First Prototype Tornado P5219
Due to space limitations at Hawker’s production facility, most Tornados were manufactured at A.V. Roe’s premises in Manchester, following the initial batch constructed at Hawker’s Langley factory. The prototype initially had a radiator bath positioned under the fuselage center section, similar to the Hurricane. However, at high speeds, compressibility caused adverse airflow conditions around the fairing, increasing the engine’s operating temperature, drag, and causing violent shuddering and vibration at speeds nearing 400 mph (640 kph).
To address these issues, the radiator was repositioned under the engine, and the prototype, P5219, made its maiden flight with this new configuration on December 6, 1939, thus establishing the familiar under-the-nose radiator setup. Although cooling around the oil cooler improved, longitudinal stability deteriorated. Wind-tunnel tests confirmed severe airflow instabilities just aft of the radiator exit vent, worsened by turbulence near the uncovered main wheels during retraction. This was noticeable in flight by a low-frequency rumble extending to the rudder. Small sprung doors were added to the main gear doors to close upon retraction, improving handling at low speeds but causing issues at higher speeds. Eventually, these doors were removed due to debris getting lodged in them, with ‘D’ doors added on the inner edges of each bay near the aircraft’s centerline.
After testing undercarriage improvements in January 1940, P5219 underwent general handling trials in February and was pushed to its limits in March, including reaching a top speed of 384 mph (618 km/h) at 20,500 ft (6,250 m) in fully supercharged mode. The control instability was still present, but extending the under-engine radiator fairing by 3 inches (7.5 cm) mitigated many airflow issues. By May 9, P5219 was the only E18/37 prototype available for flight trials, as the prototype Typhoon suffered near-catastrophic structural failure that day.
With the Typhoon undergoing repair, the Tornado was used to test a larger rudder, which improved stability when first flown on May 16. A series of test flights in early June evaluated the newly added tailwheel doors, with both modifications deemed successful. Having tested the Tornado’s flight capabilities, attention turned to pushing the Vulture engine’s performance. P5219 was sent to Rolls-Royce Hucknall for modifications focused on the oil cooling system and testing if the Vulture could deliver better performance.
After modifications, the Tornado returned to Langley in mid-July, equipped with a Rotol propeller of 13 ft 2.5 in (4 m) diameter, which seemed to enhance engine output absorption. On July 27, Tornado P5219 made its first flight at its intended all-up weight of 10,225 lb (4,638 kg), including a full fuel load, twelve Browning machine guns, and ballast representing ammunition. The aircraft achieved a top speed of 396.5 mph (638 km/h) at 20,800 ft (6,340 m) and climbed to 20,000 ft (6,000 m) in just over six minutes, considered outstanding for a fighter of its power and weight.
However, this success was short-lived, as the Vulture engine suffered a catastrophic failure on July 31, with at least two connecting rods fracturing. The subsequent crash landing damaged the airframe, though it was quickly repaired.