TYPE: Light bomber, reconnaissance aircraft
ACCOMMODATION: Crew of six
POWER PLANT: Two Pratt & Whitney “Twin Wasp” radial engines, rated at 1,200 hp each
PERFORMANCE: 246 mph
COMMENT: The Lockheed “Hudson” was an American-built light bomber and coastal reconnaissance aircraft built initially for the British Royal Air Force shortly before the outbreak of WW II and primarily operated by the RAF thereafter. The “Hudson” served throughout the war, mainly with Coastal Command but also in transport and training roles as well as delivering agents into occupied France. They were also used extensively with the Royal Canadian Air Force’s anti-submarine squadrons and by the Royal Australian Air Force.
In late 1937 Lockheed sent a cutaway drawing of the Model 14 to various publications, showing the new aircraft as a civilian aircraft and converted to a light bomber. This attracted the interest of various air forces and in 1938, the British Purchasing Commission sought an American maritime patrol aircraft for the United Kingdom to support the Avro “Anson”. On December 1938, Lockheed demonstrated a modified version of the Lockheed Model 14 “Super Electra” commercial airliner, which swiftly went into production as the “Hudson Mk I”.
A total of 350 Mk I and 20 Mk II “Hudsons” were supplied. These had two fixed Browning machine guns in the nose and two more in the Boulton Paul dorsal turret. The Hudson Mk III added one ventral and two beam machine guns and replaced the 1,100 hp Wright “Cyclone” cylinder radials with 1,200 hp versions (428 produced).
The “Hudson Mk V” (309 produced) and Mk VI (450 produced) were powered by the 1,200 hp Pratt & Whitney “Twin Wasp” 14-cylinder two-row radial. The RAF also obtained 380 Mk IIIA and 30 Mk IV “Hudsons” under the Lend-Lease programme.
By February 1939, RAF “Hudsons” began to be delivered, by the start of WW II in September, 78 “Hudsons” were in service. Due to the United States’ neutrality at that time, early series aircraft were flown to the Canada–US border, landed, and then towed on their wheels over the border into Canada by tractors or horse drawn teams, before then being flown to Royal Canadian Air Force (RCAF) airfields where they were then dismantled and “cocooned” for transport as deck cargo, by ship to Liverpool. The “Hudsons” were supplied without the Boulton Paul dorsal turret, which was installed on arrival in the United Kingdom.
Although later outclassed by larger bombers, the Lockheed “Hudson” achieved some significant feats during the first half of the war. Skilled and experienced pilots found that the Hudson had an exceptional maneuverability for a twin-engined aircraft, especially a tight turning circle if either engine was briefly feathered (Ref. 24).
TYPE: Light bomber
ACCOMMODATION: Crew of three
POWER PLANT: Two Bristol “Mercury” XXX radial engines, rated at 920 hp
PERFORMANCE: 266 mph at 11,800 ft
COMMENT: In 1940, a new specification, Spec B. 6/40, was issued by the U.K. Air Ministry to redesign the Bristol “Blenheim” Mk. IV. The major changes included the replacement of the “Mercury” XV engines with the uprated “Mercury” XXX engines, a re-designed nose area, extra armor and a new oxygen system. On February 1941, two prototypes were ready for flight at the Bristol factory. One prototype was a three-seat, high-altitude day bomber. This version had a semi-glazed, asymmetrical nose with a rear-facing blister housing two machine guns. The second prototype was a two-seater close-support aircraft, with solid nose containing four more Browning machine guns, initially known as Bristol “Bisley” (after shooting competitions held at Bisley). This latter variant was not required, probably due to the advent of the single-seater close-support fighters then under development such as the Hawker “Typhoon”. A major improvement of the “Blenheim” Mk. V over its earlier predecessors was the new Bristol B. X. upper gun turret, which was fitted with two machine guns. This turret was capable of high-speed traverse and continuous rotation in either direction. The day bomber type went into production and, by June 1943, a total of 940 aircraft had been produced for the RAF. Manufacture of the “Blenheim” Mk. V was undertaken by the firm of Rootes Security Ltd, at their “shadow” factory at Blythe Bridges, Staffordshire. Although the “Blenheim” Mk. V served in North Africa and the Far East until 1943, its lack of success resulted in many aircraft converted to dual-control and being used as trainers and target tugs (Ref.: MPM).
TYPE: Patrol and reconnaissance flying boat
ACCOMMODATION: Crew of four
POWER PLANT: Two Junkers Jumo 205C-4 liquid-cooled diesel engines, rated at 605 hp each
PERFORMANCE: 155 mph at sea level
COMMENT: In 1934, the Dornier Flugzeugwerke started development of a new twin-engined flying boat to replace the Dornier Do J “Wal“ (Whale) in both military (Do 16) and civil (Do JI and Do J II) roles. The resultant design, Do 18 retained the layout of the “Wal”, with a metal hull fitted with distinctive stabilizing sponsons, and powered by two engines above the wing in a push-pull layout, but was aerodynamically and hydrodynamically more efficient. It was planned to be powered by two of the new Junkers Jumo 205 diesel engines. Although heavy, these promised to give much lower fuel consumption than conventional petrol engines of similar power.
The Do 18G, 62 units built, was an improved version, powered by two 880 hp Jumo 205D engines, armed with a 13 mm MG machine gun in the bow, and a 20 mm MG 151 cannon in a power-operated dorsal turret.
In German Luftwaffe service, the Dornier Do 18G was obsolete by the outbreak of World War II, but – as the only military flying boat – 62 (58 serviceable) aircraft in five squadrons were in use mainly on North Sea reconnaissance missions. In 1940 some squadrons changed their base to Norway. The vulnerable and underpowered flying boat was soon relegated to training and the air/sea rescue role. In the middle of 1941, only one squadron was still operational on Do 18. The Blohm & Voss Bv 138 had superseded the Dornier Do 18G.
A Dornier Do 18G was the first German aircraft to be shot down by British aircraft during the war, when one of a formation of three was caught over the North Sea by nine Fleet Air Arm Blackburn “Skua” fighter bombers of 803 Naval Air Squadron flying from HMS “Ark Royal” on 26 September 1939 (Ref.: 24).
TYPE: Reconnaissance, transport and training flying boat
ACCOMMODATION: Crew of two to four plus 8-10 passengers or equivalent freight
POWER PLANT: Two BMW VI liquid-cooled engines, rated at 700 hp each
PERFORMANCE: 143 mph
COMMENT: The Dornier Do J “Wal” (“Whale”) was a twin-engine German flying boat of the 1920s designed by Dornier Flugzeugwerke. The Do J had a high-mounted strut-braced monoplane wing with two piston engines mounted in tandem in a central nacelle above the wing; one engine drove a tractor and the other drove a pusher propeller. The hull made use of Claudius Dornier’s patented sponsons on the hull’s sides.
The Do J made its maiden flight on November, 1922. The flight, as well as most production until 1932, took place in Italy because of the restrictions on aviation in Germany after World War I under the terms of Treaty of Versailles. Dornier began to produce the “Wal” in Germany in 1931; production went on until 1936. The Dornier J I and its variant J II “Wal” were some of the most famous flying boats of the periods between the world wars.
A military version was the Dornier Do J II d and was in service with the German Luftwaffe as Dornier Do 16 “Militärwal” (“Military Whale”) according to the aircraft designation system of 1934 by the ReichsLuftsfahrtMinisterium (Reich Air Ministry, RLM). It was used as a reconnaissance and transport aircraft. A crew of two to four rode in an open cockpit close to the nose of the hull. There was one machine gun position in the bow in front of the cockpit and one or two amidships. Some 30 Dornier Do 16 “Militärwal” being delivered for the Luftwaffe in 1935. Eventually these were replaced by the Dornier Do 18 and the “Militärwal” was relegated to training roles.
Note: In many publications the Dornier J II d “Military Whale” is cited as Dornier Do 15. So done on my website, too, (but now corrected). The proper designation is Dornier Do 16 (Ref. 24).