All posts by Gunther Arnold

Heinkel He 51B-2 (Hasegawa)

TYPE: Reconnaissance floatplane, trainer


POWER PLANT: One BMW VI 7,3 Z liquid-cooled engine, rated at 750 hp


COMMENT: The Heinkel He 51 was a single-seat biplane which was produced in a number of different versions. It was initially developed as a fighter, it was also developed as a ground-attack aircraft and a floatplane.
In 1931, Heinkel Aircraft Company developed the Heinkel He 49, officially an advanced trainer in fact it was a fighter. The first prototype flew in November 1932, and was followed by two further prototypes with a longer fuselage, and a revised engine. The type was ordered into production for the still secret Luftwaffe as Heinkel He 51, the first pre-production aircraft flying in May 1933. Deliveries started in July of the next year.
The He 51 was a conventional single-bay biplane, with all-metal construction and fabric covering. It was powered by a BMW VI engine, with an armament of two machine guns mounted above the engine. The He 51 was intended to replace the earlier Arado Ar 65, but served side-by-side with the slightly later Arado Ar 68. The He 51 was outdated the day it entered service, and after an initial run of 150 production fighters, the design was switched into the modified He 51B, with approximately 450 built, including about 46 He 51B-2 floatplanes. With begin of WW II the Heinkel He 51B-2 was only used in a role as trainer (Ref.: 24).

Heinkel He 60C (Airmodel, Vacu)

TYPE: Reconnaissance floatplane

ACCOMMODATION: Pilot and observer

POWER PLANT: One BMW VI 6.0 liquid-cooled engine, rated at 660 hp

PERFORMANCE: 150 mph at sea level

COMMENT: The Heinkel He 60 was a reconnaissance floatplane designed for the German Kriegsmarine (German Navy) to be catapulted from warships of the 1930s.
The Heinkel He 60 was designed as a single-engined biplane of mixed wood and metal construction with fabric covering. Its single bay wings were of equal-span and had significant stagger.
The first prototype flew early in 1933 and proved to be underpowered with its 660 hp BMW VI engine. The second prototype had a more powerful version of the BMW engine, but this only marginally improved its performance and was unreliable, so production aircraft reverted to the original engine. Of conventional configuration, the He 60 was a sturdy aircraft, designed  to be capable of operating on the open sea. As a result, it was always somewhat underpowered for its weight, which made handling sluggish and the aircraft vulnerable to enemy fire. Attempts were made to solve its lack of power by fitting one aircraft with a Daimler-Benz DB 600 engine, but engines were not available for production.
Initial deliveries of the He 60 were to Kriegsmarine training units in June 1933. From 1934, the major production version, the He 60C began to be delivered to the shipboard floatplane units of the Kriegsmarine, operating from the catapults of all German cruisers. It also saw action with Spanish Nationalist forces during the Civil War.
In 1939 it was replaced as a shipboard aircraft first by the Heinkel he 114 in service, then soon after by the Arado Ar 196, but it remained in service with several coast reconnaissance Staffeln (squadrons) when WW II began. It had been withdrawn from front-line service by 1940, but returned to use following Germany’s invasion of the Soviet Union in 1941, being used for coastal patrol work in the Baltic and Mediterranean Seas. All He 60s were removed from service by October 1943 (Ref.: 24).

Tachikawa Ki-94-II (A + V Model, Resin)

TYPE: High-altitude fighter

ACCOMMODATION: Pilot in pressurized cockpit

POWER PLANT: One Nakajima Ha-44 radial engine, rated at 2,450 hp

PERFORMANCE: 442 mph at 39,370 ft (estimated)

COMMENT: In mid-1942, the Imperial Japanese Army Air Force wanted to obtain a high-altitude fighter fitted with a pressure cabin and capable of reaching a top speed of 497 mph and having a maximum range of 1,850 miles. As these performance requirements were rather stringent, the Koku Hombu decided to instruct Tachikawa to proceed with the design of the aircraft designated Ki- 94 while they placed a contract with Nakajima for another high-altitude fighter, the Ki- 87, with less stringent range requirements.
The initial aircraft was a large twin-boom monoplane with two engines mounted in tandem driving four-blade tractor and pusher propellers. But it was judged that the design was too complex and in 1943 Tachikawa submitted a new proposal to meet the same requirements as the competitive Nakajima Ki-87. The new aircraft was a single-engine high-altitude fighter of conventional design with laminar-flow wing and featuring a pressure cabin mounted in the fuselage behind the wing trailing edges. The aircraft was to be powered by a fan-cooled turbo-supercharged 2,400 hp Nakajima radial engine driving a six-blade propeller. This design was approved by the Koku Hombu, and the aircraft was designated Ki-94-II (the scrapped earlier Ki-94 design was named the Ki-94-I). An order was placed for one static test airframe, three prototypes, and eighteen pre-production aircraft. Only two prototypes were built in the event; the first was equipped with a single 2,541 hp Nakajima Ha-219 (Ha-44) engine, driving a four-blade propeller because the six-blade one was not ready. The second prototype was to be fitted with a six-blade propeller. The war’s end however stopped the construction of the second prototype and also found the first prototype still being readied for its intended maiden flight, the Ki-94-II never taking to the air (Ref.: 1, 24).

Focke Wulf Fw 190TL (Unicraft, Resin, Parts from Airfix)

TYPE: Fighter project with turbojet engine


POWER PLANT: One Focke-Wulf T.1 radial turbojet engine, rated at 600 kp

PERFORMANCE: 515 mph at 29.530 ft

COMMENT: The Focke-Wulf 190TL was one of the earliest jet projects of the Focke-Wulf Company. First design studies began in 1941 on the basis of a standard Focke-Wulf  Fw 190 fighter then in production. The original BMW 803 radial piston engine was replaced by a Focke-Wulf T. 1 turbojet engine. This comprised a two-stage radial compressor, an annular combustion chamber and a single-stage turbine. The exhaust passed through an annular outlet streaming around the surface of the fuselage. Further work on this project was cancelled in 1942.

Focke Wulf Fw 190A-4 Falcon-wing (Unicraft, Resin, Parts from Airfix)

Bell L-39-1 (IPMS Canada, Resin)

TYPE: Experimental swept-wing aircraft


POWER PLANT: One Allison V-1710-117 liquid-cooled engine, rated at 1,800 hp

PERFORMANCE: 410 mph at 25,000 ft

COMMENT: Two war surplus Bell P-63C Kingcobra fighter aircraft were modified by Bell under Navy contract for flight testing of low-speed and stall characteristics of high-speed wing designs. The aircraft received new wings with adjustable leading edge slats, trailing edge flaps and a pronounced sweep of 35 degrees. The wings had no wheel wells; only the nose gear was retractable. L-39-1 first flew 23 April 1946, demonstrating a need for extra tail surface and rear fuselage length to balance the aircraft in flight—the wing repositioning reduced empennage effectiveness and moved the center of lift aft. A lighter three-bladed propeller from a Bell P-38Q-10 was mounted and the necessary changes to the empennage were made. L-39-2 incorporated these adjustments from the start. L-39-1 later went to NACA at Langley for wind tunnel testing, where much valuable data were gathered. Bell L-39-2 also served as a testbed for the Bell X-2 40-degree wing design (Ref.: 24).

Lockheed “Hudson Mk.V”, RAF, 500rd Squadron (Academy Models)

TYPE: Light bomber, reconnaissance aircraft


POWER PLANT: Two Pratt & Whitney “Twin Wasp” radial engines, rated at 1,200 hp each


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).

Bristol Blenheim Mk. V, RHAF, 13th Squadron (MPM Models)

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).