POWER PLANT: Two BMW 003 turbojet engines, rated at 900 kp each
PERFORMANCE: 553 mph at 16,405 ft
COMMENT: This Blohm & Voss dive bomber and ground attack aircraft project of 1944 was of a twin boom design with each boom having a bomb bay in the forward section capable of holding a SC 250 bomb. The aircraft was powered by two BMW 003 turbojet engines mounted side-by-side under the center nacelle in which the cockpit and armament was located. The heavy armament consisted of four fuselage mounted MG 151/20 20mm cannon. The landing gear was a conventional “tail-dragger” arrangement with extended track width. Although detail planning was in advanced stage the project was not favored by the “Technische Amt” (Technical bureau) of the RLM (Ref.: 17).
TYPE: Long-range Maritime Reconnaissance and Bomber Flying Boat
ACCOMMODATION: Crew of nine
POWER PLANT: Four Mitsubishi “Kinsei 46” radial engines, rated at 930 hp each
PERFORMANCE: 211 mph at 19,685 ft
COMMENT: The Kawanishi H6K4 was an Imperial Japanese Navy flying boat used during WW II for maritime patrol duties. The IJ Navy designation was “Type 97 Large Flying Boat”, The Allied reporting name for the type was “Mavis”.
The aircraft was designed in response to a Navy requirement of 1934 for a long range flying boat and incorporated knowledge gleaned by a Kawanishi team that visited the Short Brothers factory in the UK, at that time one of the world’s leading producers of flying boats, and from building the Kawanishi H3K, a license-built, enlarged version of the Short “Rangoon”. The Type S, as Kawanishi called it, was a large, four-engine monoplane with twin tails, and a hull suspended beneath the parasol wing by a network of struts. Three prototypes were constructed, each one making gradual refinements to the machine’s handling both in the water and in the air, and finally fitting more powerful engines. The first of these flew on 14 July 1936 and was originally designated “Navy Type 97 Flying Boat”, later H6K. Eventually, 217 would be built.
H6Ks were deployed from 1938 onwards, first seeing service in the Sino-Japanese War and were in widespread use by the time the full-scale Pacific War erupted, in 1942. At that time of the war, four Kokutai (Air Groups) operated a total of 66 H6K4s.
The type had some success over South East Asia and the South Pacific. H6Ks had excellent endurance, being able to undertake 24-hour patrols, and were often used for long-range reconnaissance and bombing missions. From bases in the Dutch East Indies, they were able to undertake missions over a large portion of Australia. However, the H6K became vulnerable to a newer generation of heavier armed and faster fighters. It continued in service throughout the war, in areas where the risk of interception was low. In front-line service, it was replaced by the Kawanishi H8K “Type 2 Large-sized Flying Boat“, Allied code name “Emily” (Ref.: 24).
TYPE: Amphibious biplane reconnaissance and air-sea rescue aircraft
ACCOMMODATION: Crew of three to four
POWER PLANT: One Bristol “Pegasus VI” radial engine, rated at 680 hp
PERFORMANCE: 135 mph at 4,750 ft
COMMENT: The Supermarine “Walrus” (originally known as the Supermarine “Seagull V”) was a British single-engine amphibious biplane reconnaissance aircraft first flown in 1933. It was operated by the Fleet Air Arm (FAA) and also served with the Royal Air Force (RAF). It was the first British squadron-service aircraft to incorporate in one airframe a fully retractable main undercarriage, completely enclosed crew accommodation and all-metal fuselage.
Designed for use as a fleet spotter to be catapult launched from cruisers or battleships, the “Walrus” was later employed in a variety of other roles, most notably as a rescue aircraft for downed aircrew. It continued in service throughout WW II.
The single-step hull was constructed from aluminium alloy, with stainless-steel forgings for the catapult spools and mountings. Metal construction was used because experience had shown that wooden structures deteriorated rapidly under tropical conditions. The wings, which were slightly swept back, had stainless–steel spars and wooden ribs and were covered in fabric. The lower wings were set in the shoulder position with a stabilising float mounted under each one. The horizontal tail surfaces were positioned high on the tail fin and braced on either side by N struts. The wings could be folded on ship for stowage. The single “Pegasus” radial engine was housed at the rear of a nacelle mounted on four struts above the lower wing and braced by four shorter struts to the centre-section of the upper wing. This powered a four-bladed wooden pusher propeller. The pusher configuration had the advantages of keeping the engine and propeller further out of the way of spray when operating on water and reducing the noise level inside the aircraft. Also, the moving propeller was safely away from any crew standing on the front deck, which would be done when picking up a mooring line.
Although the aircraft typically flew with one pilot, there were positions for two. The left-hand position was the main one, with the instrument panel and a fixed seat, while the right-hand seat could be folded away to allow access to the nose gun-position via a crawl-way. Behind the cockpit, there was a small cabin with work stations for the navigator and radio operator.
A total of 740 Walruses were built in three major variants: the “Seagull V”, “Walrus I”, and the “Walrus II”. The Mark IIs were all constructed by Saunders-Roe and the prototype first flew in May 1940. This aircraft had a wooden hull, which was heavier but had the advantage of using less of the precious wartime stockpiles of light metal alloys. Saunders-Roe would go on to build under license 270 metal Mark Is and 191 wooden-hulled Mark IIs.
The successor to the “Walrus” was the Supermarine “Sea Otter” – a similar but more powerful design. “Sea Otters” never completely replaced the “Walruses”, and served alongside them in the air-sea rescue role during the latter part of the war.
The “Walrus” was known as the “Shagbat” or sometimes “Steam-pigeon”; the latter name coming from the steam produced by water striking the hot “Pegasus” engine.
The main task of ship-based aircraft was patrolling for Axis submarines and surface-raiders, and by March 1941, “Walruses” were being deployed with Air to Surface Vessel (ASV) radars to assist in this.
By 1943, catapult-launched aircraft on cruisers and battleships were being phased out; their role at sea was taken over by much-improved radar. Also, a hangar and catapult occupied a considerable amount of valuable space on a warship. However, “Walruses” continued to fly from Royal Navy carriers for air-sea rescue and general communications tasks. Their low landing speed meant they could make a carrier landing despite having no flaps or tailhook (Ref.: 24).
TYPE: Anti-ship and -fortification explosive filled glide bomb as “Mistel” composition. Project
ACCOMMODATION: Pilot only in Arado Ar 234C-3
POWER PLANT: None with glide bomb, two BMW 003A turbojet engines with Arado Ar 234C-2, rated at 850 kp each
PERFORMANCE: Data not available
COMMENT: This “Mistel 5” project was one of the last glide bomb developments submitted to the RLM before the end of WW II. Arado, working with Rheinmetall-Borsig, designed a simple glide bomb that would be powered (version B) or unpowered (version A) and carried beneath the Arado 234 “Blitz” bomber or Heinkel He 162 “Spatz” interceptor. The purpose of this glide bomb, which could be guided by radio control or a target guidance system, was to attack targets such as ships or military facilities.
construction of the Arado Ar E.377 was wooden throughout the entire aircraft. The fuselage was circular in cross section and was cigar shaped. The nose held 2,000 kg of high explosive especially suitable for ship attacks. In addition 500 kg of an incendiary liquid was stored in the rear fuselage which also acted as ballast to counterbalance the forward warhead. The wings were tapered and shoulder mounted. They also served as auxiliary fuel tanks for the guide aircraft. A cruciform tail unit was mounted at the rear of the fuselage. For take-off the “Mistel 5” composition was set on a releasable trolley, developed by Rheinmetal-Borsig.
Upon arrival of the target the E.377 glide bomb was released by means of explosive bolts and flew to the target by means of a radio-control (Ref.:17).
COMMENT: The Yokosuka MXY8 “Akigusa” (“Autumn grass”) was a training glider built in parallel with the Mitsubishi J8M rocket-powered interceptor aircraft.
The J8M was to have simply been a licence-built Messerschmitt Me 163 “Komet” (“Comet”), but due to difficulties in obtaining technical materials from Germany, it eventually had to be designed almost from scratch. The MXY8 was designed in parallel with the J8M to validate the design, and then to provide pilot training during the development of the actual interceptor. The Imperial Japanese Army Airforce designation for the trainer was Mitsubishi Ku-13
The MXY8 was built entirely of wood, and fitted with ballast tanks that would be filled with water to simulate the weight and therefore flight characteristics of a fully equipped J8M. Some 50-60 of these gliders were eventually built.
A more advanced trainer, the MXY9, equipped with a primitive turbojet engine was planned, but was never produced (Ref.: 24).