TheAichi B7ARyusei(Sao băng,Ryūsei,"Shooting Star";Allied reporting name"Grace")was a large and powerful carrier-bornetorpedo-dive bomberproduced byAichi Kokukifor theImperial Japanese Navy Air Serviceduring the Second World War. Built in only small numbers and deprived of the aircraft carriers it was intended to operate from, the type had little chance to distinguish itself in combat before the war ended in August 1945.
| B7ARyusei | |
|---|---|
 | |
| General information | |
| Type | Torpedo bomberandDive bomber[1] |
| National origin | Japan |
| Manufacturer | Aichi Kokuki 21st Naval Air Arsenal |
| Primary user | Imperial Japanese Navy Air Service |
| Number built | 114 total |
| History | |
| Manufactured | 1942–1945 |
| First flight | May1942[1] |
| Retired | September 1945 |
Design and development
The B7ARyusei(originally designated AM-23 by Aichi)[2]was designed in response to a 1941 16-Shi requirement issued by the Imperial Japanese Navy Air Service for a carrier attackbomberthat would replace both theNakajima B6NTenzantorpedoplane and theYokosuka D4YSuiseidive bomber in IJN service.[1]It was intended for use aboard a new generation ofTaihō-class carriers, the first of which was laid down in July 1941. Because the deck elevators on theTaihōs had a larger square area than those of older Japanese carriers, the longstanding maximum limit of 11 m (36 ft) on carrier aircraft length could now be lifted.[3]
Chief Engineer Toshio Ozaki (name often seen as Norio Ozaki, but this is incorrect because theKanjifor both first names are the same and often confused) chose a mid-wing arrangement for the B7A to provide for an internal bomb-bay and to ensure enough clearance for the plane's 3.5 m (11 ft) four-bladedpropeller.This in turn necessitated the adoption of an invertedgull wing,similar to theF4U Corsair,in order to shorten the length of the main landing gear. The wing featured extendableaileronswith a ten-degree range of deflection, enabling them to act as auxiliary flaps.Dive brakeswere fitted underneath just outboard of the fuselage. The B7A's outer wing panels were designed to fold upwards hydraulically for carrier stowage, reducing its overall span from 14.4 m (47 ft) to approximately 7.9 m (26 ft).[2]
Selection of a powerplant was dictated by the Japanese Navy which requested that Aichi design the aircraft around the 1,360 kW (1,825 hp)Nakajima NK9CHomare1218-cylinder two-row air-cooledradial engine.This was expected to become the Navy's standard aircraft engine in the 1,340 kW (1,800 hp) to 1,641 kW (2,200 hp) range.[1]One production model B7A2 was later fitted with a 1,491 kW (2,000 hp) NakajimaHomare23 radial engine and plans were also made to fit the 1,641 kW (2,200 hp)Mitsubishi MK9 radialto an advanced version of theRyusei(designated B7A3Ryusei Kai) but the latter effort never came to fruition.
The B7A had a weight-carrying capacity stemming from its requirements,[3]resulting in a weapons load no greater than its predecessors. The presence of an internal bomb bay with two high-load-capability attachment points allowed the aircraft to carry two 250 kg (550 lb) or six 60 kg (132 lb)bombs.Alternatively, it could carry a single externally mountedType 91 torpedo,weighing up to 848 kg (1,870 lb).[4]
Defensive armament initially consisted of two 20mm Type 99 Model 2 cannons in the wing roots and one flexible 7.92mm Type 1 machine-gun mounted in the rear cockpit. Later production models of the B7A2 featured a 13mm Type 2 machine-gun in place of the 7.92mm gun.[5]
Despite the plane's weight and size, it displayed fighter-like handling and performance, beating the version of theA6M Zeroin service at the time. It was fast and highly maneuverable.[6]
Given the codename "Grace"by theAllies,the B7A first flew as aprototypein May 1942, but teething problems with the experimental NK9CHomareengine and necessary modifications to the airframe meant that the type did not enter into production until two years later in May 1944.[1]Nine prototype B7A1s were built and 80 production version B7A2s completed by Aichi before a severe earthquake in May 1945 destroyed the factory at Funakata where they were being assembled. A further 25 examples were produced at the 21st Naval Air Arsenal at Omura.[7]
Operational history
In June 1944, theTaihōwas the only Imperial Japanese Navy aircraft carrier then modern enough to operate the B7ARyuseiin its intended role. Other Japanese carriers lacked the modern arresting gear necessary to assist the recovery of aircraft weighing over 4000 kg. However,Taihowas sunk during theBattle of the Philippine Seabefore enough B7As were even available to embark. Afterward, the B7A was relegated to operating from land bases, primarily with the Yokosuka and 752ndAir Groups.[1]The Japanese completed only one other carrier capable of operating the B7A, theShinano,which was sunk by Balao-class submarineArcherfishin November 1944, just ten days after being commissioned.
Variants
- B7A1
- One prototype and eight supplementary prototypes.
- B7A2
- Two-seat torpedo-dive bomber aircraft for theImperial Japanese Navy;105 built.[8]
- B7A2 Experimental
- One aircraft fitted with a 1,491 kW (2,000 hp) NakajimaHomare23 radial engine.
- B7A3
- Proposed version with a 1641 kW (2,200 hp) Mitsubishi MK9A (Ha-43). Not built.
Number built
According to Model Art (2000), p. 72.
- Funakata Factory,Aichi Kokuki,Nagoya,work number 3201-3289.
| January | February | March | April | May | June | July | August | September | October | November | December | Sub total | |
| 1942 | 1 | 1 | |||||||||||
| 1943 | 0 | 0 | 0 | 1 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 0 | 6 |
| 1944 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 1 | 2 | 5 | 5 | 9 | 26 |
| 1945 | 7 | 12 | 11 | 13 | 8 | 3 | 2 | 0 | 56 | ||||
- 21st Naval Air Arsenal, Imperial Japanese Navy,Ōmura,work number 1-25.
| January | February | March | April | May | June | July | August | September | October | November | December | Sub total | |
| 1944 | 1 | 0 | 1 | 0 | 1 | 4 | 1 | 0 | 0 | 8 | |||
| 1945 | 2 | 1 | 3 | 2 | 4 | 0 | 4 | 1 | 17 | ||||
Operators
- Imperial Japanese Navy Air Service
- Yokosuka Naval Air Group
- 131st Naval Air Group
- 752nd Naval Air Group
- 1001st Naval Air Group
- 5th Attack Squadron,a part of 131st/752nd Naval Air Group
Specifications (B7A2)
Data fromAircraft of World War II - 300 of the World's Greatest aircraft 1939–45,[1]Aichi B7A Ryusei (Shooting Star),[8]and Japanese Aircraft of the Pacific War[5]
General characteristics
- Crew:2
- Length:11.49 m (37 ft 8 in)
- Wingspan:14.4 m (47 ft 3 in)
- Height:4.075 m (13 ft 4 in)
- Wing area:35.4 m2(381 sq ft)
- Empty weight:3,810 kg (8,400 lb)
- Gross weight:5,625 kg (12,401 lb)
- Max takeoff weight:6,500 kg (14,330 lb)
- Powerplant:1 ×Nakajima NK9C Homare 1218-cylinder air-cooled radial piston engine, 1,361 kW (1,825 hp) for take-off
- 1,250 kW (1,670 hp) at 2,400 m (7,900 ft)
- 1,160 kW (1,560 hp) at 6,550 m (21,490 ft)
- Propellers:4-bladed constant-speed propeller, 3.5 m (11 ft 6 in) diameter
Performance
- Maximum speed:567 km/h (352 mph, 306 kn) at 6,550 m (21,490 ft)
- Range:3,038 km (1,888 mi, 1,640 nmi)
- Service ceiling:11,250 m (36,900 ft)
- Rate of climb:9.6 m/s (1,890 ft/min)
- Time to altitude:4,000 m (13,000 ft) in 6 minutes 55 seconds
- Wing loading:158.9 kg/m2(32.5 lb/sq ft)
- Power/mass:0.242 kW/kg (0.147 hp/lb)
Armament
- Guns:
- 2× 20 mm (0.787 in)Type 99 Model 2 cannonin the wings
- 1× 7.92 mm (0.312 in)Type 1 machine gunor 13 mm (0.512 in)Type 2 machine gunin the rear cockpit
- Bombs:
- 800 kg (1,764 lb) of general ordnanceor
- 1× 800 kg (1,764 lb) torpedo
See also
Aircraft of comparable role, configuration, and era
Related lists
Notes
- ^abcdefghChant 1999, p. 15.
- ^abFrancillon 1979, p. 289.
- ^abFrancillon 1979, p. 288.
- ^NOT the famous "Long Lance",Type 93 torpedo,much too heavy and unfit to aerial drop from a plane; a derived "type 94" for plane use had been developed but not deployed
- ^abFrancillon 1979, p. 291.
- ^Gunston 1985, p. 26.
- ^Mondey 1984, p. 8.
- ^abMatsuura 1997Aichi B7A Ryusei (Shooting Star)retrieved: 16 September 2010.
Bibliography
- Chant, Chris.Aircraft of World War II - 300 of the World's Greatest aircraft 1939-45.Amber Books Ltd., 1999.ISBN0-7607-1261-1.
- Francillon, Ph.D., René J.Japanese Aircraft of the Pacific War.London: Putnam & Company Ltd., 1979.ISBN0-370-30251-6.
- Gunston, Bill.Military Aviation Library World War II: Japanese & Italian Aircraft.Salamander Books Ltd., 1985.ISBN0-89009-899-9.
- Millot, Bernard (October 1976). "Aichi B7A" Ryusei "(Grace)".Le Fana de l'Aviation: Le Fanatique de l'Aviation(in French) (83): 26–29.ISSN0757-4169.
- Mondey, David.Concise Guide to Axis Aircraft of World War II.Temple Press, 1984.ISBN0-600-35027-4.
- Model Art Special IssueCarrier Attack Bombers of the Imperial Japanese Navy.Model Art Co., Ltd., 2000.
External links
- Joao Paulo Julião Matsuura (1997)."Aichi B7A Ryusei (Shooting Star)".combinedfleet.WWII Imperial Japanese Naval Aviation Page.Retrieved16 September2010.
- Aichi B7A2 Ryusei (Shooting Star) GRACEArchived2010-04-08 at theWayback Machine-National Air and Space Museum
- IJN Pics