What if America built De Havilland Mosquitoes instead of the B-17 Flying Fortress?

[wuzak]

But to claim that by examining holes to determine what armament a certain fighter had, is curious at best.

I recall being told on this forum that the Germans checked the bullet holes on their downed aircraft and from the location and angles of those holes determined that the majority were shot down by defensive fire from bombers.

 

[WARSPITER]

In other words you are an acolyte of some obscure metric offered by some yet another summary report with some obscure logic to extract armament data in lieu of seeking source documents again?

What he said....

 

[Geoffrey Sinclair]

Imperial and US customary measurement systems - Wikipedia

en.wikipedia.org

"In 1893 the United States fixed the yard at 3600⁄3937 metres, making the yard 0.9144018 metres and 1896 the British authorities fixed the yard as being 0.9143993 metres". And to quell the "Too small to matter" chorus, the point was about differences before getting to aircraft production, with length as the headline.

Oh, they determined upgunning by counting holes in the returning a/c? to estimate change in LW fighter lethality in 1943 vs 1944?

In the book Brute Force by Ellis he lists the figures as in 1942 2.3 bombers lost per 100 combats and in mid 1944 17.7 bombers lost per 100 combats.

In To Command The Sky by McFarland and Newton they note that in Q4/42 5.8 heavy bombers were being lost per 100 cases of reported combat and this had climbed to 11.6 per 100 cases in Q1/44. The statistics for the ratio of cannon shell to machine gun bullet hits for damaged bombers. The data reported on starts
in August 1942 and ends in June 1944. The figures are date, cannon shell hits per 100 machine gun bullet hits.

8-12/42 40, 1-4/43 77, 5-8/43 70, 9-12/43 81, 1-2/44 88, 3-4/44 127, 5-6/44 135. People generally conclude the cannon had more firepower than the machine guns.

And yet post VE investigations of LW loss records (intact for 1939-most of 1944) show that 8th/15th AF claims for destroyed LW fighters ran about 10:1 (average over 1942 thriugh 1944) by returning crews claims for destroyed LW fighters. Severly overstated by 8th AF/15th AF. Some were off by only 7:1 but there ya go.

So, 'esplain 'simplified by th number of unescorted missions?'

Given the passion for methodology how did the post war investigations for Luftwaffe losses account for the split between allied fighters and bombers or in fact is it as written, the fighters and bombers between them overclaimed by 10 to 1, and only for air to air? And of course did they count the kill claims of the aircraft that failed to return, those "from N. Sea, the Channel, Holland, Belgium, France, Germany"? And if it is only the bomber kill claims at 10 to 1 how were the losses separated versus those to fighters. As of mid October the 8th stayed within escort range. If the bombers are unescorted it is a straight fight, no escort claims to account for.

Well, maybe you are gaining clues that telephone book data dumps are less than satisfying to many of the cold hearted viewers of your deathless prose?

Rather I note the clues are if I put in a full explanation it is boring, or deathless prose, if I do not put it in one will be provided, along with the usual attempts to claim the extra detail is important and should have been there before.

Ah, another macro insight trying to make a micro analysis? And of course you carefully annotated, en bloc, the useful discriminants like:

For the rest I refer people to the USSBS Bombing Accuracy report. I cannot put it in, that would be against the preferences of the group spokesperson and unilateral standards enforcer. Besides it is already done. People should be aware quoting the USSBS will require a full contextual explanation, none of this just quote the results. So sit back, relax, and wait for the detailed methodolgy explanation, data sources, how the claims of US aircraft shot down were included, how kills by non US units were excluded, Axis Allied losses accounted for, how Luftwaffe non combat losses were handled and the no doubt long list of factors affecting the results for the USAAF 10 to 1 overclaim report. Thereby showing the standards required around here and act as a beacon to inspire others. Plus how it is a good macro report, not a bad one.

McFarland and Newton give the Luftwaffe day fighter losses from three different sources for a number of dates between 2 October 1943 and 30 May 1944. The three sources are

A)Auswertung der Einsatzbereitsch der fliegenden Verb. Vom 1 August 1943 bis November 1944", which are the fighter losses for all units in the west
and reich. The figures quoted from this source actually stop on 19 April 1944.

B) Generalleutenant Josef Schmid "Day and Night Aerial Warfare over the Reich 1943-44", first published in 1954. Schmid was the commander of I Jagdkorps which controlled most of the fighters defending Germany. In checking his figures with the text of McFarland and Newton it looks like at times Schmid does not include write offs in his casualty list.

C) British translations of captured German Documents, "German Air Force Losses in the West 1 September 1943 to 31 December 1943" also losses for the area of Luftflotte Reich for the same dates and for the west and Luftflotte Reich for the period 1 January 1944 to May 1944. These are the documents from the Luftwaffe Quartermaster General.

The 17th August 1943 raid B-17 losses are reported as 41 to fighter, 11 to flak, 4 to battle damage and 10 to other reasons while on operations. Luftwaffe fighter losses for the day are reported as high as 36 shot down with another 12 written off. USAAF fighters claimed 19 kills for 3 losses, RAF fighters claimed 14 kills as well. So you can look at the numbers, 41 bombers to 48 fighters raw score, assuming "other" and battle damage cause of loss for the bombers were not due to fighters. Assume all the allied fighter kill claims are correct you end up with 15 to 41, near 1 fighter per 3 bombers. Assume half the allied fighter claims are
correct and you end up with 30.5 to 41, throw in the bomber battle damage losses, it is 30.5 to 45. The bombers were awarded 288 kill claims, at 10 to 1 that gives 29 actual kills, versus 41 lost to fighters or 2 to 2.8.

Another example second Schweinfurt 14 October 1943, the USAAF reported 56 B-17s shot down by fighters, 1 by flak, 3 others written off to battle damage and 7 lost on operations for other reasons. Luftwaffe losses were around 31 shot down and 12 written off, total 43. So the raw score is 56 to 43, the USAAF fighters lost 1 shot down and 4 written off while claiming 13 kills. A 3 to 2 ratio would be around 37 Luftwaffe fighters lost to the bomber gunners, or around half the USAAF fighter kill claims being correct. A near 2 to 1 ratio would be the result of assuming all the USAAF fighter kill claims were correct.

186 kill claims by the bombers or about 5 to 1 if the actual tally was 37, to hit a 7 to 1 ratio requires 26 or 27 Luftwaffe fighters lost to bombers. At a 10 to 1 overclaim by the bombers it is 19 fighters to 56 bombers, or about 3 to 1.

It is highly useful to present data to hostile audiences, friends have errors glossed over or "understood", a hostile audience will be looking for anything wrong, down to the font and ink composition if necessary.

 

[pbehn]

Imperial and US customary measurement systems - Wikipedia

en.wikipedia.org

"In 1893 the United States fixed the yard at 3600⁄3937 metres, making the yard 0.9144018 metres and 1896 the British authorities fixed the yard as being 0.9143993 metres". And to quell the "Too small to matter" chorus, the point was about differences before getting to aircraft production, with length as the headline.

A major part of my career was spent in metrology and standards, frequently having to go back to base standards of calibration across international standards, it makes no difference at all either in theory or practice. Rolls Royce imported a precision machining set up for its Manchester factory from Switzerland via the USA. Among the first people to be interned on the declaration of war between UK and Germany were technicians installing machining tools from German companies, while an American precision machine set up was sent after much discussion at the top of government to try to solve sleeve valve issues in UK. The standard length used for calibration is exactly that, any length that isnt exactly one metre is a fraction of a metre, just as any imperial measure is, using a conversion which is as you state. I thought everyone knew this simple stuff.

Incidentally out of 50 states and six other jurisdictions, 40 have legislated that surveying measures should be based on the U.S. survey foot, six have legislated that they be made on the basis of the international foot, and ten have not specified the conversion factor from metric units.

 

[MiTasol]

There was a problem in Australia with the Australian Lee Enfield rifles where certain parts would not fit Lee Enfields made in the UK because the Lee Enfield inch was not the standard British inch.
If the US built Mosquitos this would probably cause no interchangeability problems on most parts but those with close tolerances would possibly not fit because of the minute difference in standards.

 

[ThomasP]

The US and the UK (& Commonwealth?) had adopted a standard inch definition for precision manufacturing purposes by the mid-1920s, and both subsequently adopted the exact same standard (for anything other than scientific experiments) of exactly 25.4mm = /1" - the UK in 1930 and the US in 1933. So by the time the US and UK started manufacturing each other's products in preparation for WWII they were already using the same standard for precision products.

The yard was not considered a precision measurement for manufacturing in the 1930s, and was used as a length specification only when the precision was not important enough to warrant a specification in inches with the associated tight tolerances. Manufacturers simply did not have the technology available to measure the lengths precisely enough for the differences in the pre-1930s US or Imperial yard to matter.

 

[Howard Gibson]

There was a problem in Australia with the Australian Lee Enfield rifles where certain parts would not fit Lee Enfields made in the UK because the Lee Enfield inch was not the standard British inch.
If the US built Mosquitos this would probably cause no interchangeability problems on most parts but those with close tolerances would possibly not fit because of the minute difference in standards.

This is not necessarily Australian and American inches versus UK inches. Engineering drawing dimensioning and tolerancing has come a long way since WWII. Many lessons were learned. I have posted the following figure on my website in an article of Geometric Dimensioning and Tolerancing.

Try to make sense of this drawing! Assume it was prepared in England and that somebody in the USA is trying to make sense of it. Here in Canada, we had expatriate Brits running around and we could ask, but we still had problems.

 

[drgondog]

Imperial and US customary measurement systems - Wikipedia

en.wikipedia.org

"In 1893 the United States fixed the yard at 3600⁄3937 metres, making the yard 0.9144018 metres and 1896 the British authorities fixed the yard as being 0.9143993 metres". And to quell the "Too small to matter" chorus, the point was about differences before getting to aircraft production, with length as the headline.

In the book Brute Force by Ellis he lists the figures as in 1942 2.3 bombers lost per 100 combats and in mid 1944 17.7 bombers lost per 100 combats.

I'm ot familiar with Ellis, What are his soucess? Does he define loss as MIA (failed to return), or MIA plus Cat E/Salvage? How does he define Combats?

In To Command The Sky by McFarland and Newton they note that in Q4/42 5.8 heavy bombers were being lost per 100 cases of reported combat and this had climbed to 11.6 per 100 cases in Q1/44. The statistics for the ratio of cannon shell to machine gun bullet hits for damaged bombers. The data reported on starts
in August 1942 and ends in June 1944. The figures are date, cannon shell hits per 100 machine gun bullet hits.

I'll have to re-read to see if you have the context correct, but if so - what a sloppy way to draw a conclusion regarding timing and comprehensiveness of LW upgunning from machine gun (MG 17??) to 20 and 30mm. The primary replacement to cowl mounted machine cannon from machine gun on Bf 109 and Fw 190 and Me 110/210/410 occured in early 1943 for virtualy all Day Fighters opposed to 8th AF. The MG 17 7.92mm was long gone in 1943. I wonder how many friendly fire hoes from surrounding M2 50 caliber were counted?

8-12/42 40, 1-4/43 77, 5-8/43 70, 9-12/43 81, 1-2/44 88, 3-4/44 127, 5-6/44 135. People generally conclude the cannon had more firepower than the machine guns.

Given the passion for methodology how did the post war investigations for Luftwaffe losses account for the split between allied fighters and bombers or in fact is it as written, the fighters and bombers between them overclaimed by 10 to 1, and only for air to air? And of course did they count the kill claims of the aircraft that failed to return, those "from N. Sea, the Channel, Holland, Belgium, France, Germany"? And if it is only the bomber kill claims at 10 to 1 how were the losses separated versus those to fighters. As of mid October the 8th stayed within escort range. If the bombers are unescorted it is a straight fight, no escort claims to account for.

They didn't. LW Pramatic - five took off, two returned. They were meticulous in specifying probable cause (speculation frequently)) as day fighter or flak in KG reports for Allied crash remains analyzed recovered - but that was not very accurate

The Ratio discussions began after WWII an has continued as Prien and others from German POV have painstakenly recovered diaries, logs etc.

Rather I note the clues are if I put in a full explanation it is boring, or deathless prose, if I do not put it in one will be provided, along with the usual attempts to claim the extra detail is important and should have been there before.

For the rest I refer people to the USSBS Bombing Accuracy report. I cannot put it in, that would be against the preferences of the group spokesperson and unilateral standards enforcer. Besides it is already done. People should be aware quoting the USSBS will require a full contextual explanation, none of this just quote the results. So sit back, relax, and wait for the detailed methodolgy explanation, data sources, how the claims of US aircraft shot down were included, how kills by non US units were excluded, Axis Allied losses accounted for, how Luftwaffe non combat losses were handled and the no doubt long list of factors affecting the results for the USAAF 10 to 1 overclaim report. Thereby showing the standards required around here and act as a beacon to inspire others. Plus how it is a good macro report, not a bad one.

Bovine fecal matter tenderly cooled with flailing. USSBS did perhaps the best they could given the facts at and.

McFarland and Newton give the Luftwaffe day fighter losses from three different sources for a number of dates between 2 October 1943 and 30 May 1944. The three sources are

A)Auswertung der Einsatzbereitsch der fliegenden Verb. Vom 1 August 1943 bis November 1944", which are the fighter losses for all units in the west
and reich. The figures quoted from this source actually stop on 19 April 1944.

Good source for aggragate losses.

B) Generalleutenant Josef Schmid "Day and Night Aerial Warfare over the Reich 1943-44", first published in 1954. Schmid was the commander of I Jagdkorps which controlled most of the fighters defending Germany. In checking his figures with the text of McFarland and Newton it looks like at times Schmid does not include write offs in his casualty list.

C) British translations of captured German Documents, "German Air Force Losses in the West 1 September 1943 to 31 December 1943" also losses for the area of Luftflotte Reich for the same dates and for the west and Luftflotte Reich for the period 1 January 1944 to May 1944. These are the documents from the Luftwaffe Quartermaster General.

The 17th August 1943 raid B-17 losses are reported as 41 to fighter, 11 to flak, 4 to battle damage and 10 to other reasons while on operations. Luftwaffe fighter losses for the day are reported as high as 36 shot down with another 12 written off.

A better summary in my opinion combines Don Caldwell's table for LW losses on August 17 are 42 lost/27 damaged to all operational reasons including 9-1-8 single and T/e fighters to P-47 escort. His sources included Schmid, Prien and so many other German and Brit sources, as well as McF/N and Craven, Wesley and Cates, USAF HRC studies,
Taking B-17s Claims and losses per 8th AF Summary Reports used by both Freeman and McFarland/Newton were 36-3-118 for 1st BW and 24-1-50 for 4th BW, Between 1st and 4th BW, the claims for LW aircraft were 148-18-63 and 140-19-36. Total Bomber claims = 288-37-99 --------> compared to 42-27 reported by LW to both Fighters and bombers. If US Fighters, with much more rigorous examination of claims is assumed '0" then Bomber over claim is ~ 7:1.

8th FC claims were 19-3-4 for loss of 3. Asume for moment that 56th/78th and 353rd FG claims of 19-3-4 were further reduced by Victory Credits Board (source of USAF 85) to 19-0-9 and that they are accurate correspondence with LW losses. Subtract 19 from 42 (LW reported loss) = 23 remaining for B-17

288/23 = ~12.5:1 overclaim for B-17 on August 17, 1943..

USAAF fighters claimed 19 kills for 3 losses, RAF fighters claimed 14 kills as well. So you can look at the numbers, 41 bombers to 48 fighters raw score, assuming "other" and battle damage cause of loss for the bombers were not due to fighters. Assume all the allied fighter kill claims are correct you end up with 15 to 41, near 1 fighter per 3 bombers. Assume half the allied fighter claims are
correct and you end up with 30.5 to 41, throw in the bomber battle damage losses, it is 30.5 to 45. The bombers were awarded 288 kill claims, at 10 to 1 that gives 29 actual kills, versus 41 lost to fighters or 2 to 2.8.

See above
Skip the rest - tell me why YOU believe that LW day fighters were not upgunned to 15mm/20mm and 30mm cannon from early 1943 forward?

Tell me again about 'hole counting science' that YOU believe is statistically significant to postulate prsence of machine gun to cannon ratio of returned bombers with battle damage - and perhaps methods to differentiate from a.) exploding 20mm shrapnel or b,) Splinters from heavy flak, or c.) Friendly Fire from fighters and bombers?

 

[FLYBOYJ]

This is not necessarily Australian and American inches versus UK inches. Engineering drawing dimensioning and tolerancing has come a long way since WWII. Many lessons were learned. I have posted the following figure on my website in an article of Geometric Dimensioning and Tolerancing.

View attachment 648494

Try to make sense of this drawing! Assume it was prepared in England and that somebody in the USA is trying to make sense of it. Here in Canada, we had expatriate Brits running around and we could ask, but we still had problems.

Actually this is a simple drawing, it's straight dimensioning. It is not calling out a "Least Material Condition" (LMC). That's when ANSI starts getting confusing.

 

[Howard Gibson]

Actually this is a simple drawing, it's straight dimensioning. It is not calling out a "Least Material Condition" (LMC). That's when ANSI starts getting confusing.

View attachment 648495

It's ASME now, and I did not apply a feature control frame (FCF) or call up datums in my figure above. Datums and FCFs are the things we learned to do as a result of WWII. The circle M shows maximum material condition (MMC), not LMC. MMC and LMC are perfectly logical, understandable and practical if you are trained in this stuff.

Of course, in addition to ASME's standard on GD&T, there is an ISO standard, a British standard and a Japanese standard, so perhaps we haven't learned.

 

[FLYBOYJ]

It's ASME now, and I did not apply a feature control frame (FCF) or call up datums in my figure above. Datums and FCFs are the things we learned to do as a result of WWII. The circle M shows maximum material condition (MMC), not LMC. MMC and LMC are perfectly logical, understandable and practical if you are trained in this stuff.

Of course, in addition to ASME's standard on GD&T, there is an ISO standard, a British standard and a Japanese standard, so perhaps we haven't learned.

I did a lot of machine part inspections when I worked in manufacturing. Lockheed did not use GDT drawings until after the F-117A (at least from I seen). McDonnel Douglas and Boeing got into it a little earlier. My first exposure was in the early 1990s and it took a bit to understand but after awhile got the hand of it.

 

[Howard Gibson]

I did a lot of machine part inspections when I worked in manufacturing. Lockheed did not use GDT drawings until after the F-117A (at least from I seen). McDonnel Douglas and Boeing got into it a little earlier. My first exposure was in the early 1990s and it took a bit to understand but after awhile got the hand of it.

I am a mechanical designer, and I tried to do old fashioned plus/minus dimensioning on a welded steel tube frame to go in an aircraft. Welding is not very accurate, which makes the application of dimensions and tolerances difficult. Any idiot can dimension and tolerance machined components. This was in the early eighties. When I saw articles on GD&T, I knew I had to pay attention.

 

[GrauGeist]

I wonder how many friendly fire hoes from surrounding M2 50 caliber were counted?

Unless it's on an episode of CSI: Miami, there is no way to tell the difference between US AN/M2 .50 (12.7mm) and Luftwaffe MG131 13mm (.51) bullet strikes, either...

 

[MiTasol]

This is not necessarily Australian and American inches versus UK inches. Engineering drawing dimensioning and tolerancing has come a long way since WWII. Many lessons were learned. I have posted the following figure on my website in an article of Geometric Dimensioning and Tolerancing.

View attachment 648494

Try to make sense of this drawing! Assume it was prepared in England and that somebody in the USA is trying to make sense of it. Here in Canada, we had expatriate Brits running around and we could ask, but we still had problems.

No it was not at all a problem of UK vs US inches - it was that Lee Enfield had their own inch that nobody else used.

 

[nuuumannn]

It's an interesting point that the Mosquito was a private venture initially, leaving the government purchasing spec out of the equation at least initially.

It had a long and convoluted story, but essentially it was a private venture set against discussions the Air Ministry had had pre-war regarding fast bombers, and, it wasn't the only high speed bomber planned at the time. It took the Air Ministry some convincing to invest in it, but not for the reasons most people think, the biggest hindrance was that few believed de Havilland's figures, believing he was overestimating its performance, also, there was a strident belief in the powered gun turret and a version with a tail turret was in fact planned and ordered into production, but Wilfred Freeman managed to talk the Air Ministry out of that idea, on the basis that if the prototype's performance was as good as de Havilland stated it would be, there'd be no need for the turret armed variant. That the fourth prototype had a gun turret was because it was designed as a night fighter, not an armed bomber. A different story.

I just can't see any scenario of medium to high altitude, long range, daylight attacks in which the Mossie is a better choice. Begs the questions ' what were Mosquito bomb aiming advantages over AAF doctrine at long range, what were acceptable loss rates for basically unarmed Mosquitos in daylight operations deep into Germany or Rumania, and what were crew/aircraft replacement considerations?

I agree!

Actually you raise a very valid point that most ignore.

Except I've been raising it since the beginning of the thread...

The Mosquito benefits from the idea that a plane can be untouchable and operate with impunity, but that also comes from the type of missions it was engaged in.

Exactly, the success of the Mosquito was built on the concept of the unarmed bomber using non-strategic materials, but the examples it set came from its universal usage in roles outside that of long range bomber, as a night fighter, photographic reconnaissance platform, fighter-bomber, maritime strike aircraft etc. It's telling that the greatest number of the type built was as the low altitude fighter-bomber variant.

If the Soviets could ramp up production of their various fighters (good, bad and in between) I think the US could certainly have done so as well.

Which then leads us to the point I made earlier, which is that the airframe needs to be redesigned from scratch, which in that case, the US might as well invest in something it already has, because new production facilities need to be built if it is to be built out of wood or metal, and then, whose to say that any advantage the new US Mossie might have in performance would be greater than what was in use at the time?

The Mosquito's performance got better throughout the war, it didn't stay stagnant, so what variant of the Mosquito is going to be built? The B.IV? That was superceded within a year or so by types with two-speed-two-stage Merlins. So why invest in all that effort to redesign the type then build up the production facilities to produce something that might not offer any advantage than what is already in existence or emerging elsewhere?

The British for example cancelled the Halifax Mk.IV powered by two-speed-two-stage Merlins because it didn't offer sufficient performance margins over the interim Halifax Mk.III, let alone the Lancaster Mk.III.

 

[wuzak]

As an aside, there were plans for a twin carrier for the 2,000lb armour piercing bombs for the Mosquito.

The obvious target for such a load would be ships, but would they be useful against reinforced bunkers?

 

[nuuumannn]

Try to make sense of this drawing!

When you're rivetting, edge distance is key as much as measuring the lengths etc. Each hole has to be a minimum of twice the diameter of the fastener in distance from the nearest edge, as per standard practise. The shape of the object shouldn't be an issue, as long as it matches the drawing in measurement and the holes follow edge distance requirements.

 

[drgondog]

Unless it's on an episode of CSI: Miami, there is no way to tell the difference between US AN/M2 .50 (12.7mm) and Luftwaffe MG131 13mm (.51) bullet strikes, either...

Hi Dave - I wonder if I should have spellchecked 'hoes'?

When you're rivetting, edge distance is key as much as measuring the lengths etc. Each hole has to be a minimum of twice the diameter of the fastener in distance from the nearest edge, as per standard practise. The shape of the object shouldn't be an issue, as long as it matches the drawing in measurement and the holes follow edge distance requirements.

You're correct of course for flush rivet ED, the pan head rivet will meet requirements with 1 1/2 Dia.

 

[pbehn]

Unless it's on an episode of CSI: Miami, there is no way to tell the difference between US AN/M2 .50 (12.7mm) and Luftwaffe MG131 13mm (.51) bullet strikes, either...

All Luftwaffe ammunition left tell tale traces of potato pollen and schnapps residue. an internet fact now you read it.

 

[drgondog]

As an aside, there were plans for a twin carrier for the 2,000lb armour piercing bombs for the Mosquito.

The obvious target for such a load would be ships, but would they be useful against reinforced bunkers?

IMO - a mix of 2000# AP with 2000#HE would have been a far superior load out for B-17/B-24 against targets like Schweinfurt and Petroleum/synthetic plants.