lesofprimus
Brigadier General
Rudel also flew the Fw 190 and scored his "kills" in that seat.... His numbers are inflated by anyones measure, and he lost several backseaters while flying the Stuka....
SBD vs. JU-87 vs. Aichi D3A
- Thread starter Velius
- Start date
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Its that way for any Dive Bomber. If you dont have air superiority you are going to take heavy losses.
Hi Udet,
>You assertion the Dauntless was never withdrawn from service means virtually nothing for concluding which plane was the best.
Hm, the USAAF's A-24 seems to have been withdrawn from combat service after suffering serious losses (on a small scale).
David Donald's "Bomber" gives the A-24 versions as follows:
A-24 = SBD-3 (minus arrestor gear), 78 examples factory build
A-24 = SBD-3A, 90 examples from a Navy batch converted to A-24 standards
A-24A = SBD-4, 100/170? examples
A-24B = SBD-5, 615 examples, Tulsa-built
I figure all of the Army A-24 variants had the arrestor gear removed, but Donald mentions it only specifically for the first batch.
Accordingly to Donald, armour and self-sealing tanks were introduced with the SBD-2 variant.
Regards
Henning (HoHun)
>You assertion the Dauntless was never withdrawn from service means virtually nothing for concluding which plane was the best.
Hm, the USAAF's A-24 seems to have been withdrawn from combat service after suffering serious losses (on a small scale).
David Donald's "Bomber" gives the A-24 versions as follows:
A-24 = SBD-3 (minus arrestor gear), 78 examples factory build
A-24 = SBD-3A, 90 examples from a Navy batch converted to A-24 standards
A-24A = SBD-4, 100/170? examples
A-24B = SBD-5, 615 examples, Tulsa-built
I figure all of the Army A-24 variants had the arrestor gear removed, but Donald mentions it only specifically for the first batch.
Accordingly to Donald, armour and self-sealing tanks were introduced with the SBD-2 variant.
Regards
Henning (HoHun)
According to this site, the SBD-3 introduced armor and fuel protection.
The Douglas SBD Dauntless Curtiss SB2C Helldiver
However the same chart confirms that the A-24's were SBD-3's or higher so it would seem the USAAF was armored. Do you have any info on these heavy losses and the circumstances? It would be useful to take a look at em.
Fighter escort doesn't mean the bombers are safe. I agree. I think however it's relevent that the Stuka proved so difficult to escort even when ample support was available. The facet that keeps getting mentioned in multiple sources is not the DUR of the bomber but rather that it was too slow. [unweildyness is less mentioned but there] This would appear to be in part due to the nature of the 109 itself however. I'm getting an impression from current reading that the situation was improved with a mixture of 109's and 190's on the escort.
Re: A-24, their reputation in USAAF seems to have been based a lot on one mission, July 29, 1942 in New Guinea. A 7 plane formation of the 8th BG, flying from Port Moresby to attack Japanese shipping on the north coast. They became separated from their P-39 escort but pressed on, were intercepted by Zeroes (Tainan Air Group) and all but one or two (sources vary) of the A-24's were lost. Thereafter A-24's were only used in areas of low fighter threat, v bypassed Japanese garrisons, v Kiska after Japanese air opposition there had ceased, etc.
The first use of A-24's was in Java where on a few missions the 91st BS managed to disable a Japanese transport (real successes v Japanese ships were pretty rare up to then, so it's notable) and avoided Zeroes, though their P-40 escort suffered heavily on one of those missions.
A-24 was SBD-3 as mentioned. SBD-3's had factory fitted armor and tank protection but SBD-2 were probably re-fitted in the field with those measures as F4F-3's were (F4F-4's from factory), in early 1942.
An assumption which might be examined further though is whether self sealing tanks and armor had a dramatic effect on *aircraft* loss rates. It helped a significant % of air crews to survive (to escape or crashland their a/c, often) who otherwise wouldn't have, that's pretty clear. And that was important for morale, and in number of pilots available if they could be recovered. But, on questions like this we're generally speaking of comparative plane losses rather than aircrew losses. Anecdotal evidence in this regard from Allied side will base the performance of Japanese planes on the numerous ones 'blowing up', but those will be seriously exaggerated estimates of the numbers compared to known certain Allied losses; and may amplify the effect of fire on pre-tank protection Allied a/c, again from the understandable perspective of avoiding getting burned to death, as opposed to plane loss rate.
Joe
The first use of A-24's was in Java where on a few missions the 91st BS managed to disable a Japanese transport (real successes v Japanese ships were pretty rare up to then, so it's notable) and avoided Zeroes, though their P-40 escort suffered heavily on one of those missions.
A-24 was SBD-3 as mentioned. SBD-3's had factory fitted armor and tank protection but SBD-2 were probably re-fitted in the field with those measures as F4F-3's were (F4F-4's from factory), in early 1942.
An assumption which might be examined further though is whether self sealing tanks and armor had a dramatic effect on *aircraft* loss rates. It helped a significant % of air crews to survive (to escape or crashland their a/c, often) who otherwise wouldn't have, that's pretty clear. And that was important for morale, and in number of pilots available if they could be recovered. But, on questions like this we're generally speaking of comparative plane losses rather than aircrew losses. Anecdotal evidence in this regard from Allied side will base the performance of Japanese planes on the numerous ones 'blowing up', but those will be seriously exaggerated estimates of the numbers compared to known certain Allied losses; and may amplify the effect of fire on pre-tank protection Allied a/c, again from the understandable perspective of avoiding getting burned to death, as opposed to plane loss rate.
Joe
fer-de-lance
Airman
- 64
- Jun 12, 2007
Aren't we forgeting that the D3A "Kanbaku" achieved the highest hit rate of any divebomber in WWII - vide sinking of HMS Hermes, Dorsetshire and Cornwall.
renrich
Chief Master Sergeant
One factor regarding the discussion of the SBD, Stuka, Val comparison is that the SBD was used and I believe designed for a dual role. That is as a scout plane as well as a dive bomber. Because of that it had a longer range than the Stuka and probably more range than a Val. The IJN typically used float planes off the cruisers and BBs as scout whereas early in the war the USN would normally designate one squadron of SBDs on a CV as scouts, one Sq as dive bombers. of course the SB in SBD stood for scout bomber.
Hi Renrich,
>One factor regarding the discussion of the SBD, Stuka, Val comparison is that the SBD was used and I believe designed for a dual role. That is as a scout plane as well as a dive bomber. Because of that it had a longer range than the Stuka and probably more range than a Val.
Unfortunately, I don't have a range table for the Stuka, but the Ju 87C, D and R variants could carry two external tanks to bring the fuel capacity up to 1370 L, while the similarly loaded SBD had a capacity of 1400 L.
The SBD had an internal tank twice as large as the Stuka's though - 960 L vs. the 480 L.
(On the other hand, the Ju 87D could carry a 1800 kg bomb in the extreme, while the SBD was limited to a 726 kg bomb if fuel load was restricted - we're really seeing a difference in specialization here.)
I'd say that even with external tanks, the SBD-5 probably held a fair range advantage over the Ju 87C and R - and possibly over the Ju 87D as well. Still, it would be interesting to see accurate data on the Stuka!
Regards,
Henning (HoHun)
>One factor regarding the discussion of the SBD, Stuka, Val comparison is that the SBD was used and I believe designed for a dual role. That is as a scout plane as well as a dive bomber. Because of that it had a longer range than the Stuka and probably more range than a Val.
Unfortunately, I don't have a range table for the Stuka, but the Ju 87C, D and R variants could carry two external tanks to bring the fuel capacity up to 1370 L, while the similarly loaded SBD had a capacity of 1400 L.
The SBD had an internal tank twice as large as the Stuka's though - 960 L vs. the 480 L.
(On the other hand, the Ju 87D could carry a 1800 kg bomb in the extreme, while the SBD was limited to a 726 kg bomb if fuel load was restricted - we're really seeing a difference in specialization here.)
I'd say that even with external tanks, the SBD-5 probably held a fair range advantage over the Ju 87C and R - and possibly over the Ju 87D as well. Still, it would be interesting to see accurate data on the Stuka!
Regards,
Henning (HoHun)
renrich
Chief Master Sergeant
Henning, My reference "Great Book of WW2 Airplanes" shows Ju87B2 with internal fuel of 480 liters and max range without bombs of 372 miles. On SBD5, "Aircraft of WW2" shows max range of 1115 miles. Doesn't sound like the Stuka would do well in the Pacific. Same book shows D3A2 with max range of 970 miles.
Hi Renrich,
>Henning, My reference "Great Book of WW2 Airplanes" shows Ju87B2 with internal fuel of 480 liters and max range without bombs of 372 miles. On SBD5, "Aircraft of WW2" shows max range of 1115 miles. Doesn't sound like the Stuka would do well in the Pacific.
Well, the Ju 87B was not configured to use drop tanks, but the naval version Ju 87C and the long-range version Ju 87R were - as was the Ju 87D, the contemporary to the SBD-5.
As a very rough estimate, on 1370 L instead of 480 L the Ju 87R-2 (the exact counterpart to the B-2) could do 1060 miles - neglecting the unknown drag of the drop tanks. This drag is an unknown quantity, but probably not all that important for a low-speed aircraft of the size of the Stuka. The Ju 87D featured improved aerodynamics, which of course help range, too.
Based on your figures (and ignoring the uncertainties that stem from the exact conditions for these range figures not being listed for the moment
, I'd think the Ju 87D would not have quite the range of the SBD-5, but probably about the same range as the Aichi D3A, so it should certainly be an effective aircraft type in the Pacific Theatre.
(What range does your book list for the SB2C, by the way? I vaguely seem to remember that it sacrificed some range compared to the SBD to carry a havier bombload, but I might be wrong ...)
Regards,
Henning (HoHun)
>Henning, My reference "Great Book of WW2 Airplanes" shows Ju87B2 with internal fuel of 480 liters and max range without bombs of 372 miles. On SBD5, "Aircraft of WW2" shows max range of 1115 miles. Doesn't sound like the Stuka would do well in the Pacific.
Well, the Ju 87B was not configured to use drop tanks, but the naval version Ju 87C and the long-range version Ju 87R were - as was the Ju 87D, the contemporary to the SBD-5.
As a very rough estimate, on 1370 L instead of 480 L the Ju 87R-2 (the exact counterpart to the B-2) could do 1060 miles - neglecting the unknown drag of the drop tanks. This drag is an unknown quantity, but probably not all that important for a low-speed aircraft of the size of the Stuka. The Ju 87D featured improved aerodynamics, which of course help range, too.
Based on your figures (and ignoring the uncertainties that stem from the exact conditions for these range figures not being listed for the moment
, I'd think the Ju 87D would not have quite the range of the SBD-5, but probably about the same range as the Aichi D3A, so it should certainly be an effective aircraft type in the Pacific Theatre.(What range does your book list for the SB2C, by the way? I vaguely seem to remember that it sacrificed some range compared to the SBD to carry a havier bombload, but I might be wrong ...)
Regards,
Henning (HoHun)
According to this website, the -D varient with tanks had a max range of 830 nautical miles.
The SBD-5 in a max fuel config lists as 970 nautical miles. (same site)
Air Vectors
D3A2 from another site lists max range as 915 miles
Aichi D3A (Val) - Japan
Not really a whole lot of difference to remark about. Ultimately effective range would be governed by ordinance loadout and more importantly, the range of the escorts. A carrier cat and mouse game also would govern max effective range due to the target mobility and the need for a safety margin in order to return to the home carrier
The SBD-5 in a max fuel config lists as 970 nautical miles. (same site)
Air Vectors
D3A2 from another site lists max range as 915 miles
Aichi D3A (Val) - Japan
Not really a whole lot of difference to remark about. Ultimately effective range would be governed by ordinance loadout and more importantly, the range of the escorts. A carrier cat and mouse game also would govern max effective range due to the target mobility and the need for a safety margin in order to return to the home carrier
The Japanese sometimes used their B5N's in the scout role. They did prefer floatplanes or land based scouts in order to preserve carrier firepower.
renrich
Chief Master Sergeant
My ref "Aircraft of WW2" gives max range of Helldiver as 1925 miles and normal range of JU87D-1 as 620 miles. Those numbers don't tell us much. The numbers I quoted on the SBD, 1115 miles are, I suspect, with internal fuel only, a 500 pound bomb and are a "yardstick" range, that is do not include warmup, takeoff, climb out, combat, return and reserve fuel. A realistic range would be around 70% of that. The reason I say that is internal fuel only is that I don't believe the SBD, especially in the early going ever carried external fuel and those range figures pretty much match the "yardstick" range of the Wildcat which would be the escort fighter for the SBD. I don't believe the Stuka could ever match the range of the Dauntless on internal fuel and carrying a 500 or 1000 lb bomb.
Hi Renrich,
>I don't believe the Stuka could ever match the range of the Dauntless on internal fuel and carrying a 500 or 1000 lb bomb.
Hm, as (unlike the Dauntless) the Stuka could combine carriage of a 500 kg (1100 lbs) bomb and drop tanks, it actually could match the Dauntless' range under the stated conditions.
(At least, as far as I can tell from the fragmentary data we have.)
On internal fuel alone, that would obviously not possible, but the use of the underwing tanks seems to have been standard operating procedure with the Ju 87R in anti-shipping operations in the mediterranean, so it seems natural to assume they could have been used in the Pacific Theatre as well.
Regards,
Henning (HoHun)
>I don't believe the Stuka could ever match the range of the Dauntless on internal fuel and carrying a 500 or 1000 lb bomb.
Hm, as (unlike the Dauntless) the Stuka could combine carriage of a 500 kg (1100 lbs) bomb and drop tanks, it actually could match the Dauntless' range under the stated conditions.
(At least, as far as I can tell from the fragmentary data we have.)
On internal fuel alone, that would obviously not possible, but the use of the underwing tanks seems to have been standard operating procedure with the Ju 87R in anti-shipping operations in the mediterranean, so it seems natural to assume they could have been used in the Pacific Theatre as well.
Regards,
Henning (HoHun)
renrich
Chief Master Sergeant
Henning, some thoughts on the Stuka. Is there any single engine AC in WW2 that looks draggier? External fuel tanks because of additional drag and weight don't yield but about a 50% range gain and of course decrease bomb load. Often, big horsepower increases don't increase speed much but do increase load carry. To me, the performance figures on the Stuka look suspect. Were there any actual flight tests performed by the allies on JU87s?
Hi Renrich,
>Henning, some thoughts on the Stuka. Is there any single engine AC in WW2 that looks draggier?
Drag is in the eye of the beholder Seriously, you'd need a wind tunnel test to know.
The Junkers Flugzeugwerke had a long wind tunnel tradition, and they included the interior aerodynamics of radiators in their design considerations. Interior aerodynamics would not be immediately visible, of course. The Ju 87 also had an inline engine, featuring a smaller frontal area than a radial, and over the SBD it had the additional advantage of featuring a spinner - it does make a difference even for radials, even though sometimes considerations other than streamlining prevent its installation.
>External fuel tanks because of additional drag and weight don't yield but about a 50% range gain and of course decrease bomb load.
Hm, a 50% range gain compared to what? You have to remember that the power required to overcome parasitic drag increases to the cube of speed, and the Junkers Ju 87 cruised rather slowly. The impact of the drop tanks has also to be seen in relation to the size of the aircraft, and the Ju 87 was rather big.
With regard to the bomb load, the Ju 87's decreased load was the SBD's normal load - 500 kg with drop tanks for the Ju 87 match the 1000 lbs of the SBD quite nicely,
>To me, the performance figures on the Stuka look suspect. Were there any actual flight tests performed by the allies on JU87s?
I'm only aware of the handling tests performed by Eric Brown, but of no actual performance testing. However, which numbers exactly are suspect in your opinion? It's not like we have a lot of Stuka data, I'm afraid.
Regards,
Henning (HoHun)
>Henning, some thoughts on the Stuka. Is there any single engine AC in WW2 that looks draggier?
Drag is in the eye of the beholder
Seriously, you'd need a wind tunnel test to know. The Junkers Flugzeugwerke had a long wind tunnel tradition, and they included the interior aerodynamics of radiators in their design considerations. Interior aerodynamics would not be immediately visible, of course. The Ju 87 also had an inline engine, featuring a smaller frontal area than a radial, and over the SBD it had the additional advantage of featuring a spinner - it does make a difference even for radials, even though sometimes considerations other than streamlining prevent its installation.
>External fuel tanks because of additional drag and weight don't yield but about a 50% range gain and of course decrease bomb load.
Hm, a 50% range gain compared to what? You have to remember that the power required to overcome parasitic drag increases to the cube of speed, and the Junkers Ju 87 cruised rather slowly. The impact of the drop tanks has also to be seen in relation to the size of the aircraft, and the Ju 87 was rather big.
With regard to the bomb load, the Ju 87's decreased load was the SBD's normal load - 500 kg with drop tanks for the Ju 87 match the 1000 lbs of the SBD quite nicely,
>To me, the performance figures on the Stuka look suspect. Were there any actual flight tests performed by the allies on JU87s?
I'm only aware of the handling tests performed by Eric Brown, but of no actual performance testing. However, which numbers exactly are suspect in your opinion? It's not like we have a lot of Stuka data, I'm afraid.
Regards,
Henning (HoHun)
renrich
Chief Master Sergeant
For instance it's speed and range figures as well load carrying. What I was referring to on external fuel is that I believe the rule of thumb in WW2 was that half the fuel in an external tank was used for overcoming the additional drag and the other half went to extend the range.
Hi Renrich,
>For instance it's speed and range figures as well load carrying.
Here is the Ju 87B manual:
http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/ju-87b-pilots-manual-5085.html
It does not have top speed or range figures, but at least lists a true air speed in the cruise of circa 350 km/h @ 5.2 km at maximum continuous power, and a more economical 325 km/h @ 4.0 km for a range of 505 km in supercharger low gear. (This is not best range, which would be achieved at a considerably lower power setting. It's not "theoretical still air range" either, as some deductions have already been made from the figure compared to the theoretical figure you'd derive from true airspeed, fuel supply and fuel consumption.)
For the Ju 87D that was the contemporary of the SBD-3 and -5, I only have the loading diagram from the manual, so I'm afraid I don't have performance figures.
However, you can see the load cases 13 and 14 in the diagram: Two external tanks in combination with a 250 kg or a 500 kg bomb. Load case 15 actually is a 1000 kg bomb in combination with the two tanks, but it's marked as "take-off with overload - only by special RLM operations order", so it's not a standard configuration.
In short, I see little reason to doubt the load carrying figures and the typically quoted top speeds for the Ju 87. Range, as always, is difficult to determine from incomplete data, but with the external tanks, it would probably have had the range for carrier operations in the Pacific theatre, even if other dive bombers still would hold a range advantage over the Stuka.
>What I was referring to on external fuel is that I believe the rule of thumb in WW2 was that half the fuel in an external tank was used for overcoming the additional drag and the other half went to extend the range.
Hm, interesting rule of thumb, I hadn't heard this one before. Seems a bit pessimistic to me, though ... are you sure it's not actually a Vietnam era rule? For high-speed jets, it would make more sense in my opinion.
Looking at WW2 aircraft, the Me 109G-6's top speed at sea level for example dropped by 8% when a 300 L drop tank was carried, while the fuel load increased by 75% ... more like 10% of the additional fuel burnt to carry the drop tank.
Kurfrst - Leistungzusammenstellung Me 109 G.
And remember "speed cubed" ... if you fly as slow as the dive bombers, the additional drag pretty much collapses into irrelevance. If the Me 109G-6 travels at 1/2 its top speed, the drop tank drag penalty is only 1/(2^3) = 1/8 of the high speed value. That's very roughly 1% of the unencumbered speed ... not a concern at all.
Regards,
Henning (HoHun)
>For instance it's speed and range figures as well load carrying.
Here is the Ju 87B manual:
http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/ju-87b-pilots-manual-5085.html
It does not have top speed or range figures, but at least lists a true air speed in the cruise of circa 350 km/h @ 5.2 km at maximum continuous power, and a more economical 325 km/h @ 4.0 km for a range of 505 km in supercharger low gear. (This is not best range, which would be achieved at a considerably lower power setting. It's not "theoretical still air range" either, as some deductions have already been made from the figure compared to the theoretical figure you'd derive from true airspeed, fuel supply and fuel consumption.)
For the Ju 87D that was the contemporary of the SBD-3 and -5, I only have the loading diagram from the manual, so I'm afraid I don't have performance figures.
However, you can see the load cases 13 and 14 in the diagram: Two external tanks in combination with a 250 kg or a 500 kg bomb. Load case 15 actually is a 1000 kg bomb in combination with the two tanks, but it's marked as "take-off with overload - only by special RLM operations order", so it's not a standard configuration.
In short, I see little reason to doubt the load carrying figures and the typically quoted top speeds for the Ju 87. Range, as always, is difficult to determine from incomplete data, but with the external tanks, it would probably have had the range for carrier operations in the Pacific theatre, even if other dive bombers still would hold a range advantage over the Stuka.
>What I was referring to on external fuel is that I believe the rule of thumb in WW2 was that half the fuel in an external tank was used for overcoming the additional drag and the other half went to extend the range.
Hm, interesting rule of thumb, I hadn't heard this one before. Seems a bit pessimistic to me, though ... are you sure it's not actually a Vietnam era rule? For high-speed jets, it would make more sense in my opinion.
Looking at WW2 aircraft, the Me 109G-6's top speed at sea level for example dropped by 8% when a 300 L drop tank was carried, while the fuel load increased by 75% ... more like 10% of the additional fuel burnt to carry the drop tank.
Kurfrst - Leistungzusammenstellung Me 109 G.
And remember "speed cubed" ... if you fly as slow as the dive bombers, the additional drag pretty much collapses into irrelevance. If the Me 109G-6 travels at 1/2 its top speed, the drop tank drag penalty is only 1/(2^3) = 1/8 of the high speed value. That's very roughly 1% of the unencumbered speed ... not a concern at all.
Regards,
Henning (HoHun)
Attachments
Zeke_Freak
Airman
- 64
- Dec 30, 2010
Agreed. However, the biggest factor IMO, is the skill of the pilots. As an example of this, I recall reading that some Midway Dauntless' in marine hands were not used as dive bombers at all, simply because the pilots didn't have verticle dive bomb training. Instead they used glide bombing techniques and were much less effective as a result.
Right now I'm reading a great book entitled 'Beyond Pearl Harbor' which recounts the 'untold' stories of Japanese naval pilots during WWII. In one of the accounts the point is made by one of the pilots that the window of conditions for effective dive bombing was very limited compared to level bombing, so many times the kanbaku had to simply turn back if conditions weren't right. Their reputation proved to be a two edged sword though as some Japanese commanders apparently expected more of them than was realistic.
Probably the biggest factor for the Japanese was that they had a finite number of experienced pilots, and they didn't protect them well, or make the most effective use of their experience while they still had them. They had some well experienced pilots going into WWII, thanks to their war with China, but wasted many of them.
Regarding the type 99 kanbaku (Val) in particular, one of the IJN pilots interviewed in the book I mentioned above, really liked the aircraft, but had one negative comment about it. He said the oil leakage from the engine cylinders was excessive, and he was always having to wipe the wind screen in order to see properly.
I vote SBD overall; though I'm a big fan of the Stuka and 'Val' (type 99 kanbaku) aswell. I just came back from the Pacific Aviation Museum on Ford Island in Pearl Harbor. I'd pass up the opportunity to fly any (or all) of the aircraft I saw there (inclduing their 'Zeke') for a chance to ride in the SBD-5 they had on display. Such a beautiful aircraft.
Leif
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