the line (as well as similar changes to the Perseus), and by 1936 it had improved to . This would have made it an excellent replacement for the

Bristol Jupiter The Bristol Jupiter was a British nine-cylinder single-row piston radial engine built by the Bristol Aeroplane Company. Originally designed late in World War I and known as the Cosmos Jupiter, a lengthy series of upgrades and developments turn ...

, which ended production at three years earlier, but by this time almost all interest was on ever-larger engines.

Applications

''Note:''List from Lumsden, the Bulldog and Bullpup were test aircraft only. * Bristol Bulldog * Bristol Bullpup * Bristol Type 143 * Vickers Venom

Specifications (Aquila I)

References

Notes

Bibliography