Stukas and HMS Illustrious.
 

Esteemed Stuka- experts on this forum :)

I turn to you to clarify what excactly hit HMS Illustrious on January 10th 1941. I have tried to search the forum, but cannot find anything on these events.

There is a long-standing disagreement, among those interested in naval warfare, about the value of the british armoured carriers of the Illustrious class.
The argument centers on the survivability of armour, versus the defence offered by a larger airgroup of modern fighters.

The most important example to the defenders of the armoured (box) carriers is the survival of HMS Illustrious in January 1941.

However, I am finding conflicting data about what happened. The standard account is that it was hit by 6-8 bombs, mostly 500 kg armour piercing bombs, maybe 1-2 250 kg SAP bombs. (The official record is 10 550kg bombs, (D.K. Brown, Nelson to Vanguard, p.205), but on p.51 he says 7 hits, probably 500kg.)
That the attack on jan. 10th was carried out by 50-100 Stukas of I. StG 1 and II. StG 2.

Paul-Werner Hözzel, Kommandeur I. StG 1, wrote an account for Charles Lamb, published in "War in a Stringbag". He differs in two respects from the "standard account". A) He only arrived on january 13th, and therefore did not take part in the Jan.10th attack, and B) that in later attacks on Illustrious in Valetta harbour, the Stukas carried 1000 kg bombs, which broke up on the armour.

However. I recall reading an account by a former Stuka ace in a british aviation magazine about a decade ago, where he claimed that the heavy bombs were reserved for the battleships, and Illustrious was attacked by planes carrying the 250 kg bombs. Unfortunately, I didn´t buy the magazine, so I don´t have it, and don´t recall other details.

The questions I have are;
1) How many Stukas attacked on January 10th.?
2) What kind of bombs did they carry?
3) How many were Ju 87B and how many Ju 87R?
4) Could the Ju 87R carry 500kg bombs?
5) Could the Ju 87 carry 1000kg bombs?
6) Could the Ju 87B trade off bombload for range. (i.e. carry external drop tanks?) (This question because of the claim that the Germans knew that Illustrious was armoured, and therefore had to be attacked by 500kg AP bombs, thus reducing the range at which Stukas could attack, in a round-about way, creating a sort of an immunity zone for the carriers).
7). How long would it take the Stukas to arrive over the carrier at attacking height (I have seen both 12000 feet and 16000 feet mentioned), from the moment the incoming strike was detected on Radar?
(Both the Illustrious, and the battleship HMS Valiant had radars?
8) What was the radius of action of the Stuka? (Was it greater than the Bf 109?)

The last two questions pertain to the value of shipborn interceptors as an alternative defence for the ship.


Birgir Thorisson

Re: Stukas and HMS Illustrious.
 

Hello Birgir
I'm not a Ju 87 expert but some info
43 Stukas attacked, both Bs and Rs but I have not info how many were Bs and how many Rs.
identified bombs were 500kg
R could carry a 500 kg bomb
According to an article in Oct 1984 Air International, B-2 could carry a 1000kg bomb as single-seater, ie when WO/AG was left out.
IIRC of the pre-D types only Cs and Rs had capacity to use drop tanks.

HTH
Juha

Re: Stukas and HMS Illustrious.
 

Thank you Juha for your response.

I have the said article, and it is there that I picked up the info-snippet that the R could only carry one 250 kg bomb.("resticted to a maximum offensive load" of 250 kg. Closer look shows that it is in fact said about the R-1 model, but the R-2 is said to have primarily differed in installed equipment.

On the other hand, there is no logical explanation of why the R should be structurally limited to carrying only the 250 kg bomb. After all, you ought always to be able to trade off one form of payload (fuel) for another (bombs). But in that case, the R should be even shorter ranging than the B-2, which the article credits with 595 km max range, which should equate a radius of action of ca. 200 km, using the 1/3 rule of thumb.

There is no data on economica cruise speed, but using continous max cruise, (ca 300 km/h) with radar range of 100 km. (I don´t have it for the radar installed in Illustrious and Valiant), 20 minutes warning time would have been available for the carrier, before the Stukas were overhead. Which would, or would not, have been sufficent to scramble fighters, depending on the state of the organization onboard the carrier. (It would have been enough for the US at Coral Sea, but that is a different story.).

Birgir Thorisson

Re: Stukas and HMS Illustrious.
 

Hello Birgir
I don't have time to check but IIRC Rs could carry only a 250kg bomb if they had the drop tanks but were able to carry a 500kg if not burdened with drop tanks.

Juha

Re: Stukas and HMS Illustrious.
 

Hello Birgir
I read again Your message #3, and IIRC R had also bigger internal fuel tankage than B. And on 11.1. Stukas attacked RN CLs (IIRC HMS Southampton and HMS Glouchester plus some others) some 300 mls from Sicily, then they carried 250kg bombs.

Juha

Re: Stukas and HMS Illustrious.
 

Just a thought but what about the crutch that swung the bomb outside the airscrew arc when dive-bombing? Might not the strength of that be a limitation?

Re: Stukas and HMS Illustrious.
 

Hi Birgir,
Back in Feb 2002, Les Whitehouse submitted the three posts below about the differences between the Ju 87 B and R variants.

Hope that helps,
Leon Venter

------------------------------------------------------
Ju87R - Les Whitehouse 13 Feb 2002
The reason for the classification of B-1 = R-1 and B-2 = R-2 was probably based upon engine. In actual fact the two types B-2/R-2 were built in parallel on the production lines at Weser only a few being later conversions so the serial numbers intermingle. All R aircraft had an enlarged (or additional?) oil tank in the fuselage over and above the two 300 litre drop tanks so they carried extra fuel and oil. They also had a dinghy and survival equipment etc.

The main rack capacity was changed between the B-1 and B-2 from 500 kg (500 XI B rack) to 1000 or 500 kg (1000/500 XI B rack). A similar capacity existed between the R-1 & R-2. Although the carriage of a 1000 kg bomb in anger was rare, photographs exist of both R-2 and B-2 with such weapons in use. Also remember the bomb load was potentially reduced anyway as the addition of external fuel removed the ability to load the wing bomb racks. In some cases the early R’s appear to have sacrificed any wing bomb capacity by having what look like “rackless” or “half-rack” installations with simple struts. In the main however, most R’s photographed appear to have had fitments which linked to basic 50 kg racks, suggesting they could convert and operate like normal B’s where range was unimportant. In essence, at short ranges, there was no deterioration in bomb load capacity on the centreline rack

The R-1 (like the B-1) used the Ju211A engine
The R-2 (like the B-2) used the Ju211D engine
Others:-
R-2/trop – Ju211D engine and enlarged sand filter
R-3 - Ju211D engine but fitted for glider tow and having radio equipment which could be linked through the tow cable.
R-4 used the Ju211J engine like the 87D and had modified inner wing structure similar to the D series to take self-seal tanks. It also probably had the /trop filter as standard.

The major trade-off on the B to R saga was in fuel load+bomb load vs range to target and return - with the airframes constantly reducing fuel load/all-up-weight. Its total of fuel load and bomb load could not exceed the gross weight limit and it had to reach the target chosen. Hence if you wanted max range you had to reduce the bomb load. This and the target would dictate the bomb load on any mission.

R speed was 320 km/h compared to 340 km/h for the B
R climb to height was 16 min compared to 7 min for the B
R average range was 1210 km compared to 850 km for the B (could be improved by leaving out armour) but in order to use this range you had no underwing bombs and probably only a 250 kg centreline load.

If we look at weights based upon Junkers own figures, which are also not directly comparable because of variations in armour plate etc:-

Basic Weight B-1 2750 kg, R-2 3450 kg
Gross Weight B-1 4300 kg, R-2 5600 kg
(The B-2 had trial tests up to 5500 kg gross)

The B had 480 litres of internal fuel in two 240 litre tanks. The R added to this with two external 300 litre tanks only. The R-4 had the D inner wing structure so as to use its self seal tank design but still only had 480 litres internally and 600 externally. There is some confusion in early writings about internal tankage which confuses the R tankage with that of the D series. This type (D) had the same inner wing tanks but also an auxiliary 150 litres in each outer wing (480 + 300 internally) and usually the capacity to take a 300 litre tank under each outer wing also – hence a “long range” version of the D, for example, was inappropriate.

For your information – noting the replies about fuel weight - the Luftwaffe staff RLM GL/C B2 at the time used a fuel weight conversion of 0.74 kg/litre for their data charts – this is taken from a GL/C B2, Bf110 equipment and range datasheet. I have not ever seen a similar datasheet for the Ju87 B or R but one would certainly have existed.

------------------------------------------------------
Ju87R Sources - Les Whitehouse 14 Feb 2002
Best published source is the Ju87 Stuka by Griehl – German edition by Motorbuch Verlag 1998, English Edition by Airlife 2001 ISBN 1 84037 198 6.

RLM Development Bureau Programme C listed all planned R production at Weser Aircraft.

B-1’s by Weser were planned 1937 through to March 1940 and B-2 production was to cover from July to October 1940. In parallel from June 1940, Weser were also tasked with the R-1 (presumably because they could then use the existing B-1 tooling with additions for the R-1?) and were tasked with delivering these July to October 1940 as well. R-2 production was intended to follow on from the R-1 once B-2 production was completed. In reality by that time not only had all the R-1’s been completed but a further qty of 123 R-2’s had been completed in advance of the original programme - presumably because the various sites used by Weser, including the opening of Berlin-Templehof allowed an expansion of throughput on the Ju87 B and R.

Note: there is photographic evidence of R-1 in service as early as April 1940 even in Greihl’s book (captioned as an R-2) and the first operational R-1’s were used in Norway – so Weser production appears to have been in advance of formal order documents and planned programmes

Rest of the data has come from my own research on serial numbers etc., but everything I have said is collaborated in Griehl’s account. Although, to be honest, it is not laid out as clearly and tankage in particular has to be pieced together from separate sections to get and overall picture of the changes. It is also not in his usual style and does not have production or loss lists like his He177 book. Griehl actually states a 1941 publication date for the Rechlin produced data table for the R-2 but does not publish the table. Griehl also confirms that, because of the engine type and component standards, the R-1 was “in effect” a long range B-1 and the R-2 a long range B-2, but as the R-1 came in during the latter half of B-1 production it had (as did the late B-1) the later style full exhaust stacks.

One other publication I could refer you to is the booklet “Stuka – Ju87” by Richard P.Bateson, Ducimus Books, 1972. However, not only would it be difficult to find a copy, it is simply a good historical account with lots of photographs. It has little on the technical side once past the prototypes, so would probably be a waste of effort. In this one the modified fuel system (R-4) is reported only as a modified "lubrication" system.

------------------------------------------------------
Range - Les Whitehouse 15 Feb 2002
Range figures can be confusing. Some records/writers will quote a figure which is an actual “radius of action” - Allowing the machine to reach its target and return. Others will quote a straight line range, presumably on the basis that the aircraft will land at its destination. In most cases the data is incomplete unless all of the conditions are known. Ie: the weight (including crew, ammo, fuel and bombs), height and speed flown (hence rate of fuel usage). Unless all of this information is considered then calculations will be inaccurate and at best a prediction.

For your information:

There were formulae developed pre war for design approximations which allow both a crude prediction (UK - spot air range) and a more accurate prediction of range (UK – optimum performance range) to be made based upon the type of airframe (its drag efficiency), fuel consumption, airscrew efficiency and ratio of airframe and disposable load. I have had good correlation between these formulae and RLM documents applying the formulae to situations with the Bf110 (such as the flight by Hess). However the application is not easy and uses a lot of approximation (that’s technical for guessing!). At Boulton Paul the problem of a consistent basis of performance prediction and comparison with other manufacturers was so frustrating that they introduced a term in their proposals known as “reinforcing range”. This was the clear “non-radius of action” situation where extra tanks were fitted and the aircraft was simply to fly a basic route and land away from base – ie: reinforce a distant base.

Fortunately, in this case, we are concerned with data which has already been obtained from technical sources and a simple sum will clarify the loading conditions of the R Airframe.

Loads:

The following range figures were reported by Bateson in the Ducimus Publication but because they are in English figures it is not known if they are the result of tests on captured aircraft or taken from German documents. I have converted back to the SI system. They look to me like typical Rechlin/RLM style altitudes and the speeds are typical of optimum cruising speeds at the time for what were termed clean, low-drag monoplane airframes like the 109/110/87 etc. so I think they have come from “official” RLM sources. This is further backed up by the presentation style of two maximum weights:-

R-1 1429 km at 270 km/h outbound, 324 km/h inbound at 5000 m altitude

R-2 1254 km at 290 km/h outbound, 330 km/h inbound at 4000 m altitude

The speed difference inbound and outbound suggests a “chosen” load for the tests but that load is not specified.

The max weight limit of the R-2 was stated as 4700 kg stressed to H5 (full aerobatics) and 5650 kg stressed to H3.

Using these and Junkers “empty” limit for the R-2, I have calculated weight in Kg, based on Air Ministry style summation, assuming all disposable load plus weapons and radio are added to the empty weight:-
Basic 3450
Crew 180
Radio 160
Oil 45
Maps etc 2
3xMG17 38
1500 rounds 90
Fuel 799
Total 4764

250 kg bomb +250
Total 5014

This suggests to me that the airframe is overloaded by more than 300 Kg on take-off for the full H5 stressing. It would have had to use up at least 2/5ths of its fuel before it could dive bomb a target.

500 kg +500
Total 5264

This suggests ok for H3 stressing but the aircraft would have to be down to 4700 Kg before it could actually dive bomb a target (over 2/3rds of its fuel load). This would be unrealistic at maximum range as it could not return to base.

Re: Stukas and HMS Illustrious.
 

Hello Leon
Peter C. Smith in his Junkers Ju 87 Stuka also gave the same B-1/R-1 and B-2/R-2 connection and IIRC that was also mentioned in Oct 84 AI article, but according to Smith already R-1 had two additional 150 litres wing tanks.

And Ju 87 needed less than ½ fuel to return after bombing, no external (draggy) load to carry and being much lighter during the climb back to optimum cruise height than after take off.

On ability to dive bomb, Ju 87 was already released its bomb before pull out ie before max stress to its structure.

Juha

Re: Stukas and HMS Illustrious.
 

Leon Venter:

Thank you, very informative.

Question: If each droptank fully loaded weighed about 240 kg, that is more than the bombload carried by the B on the wing racks. It is hardly compatible with extra internal tanks, as reported for R-1 in AI. But:

Basic Weight B-1 2750 kg, R-2 3450 kg
Gross Weight B-1 4300 kg, R-2 5600 kg
(The B-2 had trial tests up to 5500 kg gross)

If the empty weight of the R-2 is 700 kg. more than B1, the structure must be heavily reinforced. (The more appropriate comparison would have been with the B-2)

Birgir Thorisson

PS,
I am experiencing the disappearance of posts. E.g. the post #3 above is just a part of what I posted yesterday, which I actually saw in the full form when looking at the thread on my computer screen. Does anyone have similar experiences?
(I edited the piece twice, because I find it uncomfortable to read through my posts in the miniscule window offered by the "quick reply" option.)
Also, on the Polikarpov thread I started, two very long pieces disappeared when I tried to use the quote option to move paragraphs from previous posts into my reply. Apparently I was not doing something right there.
Is it possible in some way to go back and recover what was written in these windows, if one has lost it by some accident, before it got posted?

Edited.
PPS. when I posted this comment, the computer returned the message that it was a duplicate of a message I had posted few minutes before. Something is wrong.

Birgir

Re: Stukas and HMS Illustrious.
 

Good point. There were problems with that device (the normal, not strenghtened one was damaged many times by 500 kg bombs) Perhaps the Bertas used mostly 250 kg bombs on that sortie (I guess, so numerous 500 kg hits would be fatal despite of the armoured deck)

Re: Stukas and HMS Illustrious.
 

Hello
while trying without luck to find out info on the crunch and possible problems with the early one from Smith's Stuka book I noticed that according to the book R-2 didn't have the extra two 150 l fuel tanks inside outer wings like R-1, so R-2's internal fuel capacity was same as B-2s. So there were three max ranges, B-2, R-1 and R-2 all had different max range and if B-1's weaker engine was less thirsty than that of in B-2/R-2 then we had 4th max range.
And of those Stukas which attacked HMS Illustrious, those from I/StG 1 were Rs and those from II/StG 2 were Bs.

Juha

Re: Stukas and HMS Illustrious.
 

I offer the account given in Norman Friedman's British Carrier Aviation, which I think should be a fairly definitive source.

On 10th January there were eight hits:
1. 500lb bomb on S2 pom-pom
2. 1000lb bomb through port forward end of flight deck, bursting above the water outside the ship
3. 1000lb bomb through the aft lift exploding above the lift platform
4. 1000lb bomb through the flight deck on the centreline, exploding above the hangar deck
5. 500lb bomb on the edge of the aft lift, exploding high in the well
6. 1000lb bomb through P1 pompom, hit edge of armour deck but did not explode, did cause fire
7. 1000lb bomb near miss starboard side aft
8. 500lb bomb down aft liftwell.

On 16th January in Valetta harbour
Several near misses
9. 1000lb bomb through flight deck exploding in captain's day cabin
10. 1000lb bomb nearmiss on portside, causing 5 degree list due to smashed plating, cracking the port turbine feet.

I believe I've seen it written that the Luftwaffe carried 1000lb bombs, the Regia Aeronautica 500lb, but cannot quote a source. This would seem reasonable enough.

Re: Stukas and HMS Illustrious.
 

I guess Friedmans account is the same official one as cited by Brown. How reliable is it re. the bomb size. How did they distinguish between the effects of 500 kg AP and 250 kg SAP bombs? The size of the explosives should not be proportionate? (But it would have been far more embarrazing to have a 550lb bomb penetrate the deck armour than a 1000lb, which was actually a 1100lb bomb).

There must be some german account available, with hits credited to individual pilots, and bomb sizes given.

Juha;
Did the R-1 carry external drop tanks, (giving it max fuel of 1380 liters)? or were the droptanks maybe replacements in the R-2, increasing max fuel from 780 l. to 1080 l. rather than reducing it.

An order of battle for the Stuka groups for the invasions of Jugoslavia and Greece shows a mix of Bs and Rs in individual groups (e.g 9 Rs and 30 Bs). Do we know that II StG 2 and I StG 1 had uniform equipment in january?

I found a range figure for the Type 79Z radar carried by Illustrious. 90 miles at 20.000 feet. I reckon it means less at lower attitude, but is it proportional? (say 45 miles at 10000 feet, or 72 miles at 16000 feet?)

Csaba and Nick. With the bomb crutch being a standard item, why complicate the assembly process with two different types? Certainly the few kilos saved are hardly worth the problems. And if the "standard" crutch was not strong enough for the 500 kg bomb, how did they deal with the 1000 kg. bomb? Was it maybe dropped in level flight? Csaba; your post implies that at some stage, the standard crutch was strengthened. Do you know when? Would the planes operated in januar 1941 have had a uniform fit, or would the individual aircraft maybe have carried different versions, depending on age and sub-type. (was this maybe the limiting factor on ordnance carried by the Ju 87R-1, subsequently removed?)

Birgir Thorisson.

Re: Stukas and HMS Illustrious.
 

I just realized that my reference to Brown in the post above is incomprehensible, because it refers to a part of my previous post 3 that disappeared. To clarify, D.K. Brown (Nelson to Vanguard) cites the official report, but gives a different tally of hits elsewhere in his book.

Birgir Thorisson.

Re: Stukas and HMS Illustrious.
 

Birgir,

I don't know exactly, when the crutch was strenghtened, but the Dora definitely used the stronger one. Despite of this, there were crutch defects even with Doras, caused by SC 500 bombs (some of them were maybe cause by material failure, though).

Re: Stukas and HMS Illustrious.
 

Hello Birgir
R-1 could also use drop tanks and had longer max range than R-2.

On radar, radar ranges are bit problematic, it varied depending on target height but not linearly, at least those of USN air warning radars in 1944, say target could be "seen" from 75 mls if at 20000ft, from 76 mls but disappearing between 73 and 65 mls if at 17000ft and from 78 mls if at 15000ft and then the horizon was the determining factor, numbers are only to give the idea. Japanese were very skillful to utilize the height anomalies but those anomalies also gave a good indication of target height to good radar operators.

Did the gruppen had uniform equipment, my info that they had is from A. Price large article on Ju 87 in Feb 2005 Aeroplane Monthly, so I'm not absolutely sure that the info is correct. I'm pretty sure that 54 Ju 87s had just arrived on Sicily and 43 participied the 10 Jan attack against Illustrious, these numbers are given in Shores et al Malta Hurricane Years and in Smith's Ju 87 book.

IMHO the limiting factor for R-1 was more probably that with full fuel load the max permissible t/o weight didn't allow 500 kg bomb load.

Juha

Re: Stukas and HMS Illustrious.
 

Illustrious's flight deck had 3in armour, intended to protect against a 500lb SAP bomb. There does not seem to have been such a hit. There are more details of the armour coverage in Friedman. The lift was not protected. Only one of the bombs dropped on 10th penetrated the armoured deck, hit 4 - possibly hit 2 as well - with one other such hit on the 16th.

I don't know how they judged the matter, but they are likely to have been experienced in such matters. Discussions about damage to USS Franklin, on one of the warship sites (modelwarship.com, I think) quote a report which compared the size of the entry holes, rather than the damage. From memory, this was part of a discussion on whether one or two bombs had been dropped. One hole was determined to have been made by a rocket that "cooked off" in the fire.

Re: Stukas and HMS Illustrious.
 

Graham Boak;

I find the information given by Friedman (p.134) a bit confusing: It is a report of the relative qualities of 3.5, 3.0 and 2.5. inch thick armoured flight decks. 3.5in deck is supposedly proof against all 500 lb dive bombs, as well as 1000 lb AP bombs from 5500 feet (and lower). 2.5in is supposedly proof against all 500 lb bombs from 5000 ft and lower. The chosen 3in deck was proof against all 500 lb divebombs, as well as level bombs from 7000 ft. and lower.
But is the assumption valid that a bomb released in a dive has lower impact velocity than a bomb dropped from level flight?
If the RN in 1935 was thinking in terms of Swordfish type "dive bomber", described somewhere as "floating gently downwards" and in no need of airbrakes, they would be seriously underestimating the impact velocity achieved by monoplanes like the Stuka and SBD.
This, along with the 10 % greater weight of the German 250 kg bomb, makes me unsure if the Illustrious´ armored deck was in fact proof against the 250 kg SAP bomb.

Juha.
I was just reading the account in "Air War for Yugoslavia, Greece, and Crete", about the attack by II. StG 2 on Formidable. It seems to imply a serious failure of radar warning. The Stuka Gruppe was out searching for supply ships for Tobruk when they stumbled upon the main force of the Mediterranean fleet, and the account (rather unclear) is that first one staffel, and later the others found and bombed the Formidable, without being intercepted by Fulmars. There was no TB ruse, as with the Illustrious. For that to happen, the radar warning system must have been very much "at sea", weather it was because of human errors by the radar operators, or if there were serious technical gaps in the coverage that the germans just happened upon.

Birgir Thorisson.

Re: Stukas and HMS Illustrious.
 

Don't expect too much from wartime radar. Coverage was not 100% at all altitudes, but the transmission produced a number of lobes. Detection would be good for the quoted distances inside the lobes, but aircraft at the correct altitude could get close to the fleet without being detected. The Japanese are known to have made use of this in their attacks on the USN.

It is perhaps an open question whether ay this stage the Germans would have been aware of this as a technique, but it could well have worked to their benefit by chance.

Re: Stukas and HMS Illustrious.
 

Hello Birgir
Quote:"But is the assumption valid that a bomb released in a dive has lower impact velocity than a bomb dropped from level flight?"

To my understandig the assumption is valid, bomb is more solid than a/c, so it has more mass per given frontage so it accelerates better. And to increase even more the difference in acceleration, bomb doesn't have dive brakes.

Juha

Re: Stukas and HMS Illustrious.
 

This would depend upon whether the bomb had enough time to reach its terminal velocity. Dropped from medium altitude, level bombers presumed, this would be so. Dropped from lower altitudes, it might not. For a given lower altitude, the bomb dropped from a Stuka would initially have a greater speed than one dropped from a Swordfish, so from very low altitudes it would have greater penetrating power from a Stuka than a Swordfish, but still less than from a bomb that had reached its terminal velocity. However, the whole point of the dive brakes on a Stuka is to maintain a slow speed in a dive: the actual difference may be less than we would assume.

Bearing in mind that the RN's expected dive bomber was not the Swordfish but the Skua, I doubt that there would be any difference in the release speed achieved or assumed.

So is the ideal release height for a divebomber judged on maximum penetration, or maximum accuracy? I presume the latter. In which case the energy on impact would be less than that dropped from a medium altitude bomber, but the chances of a hit that much greater. As demonstrated.

Re: Stukas and HMS Illustrious.
 

That really is a very interesting question Graham that you have posed. Another might be did the drop height vary depending on the type of bomb load carried?

I have a number of books on dive bombers - Vultee, Ju87, SBD, D3A etc, but none of them actually address your question.

I wonder if anyone knows the answer?

Re: Stukas and HMS Illustrious.
 

Hello Jim
in the end it was up to pilot. When Barracudas dive bombed Tirpitz in 44, they used 1600 lb AP bombs, they were ordered to drop at certain height so that bombs could get enough speed before hitting and so be able to penetrate the armoured deck of Tirpitz but pilots dropped their bombs lower than ordered in order to max the number of hits, they got some hits but impact velocities were too low to armour deck penetrations so bombs exploded on armoured deck, some might even exploded before the armoured deck but of course inside Tirpitz. Not time to check exact number of hits and where they exploded but that info should be available in any good books on Tirpitz.

Juha

Re: Stukas and HMS Illustrious.
 

Thanks for that info Juha. So are you saying that there was no 'doctrine' as such for dropping bombs? Rather just advice or directions?

Re: Stukas and HMS Illustrious.
 

Hello Jim
No, what I’m saying is that the info on target specified the load and release height but in the end it’s up to pilots. They seemed to prefer maximum accuracy. Why, you guess is as good as mine. Possibilities: the reason of attack is getting hits, it’s frustrating to risk one life in attack and miss, it’s more macho to release at low level than at high level. See British comments on 10 Jan attack against Illustrious, all seem to admire the low height releases by Stuka pilots, they dived so low. It is part of military ethos to take risks to achieve results, dropping bombs higher is safer and so also less admired among pilots, whatever higher hierarchy says. That’s true also generally among young men, one of the reasons why more young men die in traffic accidents than young women.

Juha