[7] More than 700 Australian-built Beauforts saw service with the Royal Australian Air Force in the South West Pacific theatre, where they were used until the end of the war.

The Beaufort came from Bristol's submission to meet Air Ministry Specifications M.I5/35 and G.24/35 for a land-based, twin-engined torpedo-bomber and a general reconnaissance aircraft.

It was soon determined that even with the Perseus, the Beaufort would be slower than the Blenheim and so a switch was made to the larger Bristol Taurus engine, another sleeve valve design.

[8] For these engines, chief designer Roy Fedden developed special low-drag NACA cowlings, which exhausted air through vertical slots flanking the nacelles under the wings.

[11] The Vickers main undercarriage units were similar to but larger than those of the Blenheim and used hydraulic retraction, with a cartridge operated emergency lowering system.

As flight testing progressed, it was found that the large apron-type undercarriage doors, similar to those on the Blenheim, were causing the aircraft to yaw on landing.

[13] After 1941, British Beauforts were fitted with semi-circular plates on the trailing edges of the upper wing behind the engine nacelles to smooth airflow and improve directional stability.

Several of the first production Beauforts were engaged in working-up trials and final service entry began in January 1940 with 22 Squadron of RAF Coastal Command.

It was found that the curved alloy extensions on the trailing edges improved the flight characteristics and similar panels were fitted on all later production Beauforts.

[18] When it became apparent that the Taurus engines had problems, planning commenced to re-engine the aircraft with 1,200 hp (890 kW) Pratt & Whitney R-1830 Twin-Wasp radials, which were of similar diameter and slightly lighter, driving Hamilton Standard bracket-type variable-pitch propellers.

ASV Mk III was added with yagi antennae under the nose and wings and a Bristol B1.Mk.V turret with two .303 in (7.7 mm) Browning machine guns was fitted.

[7] As the design for the Beaufort began to mature, the Australian Government invited a British Air Mission to discuss the defence needs of Australia and Singapore.

[7] The Australian Beauforts were to be built at the established DAP plant in Fishermans Bend, Melbourne and a new factory at Mascot, New South Wales; to speed up the process drawings, jigs and tools and complete parts for six airframes were supplied by Bristol.

Because of this, railway workshops were key subcontractors: Taurus engines, aircraft components and the associated equipment were shipped out to be joined in October 1939, by the eighth production Beaufort L4448.

It was proposed that a change of powerplant could be made to the Pratt & Whitney Twin Wasp, which was already in use on Royal Australian Air Force Lockheed Hudsons.

[29] Because of this, and because of a shortage of torpedoes, the squadron's first operations consisted of laying magnetic mines ("Gardening" in RAF parlance) and dropping conventional bombs.

[32] Beauforts also equipped some Commonwealth Article XV squadrons serving within the RAF but because of supply shortages, were replaced by other aircraft types before the units flew operationally.

An estimated 1,000 flak guns of all calibres protected the base and adding complication to the danger was the realisation that Gneisenau was only about 500 yd (460 m) from a harbour mole, requiring extremely accurate torpedo drops.

[41] In spite of these dangers 22 Squadron, based at RAF St Eval, was ordered to make a torpedo attack, timed to take place just after dawn on 6 April 1941.

Because of a sea mist, the other three Beauforts arrived at Brest independently; one, flown by F/O Kenneth Campbell, managed to penetrate the harbour and torpedo Gneisenau but was shot down immediately afterwards.

Copying the recognition signals that other Junkers Ju 88 and Messerschmitt Bf 110 exchanged with the German ships, Loveitt was able to attack without a defensive shot being fired, Loviett's torpedo hit her on the port side.

[44][45] During the famous Operation Cerberus, the "Channel Dash" by Scharnhorst and Gneisenau and the heavy cruiser Prinz Eugen, which took place from 12 February 1942, three Beaufort units, with 33 serviceable aircraft were available: 22 Squadron was under orders to move to Singapore.

[55][56] In another operation, during the early hours of 15 June 1942, nine Beauforts of 217 Squadron, which had just flown in from England, took off from RAF Luqa, Malta to intercept ships of the Regia Marina, which had sailed from Taranto.

In the confusion and the smokescreen that had been laid by the Italian warships, 217 Squadron claimed several torpedo hits for the loss of one Beaufort, which belly-landed at Luqa.

[59][60][N 9] Over the next 11 months, the Beaufort force, now usually accompanied by Beaufighters, was instrumental in crippling the convoy supply lines that were vital to Rommel's Afrika Korps.

[71] During the first years of World War II, the Australian government found itself unable to procure twin-engine bomber aircraft for home duties in Australia.

One Beaufort, attached to Air Headquarters, Singapore as a reconnaissance aircraft was attacked, during its first sortie, by Japanese fighters, severely damaged and written-off.

As Japanese forces approached Singapore in early 1942, RAF bases there were abandoned; the remaining Beauforts and 100 Squadron personnel were evacuated to Australia.

The Beaufort served with 19 RAAF squadrons and played an important role in the South West Pacific Area, as a maritime patrol/strike aircraft and bomber.

Aviation historian William Green has written that the Beaufort's "part in the defeat of the Japanese forces in the South-West Pacific was probably of greater importance than that of any other single aircraft type.