Info: Early Japanese Army Air Force Aircraft

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#46

Post by Robert Hurst » 09 Jul 2003, 16:27

Hi

Nakajima Ki-27 - Pt 6

In 1940, as the Ki-43 was experiencing considerable difficulties, Nakajima designed a lightweight version of the Ki-27 and two machines of this type, the Ki-27 KAI, were built in July and August 1940. Maximum speed was increased to 474 km/h (295 mph) and wing loading reduced to 80 kg/sq m (16.4 lb/sq ft) but further development was not warranted as the Ki-43 had finally overcome its teething troubles.

Units Allocated

1st,4th, 5th, 11th, 13th, 18th, 21st, 24th, 33rd, 50th, 54th, 59th, 63rd, 64th, 70th, 77th, 85th, 87th, 144th and 246th Sentais; 9th, 10th, 228th, 47th and 84th Dokuritsu Dai Shijugo Chutais; 17th, 27th and 32nd Kyo-iku Hikotais; 5th Lensei Hikotai; Akeno Army Fighter Training School.

Technical Data

Manufacturer: Nakajima Hikoki KK (Nakajima Aeroplane Co Ltd).
Type: Single-engine fighter.
Crew (1): Pilot in enclosed cockpit.
Powerplant: (Type PE, Ki-27 prototypes and pre-production aircraft) One 650 hp Army Type 97 (Nakajima Ha-Ia) nine-cylinder air-cooled radial, driving a two-blade variable-pitch propeller. (Ki-27a, Ki-27b, Ki-27 KAI and Ki-27 Trainer) One 650 hp Army Type 97 (Nakajima Ha-Ib) nine-cylinder air-cooled radial, driving atwo-blade variable-pitch propeller.
Armament: (All versions) Two synchronised 7.7 mm (0.303 in) Type 89 machine-guns. External stores: (Ki-27b, Ki-27 KAI and Ki-27 Trainer) four 25 kg (55 lb) bombs, or two 130 litre (28.6 Imp gal) drop tanks.
Dimensions: 11.31 m (37 ft 1 1/4 in); length 7.54 m (24 ft 8 7/16 in); height 3.25 m (10 ft 7 15/16 in); wing area 18.56 sq m (199.777 sq ft).
Weights: Empty 1,110 kg (2,447 lb); loaded 1,790 kg (3,946 lb); wing loading 96.5 kg/sq m (19.75 lb/sq ft); power loading 2.35 kg/hp (5.2 lb/hp).
Performance: Maximum speed 470 km/h (292 mph) at 3,500 m (11,480 ft); cruising speed 350 km/h (217 mph) at 3,500 m (11,480 ft); climb to 5,000 m (16.405 ft) in 5 min 22 sec; range - normal 627 km (390 miles), maximum 1,710 km (1,060 miles).
Production: A total of 3,399 Ki-27s were built as follows:

Nakajima Hikoki KK at Ota:

1 PE - July 1936.
2 Ki-27 prototypes - October-December 1936.
10 Ki-27 pre-production aircraft - June-December 1937.
2,005 Ki-27a and Ki-27b production aircraft, including Ki-27 Trainer conversions - December 1937-December 1942.
2 Ki-27 KAI prototypes - July-August 1940.

Mansyu Hikoki Seizo KK at Harbin.

1,379 Ki-27a and Ki-27b production aircraft.

Regards

Bob
Attachments
Ki-27b (col 2).jpg
Ki-27b (col 2).jpg (24.63 KiB) Viewed 10676 times
Ki-27b (col 1).jpg
Ki-27b (col 1).jpg (23.07 KiB) Viewed 10677 times
Ki-27a.jpg
A gaggle of Ki-27s flying in formation.
Ki-27a.jpg (8.27 KiB) Viewed 10680 times
Last edited by Robert Hurst on 21 Jul 2003, 16:22, edited 4 times in total.

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#47

Post by Robert Hurst » 10 Jul 2003, 14:31

Hi

Kawasaki Ki-28

For various reasons the Army did not accept any of the low-wing monoplane fighter proposals submitted in 1934 by the three major aircraft manufacturers; Kawasaki Ki-5, Mitsubishi Ki-18 and Nakajima Ki-11. Instead, until an acceptable monoplane design was available, the Army chose the classic biplane and more manoeuvrable Kawasaki Ki-10 fighter for production beginning in December 1935, hoping its troublesome engine problems would be solved. Recognising that the next generation of fighters would be monoplanes, the Army announced a new competition in April 1936.

Nakajima and Mitsubishi selected air-cooled engines for their designs, but Kawasaki chose the traditional water-cooled engine for its entry. There was considerable controversy at this time as to which engine would be the better choice. Retractable undercarriages were being adopted for United States and European fighters, but Japanese designers decided to retain the lighter and less troublesome non-retractable undercarriage, and to concentrate their attention on better streamlining.

For Kawasaki, Takeo Doi was assigned as chief designer for the project designated Ki-28. Using his previous experience with the Ki-5 as a starting point, his major differences included a manually-retractable radiator for the engine coolant, a straight wing centre section with taper on the outer panels, and an aspect ratio greater than seven to enhance speed, climb and manoeuvrability. A semi-enclosed cockpit was faired into the fuselage, and Kawasaki adopted for the first time manually-operated split flaps. The Ki-28 was Powered by an 800 hp Kawasaki Ha-9-IIa water-cooled inline engine, and armament consisted of two synchronised 7.7 mm (0.303 in) Type 89 machine-guns.

The design of the Ki-28 was begun in November 1935, and a year later the first prototype was completed and the second in December 1936. After company testing at Kagamigahara, the two prototypes were flown to the Army for evaluation at Tachikawa. Tested against the other contenders, Nakajima's Ki-27 and Mitsubishi's Ki-33, all three were evenly matched.

The Ki-28 recorded the highest speed at 486 km/h (302 mph) and was superior to the others above 5,000 m (16,405 ft) in climb and acceleration. The Ki-28 was really a 'heavy fighter' when compared with the other entries. Its turning radius was greater, but able to fly faster than the two other competitors, the time taken to make a turn was the same. Therefore, in this aerial combat test, it was difficult to conclude which was the better fighter. The Army's steadfast policy in demanding the best in close-in dog fighting capability prevailed; thus in March 1937 the Ki-28 was regarded as unaccpetable. Had the Army recognised the advantage of high-speed hit-and-run tactics sooner, the Ki-28 would have been much more highly regraded. Later, the Army reversed this policy, which made possible its acceptance of the Kawasaki Ki-60 and Ki-61 fighters.

Technical Data.

Manufacturer: Kawasaki Kokuki Kogyo KK (Kawasaki Aircraft Engineering Co Ltd).
Type: Single-engine fighter.
Crew (1): Pilot in semi-enclosed cockpit.
Powerplant: One 720-800 hp Kawasaki Ha-9-IIa twelve-cylinder vee water-cooled inline engine, driving a two-blade fixed-pitch metal propeller.
Armament: Two fixed forward-firing 7.7 mm (0.303 in) Type 89 machine-guns.
Dimensions: Span 12 m (39 ft 4 1/2 in); length 7.90 m (25 ft 11 in); height 2.60 m (8 ft 6 1/2 in); wing area 19 sq m (204.521 sq ft).
Weights: Empty 1,420 kg (3,130 lb); loaded 1,760 kg (3,880 lb); wing loading 92.6 kg/sq m (18.9 lb/sq ft); power loading 2.2 kg/hp (4.8 lb/hp).
Performance: 486 km/h (302 mph) at 3,500 m (11,480 ft); climb to 5,000 m (16,405 ft) in 5 min 10 sec; service ceiling 11,000 m 36,089 ft); range 1,002 km (623 miles).
Production: A total of two Ki-28 prototypes were built by Kawasaki in November and December 1936.

The top photo was taken from the Complete Book of Fighters, by William Green & Gordon Swanborough, and the bottom photo was taken from Japanese Aircraft 1910-1941, by Robert C Mikesh and Shorzoe Abe.

Regards

Bob
Attachments
Ki-28 (2).jpg
The Kawasaki Ki-28 Experimental Fighter.
Ki-28 (2).jpg (7.3 KiB) Viewed 10677 times
Ki-28 (1).jpg
Ki-28 (1).jpg (10.76 KiB) Viewed 10676 times
Last edited by Robert Hurst on 21 Jul 2003, 16:23, edited 3 times in total.


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#48

Post by Robert Hurst » 11 Jul 2003, 12:34

Hi

Mitsubishi Ki-30 - Pt 1

Although remembered as the first Japanese light bomber fitted with a double-row air-cooled radial engine, variable-pitch propeller, internal bomb-bay and split flaps, the Ki-30 cannot boast any claim to fame. Its operational career was inconspicuous as it served mainly in China at a time when little or no enemy opposition faced the Imperial Japanese Army, but, being a remarkably easy aircraft to fly and maintain and possessing few or no vices, the Ki-30 was long remembered by its crews.

In the mid-thirties the Army began an ambitious expansion and modernisation programme based on a new series of aircraft designed and built in Japan. By the spring of 1936 prototypes of fighter, heavy bomber and reconnaissance aircraft - leading to the production of the Nakajima Ki-27, Mitsubishi Ki-21 and Mitsubishi Ki-15 - had been ordered and it only remained to provide a suitable replacement for the Kawasaki Ki-3 and Mitsubishi Ki-2 then serving in the Army's light bomber units.

This gap in their re-equipment programme was filled in May 1936 when the Koku Hombu instructed Mitsubishi and Kawasaki each to build before December 1936 two prototypes of light bombers. Requirements included: (1) maximum speed, 400 km/h (248.5 mph) at 3,000 m (9,845 ft); (2) operating alititude, 2,000 to 4,000 m (6,560 to 13,125 ft); (3) climb to 3,000 m (9,845 ft) in 8 min; (4) powerplant, one 825 hp Mitsubishi Ha-6 radial, or one 850 hp Nakajima Ha-5 radial, or one 850 hp Kawasaki Ha-9-IIb liwuid-cooled engines; (5) normal bomb-load 300 kg (661 lb) and maximum bobm-load, 450 kg (992 lb); (6) armament, one forward-firing machine-gun and one flexible rear-firing machine-gun; (7) ability to perform 60 degree dives; (8) crew of two; and (9) loaded weight not to exceed 3,200 kg (7,275 lb).

The photos were taken from Japanese Aircraft of the Pacific War, by Rene J Francillon.

Regards

Bob
Attachments
Ki-30 (3).jpg
Mitsubishi Ki-30s of the 90th Sentai.
Ki-30 (3).jpg (11.21 KiB) Viewed 10662 times
Ki-30 (2).jpg
A Mitsubishi Ki-30 Army Type 97 Light Bomber.
Ki-30 (2).jpg (13.04 KiB) Viewed 10659 times
Ki-30 (1).jpg
A Mitsubishi Ki-30 in factory finish.
Ki-30 (1).jpg (7.16 KiB) Viewed 10665 times
Last edited by Robert Hurst on 21 Jul 2003, 16:24, edited 2 times in total.

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#49

Post by Robert Hurst » 11 Jul 2003, 16:23

Hi

Mitsubishi Ki-30 - Pt 2.

Designed by Engineers Kawano, Ohki and Mizuno working under the supervision of Col. Komamura, the Mitsubishi Ki-30 was originally conceived with a retractable main undercarriage. However, when wind-tunnel tests indicated that the gain in speed would be more than offset by the added weight and complexity of the retractable undercarriage, a fixed gear with spatted main wheels was adopted. The design team also selected a mid-mounted wing fitted with landing flaps to allow the installation of a fuselage bomb-bay. So fitted, and powered by a Mitsubishi Ha-6 radial, driving a three-blade variable-pitch propeller, the first prototype made its maiden flight at Kagamigahara on 28 February, 1937 with test pilot Yamaguchi at the controls. A second prototype, powered by a Nakajima Ha-5 radial, was completed the same month. Although these aircraft were completed two months behind schedule and were slightly overweight, their handling characteristics and performance exceeded requirements. A maximum speed of 423 km/h (263 mph) at 4,000 m (13,125 ft) was achieved and satisfied the Army's most sanguine hopes.

Sixteen Service trials aircraft, each powered by a 850 hp Nakajima Ha-5 KAI radial rated at 950 hp for take-off amd 960 hp at 3,000 m (11,810 ft), were built by January 1938 and differed from the prototypes by the relocation in the left wing of the forward-firing 7.7 mm (0.303 in) Type 89 machine-gun previously mounted in the left main undercarriage and by the removal of the outboard wheel covers to facilitate operations from muddy fields, a modification dictated by the results of special tests conducted in October 1937 with one of the prototypes. Ski-operations were also tested in May 1939. Mass produciton of the Ki-30 as the Army Type 97 Light Bomber began at Mitsubishi's Nagoya plant in March 1938 where 618 production aircraft were built up to Arpil 1940, and a further 68 aircratf were built at Tachikawa by the Tachikawa Dai-Ichi Rikugun Kokusho (First Army Air Arsenal).

The Ki-30's two-man crew were housed beneath a long raised glazed canopy. Armament comprised a wing-mounted forward-firing 7.7 mm (0.303 in) machine-gun with a similar weapon on a flexible mounting in the rear cockpit operated by the observer. The Normal bomb-load of 300 kg (661 lb) was carried internally in the bomb-bay.

The Ki-30 began its operational career on the Chinese mainland in 1938 where it proved to be one of the Japanese Army's most reliable aircraft, and losses caused by enemy aircraft were low as it operated within the range of the Ki-27 fighter. The Ki-30 was used mainly in attacks on enemy troops and strong points . When the Pacific War started Ki-30 units were also committed to operations in the Philippines after Allied aircraft had been driven off, but the type was already reaching the end of its operational life as losses increase sharply as soon as it was committed to theatres where Allied aircraft were operating. The Ki-30 from then on was gradually transferred to the crew training role while others were delivered to the Royal Thai Air Force which first deployed the their Ki-30s in January 1941 against French forces in Indo-China. Finally the Ki-30, code named 'Ann' by the Allies, joined other obsolete aircraft allocated to suicide operations towards the end of the war.

Units Allocated

6th, 16th, 31st, 32nd and 90th Sentais. 82nd and 87th Dokuritsu Hiko Chutais.

Technical Data

Manufacturer: Mitsubishi Jukogyo KK (Mitsubishi Heavy Industries Co Ltd)
Type: Single-engine light bomber.
Crew (2): Pilot and observer in tandem enclosed cockpits.
Powerplant: (first prototype) One 825 hp Mitusibish Ha-6 fourteen-cylinder air-cooled radial, driving a three-blade variable-pitch metal propeller; (remainder of Ki-30s built) One 850 hp Army Type 97 (Nakajima Ha-5 KAI) fourteen-cylinder air-cooled radial, driving a three-blade variable-pitch metal propeller.
Armament: One wing-mounted 7.7 mm (0.303 in) Type 89 machine-gun and one flexible 7.7 mm (0.303 in) Type 89 machine-gun; Bomb-load - normal 300 kg (661 lb), maximum 400 kg (882 lb).
Dimensions: Span 14.55 m (47 ft 8 27/32 in); length 10.34 m (33 ft 11 3/32 in); height 3.645 m (11 ft 11 1/2 in); wing area 30.58 sq m (329.159 sq ft).
Weight: Empty 2,230 kg (4,916 lb); loaded 3,322 kg (7,324 lb); wing loading 108.6 kg/sq m (22.3 lb/sq ft); power loading 3.5 kg/hp (7.7 lb/hp).
Performance: maximum speed 432 km/h (263 mph) at 4,000 m (13,125 ft); crusing speed 380 km/h (236 mph); climb to 5,000 m (16,405 ft) in 10 min 36 sec; service ceiling 8,570 m (28,120 ft); range 1,700 km (1,056 miles).
Production: A total of 704 Ki-30s were built by Mitsubishi Jukogyo KK at Nagoya and Tachikawa Dai-Ichi Rikugun Kokusho at Tahikawa as follows:

Mitsubishi Jukogyo KK:

2 prototypes - February 1937
16 Service trials aircraft - March 1937-January 1938
618 production aircraft - March 1938-April 1940

Tachikawa Dai-Ichi Rikugun Kokusho:

68 production aircraft - 1939-September 1941

The top photo and bottom colour print were taken from The Encyclopedia of World Aircraft, by David Donald.

Regards

Bob
Attachments
Ki-30 (col).jpg
Ki-30 (col).jpg (11.05 KiB) Viewed 10635 times
Ki-30 (5).jpg
Ki-30 (5).jpg (8.69 KiB) Viewed 10633 times
Ki-30 (4).jpg
Ki-30 (4).jpg (9.62 KiB) Viewed 10637 times
Last edited by Robert Hurst on 21 Jul 2003, 16:24, edited 1 time in total.

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#50

Post by Robert Hurst » 14 Jul 2003, 15:37

Hi

Kawasaki Ki-32 - Pt 1

The Kawasaki Ki-32, which was the last type of bomber aircraft powered by a liquid-cooled engine to be used by the Japanese Army, had more than the average share of teething troubles, and although as technically remarkable as the contemporary Mitsubishi Ki-30 designed to meet the same military requirements, it never achieved the fame of its Mitsubishi rival.

In May 1936, the Army instructed Mitsubishi and Kawasaki to design a single-engine light bomber to replace the obsolete Army Type 93 Single-engined Light Bomber (Kawasaki Ki-3). Possessing a maximum speed of 400 km/h (248.5 mph) at 3,000 m (9,845 ft), the aircraft was required to carry a bomb-load of 300 to 450 kg (661 to 992 lb) at a cruising speed of 300 km/h (186 mph) between 2,000 and 4,000 m (6,560 to 13,125 ft) and was to carry a defensive armament comprising a fixed forward-firing 7.7 mm (0.303 in) machine-gun, and a flexible rear-firing 7.7 mm (0.303 in) machine-gun.

Like the their rivals at Mitsubishi, the Kawasaki design team, led by engineers Isamu Imashi and Shiro Ota, adopted for the Ki-32 a mid-wing cantilever monoplane configuration with a fixed spatted undercarriage and an internal bomb-bay but, whereas the Mitsubishi engineers had selected an air-cooled engine, Kawasaki decided to use an Ha-9-II engine of their own design, the choice of this twelve-cylinder liquid-cooled engine later proving to be the source of considerable difficulty.

The photos were taken from Japanese Aircraft of the Pacific War, by Rene J Francillon.

Regards

Bob
Attachments
Ki-32 (3).jpg
The Kawasaki Ki-32 Army Type 98 Single-engined Light Bomber.
Ki-32 (3).jpg (6.07 KiB) Viewed 10620 times
Ki-32 (2).jpg
Kawasaki Ki-32s of the 75th Sentai, 2nd Chutai. Rudder markings were red.
Ki-32 (2).jpg (13.74 KiB) Viewed 10621 times
Ki-32 (1).jpg
The Kawasaki Ki-32 light bomber resulted from a specification issued in May 1936. In 1942 Ki-32s were relegated to training duties.
Ki-32 (1).jpg (19.33 KiB) Viewed 10628 times
Last edited by Robert Hurst on 21 Jul 2003, 16:25, edited 1 time in total.

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#51

Post by Robert Hurst » 14 Jul 2003, 16:04

Hi

Kawasaki Ki-32 - Pt 2

A wooden mock-up was constructed in the summer of 1936. The first of eight Ki-32 prototypes was completed and flown in March 1937 but flight trials were marred by protracted engine teething troubles necessitating several redesigns of the engine nacelle and a strengthening of the crankshaft. During competitive trials against the Mitsubishi Ki-30, the Ki-32 was found to possess better flying characteristics. However, the Japanese Army, which by now had a fully-fledged war on their hands, decided first to order the Mitsubishi aircraft with its more reliable powerplant. Finally, in July 1938, the Ki-32 was also placed in production as the Army Type 98 Single-engined Light Bomber, and ultimately more Ki-32s than Ki-30s were built.

The Ki-32 was very manoeuvrable despite its bulk and had a very pleasing appearanvce, with beautifully tapered wings and tail surfaces, a long raised canopy for its two-man crew, and fixed single-strut cantilever undercarriage legs, which had open-sided spats on the lines of the Mitsubishi Ki-30. Although the Ki-32 was fitted with a fixed undercarriage it was slightly faster than the contemporary British Fairey Battle with its retractable undercarriage and it should be remembered as one of the types which brought Japanese military aviation on a par with the air forces of the Western nations.

In service the Ki-32 was liked by its crews for its manoeuvrability, superior to that of the Ki-30, and it took an active part in the second Sino-Japanese conflict despite the fact that its liquid-cooled engine proved susceptible to battle damage. They flew with considerable success with seven operational Sentais (Groups) in China, where they made many devastating low-level sorties, particularly in the campaigns to capture the cities of Hangchow and Wuchang during 1938-39. They equipped two operational Sentais during the fierce fighting over the Khalkin Gol and Nomonhan on the border of Manchuria and Outer Mongolia against Soviet ground and air units in 1939. In December 1941 the Ki-32 was still in front-line service and the type took part in the bombing operations leading to the surrender of the Commonwealth forces defending Hong Kong. During 1942 the Ki-32, code-named 'Mary' by the Allies were nearly all relegated to training duties.

The top photo was taken from Japanes Aircraft of the Pacific War, by Rene J Francillon, the centre photo was taken from The Concise Guide to Axis Aircraft of World War II, by David Mondey and the bottom photo was taken from The Encyclopdeia of World Aircraft, by David Donald.

Units Allocated

3rd, 6th, 10th, 35th, 45th, 65th and 75th Sentais.

Technical Data

Manufacturer: Kawasaki Kokuki KK (Kawasaki Aircraft Engineering Co Ltd).
Type: Single-engine light bomber.
Crew (2): Pilot and radio-operator/bombardier in tandem enclosed cockpit.
Powerplant: One 850 hp Army Type 98 (Kawasaki Ha-9-IIb) twelve-cylinder vee liquid-cooled engine, driving a three-blade variable-pitch metal propelller.
Armament: One forwar-firing 7.7 mm (0.303 in) Type 89 machine-gun in the engine cowling and one flexible 7.7 mm (0.303 in) Type 89 machine-gun; Bomb-load - normal 300 kg (661 lb), maximum 450 kg (992 lb).
Dimensions: Span 15 m (49 ft 2 9/16 in); length 11.64 m (38 ft 2 9/32 in); height 2.9 m (9 ft 6 3/16 in); wing area 34 sq m (365.972 sq ft).
Weight: Empty 2,349 kg (5,179 lb); loaded 3,539 kg (7,802 lb); maximum 3,762 kg (8,294 lb); wing loading 104.1 kg/sq m (21.3 lb/sq ft); power loading 4.2 kg/hp (9.2 lb/hp).
Performance: maximum speed 423 km/h (263 mph) at 3,940 m (12,925 ft); cruising speed 300 km/h (186 mph); climb to 5,000 m (16,405 ft) in 10 min 55 sec; service ceiling 8,920 m (29,265 ft) range - normal 1,300 km (826 miles), maximum 1,960 km (1,218 miles).
Production: A total of 854 Ki-32s were built by Kawasaki Kokuki Kogyo KK as follows:

8 Ki-32 prototypes - 1937
846 Ki-32 production aircraft - July 1938-May 1940

Regards

Bob
Attachments
Ki-32 (6).jpg
A Kawasaki Ki-32 Army Type 98 Single-engined Light Bomber.
Ki-32 (6).jpg (10.51 KiB) Viewed 10607 times
Ki-32 (5).jpg
Ki-32 (5).jpg (8.96 KiB) Viewed 10609 times
Ki-32 (4).jpg
Kawasaki Ki-32s with segmented camouflage.
Ki-32 (4).jpg (14.99 KiB) Viewed 10612 times
Last edited by Robert Hurst on 21 Jul 2003, 16:25, edited 1 time in total.

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#52

Post by Robert Hurst » 15 Jul 2003, 12:01

Hi

Mitsubishi Ki-33

After the failure of the Ki-11 and the non-acceptance of the Ki-18, the Army informed three of the major manufacturers in December 1935 that a new competition would be held for a new fighter the following April. This date was based upon the expected availability of the new Army Ha-1a engine. Features asked for in the competition closely followed those of the rejected Ki-18.

In response, Mitsubishi engineers felt that the company was too involved with two 9-Shi aircraft, the A5M fighter and the G3M bomber, both of which had recently been accepted by the Navy. There was no advantage in diluting manpower resources with separate projects for both the Army and Navy. In addition, the rejection by the Army of the Ki-18 in light of outstanding capability was considered to be a second rejection on principles rather than quality.

An internal debate between Mitsubishi's marketing division and its engineers brought about a compromise that the Army's purchase order would be honoured provided it did not noticeable drain on engineering resources unless such design work was absolutely necessary.

The new fighter was designated Ki-33. Chief designer was Jiro Horikoshi, who had designed the 9-Shi Fighter. By August 1936, the first prototype was completed, far earlier than the other companies' prototypes. This was understandable because Mitsubishi had current fighter designs and fabrication experience with its existing models. When the second prototype was completed, both aircraft were delivered to the Army after company tests flights at Kagamigahara. During competitive trials with the Ki-27 and Ki-28 from November 1936 until the spring of 1937, it was found to offer marginally superior max speeds between 2,500 (8,200) and 3,500 m (11,480 ft) over the 167 kg (257 lb) lighter Ki-27, but the Ki-33 revealed an inferior turn rate and climb to those of the Nakajima contender.

In appearance, the Ki-33 closely resembled the Navy A5M1 Fighter, as did the Ki-18 which had been rejected. What made the this aircraft significant, aside from the Ha-1 replacing the Kotobuki 5 engine, was the wash-out of the wing that Horikoshi introduced into the design of the second prototype for comparison with the first prototype which had a conventional wing. This wash-out reduced wingtip stall at high angles of attack, which is so essential for improved manoeuvrability when dog-fighting.

The Ki-33 was low-wing monoplane of all-metal construction with fabric-covered control surfaces, fitted with a 620 hp Nakajima Ha-Ia radial rated at 710 hp for take-off and 745 hp at 3,700 m (12,140 ft) and enclosed by a broad-chord cowling. The pilot was housed in an enclosed cockpit with aft-sliding canopy.

Mitsubishi's competitors were much later with their test aircraft. By the time they produced their second prototypes, they too had the wash-out feature incorporated into the wingtips. The results of the evaluation concluded that the Ki-33 was superior to the Nakajima Ki-27 both in speed and control. However, the prolonged evaluation of the two designs resulted in modifications made by Nakajima to the Ki-27, some of which included three newer wing designs with different wing area and wash-out. Mitsubishi made few if any changes to its Ki-33, recognising a pattern, either real or imagined, of the rejection cycle that had occured with its Ki-18.

As a consequence, the Nakajima Ki-27 was determined to be the superior fighter and was accepted by the Army as the Type 97 Fighter. Kawasaki's Ki-28 with its Water-cooled Ha-9-IIa recorded the maximum speed of 482 km/h (300 mph) during the winter season (speed would have decreased by 10.1 km/h (6.3 mph) during the heat of the summer). The fighter failed in the competition because Kawasaki ignored the importance placed by the Army on manoeuvrability for dog-fighting rather than pure speed.

Technical Data

Manufactuer: Mitsubishi Jukogyo KK (Mitsubishi Heavy Industries Co Ltd).
Type Single-engine fighter.
Crew (1): Pilot in enclosed cockpit.
Powerplant: One 620-745 hp Nakajima Ha-Ia nine-cylinder air-cooled radial engine, driving a two-blade metal propeller.
Armament: Two fixed forward-firing 7.7 mm (0.303 in) Type 89 machine-guns.
Dimensions: Span 11 m (36 ft 1 3/16 in); length 7.545 m (24 ft 9 1/16 in); height 3.19 m (10 ft 5 19/32 in); wing area 17.80 sq m (191.597 sq ft).
Weights: Empty 1.132 kg (2,496 lb); loaded 1,462 kg (3,223 lb); wing loading 82.1 kg/sq m (16.8 lb/sq ft); power loading 2.1 kg/hp (4.5 lb/hp).
Performance: Maximum speed 475 km/h (295 mph) at 3,000 m (9,845 ft); climb to 5,000 m (16.405 ft) in 5 min 56 sec
Production: A total of two Ki-33 prototypes were built in 1936 by Mitsubishi Jukogyo at Nagoya.

The top photo was taken from Japanese Aircraft 1910-1941, by Robert C Mikesh & Shorzoe Abe, and the bottom photo was taken from The Complete Book of Fighters, by William Green & Gordon Swanborough.

Regards

Bob
Attachments
Ki-33 (2).jpg
Ki-33 (2).jpg (14.25 KiB) Viewed 10584 times
Ki-33 (1).jpg
The Mitsubishi Ki-33 Experimental Fighter.
Ki-33 (1).jpg (7.09 KiB) Viewed 10590 times
Last edited by Robert Hurst on 21 Jul 2003, 16:26, edited 1 time in total.

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#53

Post by Robert Hurst » 16 Jul 2003, 15:02

Hi

Nakajima Ki-34

Having acquired the manufacturing rights for the Douglas DC-2, in 1935 Nakajima undertook the design of a smaller twin-engined aircraft for use on short-haul light traffic routes. Engineer Akegawa was assigned the responsibility of designing the aircraft then known as the Nakajima Aerial Transport No.1, or AT-1, and took his inspiration from the Douglas DC-2, Northrop 5A and Clark GA-43. During its design the aircraft was extensively modified and when completed in 1936 was designated Nakajima AT-2, the letter A standing for Akegawa.

The AT-2 was a racy all-metal low-wing cantilever monoplane with slim tapered wings and tailplane and retractable undercarriage, accommodation was provided for a crew of three and eight passengers. Powered by two 580 hp Nakajima Kotobuki 2-I radials driving two-blade fixed-pitch propellers, the prototype was first flown on 12 September, 1936, from Ojima Airfield. During its tests the aircraft was flown by pilots from the manufacturer, Japan Air Transport Co, Manchurian Airlines Co, the Japanese Civil Aeronautics Authority and the two military Services. The AT-2 demonstrated excellent performance and was quite stable, but minor problems arose with engine cooling, equipment and undercarriage retraction mechanism. These deficiencies were corrected on the production machines, and powered by two 710 hp Nakajima Kotobuki 41 engines, rated at 780 hp at 2,800 m (9,185 ft), thirty-two aircraft were built between 1937 and 1940 for Dai Nippon Koku KK (Greater Japan Air Lines Co Ltd) and Manchurian Airlines Co with which they served on internal and external routes until the end of the war.

In 1937, the Koku Hombu, anxious to introduce a modern transport aircraft into the air force inventory, decided to adopt the AT-2., the aircraft being adopted into the JAAF as a communication and paratroop transport aircraft, the Army machines being designated Army Type 97 Transport (Ki-34). Powered by two 710 hp Nakajima Ha-Ib engines rated at 780 hp at 2,800 m (9,185 ft), and enclosed in smooth NACA-type cowlings similar to those fitted to late production civil AT-2s, nineteen Ki-34s were built by Nakajima between 1937 and 1940. However, more Ki-34s were manufactured by Tachikawa Hikoki KK which delivered 299 machines of this type. Some ki-34s were handed over to the Japanese Navy and were designated Navy Type AT-2 Transport (Nakajima L1N1) by that Service.

Both civil and military versions were allocated the Allied code name 'Thora', and were used as transports throughout the Pacific war.

Technical Data

Manufacturer: Nakajima Hikoki KK
Type: Twin-engined transport
Crew (3+8): Pilot, co-pilot & navigator plus eight passengers.
Powerplant: (AT-2 prototype) Two 580 hp Nakajima Kotobuki 2-I nine-cylinder air-cooled radial engines, driving two-blade fixed-pitch wooden propellers; (production AT-2, Ki-34 & LINI) Two 710 hp Nakajima Kotobuki 41 or Nakajima Ha-Ib nine-cylinder air-cooled radial engines, driving two-blsade variable-pitch propellers.
Dimensions: Span 19.916 m (65 ft 0 1/8 in); length 15.3 m (50 ft 2 3/8 in); height 4.15 m (13 ft 7 3/8 in); wing area 49.2 sq m (529.582 sq ft).
Weights: Empty 3,500 kg (7,716 lb); loaded 5,250 kg (11,754 lb); wing loading 106.7 kg/sq m (21.9 lg/sq ft); power loading 3.7 kg/hp (8.15 lb/hp).
Performance: Maximum speed 360 km/h (224 mph) at 3,360 m (11,025 ft); crusing speed 310 km/h (193 mph); climb to 3,000 m (9,840 ft) in 6 min 38 sec; service ceiling 7,000 m (22,965 ft);range 1,200 km (745 miles).
Production: A total of 351 AT-2, Ki-34 and L1N1 were built as follows:

Nakajima Hikoki KK at Ota:

1 AT-2 prototype - October 1936
32 AT-2 production aircraft 1937-1940
19 Ki-34 and L1N1 produciton aircraft 1937-1940

Tachikawa Hikoki KK at Tachikawa:

299 Ki-34 and L1N1 production aircraft 1939-1942.

The top photo was taken from Japanese Aircraft of the Pacific War, by Rene J Francillon, and the bottom photo was taken from The Encyclopedia of World Aircraft, by David Donald.

Regards

Bob
Attachments
Ki-34 (2).jpg
The AT-2 was inspired by the Douglas DC-2, and despite problems with engine cooling, landing gear retraction, and some other equipment, it proved popular.
Ki-34 (2).jpg (5.83 KiB) Viewed 10579 times
Ki-34.(1) jpg.jpg
An early production AT-2 transport of Japan Air Transport. This was the forerunner of the Japanese Army Ki-34.
Ki-34.(1) jpg.jpg (11.09 KiB) Viewed 10576 times
Last edited by Robert Hurst on 25 Jul 2003, 16:07, edited 4 times in total.

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#54

Post by Perfectionistul » 16 Jul 2003, 17:45

this deserves to be a sticky! 8O

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Robert Hurst
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#55

Post by Robert Hurst » 17 Jul 2003, 11:42

Hi

Tachikawa Ki-36

In May 1937 the Koku Hombu issued a specification calling for a two-seat army co-operation machine. The aircraft was to be a fast single-engined monoplane capable of operating from small rough strips immediately behind the front lines. Good downward visibility from the cockpit and extreme manoeuvrability at low altitudes were among the prime requirements for the aircraft, which was to incorporate provision for photographic and radio equipment in addition to bomb racks for light anti-personnel bombs.

Competitive designs to this specification were submitted by Mitsubishi Jukogyo KK (Ki-35) and Tachikawa Hikoki KK (Ki-36), but only the conctruction of Tachikawa Ki-36 prototypes was authorised by the Koku Hombu. Despite the stringent demands for good cockpit visibility, manoeuvrability and short-field performance, Ryokichi Endo, who led the Tachikawa engineering team, designed a conventional all-metal low-wing monoplane with considerable dihedral on the outer wing sections and a fixed single-cantilever strut-type spatted undercarriage. To obtain the necessary low speed handling characteristics Endo strove to design a light airframe which, combined with a large wing area, resulted in a low wing loading. Sensitivity of controls was achieved by using large-size elevators and rudder. Despite the cockpit location over the wings, the pilot had a good field of view forward and downward due to the large degree of sweepback incorporated in the wing leading edges, while large windows under the wing centre-section provided a good field of view for the observer.

Powered by a 450 hp Hitachi Ha-13a nine-cylinder air-cooled radial, rated at 510 hp for take-off and 470 hp at 1,700 m (5,580 ft), and driving a two-blade wooden propeller, the first prototype was completed in March 1938 and made its maiden flight at Tachikawa on 20 April, 1938. During flight tests the aircraft performed satisfactorily and demonstrated brisk take-off and flight performance. Because the first Ki-36 suffered from wingtip stall, the second prototype had fixed leading edge slots near the wingtips to correct this deficiency. Both prototypes were armed with a fixed forward-firing 7.7 mm (0.303 in) Type 89 machine-gun mounted offset to starboard within the engine cowling and with a similar flexible rear-firing machine-gun manned by the observer, and racks were mounted under the wings for ten 12.5 kg (27.5 lb) or 15 kg (33 lb) anti-personnel bombs. In this form the aircraft was ordered into production as the Army Type 98 Direct Co-operation Plane, beginning at Tachikawa in November 1938, and in 1940 production was also initiated by Kawasaki Kokuki Kogyo KK. Late production aircraft built by Tachikawa and Kawasaki featured a two degree wing wash-out to improve stall characteristics.

Assigned in small detachments to ground units of the Japanese Army, the Ki-36s operated successfully during the second Sino-Japanese conflict. The ability of this aircraft to utilize small airstrips close to the battlefields made it popular with ground commanders, and by using all its qualities to the full when deployed in small numbers in support of attacking Japanese ground forces, the Ki-36 contributed significantly to the demoralisation of the hard-pressed Chinese troops.

However, when the Pacific War began, the Ki-36, Allied code name 'Ida' suffered heavy losses when faced by Allied fighters, and from 1943 onwards, the aircraft was relegated to units operating in China where they encountered fewer Allied aircraft, while a small number of Ki-36s were suppplied to Thailand.

During the last year of the war a number of Ki-36s, were expended in suicide sorties for which they carried externally a single 250 or 500 kg (551 or 1,102 lb) bomb.

An advanced version of the Ki-36 featuring a retractable undercarriage and powered by a 600 hp Hitachi Ha-38 nine-cylinder radial driving a three-blade propeller was designed by Tachikawa under the designation of Ki-72 but was not built.

The top photo was taken from Japanese Aircraft of the Pacific War, by Rene J Francillon, the centre photo was taken from The Concise Guide to Axis Aircraft of World War II, by David Mondey and the bottom photo was taken from War Machine Pt 11: Light Aircraft of World War II.

Units Allocated.

29th and 44th Sentais; 17th , 44th, 45th, 66th and 74th Dokuritsu Dai Shijugo Chutais; Korean Command; Central Command; 7th and 8th Ground Support Units.

Technical Data

Manufacturer: Tachikawa Hikoki KK (Tachikawa Aeroplane Co Ltd).
Type: Single-engined army co-operation aircraft.
Crew (2): Pilot and observer in enclosed cockpit.
Powerplant: One 450 hp Army Type 98 (Hitachi Ha-13a) nine-cylinder air-cooled radial engine, driving a two-bloade wooden propeller.
Armament: One forward-firing 7.7 mm (0.303 in) Type 89 machnine-gun and one flexible rear-firing 7.7 mm (0.303 in) Type 89 machine-gun; external load: ten 12.5 or 15 kg (27.5 or 33 lb) bombs; Suicide sorties: one 250 or 500 kg (551 or 1,102 lb) bomb.
Dimensions: Span 11.8 m (38 ft 8 9/16 in); length 8 m (26 ft 2 31/32 in); height 3.64 m (11 ft 11 5/16 in); wing area 20 sq m (215.277 sq ft).
Weights: Empty 1,247 kg (2,749 ft); loaded 1,660 kg (3,660 lb); wing loading 83 kg/sq m (17 lb/sq ft); power loading 3.3 kg/hp (7.2 lb/hp).
Performance: 348 km/h (216 mph) at 1,800 m (5,905 ft); crusing speed 236 km/h (147 mph); climb to 3,000 m (9,845 ft) in 6 min 39 sec; service ceiling 8,150 m (26,740 ft); range 1,235 km (767 miles).
Production: A total of 1,334 Ki-36s were built as follows:

Tachikawa Hikoki KK at Tachikawa:

2 Ki-36 prototypes - spring 1938
860 Ki-36 production aircraft - November 1938-January 1944

Kawasaki Kokuki Kogyo KK at Gifu:

472 Ki-36 production aircraft - June 1940-may 1942.

Regards

Bob
Attachments
Ki-36 (1).jpg
Tachikawa Ki-36 Army Type Direct Co-operation Plane.
Ki-36 (1).jpg (14.61 KiB) Viewed 10544 times
Ki-36 (3).jpg
The Tachikawa Ki-36 Chokusetsu-Kyodoki (Direct Co-operation Plane).
Ki-36 (3).jpg (59.36 KiB) Viewed 10536 times
Ki-36 (2).jpg
The Tachikawa Ki-36 was used as an army co-operation aircraft.
Ki-36 (2).jpg (14.84 KiB) Viewed 10535 times

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#56

Post by Robert Hurst » 23 Jul 2003, 16:09

Hi

Kawasaki Ki-48 - Pt 1

Early in the second Sino-Japanese conflict the appearance of the Russian-built Tupolev SB-2 in Chinese skies took the Japanese Army completely by surprise. Initially at least, the SB-2 appeared virually immune from fighter interception as it was almost as fast at altitude as the Nakajima Ki-27, then just entering service with the fighter units of the JAAF. The performance of the Russian aircraft so impressed Japanese staff officers that they obtained authorisation from the Koku Hombu to begin development of a similar aircraft in Japan. Accordingly in December 1937 Kawasaki Kokuki Kogyo KK were instructed to design a twin-engined light bomber to meet the following requirements: (1) maximum speed, 480 km/h (298 mph) at 3,000 m (9,845 ft); (2) cruising speed, 350 km/h (217 mph) at 3,000 m (9,845 ft); (3) climb to 5,000 m (16,405 ft) in 10 min: (4) bomb-load, 400 kg (882 lb); (5) defensive armament, including three or four flexible 7.7 mm (0.303 in) machine-guns: (6) powerplant, two Nakajima Ha-25 radials, and (7) ability to operate under extreme cold weather conditions such as those prevailing during the winter months on the Manchukuo-Siberian border.

Actual design work on the Ki-48 began in January 1938 with Takeo Doi acting as chief engineer. The Ki-48 was a mid-wing all-metal cantilever monoplane, the mid-wing cantilever configuration being selected to allow the use of an internal bomb-bay. The fuselage was cut down aft of the dorsal gunner's cockpit and the ventral gunner's stepped position. The bomb-aimer/nose gunner's position was fully glazed. There was a single curved fin and rudder, and the main undercarriage legs retracted backwards to lie fully enclosed in the engine nacelles.

The crew of four consisted of a pilot, a bombardier/gunner manning the flexible 7.7 mm (0.303 in) Type 89 machine-gun mounted in the nose, a radio-operator/gunner manning the flexible dorsal mounted gun, and a navigator/gunner manning the flexible Type 89 machine-gun in the ventral position. Normal bomb-load consisted of either twenty-four 15 kg (33 lb) or six 50 kg (110 lb) bombs. The aircraft was powered by two 950 hp Nakajima Ha-25 radial engnes rated at 1,000 hp for take-off and 980 hp at 5,600 m (18,375 ft), and driving variable-pitch propellers. Completion of design work on the Ki-48 was delayed because of difficulties encountered with the Ki-45 programme required Takeo Doi's constant attention and the first of four Ki-48 prototypes was not competed until July 1939.

The top photo was taken from Japanese Aircraft of the Pacific War, by Rene J Francillon, the middle photo was taken from, and the bottom photo was taken from The Concise Guide to Axis Aircraft of World War II, by David Mondey.

Regards

Bob
Attachments
Ki-48-I (2).jpg
Ki-48-I (2).jpg (7.33 KiB) Viewed 10492 times
Ki-48-I.(1) jpg.jpg
A formation of Kawasaki Ki-48 Army Type 99 Twin-engined Light Bomber Model 1s.
Ki-48-I.(1) jpg.jpg (8.37 KiB) Viewed 10495 times
Ki-48-Ia.jpg
This picture of a Kawasaki Ki-48-Ia shows its similarity in concept to the Tupolev SB-2.
Ki-48-Ia.jpg (10.18 KiB) Viewed 10492 times
Last edited by Robert Hurst on 24 Jul 2003, 14:37, edited 1 time in total.

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#57

Post by Robert Hurst » 23 Jul 2003, 16:31

Hi

Kawasaki Ki-48 - Pt 2

During flight trials the Ki-48 easily met all performance requirements and the manoeuvrability and handling characteristics of the aircraft were praised by Service test pilots who submitted the aircraft to intensive testing at Tachikawa. However, the prototypes suffered from sever tail flutter, and five pre-production Ki-48s, built between September and November 1939, were used to test various tail surface modifications. By raising the horizontal tail surfaces 400 mm (13 3/4 in) and strengthening the rear fuselage the tail flutter problem was eradicated, and in late 1939 quantity production of the aircraft was initiated under the designation Army Type 99 Twin-engined Light Bomber Model 1A (Ki-48-Ia).

The first production Ki-48-Ia was completed in July 1940 and as soon as sufficient aircraft were available the 45th Sentai, previously flying the Kawasaki Ki-32 converted to the Army Type 99 Twin-engined Light Bomber. In the autumn of 1940, this unit was transferred to the Northern China front where the Ki-48 distinguished itself in combat. Facing virtually no opposition from the Chinese Air Force, the Ki-48-Is performed satisfactorily and the aircraft's speed was praised by its crews. In addition to purely tactical sorties, the Ki-48s were also used for strategic operations at night in preparation for forthcoming deployment against British and American forces.

Late production aircraft were designated Ki-48-Ib or Model 1B and incorporated various minor equipment changes and improved gun mountings, and a total of 557 Ki-48-Ias and -Ibs were built until June 1942. When the Pacific War began the Ki-48-Is were the Army's most important light bomber outside the Chinese front, and the aircraft of the 8th, 27th, 75th and 90th Sentais initially operated against British Commonwealth forces in Malaya and Burma and against American forces in the Philippines, prior to being deployed with the advancing forces into the Netherland East Indies/New Guinea area. Against Allied aircraft the Ki-48-I did not fare too well as its speed was too low to avoid interception, its defensive armament was ineffective, its bomb-load was insufficient and it lacked crew and petrol tank protection. To limit combat losses the aircraft were operated at night whenever possible thus reducing their effectiveness. However, an improved model of the aircraft was already under development when the Pacific War began.

The top photo was taken from Japanese Aircraft of the Pacific War, by Rene J Francillon, the bottom photo was taken from The Encyclopedia of World Aircraft, by David Donald.

Regards

Bob
Attachments
Ki-48-IIa (1).jpg
The Kawasaki Ki-48-IIa was the direct product of combat experience with the Ki-48-I.
Ki-48-IIa (1).jpg (6.93 KiB) Viewed 10480 times
Ki-48-II (2).jpg
A Ki-48-II with Ne-0 turbojet unit slung beneath the fuselage.
Ki-48-II (2).jpg (10.84 KiB) Viewed 10482 times
Ki-48-II (1).jpg
A Kawasaki Ki-48-II Army Type 99 Twin-engined Light Bomber Model 2 at Clark Field, Manila.
Ki-48-II (1).jpg (17.4 KiB) Viewed 10477 times

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#58

Post by Robert Hurst » 24 Jul 2003, 14:57

Hi

Kawasaki Ki-48 - Pt 3

Powered by two 1,150 hp Nakajima Ha-115 engines, an advanced version of the Ha-25 with two-stage blower rated at 1,130 hp for take-off, 1,070 hp at 2,800 m (9,185 ft) and 950 hp at 5,600 m (18,275 ft), three Ki-48-II prototypes were completed in February 1942. With the exception of a small increase in fuselage length introduced to improve stability, the Ki-48-II was externally identical to the Ki-48-I but as well as fuel tank protection there was armour plating for the crew in the form of a 12.5 mm (0.492 in) plate behind the bombardier's seat , a 6.5 mm (0.255 in)plate under the pilot's seat, a 16.5 mm (0.649 in) plate behind the pilot's seat and 16.5 mm (0.649 in) plates behind the ammuntion boxes of the dorsal and ventral machine-guns. Within two months of its first flight the Ki-48-II was placed in production as the Army Type 99 Twin-engined Light Bomber Model 2A. The Ki-48-II production aircraft differed from the Ki-48-II prototypes in minor details such as local srengthening of the fuselage. The Ki-48-IIb or Model 2b was a dive-bomber version incorporating retractable snow-fence type dive-breaks under the outboard wing panels, and late production Ki-48-IIas and -IIbs were fitted with a dorsal fin extension to improve stability further. Although the maximum bomb-load of the Army Type 99 Twin-engined Light Bomber Model 2 was double that of the Model 1 it was still insufficient, and in this respect the Ki-48-II compared poorly with contemporary Allied aircraft. Likewise its maximum speed was too low to avoid interception and the Ki-48, Allied code name 'Lily' was an easy target for Allied fighter aircraft. Also, a large number of Ki-48s were destroyed on the ground in New Guinea despite strenuous efforts by the Japanese to camouflage and disperse their aircraft on the jungle airfields. However, the main deficiency of the aircraft was still its wholly inadequate defensive armament.

Attempts to increase the aircraft's defensive aramment proved generally unsatisfactory and the experimental use of a dorsal turret housing a 20 mm (0.79 in) cannon was not adopted for production. However, in 1943, the Ki-48-IIc or Model 2C was armed with a 12.7 mm (0.5 in) Type 1 machine-gun replacing the previously used dorsal 7.7 mm (0.303 in) Type 89 machine-gun. The 7.7 mm (0.303 in) machine-guns in the nose and ventral positions were retained while an additional flexible weapon of the same calibre was mounted in the nose and could be fired from windows on the port and starboard sides of the bombardier's position. Despite the changes, the Ki-48-II had become obsolescent and in October 1944 production ended with the 1,408th. The Ki-48-II was still active in the Philippines campaign and was also met at night over Okinawa. However, most surviving Ki-48-IIs were expended around Okinawa in taiatari suicide attacks. Some of the aircraft, designated Army Type 99 Special Attack Plane (Ki-48-II KAI), were specially modified by the Dai-Ichi Rikugun Kokusho (First Army Air Arsenal) and carried an 800 kg (1,764 lb) bomb-load triggered by contact with the target by means of a long rod protruding from the nose.

In 1944 four Ki-48-IIbs were modified to test the air-to-ground Kawasaki I-G0-I-B guided missile and another Ki-48-II was used in the flight test programme of the experimental Ne-0 turbojet. For this purpose the bomb-bay doors were removed and the jet engine was hung under the fuselage. Uncompleted versions of the Ki-48 included the heavily armed and armoured Ki-81 for use by formation commanders and the single-seat Ki-174 special attack aircraft.

Units Allocated

3rd, 6th, 16th, 27th, 31st, 32nd, 34th, 45th, 65th, 75th, 90th, 95th and 208th Sentais. 82nd Dokuritsu Dai Shijugo Chutai. Hokota Army Light Bomber Flying School.

Technical Data

Manufacturer: Kawasaki Kokuki Kogyo KK (Kawasaki Aircraft Engineering Co Ltd).
Type: Twin-engined light bomber.
Crew (4): Pilot, bombardier/gunner, radio-operator/gunner and navigator/gunner.
Powerplant: (Ki-48-I) Two 950 hp Army Type 99 (Nakajima Ha-25) fourteen-cylinder air-cooled radial engines, driving three-blade metal propellers; (Ki-48-II) Two 1,150 hp Army Type 1 (Nakajima Ha-115) fourteen-cylinder air-cooled radial engines, driving three-blade metal propellers.
Armament: (Ki-48-Ia, -Ib, -IIa and IIb) Three (one each in nose, dorsal and ventral positions) flexible 7.7 mm (0.303 in) Type 89 machine-guns; (Ki-48-IIc) Three (two in nose and one ventral positions) flexible 7.7 mm (0.303 in) Type 89 machine-guns and one flexible 12.7 mm (0.5 in) Type I machine-gun in the dorsal position. Bomb-load (Ki-48-I) - normal 300 kg (661 lb), maximum 400 kg (882 lb); (Ki-48-II) - normal 400 kg (882 lb), maximum 800 kg (1,764 lb).
Dimensions: (Ki-48-I) Span 17.47 m (57 ft 3 25/32 in); length 12.6 m (41 ft 4 1/16 in); height 3.8 m (12 ft 5 19/32 in); wing area 40 sq m (430.555 sq ft). (Ki-48-IIb) Span 17.45 m (57 ft 3 in); length 12.75 m (41 ft 9 31/32 in); height 3.8 m (12 ft 5 19/32 in); wing area 40 sq m (430.555 sq ft).
Weights: (Ki-48-I) Empty 4,050 kg (8,929 lb); loaded 5,900 kg (13,007 lb); maximum 6,050 kg (13,338 lb); wing loading 147.5 kg/sq m (30.2 lb/sq ft); power loading 2.95 kg/hp (6.5 lb/hp). (Ki-48-IIb) Empty 4,550 kg (10,031 lb); loaded 6,500 kg (14,330 lb); maximum 6,750 kg (14,881 lb); wing loading 2.9 kg/sq m (6.3 lb sq ft); power loading 2.9 kg/hp (6.3 lb/hp).
Performance: (Ki-48-I) Maximum speed 480 km/h (298 mph) at 3,500 m (11,485 ft); cruising speed 350 km/h (217 mph) at 3,500 m (11 485 ft); climb to 5,000 m (16,405 ft) in 9 min; service ceiling 9,500 m (31,170 ft); range - normal 1,980 km (1,230 miles), maximum 2,400 km (1,491 miles). (Ki-48-IIb) Maximum speed 505 km/h (314 mph) at 5,600 m (18,375 ft); climb to 5,000 m (16,405 ft) in 8 min 30 sec; service ceiling 10,100 m (33,135 ft); range - normal 2,050 km (1,274 miles), maximum 2,400 km (1,491 miles).
Production: A total of 1,977 Ki-48s were built by Kawasaki Kokuki Kogyo KK at their Gifu plant as follows:

4 Ki-48 prototypes - 1939
5 Ki-48 pre-production aircraft - 1940
557 Ki-48-I production aircraft - July 1940-June 1942
3 Ki-48-II prototypes - February 1942
1,408 Ki-48-II production aircraft - April 1942-October 1944

Photos were taken from Japanese Aircraft of the Pacific War, by Rene J Francillon.

Regards

Bob
Attachments
Ki-48-IIa (4).jpg
Two views of a Kawasaki Ki-48-IIa Army Type 99 Twin-engined Light Bomber Model 2A with Ha-115 engines.
Ki-48-IIa (4).jpg (20.23 KiB) Viewed 10481 times
Ki-48-IIa (3).jpg
A Kawasaki Ki-48-IIa somewhere in the Philippines.
Ki-48-IIa (3).jpg (9.96 KiB) Viewed 10484 times
Ki-48-IIa (2).jpg
A captured Kawasaki Ki-48-IIa of an unidentified sentai. The aircraft is seen at Noshiro in the northern part of Honshu and has one propeller removed to comply with the surrender agreement.
Ki-48-IIa (2).jpg (7.55 KiB) Viewed 10472 times

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#59

Post by Robert Hurst » 25 Jul 2003, 16:17

Hi

Mitsubishi Ki-51 - Pt 1

At the suggestion of Capt Yuzo Fujita, one of the Japanese Army's leading flying officers, the Koku Hombu issued to Mitsubishi in December 1937 a specification calling for a ground attack aircraft to be developed from their successful Ki-30 light bomber. As compared to its forerunner, the new aircraft, designated Ki-51, was to be smaller, and emphasis was placed on manoeuvrability, protection and ability to operate from short fields close to the front lines. In February 1938 the specification was revised to incorporate the following requirements: (1) maximum speed, 420 km/h (261 mph) at 2,000 m (6,560 ft); (2) loaded weight. 2,700 kg (5,952 lb); (3) powerplant, one Mitsubishi Ha-26-II radial; (4) normal bomb-load consisting of twelve 15 kg (33 lb) bombs or four 50 kg (110 lb) bombs; and (5) armament consisting of two forward-firing machine-guns and one flexible rear-firing machine-gun.

Created by the same design team which had produced the Ki-30, the Ki-51 was a cantilever low-wing monoplane with a 'trousered' and spatted non-retractable main landing gear and a fixed tail wheel, overall construction was of metal except for the control surfaces, which were fabric covered. The Ki-51 bore a close external resemblance to its larger forerunner but had a shorter greenhouse-type cockpit, allowing better collaboration between the two crew members, a limited set of flight instruments and controls being installed in the rear cockpit. The lighter bomb-load enabled the bomb-bay to be dispensed with and the wing was lowered to reduce undercarriage length. The powerplant for both prototype and production aircraft was a single 900 hp Mitsubishi Ha-26-II radial engine rated at 940 hp for take-off and 950 hp at 2,300 m (7,545 ft). The engine was closely cowled and drove a three-blade metal propeller with a large spinner. One 7.7 mm (0.303 in) Type 89 machine-gun was mounted in each outboard wing section and a similar gun was mounted for rear defence. Normal bomb-load of 200 kg (440lb) being carried externally.

The first and second prototypes were completed in June and August 1939 respectively and were followed by eleven Service trials aircraft built between September and December 1939. During the construction of the Service trials aircraft, a few modifications were introduced and included the replacement of the side-hinging canopy sections with rear-sliding units, the fitting of fixed leading-edge slots to improve handling characterstics at low speed and the installation of 6 mm (0.236 in) steel armour plate under the engine cowling and cockpit. One of the Service trials aircraft was also modified in accordance with an Army request of December 1938 by replacing flight instruments and controls in the rear cockpit with cameras. This aircraft was intended as the prototype for the projected Army Type 99 Tactical Reconnaissance Plane (Ki-51a) but, following tests conducted at Kashizu, it was decided not to build this specialised version but rather to incorporate in the design of production Ki-51s provision for tactical reconnaissance equipment. Consequently no differences were mentioned in the official aircraft specification, and the aircraft could be quickly modified in the field for either tactical reconnaissance sorties or ground support missions, all 1,459 production Ki-51s built by Mitsubishi betwen 1940 and 1944 being designated Army Type 99 Assault Planes. During its production the Ki-51 was only modified twice to (1) install two 68 litre (15 Imp gal) wing leading edge fuel tanks and (2) replace the wing-mounted 7.7 mm (0.303 in) Type 89 machine-guns with two 12.7 mm (0.5 in) Type 1 machine-guns.

The top photo was taken from Encyclopedia of World Aircraft, by David Donald, the middle and bottom photos were taken from Japanese Aircraft of the Pacific War, by Rene J Francillon.
Regards

Bob
Attachments
Ki-51 (3).jpg
A Mitsubishi Ki-51 Army Type 99 Assault Plane of the Kumagaya Flying School.
Ki-51 (3).jpg (11.74 KiB) Viewed 10459 times
Ki-51 (2).jpg
This Mitsubishi Ki-51 was one of the eleven Service trials aircraft.
Ki-51 (2).jpg (9.79 KiB) Viewed 10445 times
Ki-51 (1).jpg
A formation of Ki-51s, which were developed from the Ki-30 as dedicated ground attack aircraft.
Ki-51 (1).jpg (11.87 KiB) Viewed 10441 times
Last edited by Robert Hurst on 28 Jul 2003, 15:32, edited 2 times in total.

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Robert Hurst
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#60

Post by Robert Hurst » 28 Jul 2003, 14:56

Hi

Mitsubishi Ki-51 - Pt 2

After initial operations in China the Ki-51, code-named 'Sonia' by the Allies, were deployed throughout the Pacific where they served with distinction. Despite its unspectacular maximum speed which made it rather an easy prey for Allied fighters, the Ki-51 was liked by its crews as it was well protected, manoeuvrable, easy to fly and maintain, and because it could operate from small airfields at the front lines. The aircraft was so successful that, as late as 1944, a new asembly line was set up by the Tachikawa Dai-Ichi Rikugun Kokusho (First Army Air Arsenal at Tachikawa). During the closing months of the war the aircraft was finally assigned to taiatari suicide mission for which it carried a 250 kg (551 lb) bomb under the fuselage. After the Japanese surrender, several Ki-51s found abandoned on Java and Sumatra were briefly used against Dutch forces by the fledgeling Indonesian Air Force.

In 1941, engineers from Mansyu Hikoki Seizo KK (Manchurian Aeroplane Manufacturing Co Ltd) were sent to the Tachikawa Dai-ichi Rkugun Kokusho to develop an advanced version of the aircraft as the Ki-71 Army Experimental Tactical Reconnaissance Plane. Powered by one 1,500 hp Mitsubishi Ha-112-II radial, armed with two wing-mounted 20 mm Ho-5 cannon and featuring a retractable undercarriage, three Ki-71 prototypes were built at the Army Arsenal. Despite a more powerful engine and the use of a retractable undercarriage, the Ki-71 had a maximum speed of only 470 km/h (292 mph) and the design was not accepted for production. However, the development of the aircraft had been discovered by the Allies, who assigned it the code name 'Edna'.

Units Allocated

6th, 27th, 32nd, 44th, 65th, 66th, 67th and 83rd Sentais. 41st, 45th, 47th, 48th, 49th, 52nd, 53rd, 71st, 73rd. 83rd, 89th, 90th and 91st Dokuritsu Hiko Chutais. 4th Kokugun Shireibu Hikodan. Koku Shikan Gakka (Army Air Academy).

Technical Data

Manufacturer: Mitsubishi Jukogyo KK (Mitsubishi Heavy Industries Co Ltd).
Type: Single-engined ground attack and reconniassance.
Crew (2): Pilot and observer/gunner in tandem enclosed cockpit.
Powerplant: One 900 hp Army Type 99 (Mitsubishi Ha-26-II) fourteen-cylinder air-cooled radial engine, driving a three-blade variable-pitch metal propeller.
Armament: (prototypes and early production) Two wing-mounted 7.7 mm (0.303 in) Type 89 (late production Ki-51) two wing-mounted 12.7 mm (0.5 in) Type I machine-guns and one flexible rear-firing 7.7 mm (0.303 in) Type 89 machine-gun. Bomb-load - normal 200 kg (441 lb); suicide operation (as single-seater) - one 250 kg (551 lb).
Dimensions: Span 12.1 m (39 ft 8 3/8 in); length 9.21 m (30 ft 2 19.32 in); height 2.73 m (8 ft 11 1/2 in); wing area 24.02 sq m ( 258.548 sq ft).
Weights: Empty 1,873 kg (4,129 lb); loaded 2,798 kg (6,169 lb); maximum 2,920 kg (6,415 lb); wing loading 116.5 kg/sq m (23.9 lb/sq ft); power loading 3 kg/hp (6.6 lb/hp).
Performance: Maximum speed 424 km/h (263 mph) at 3,000 m (9,845 ft); climb to 5,000 m (16,405 ft) in 9 min 55 sec; service ceiling 8,270 m (27,130 ft); range 1,060 km (660 miles).
Production: A total of 2,385 Ki-51s were built by Mitsubishi Jukogyo KK at Nagoya and the Tachikawa Dai-Ichi Rikugun Kokusho at Tachikawa as follows:

Mitsubishi Jugoyo KK:

2 Ki-51 prototypes - June and August 1939
11 Ki-51 Service trials aircraft - September-December 1939
1,459 Ki-51 production aircraft - January 1940-March 1944

Tachikawa Dai-Ichi Rikugun Kokusho:

913 Ki-51 production aircraft - July 1941-July 1945

In addition Tachikawa Dai-Ichi Rkugun Kokusho built three Ki-71 prototypes.

The top photo was taken from Japanese Aircraft of the Pacific War, by Rene J Francillon, the middle photo was taken from The concise Guide to Aixis Aircraft of World War II, by David Mondey, and the bottom photo was taken from

Regards

Bob
Attachments
Ki-51 (6).jpg
Ki-51 (6).jpg (10 KiB) Viewed 10428 times
Ki-51 (5).jpg
When able to operate in remote areas away from the attentions of Allied fighters, the rough-field capabilities of the Ki-51 made it a useful weapon.
Ki-51 (5).jpg (12.02 KiB) Viewed 10425 times
Ki-51 (4).jpg
A Mitsubishi Ki-51 abandoned on Okinawa.
Ki-51 (4).jpg (13.48 KiB) Viewed 10429 times

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