The invasion of Oahu, December 1941.

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T. A. Gardner
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Re: The invasion of Oahu, December 1941.

Post by T. A. Gardner » 10 Jan 2015 06:05

Carl Schwamberger wrote:Was there any use of the carrier aircraft over China in 1941? I remember Saburo Saki describing his air combat there sometime from 1938 or later. That is could any B5N2 or D3A1 been lost in combat there?
Yes there were. In fact it was IJN dive bombers that sank the Panay (Yokosuka B5N in that case). The later attack planes were used to get pilot experience and give the Navy some prestige in combat operations.

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Re: The invasion of Oahu, December 1941.

Post by glenn239 » 10 Jan 2015 15:18

I suspect most of the equipment expended in China would be the older B5N1 or D1A types, moreso than the D3A1 or B5N2.

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Re: The invasion of Oahu, December 1941.

Post by gurn » 10 Jan 2015 18:18

I have previously wondered why Kido Butai had Vals on board at all for the Pearl raid. The Kates had at least double the bomb load and while the range was reduced, it was not a factor in where the raid was launched from anyways.
Wouldn't nothing but Kates and Zeros have been a better choice? More punch for the same amount of risk?

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Re: The invasion of Oahu, December 1941.

Post by ChristopherPerrien » 10 Jan 2015 20:29

That was doctrine, and you simply can't change doctrine and training and unit organizations that took years to develope for a one-off raid. Plus the VAL's at Pearl were highly needed to conduct air-field suppression and attack point targets.

After Pearl-

High level bombing against moving ships does not work. To overwhelm air defenses and inflict decisive damage you need a dive bomber and torpedo bomber combo attack, otherwise CAP could concentrate on a one dimesional attack. So the Japanese were stuck with an out-dated dive-bomber with fixed landing gear,1930's tech, much like a German Stuka.

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Re: The invasion of Oahu, December 1941.

Post by Carl Schwamberger » 10 Jan 2015 22:02

The Germans were using extreme low level or 'skip bombing' techniques in a limited way as far back as 1938. Some US AAC pilots experimented with this before 1935, and the French gave it a try vs land targets. I wonder if the Japanese took a look at that method?

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Re: The invasion of Oahu, December 1941.

Post by glenn239 » 09 Feb 2015 18:22

http://ibiblio.org/hyperwar/USN/WarDama ... rtCV8.html

Section D "Structural damage caused by dive bomber" indicated this particular Val was armed with 1x250kg bomb and 2x60kg bomb. A quick OOB check indicates it was D3A1 versions at Santa Cruz, if so, this loadout for Hawaii should have been possible.

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Re: The invasion of Oahu, December 1941.

Post by ChristopherPerrien » 10 Feb 2015 14:46

glenn239 wrote:http://ibiblio.org/hyperwar/USN/WarDama ... rtCV8.html

Section D "Structural damage caused by dive bomber" indicated this particular Val was armed with 1x250kg bomb and 2x60kg bomb. A quick OOB check indicates it was D3A1 versions at Santa Cruz, if so, this loadout for Hawaii should have been possible.
This was brought up earlier in a roundabout way. The 2 wing bombs added some weight and drag , which would affect the VAL's range. To what extent , we never figured out. The pearl Harbor Raid was launched at the longest range range possible, i.e. the Range of the VAL- the shortest range IJN aircraft carrying its lightest effective bomb load- 1 centerline bomb.. Santa Cruz was fought at very short ranges for a carrier battle -100 miles IIRC, so the VAL's could carry their Max bomb load.- 1 centerline bomb- 2 wing bombs. Would be my guess.

It was also brought up that some IJN VALS at Pearl removed their wing racks. I assume this was also done to lighten the plane and reduce drag just that little bit. With carrier aircraft at long ranges , the ability to fly even an extra mile or a few might be the diff tween landing and drowning. I imagine them VAL pilots were highly jealous of Kate and Zero crew , with their such greater flight time and range.

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Re: The invasion of Oahu, December 1941.

Post by flakbait » 11 Feb 2015 02:19

Correct me if am mistaken, but many types of shipboard secondary and even some dedicated AA guns used by many navies of the world up to the Pearl Harbor attack and even beyond it were just not able to effectively deal with the steep angles of attack that dive bombers routinely used, hence the majority of why they were so successful; coupled with gun directors that again were just too primitive to quickly and accurately generate a correct firing solution especially if the ship itself was at speed and violently turning meant that many times the attacking dive bombers had already released their bombs before a effective gunnery solution was generated. Unless the target ships had effective air combat patrol fighters and/ or alert lookouts and responsive AA gunners the results were predictable...against stationary ships with surprised crews the results were simply tragic.

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Re: The invasion of Oahu, December 1941.

Post by OpanaPointer » 11 Feb 2015 02:39

Depends on how the diver bombers are armed.
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Re: The invasion of Oahu, December 1941.

Post by gurn » 12 Feb 2015 22:36

ChristopherPerrien wrote:
glenn239 wrote:http://ibiblio.org/hyperwar/USN/WarDama ... rtCV8.html

Section D "Structural damage caused by dive bomber" indicated this particular Val was armed with 1x250kg bomb and 2x60kg bomb. A quick OOB check indicates it was D3A1 versions at Santa Cruz, if so, this loadout for Hawaii should have been possible.
This was brought up earlier in a roundabout way. The 2 wing bombs added some weight and drag , which would affect the VAL's range. To what extent , we never figured out. The pearl Harbor Raid was launched at the longest range range possible, i.e. the Range of the VAL- the shortest range IJN aircraft carrying its lightest effective bomb load- 1 centerline bomb.. Santa Cruz was fought at very short ranges for a carrier battle -100 miles IIRC, so the VAL's could carry their Max bomb load.- 1 centerline bomb- 2 wing bombs. Would be my guess.

It was also brought up that some IJN VALS at Pearl removed their wing racks. I assume this was also done to lighten the plane and reduce drag just that little bit. With carrier aircraft at long ranges , the ability to fly even an extra mile or a few might be the diff tween landing and drowning. I imagine them VAL pilots were highly jealous of Kate and Zero crew , with their such greater flight time and range.


I thought it was the Kates that had a lower range, but were still launched at the historical distance?

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Re: The invasion of Oahu, December 1941.

Post by glenn239 » 13 Feb 2015 18:45

gurn wrote: I thought it was the Kates that had a lower range, but were still launched at the historical distance?
Kate had a longer range than Val without a weapons, but with an 800kg torpedo vs. a 250kg bomb, that was probably not true when loaded. If the Val had a shorter range with 60kg bombs, it would mean only that Nagumo would have to come closer to Oahu if making such a follow-up attack.

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Re: The invasion of Oahu, December 1941.

Post by ChristopherPerrien » 13 Feb 2015 21:07

glenn239 wrote:
Kate had a longer range than Val without a weapons, but with an 800kg torpedo vs. a 250kg bomb, that was probably not true when loaded.
Find a source or several for this. Normally aircraft ranges are stated for a full combat load. All aircraft can throw out stuff to increase range and or speed, but this is not something done in combat.
gurn wrote: I thought it was the Kates that had a lower range, but were still launched at the historical distance?
No , and there is no source that says otherwise.
If the Val had a shorter range with 60kg bombs, it would mean only that Nagumo would have to come closer to Oahu if making such a follow-up attack.
Find and dandy , if you outrank every-one in the Japanese high command
and have a crystal ball as to when then Japanese strike force can/ WILL be detected by US Forces. Maybe you can drive up to Oahu till the USS Ward (and the rest of the sortieing US Pacific fleet) is shooting it out with IJNS Kirishima* and not even worry about the Pearl Harbor Raid as planned, but I have my doubts.


* - I'll take the USS Ward in such a shoot out, as the Ward was on the ball on Dec7,1941, hitting a mIni-sub conning tower in the first salvo, and how US destroyers performed at Leyte Gulf against IJN capital ships. :)

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Re: The invasion of Oahu, December 1941.

Post by glenn239 » 14 Feb 2015 14:49

Find and dandy , if you outrank every-one in the Japanese high command
and have a crystal ball as to when then Japanese strike force can/ WILL be detected by US Forces. Maybe you can drive up to Oahu….
“follow up attack”

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Re: The invasion of Oahu, December 1941.

Post by gurn » 14 Feb 2015 17:57

Fighting Aircraft of World War Two, by Bill Gunston Salamander books limited,London

Aichi D3a1 has a range of 1,131 miles with bomb

Nakajima B5N has a range of 683 miles

These numbers seem to reflect everything I've seen on web sites or various books.

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Re: The invasion of Oahu, December 1941.

Post by ChristopherPerrien » 15 Feb 2015 05:21

gurn wrote:Fighting Aircraft of World War Two, by Bill Gunston Salamander books limited,London

Aichi D3a1 has a range of 1,131 miles with bomb

Nakajima B5N has a range of 683 miles

These numbers seem to reflect everything I've seen on web sites or various books.
Care to post a few, besides the aforementioned Gunston edit. Realize that book was a Janes book first published in 1946, and was based on wartime intel figures, not all info accurate or updated.

Personally I have never seen a source or site , putting the range of Val more than Kate.
The simple fact the Val had fixed landing gear is a big red flag that it had limited range compared to more modern Japanese carrier aircraft with folding gear.

Normally most sites and books and forum comments, put the Val range at 750-850 miles and the Kate B5N2 at 1100-1200 miles. I am surprised you have found "many", so I'd like to look them up.

Wiki even posts figures in this range, and I doubt those would be in error, given the topic Val
Performance
Maximum speed: 430 km/h (232 kn, 267 mph (430 km/h))
Range: 1,352 km (730 nmi, 840 mi (1,350 km))
Service ceiling: 10,500 m (34,450 ft)
Rate of climb: 8.62 m/s (1,869.685 ft/min)
Kate
Performance
Maximum speed: 378 km/h (204 kn, 235 mph)
Range: 1,992 km (1,075 NM, 1,237 mi)
Service ceiling: 8,260 m (27,100 ft)
Rate of climb: 6.5 m/s (1,283 ft/min)
Wing loading: 101 kg/m² (21 lb/ft²)
Power/mass: 0.20 kW/kg (0.12 hp/lb)
http://www.militaryfactory.com/aircraft/index.asp States the same figs.
840m-VAl
1237m -Kate

Addenda- If you look up the Japanese op order, http://www.ibiblio.org/pha/myths/jm-097.html The launch distance was 230 miles. This meshes nicely with carrier attacks being done at 1/3 the range of an aircraft. Fuel being allocated at 1/3 flyin, 1/3 time over target/fighting time/1/3 return., In this case 3x230 is 690, plus adding some time lost for forming up attack formations, gets real close to the max range/flying time of the Val.
Last edited by ChristopherPerrien on 15 Feb 2015 06:14, edited 7 times in total.

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