Japanese torpedo bomber design

[Spectre311]

Japanese aircraft from the Second World War have always interested me. I have always wondered why the Val and its successor, the Judy was equipped with forward firing armament but the Kate and Jill did not receive any type of forward-firing weaponry. They may have had forward-firing guns in earlier variants but it was quickly deleted. Was this because of doctrine or to save weight?


From a Western perspective, it's rather weird given the fact that the TBF/TBM Avenger did have .50 caliber machine guns at its disposal.

 

[Shinpachi]

They were not so agile as dive bombers that they were not going to fight US fighters but run spraying 7.7mm shells behind.
To reduce the weight would be better to run faster

 

[Shortround6]

Torpedo bombers in the 3 big navies rarely strafed.
depending on the torpedoes used they had to aimed ahead of the ship so even on the torpedo run the plane was not pointed at the ship, some torpedoes could be aimed at off angle.
Other job was level bombing.

Front firing machine gun was as much for moral as any aspect of actually shooting down attacking aircraft. Maybe a line of tracers could discourage a fighter from making a frontal attack?

US put .50 cal guns on anything bigger than a Motorcycle

Avengers started with one gun, after the first 1500+ they went to two guns. Not sure where the MK 13 torpedo saga was at that point but the Avenger was doing more glide bombing/low level bombing

 

[Spectre311]

They were not so agile as dive bombers that they were not going to fight US fighters but run spraying 7.7mm shells behind.
To reduce the weight would be better to run faster

They were beautiful though always had a soft spot for the Kate and Zero growing up and still do.

 

[Spectre311]

Torpedo bombers in the 3 big navies rarely strafed.
depending on the torpedoes used they had to aimed ahead of the ship so even on the torpedo run the plane was not pointed at the ship, some torpedoes could be aimed at off angle.
Other job was level bombing.

Front firing machine gun was as much for moral as any aspect of actually shooting down attacking aircraft. Maybe a line of tracers could discourage a fighter from making a frontal attack?

US put .50 cal guns on anything bigger than a Motorcycle

Avengers started with one gun, after the first 1500+ they went to two guns. Not sure where the MK 13 torpedo saga was at that point but the Avenger was doing more glide bombing/low level bombing

You learn something new every day I always assumed that the Avengers did some CAS/ground pounding because they were or at least the later variants were able to carry rockets.

 

[Admiral Beez]

...but the Kate and Jill did not receive any type of forward-firing weaponry.

The Aichi B7A Ryusei (Grace) had twin 20mm cannons in the wings. Perhaps as it was a dual role with a dive bomber and torpedo function.

B7A2 "Grace" by Ian Robertson (Hasegawa 1/48)

The Grace has some of the most powerful forward gun armament of any single-engine carrier torpedo bomber. The Fairey Spearfish was to have two .50 cal mgs in the wings. The Douglas A-1 Skyraider beats the Grace with its four 20mm cannons in the wings.

 

[Shortround6]

You learn something new every day I always assumed that the Avengers did some CAS/ground pounding because they were or at least the later variants were able to carry rockets.

The Avengers fought for just about 3 years. A lot changed in those 3 years. They actually got good torpedoes in the last year
The Avengers did do some ground pounding. There was also a 1 1/2 year gap in the carrier battles although Avengers did attack smaller surface ships during that period.
CAS is a term that gets thrown around a lot and the definition changes a bit depending on time(month/year) , country and some times theater.

British CAS in France in 1940 was a world apart from what British CAS was in France in the summer of 1944 for example.

A number of the early Avengers were refitted to carry rockets but but the trials with British style rockets and rails happened in July 1943. Shorter rails were were used by a few Avengers and the US Navy adopted the US 5in rockets and zero length launchers in late 1943. First operational use by VC-58 from the USS Block Island vs a U-boat on Jan 11 1944.
Avengers did use rockets against the Japanese held islands in 1944-45 but that was well over a year after they got the .50 cal in each wing.

 

[Shortround6]

The Douglas A-1 Skyraider beats the Grace with its four 20mm cannons in the wings.

The Skyraider didn't get 4 cannon in the 1st or early versions. They had two guns.

 

[PAT303]

The Aichi B7A Ryusei (Grace) had twin 20mm cannons in the wings. Perhaps as it was a dual role with a dive bomber and torpedo function.

View attachment 745975

B7A2 "Grace" by Ian Robertson (Hasegawa 1/48)

The Grace has some of the most powerful forward gun armament of any single-engine carrier torpedo bomber. The Fairey Spearfish was to have two .50 cal mgs in the wings. The Douglas A-1 Skyraider beats the Grace with its four 20mm cannons in the wings.

Thats a very good example of if it looks right it is right, a very good looking aircraft it is.

 

[EwenS]

The Aichi B7A Ryusei (Grace) had twin 20mm cannons in the wings. Perhaps as it was a dual role with a dive bomber and torpedo function.

View attachment 745975

B7A2 "Grace" by Ian Robertson (Hasegawa 1/48)

The Grace has some of the most powerful forward gun armament of any single-engine carrier torpedo bomber. The Fairey Spearfish was to have two .50 cal mgs in the wings. The Douglas A-1 Skyraider beats the Grace with its four 20mm cannons in the wings.

The Curtiss SB2C Helldiver had its forward armament upgunned from 2x0.5" to 2x20mm from the -1C Model. So after about the first 600 or so had been produced.

 

[EwenS]

The B7A 'Grace' was designed to fly off the next generation of Japanese carriers, the only one of which was built was the Taiho. But that ship was sunk before more than a couple of prototypes had flown. The planned modified Taiho class carriers were never laid down. So those few units that flew them, flew from land bases.

 

[Admiral Beez]

Thats a very good example of if it looks right it is right, a very good looking aircraft it is.

Japanese aircraft were almost always some of the best looking. Though I think the Ki-100's tail looks too small.

 

[Admiral Beez]

Here's what the IJN was flying before the B5N. The Yokosuka B4Y, essentially a Japanese Swordfish.

The move to the B5N must have seemed revolutionary to its pilots.

note: that's the B5N2 above, not the pudgier B5N1, but still…

 

[EwenS]

The B4Y1 (Allied codename Jean) remained on the front line until the middle of 1942. The Hosho had an air group comprising 8 of them for ASW work at Midway as part of the support for the Main Body.

In Aug 1939 it was decided that Hosho was suitable for use as a training carrier in peacetime. In wartime she had a role as an escort to the main fleet so long as the A5M Claude and B4Y Jean continued to be used. Investigations in Dec 1940 showed that Hosho was not capable of operating A6M Zeros, D3A Vals or B5N Kates operationally. After Midway she was relegated to a training role. It was March / April 1944 before more modifications were made to her flight deck to allow operation of these and later types on operations but her activities after that were limited to training in the Inland Sea.

 

[Mike Wenger]

Torpedo bombers in the 3 big navies rarely strafed.
depending on the torpedoes used they had to aimed ahead of the ship so even on the torpedo run the plane was not pointed at the ship, some torpedoes could be aimed at off angle.
Other job was level bombing.

Front firing machine gun was as much for moral as any aspect of actually shooting down attacking aircraft. Maybe a line of tracers could discourage a fighter from making a frontal attack?

US put .50 cal guns on anything bigger than a Motorcycle

Avengers started with one gun, after the first 1500+ they went to two guns. Not sure where the MK 13 torpedo saga was at that point but the Avenger was doing more glide bombing/low level bombing

The reason for the Aichi Type 99s being armed was likely two-fold... 1. They were far more agile and could give a decent account of themselves in air-to-air actions... witness the combats over O'ahu on 7Dec41. Secondly, doctrine dictated that the carrier bombers were to strafe the targets as they descended in order to scatter and demoralize the enemy. This tidbit was preserved in the Shokaku's action report from the Hawaiian Operation... the only such report known to have survived. Supposedly, Fuchida destroyed or buried the others, I think. The Nakajima Type 97s were probably too slow and unwieldy to justify the extra weight of guns and ammunition.

 

[nuuumannn]

From a Western perspective, it's rather weird given the fact that the TBF/TBM Avenger did have .50 caliber machine guns at its disposal.

The Avenger had a mix of .303s and .50s. The forward firing nose gun and the ventral gun were .30s.

Your question needs to be put into perspective. You're comparing the Avenger with aircraft such as the B5N and D3A, which were mid-1930s designs. Their equivalent was the TBD Devastator, which was armed with two .303 machine guns. It is worth noting that the Avenger was unusually heavily armed for a torpedo bomber, incorporating a power operated gun turret as well as the forward firing guns and a ventral gun, a complement of defensive armament not seen in any other single-engined torpedo bomber of the war. The majority of wartime torpedo bombers used by all sides had either one or two 30 cal machine guns.

 

[Admiral Beez]

The Avenger was unusually heavily armed for a torpedo bomber, incorporating a power operated gun turret

I believe power operated turrets were a rare thing in the Japanese air services.

Do these Nells have power turrets in front of the dorsal blister gun position?

Maybe the Mitsubishi K-1 and Ki-2 had powered nose turrets?

 

[nuuumannn]

I believe power operated turrets were a rare thing in the Japanese air services.

Yup, they were. Neither of these aircraft had powered turrets. They were a technology that wasn't widely applied, the British, the Americans and the Russians were the only ones to use power turrets extensively, while the Italians and Germans also applied them and did expend effort to develop them, but never got them to the extent that Britain and the USA did. The Avenger's turret was unique in a WW2 carrier-based aircraft.

 

[Admiral Beez]

Yup, they were. Neither of these aircraft had powered turrets. They were a technology that wasn't widely applied, the British, the Americans and the Russians were the only ones to use power turrets extensively, while the Italians and Germans also applied them and did expend effort to develop them, but never got them to the extent that Britain and the USA did. The Avenger's turret was unique in a WW2 carrier-based aircraft.

An Avenger with the Roc's 4x.303 would be something.

 

[nuuumannn]

An Avenger with the Roc's 4x.303 would be something.

Hooo boy! That would be interesting! The BP turret was quite heavy by comparison to the Avenger's turret (I have the figures for each somewhere and I'll look them up soon, but I'm busy right now). There's an interesting story I encountered when I worked in the aviation museum in Scotland. Some amateur divers were off the East Coast of Scotland and came across an aircraft fuselage on the sea bed with what they described as a gun cupola. One of the divers was an aircraft enthusiast and believed it was a Boulton Paul Defiant, which was of great interest to us at the museum as Defiants were based there during the war. The next step was getting verification for the records to establish an identity, but it turns out that the aircraft was an FAA Avenger from HMS Jackdaw, RNAS Crail, Fife. As far as I know it's still down there.