Powered by four 1,375-hp Bristol Hercules II engines, and with John Lankester Parker the pilot, and now called the Stirling, the prototype flew for the first time on the 14th May 1939. However, on landing

aircraft also served as test beds including with the Bristol Aeroplane Company who would use a number of airframes to test engines. These included the engine intended to power the Fairy Albacore, the

a Manchester Mk II, powered by either Bristol Centaurus or Napier Sabre engines was planned, but none were ever produced. This would be followed by the Manchester Mk III, this would have an increased

Bristol Hercules Powered Lancaster B.II Of the Lancaster variants produced, all would be powered by either Rolls-Royce or Packard Merlin engines, the exception was the Lancaster B.II, which was powered

The Wellesley Mk I was powered by the 925-hp Bristol Pegasus XX engine, this gave the aircraft a top speed of 222 mph, range of 1,100 miles with a service ceiling of 26,100 ft. Armament consisted of one

The Harrow Mk I was powered by a pair of 850-hp Bristol Pegasus X engines giving the aircraft a top speed of 190 mph. This was quickly followed by the 925-hp Bristol Pegasus XX powered Harrow Mk II. This

5 Westland Lysander 4 Bristol Blenheim 6 Hawker Hurricane Advanced Air Striking Force (13 squadrons) 8 Fairey Battle 2 Bristol Blenheim 3 Hawker Hurricane The two letters in () are the squadron

two Tempest Mk IIs, powered by the 2,520-hp Bristol Centaurs IV engine. The Tempest Mk III was powered by the Rolls-Royce Griffon IIB with the Tempest Mk IV installed with a Rolls-Royce Griffon 61 engine,

The Hampden Mk I was powered by a pair of 1,000-hp Bristol Pegasus XVIII engines which gave the aircraft a top speed of 254 mph, range of 1,885 miles with a service ceiling of 19,000 ft. Armament was

powered by four 950-hp Bristol Pegasus X engines, and featured a British flying boat first of power operated turrets being fitted. A large aircraft which had two levels and a crew of, normally, between