Night fighter Beaufighter SA-H of No. 456 Squadron RAAF Valley
The Beaufighter Mk.II was a variant of the Bristol Beaufighter, designed as an alternative to the Hercules-powered Mk.I, utilizing Rolls-Royce Merlin 20-series engines. The shift to the Merlin engine was intended to provide better performance, though it introduced its own set of challenges.
Key Characteristics of the Beaufighter Mk.II:
Engine and Performance:
- Engines: Two Rolls-Royce Merlin XX 12-cylinder, supercharged, in-line engines, each producing 1,250 horsepower.
- Speed: It had a maximum speed of 337 mph (540 km/h) at an altitude of 22,000 ft (6,705 m), making it slightly faster than the Mk.I.
- Rate of climb: Slower than the Mk.I, it could reach 15,000 ft (4,570 m) in 8.8 minutes.
- Service ceiling: 32,600 ft (9,935 m), higher than the Mk.I due to its lighter weight.
- Range: Approximately 1,000 miles (1,600 km).
Design Changes:
- The longer Merlin engine nacelles, borrowed from the Lancaster bomber, required the addition of an intermediate “pickup” bay to fit the Beaufighter airframe.
- The longer nacelles increased the take-off swing, requiring careful handling on the ground. In addition, the Rotol airscrews and Schwartz wooden propellers were less than fully feathering, making the aircraft more challenging to manage, especially during the climb.
- Both Mk.I and Mk.II Beaufighters suffered from a low-frequency longitudinal instability during climbs, but this issue was more pronounced in the Mk.II. A 12° dihedral tailplane was tested to improve stability, but it made the aircraft too stable for night fighting, so Mk.IIs for different roles were produced with both types of tailplane.
Weight and Dimensions:
- Wingspan: 57 ft 10 in (17.62 meters).
- Length: 42 ft 9 in (13.03 meters).
- Height: 15 ft 10 in (4.83 meters).
- Wing area: 503 sq ft (46.73 sq meters).
- Loaded weight: 21,077 lb (9,560 kg), slightly less than the Mk.I.
Armament and Radar:
- Like the Mk.I, the Mk.II was armed with:
- Four 20 mm Hispano cannons in the forward lower fuselage.
- Six 0.303-inch (7.69 mm) Browning machine guns, each with 1,000 rounds.
- It was equipped with the AI Mk.IV radar system, making it effective as a night fighter.
Service and Production:
- The first Mk.II, R2058, powered by Merlin X engines up-rated to the Mk.XX standard, flew on 14 June 1940 from Rolls-Royce’s airfield at Hucknall. However, only a limited number of Mk.IIs were produced compared to the Hercules-powered Mk.I.
- The Beaufighter Mk.II entered service with Fighter Command in April 1941 and remained in frontline service as a night fighter until May 1943, when it was replaced by the Beaufighter Mk.VI and variants of the Mosquito.
- It was also used for night-fighter training from February 1942.