Hawker's Second Generation of Violent Winds:
A Brief History of the Typhoon and Tempest
by Jason Long
"The Typhoon and Tempest had their genesis in a 1937 Air Ministry requirement for a new generation of fighters that would have a maximum level speed of no less than 400 mph. The only way to achieve that incredible speed (which wasn't exceeded until 1939) was to use 3 new engines under development that promised twice as power as the Merlin that powered the Spitfire and Hurricane. These engines were the Rolls-Royce Vulture, a liquid-cooled 24-cylinder X-type based on a pair of V-12 Peregrines fastened together back-to-back, the Bristol Centaurus, an 18-cylinder sleeve-valve radial, and the Napier Sabre, a liquid-cooled sleeve-valve 24-cylinder H-type that resembled a pair of flat twelves bolted together. The engines were expected to have horsepower per pound ratios of 0.79, 0.95, and 1.12 respectively, but the development of the latter two was expected to be prolonged as their designs pushed the "state of the art". As the lightest of these was estimated to have a weight at least 60% greater than that of the Merlin it was obvious that any fighter using them would be rather substantial in comparison with the current generation. Hawker designed a version of their submission for each of the engines, the Vulture-powered model was the Tornado, that using the Centaurus was the Tempest and the Typhoon used the Sabre.
The Air Ministry demanded a weight of firepower some 50% greater than the current generation, but didn't specify the exact armament. Hawker took care to be able to accommodate 20mm cannon with their bulky ammunition drums or a dozen .303 Brownings. Unfortunately the resulting thick wing fatally compromised the Typhoon's high-altitude performance.
The Tornado was the first to fly in October 1939 as its Vulture was more mature than its competitors. The Typhoon followed in February 1940, but the former was canceled when the Vulture-powered Manchester heavy bomber was modified to carry 4 Merlins as the Lancaster since Avro was dissatisfied with the performance and reliability of its engines. Rolls-Royce was hard-pressed to cure its problems, which really weren't all that severe, as it had quite enough to do already with the many improvements of the Merlin and the development of the Griffin engine.
One production Tornado was completed before it was canceled in the early summer of 1941. It had a maximum speed of 402 mph (647 kph) at 21,800 feet (6645 m) and a time to 20,000 feet (6090 m) of 6.9 minutes.
The second prototype Typhoon wasn't delivered until May '41, over a year after the first. The Air Ministry had been insistent that nothing could interfere with the delivery of Hurricanes during 1940 and 1941, understandably so, but that attitude proved extremely short-sighted as Hawker paid little attention to the Typhoon under Ministry pressure. It was supposed to build 15 pre-production aircraft before Gloster began series production to work out the inevitable bugs, but these aircraft were delivered after production deliveries had already commenced! Hawker should have been able to finish the second prototype and the 15 pre-production aircraft in 1940 with minimal impact on Hurricane deliveries."
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