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

[drgondog]

You need to contact Ellis. I do not have a copy of the book, only some notes from it. The theme is the allies were not that intelligent and largely buried the axis under a pile of stuff. He has another book with a focus on data, John Ellis, WWII A Statistical survey.

Apart from the rifle calibre machine guns the FW190A-3 in spring 1942 upgraded the armament to 2 high velocity and 2 low velocity 20mm cannon, Fw190A-6 was the upgrade to 4 high velocity 20mm cannon in June 1943, the A-7 introduced the heavy machine guns in late 1943. Production difficulties held up fitting the 30mm to Bf109, how many 30mm cannon equipped German fighters were there through 1943 and 1944, most histories note the rockets were the 1943 answer and the 30mm as the 1944 answer.

Perhaps for the Bf109 two of the 20mm cannon were add ons? Best avoided to keep performance, then comes the gap between production and making it to the units, the way on 30 April 1945 the 15th AF had 46 P-51B, 62 C and 251 D, the P-38 units 58J and 201 L. While the B-24 units had G, H, J, L, M models. The 16 October 1943 Luftwaffe response included Bf109E and F from the training units. See Caldwell.

As for counting friendly holes that was going on and for the 8th Air Force at least 3 B-24 and 5 B-17 are listed as shot down by other USAAF heavy bombers. Another B-17 shot itself down and a B-24 destroyed itself during a pre flight gun test. A larger number were lost after being hit by friendly bombs.

Your cuisine is your decision. So obviously having read the USSBS report in question, what are the shortcomings?

Interesting Donald Caldwell uses the USAAF Statistical Digest for bomber losses, not the David Osborne B-17 list, published a decade before. Plus all those web sites dedicated to the individual bomb groups.

So RAF fighters are listed as scored zero kills from 14 claims, the USAAF ones 9 from 19 claims, then out of 42 reported Luftwaffe fighter losses 33 lost to bomber fire, versus 288 claims.

From British Intelligence in World War II (Hinsley), talking about how the RAF tightened up on kill claims, January to June 1943, the RAF fighter command allowed 249 kill claims against Luftwaffe fighters, the true number of kills was 235.

Having dug further into the loss list for 17 August 1943, cross checked against group web sites, 3 lost to battle damage, 3 lost to flak and fighter, 49 to fighters, 6 to flak, 1 to fuel starvation, 1 to Mechanical failure over the Mediterranean after being hit by flak and fighters, total 63 or in other words 33 fighters to 49 bombers, plus shares.

And skip the 14 October raid, after all Caldwell ups the Luftwaffe fighter losses to 53 (though 51 losses is the activity table total) of which 13 claimed by US fighters, versus 186 kill claims by the bombers, assuming every US fighter claim is correct, 40 to 186, under 5 to 1 overclaim, if 6 of the fighter claims are correct 46 to 186 or 4 to 1 overclaim.

Caldwell has 36 Bf109, 10 Bf110, 3 Fw190, 2 Me410 lost, the Luftwaffe quartermaster has 33 Bf109, 3 Bf110, 3 Fw190, 1 Me410, the Bf110 difference is effectively the 6 losses from II/ZG26 (Quartermaster has another 7 Bf109 and 1 Bf110 lost to non combat causes on operations)

Updated B-17 losses, 3 Battle Damage, 2 flak and fighter, 54 fighter, 5 flak, 1 fuel starvation, 1 landing accident, 3 mechanical failure, total 69. Caldwell says 60 B-17 lost, Freeman says 60 lost, 7 Category E.

Using Caldwell, 53 or 51 fighters lost versus 54 B-17 plus shares to Luftwaffe fighters, even if all 13 USAAF fighter claims are correct out of 51 losses, that leaves 38 to 54+shares, under 2 to 3 fighter to bomber.

Good to know your ability to misunderstand things is still other people's fault. The ratio of cannon to machine gun hits (note no calibre of machine gun was reported but the cannon are reported as 20mm) shows the upgunning.

I believe that is what you call a homework assignment, for you to find and consult the relevant 8th Air Force damage reports. Rather than me boring you with more deathless prose. I note the German 20mm had contact fuses, the majority of the US aircraft present did not mount cannon.

Yawn

 

[BobB]

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.

For those not familiar with the story, Enfield used standards based on the Imperial standard yard that was destroyed when Parliament burned. The new standards distributed in 1855 were supposed to be as close as possible to the old standard based on existing copies but it didn't quite match Enfield.

 

[pbehn]

For those not familiar with the story, Enfield used standards based on the Imperial standard yard that was destroyed when Parliament burned. The new standards distributed in 1855 were supposed to be as close as possible to the old standard based on existing copies but it didn't quite match Enfield.

Oh dear, a basic mistake in QA/QC the first topic of every discussion, is everybody using the latest revision of specifications and documents.

When I worked to API X65 5 years ago the min yield strength of X65 (65,000 PSI) was 448 MPa and that is the official conversion, I looked it up yesterday on the net and the value has been rounded up to 450 Mpa.

 

[Dana Bell]

It all reminds me of the state legislature that several years ago voted to standardize pi as "3." At least we don't redefine a foot on the size of a king's foot every time a new monarch takes the throne...

Cheers,



Dana

 

[BobB]

It all reminds me of the state legislature that several years ago voted to standardize pi as "3." At least we don't redefine a foot on the size of a king's foot every time a new monarch takes the throne...

Cheers,



Dana

Pi is the ratio of circle circumference to diameter. There is a passage in the Old Testament about a giant bowl built for King Solomon and the circumference and diameter quoted for it have a ratio of three so that is the correct value for pi. Of course, if you have a six inch slide rule and aging eyes, there isn't much difference between 3 and 3.14.

 

[pbehn]

Pi is the ratio of circle circumference to diameter. There is a passage in the Old Testament about a giant bowl built for King Solomon and the circumference and diameter quoted for it have a ratio of three so that is the correct value for pi. Of course, if you have a six inch slide rule and aging eyes, there isn't much difference between 3 and 3.14.

Point of order, the Romans didnt have a decimal point, Pi is 3 to no decimal places, 3.14 is also 3 when rounded to an integer.

 

[Conslaw]

Just a quick side note about this:
The SBD (and later, TBF/TBM) was the champ for that role in the PTO.
They had the range needed fir the task.

The A-36 ruled for land ops where the SBD (and again, the TBF/TBM) were impractical to be used (except in North Africa, courtesy of the USS Ranger of course).

The problem with the A-36 was for every A-36 you built you didn't have a P-51. (But really, the A-36 was only meant to be a placeholder to keep the assembly lines running during a short funding gap. Later the USAAF found out the A-36 exceeded expectations. Then again, the Allison-engined P-51 and P-51A did too. By the time The P-51A was showing itself in service, plans were already in place for the Merlin-engined P-51B.

 

[GrauGeist]

If the Army had swallowed it's pride and had their A-24 pilots go through the Navy's SBD training, it would have been far more potent in the PTO and thus, a potential Ground attack platform in the MTO/ETO. As it was, A-24 pilots were trained to attack at a 30° to 45° angle, more of a "glide-bomb" profile, than using the A-24 as designed.
In all, the Army received 168 A-24 (SBD-3), 170 A-24A (SBD-4) and 618 A-24B (SBD-5) types. That was nearly 1,000 potentially lethal dive-bombers that could have yeilded results at time when it was much needed.

 

[drgondog]

The problem with the A-36 was for every A-36 you built you didn't have a P-51. (But really, the A-36 was only meant to be a placeholder to keep the assembly lines running during a short funding gap. Later the USAAF found out the A-36 exceeded expectations. Then again, the Allison-engined P-51 and P-51A did too. By the time The P-51A was showing itself in service, plans were already in place for the Merlin-engined P-51B.

The A-36 Mustang served two puposes and you clearly identified one - namely interim funding to bridge NA-91 Mustang IA. The second was combined 'political' and best for a job urged by Asst SoW Bob Lovett on Hap Arnold beginning in 1940 when reports of Stuka CAS were filtering in to AAF HQ. When the A-36 actually began combat ops, the AAF doctrine for CAS had moved from a posture of dive bombing capability 'useful' to the notion that a fast attack fighter (P-51A/P-51B, P-47) 'better'.

On the latter point. The production of A-36/P-51A and P-51B co-existed at Inglewood. By the time P-51A emerged for first flight in first week of February, the P-51B-1 was nearly complete, save 1650-3 engine; XP-51B#1 had been flown for two months and in the middle of solving the 'rumble isssue'.

By the time the P-51A was operational in CBI, the P-51B-1 was also beginning in combat ops in ETO.

 

[Howard Gibson]

For those not familiar with the story, Enfield used standards based on the Imperial standard yard that was destroyed when Parliament burned. The new standards distributed in 1855 were supposed to be as close as possible to the old standard based on existing copies but it didn't quite match Enfield.

Another problem, which would apply to both Merlin engines and Lee Enfield rifles would be that you have multiple shops manufacturing them. Shop A subcontracts to Billy Bob and Cousin Elmo's machine shop. The bolt does not fit. Shop A works with Billy Bob and Cousin Elmo and perhaps they ship them some receivers. BB&CE work out a solution. Meanwhile, Shop B subcontracts to Amitkumar and Cousin Ramesh's machine shop and the bolt does not fit. This time, Shop B sends bolts to A&CR's shop, and they figure out how to make matching receivers. Both guns reliably shoot .303 ammo. Are the bolts interchangeable?

Drafting standards have improved dramatically since WWII, largely because of WWII. Now, I can prepare drawings of gun and/or engine parts that precisely define the parts I need. Obviously, it helps if I understand what I need.

If you want consistency and interchangeability, you want to manufacture everything in one plant. On the other hand, if you want lots of something, you need another factory. This is especially true if you factory is within bombing range of damn foreigners.

 

[drgondog]

If the Army had swallowed it's pride and had their A-24 pilots go through the Navy's SBD training, it would have been far more potent in the PTO and thus, a potential Ground attack platform in the MTO/ETO. As it was, A-24 pilots were trained to attack at a 30° to 45° angle, more of a "glide-bomb" profile, than using the A-24 as designed.
In all, the Army received 168 A-24 (SBD-3), 170 A-24A (SBD-4) and 618 A-24B (SBD-5) types. That was nearly 1,000 potentially lethal dive-bombers that could have yeilded results at time when it was much needed.

Dave - While everything you say is true, the A-24 was already recognized as too slow to survive in MTO/ETO. Army units were already adopting P-39 and P-40 to 'fast attack and recon' combined roles per new CAS doctrine . I am not saying that A-24 would not have been a lot more effective by using 'the Navy way' - just that it didn't matter in any theatre save SWP - Over water flights encountered far less flak than over land in MTO/CBI, much less fighter intercept.

 

[GrauGeist]

Dave - While everything you say is true, the A-24 was already recognized as too slow to survive in MTO/ETO. Army units were already adopting P-39 and P-40 to 'fast attack and recon' combined roles per new CAS doctrine . I am not saying that A-24 would not have been a lot more effective by using 'the Navy way' - just that it didn't matter in any theatre save SWP - Over water flights encountered far less flak than over land in MTO/CBI, much less fighter intercept.

The Ranger's SBDs sure delivered a great deal of hurt to Vichy French assets, both Naval and shore-based in the MTO.

 

[Conslaw]

The A-36 Mustang served two puposes and you clearly identified one - namely interim funding to bridge NA-91 Mustang IA. The second was combined 'political' and best for a job urged by Asst SoW Bob Lovett on Hap Arnold beginning in 1940 when reports of Stuka CAS were filtering in to AAF HQ. When the A-36 actually began combat ops, the AAF doctrine for CAS had moved from a posture of dive bombing capability 'useful' to the notion that a fast attack fighter (P-51A/P-51B, P-47) 'better'.

On the latter point. The production of A-36/P-51A and P-51B co-existed at Inglewood. By the time P-51A emerged for first flight in first week of February, the P-51B-1 was nearly complete, save 1650-3 engine; XP-51B#1 had been flown for two months and in the middle of solving the 'rumble isssue'.

By the time the P-51A was operational in CBI, the P-51B-1 was also beginning in combat ops in ETO.

Drgondog, I have your book on the P-51B, and the thing that surprised me most was that the prototype for the P-51D (with the bubble canopy and 6-guns) was flying before the P-51B's combat debut.

 

[drgondog]

Drgondog, I have your book on the P-51B, and the thing that surprised me most was that the prototype for the P-51D (with the bubble canopy and 6-guns) was flying before the P-51B's combat debut.

True, good eye - but recall that both P-51D-NA and D-1-NT were crafted from P-51B-1-NA fuselage Spares. Both were hybrids, comprised of NA-102 and NA-106 designs, The actual NA-102 to be modified came 'as is & complete' and were staged side by side with The First P-51D Cockpit Enclosure, Sliding modifications, namely P-51B-1-NA 43-12102. The ONLY difference between the three ships is that the two Ds had D six gun wings.

If one follows the 'original Advanced Design for Production P-51D/E', via NA-106, they were planned to be NA-104 P-51B-5-NA airframe and 'bird cage' canopy with NA-106 six gun wing - and the planned break was 42-106539, with all new P-51B/D config but with new wing. USAAF and NAA changed their collective minds in March 1943 as the first P-51B-1-NA was emerging as production #1.

In September as all three ships were nearing completion, the AAF requested either 55 or 85 gal tank be installed. At this moment in time there was only Experimental Department/Fieldservice design for the 85 gallon tank - and zero kits released for NA-73-95 Field Service roll outs. P-51D-1-NT was held back, found that 85 gallon tank was infeasible and the 55 gal tank was installed. A it was being installed, the AAF decided that all production P-51B/C/D would have 85 gallon tanks and NA-106 (and NA-107) was wrapped up and folded into NA-109 and distributed to make more P-51B-10-NA beginning with 42-106540..

Lot of changes and decisions in September 1943. The 55 gal P-51D could have been in limited combat ops by March instead of June - but would have less range than the P-51B/C w/85 gal tanks - and about the same as the P-38J-15 with LE tanks.

 

[Thumpalumpacus]

Drgondog, I have your book on the P-51B, and the thing that surprised me most was that the prototype for the P-51D (with the bubble canopy and 6-guns) was flying before the P-51B's combat debut.

Name of book, please? I'd be happy to buy a copy.

 

[BobB]

Another problem, which would apply to both Merlin engines and Lee Enfield rifles would be that you have multiple shops manufacturing them. Shop A subcontracts to Billy Bob and Cousin Elmo's machine shop. The bolt does not fit. Shop A works with Billy Bob and Cousin Elmo and perhaps they ship them some receivers. BB&CE work out a solution. Meanwhile, Shop B subcontracts to Amitkumar and Cousin Ramesh's machine shop and the bolt does not fit. This time, Shop B sends bolts to A&CR's shop, and they figure out how to make matching receivers. Both guns reliably shoot .303 ammo. Are the bolts interchangeable?

Drafting standards have improved dramatically since WWII, largely because of WWII. Now, I can prepare drawings of gun and/or engine parts that precisely define the parts I need. Obviously, it helps if I understand what I need.

If you want consistency and interchangeability, you want to manufacture everything in one plant. On the other hand, if you want lots of something, you need another factory. This is especially true if you factory is within bombing range of damn foreigners.

"...it helps if I understand what I need." Unfortunately, a lot of people don't understand and some really bad drawings make it out to the shop. I have a cartoon somewhere of a supervisor rubbing an engineer's nose into a drawing on a drafting board and saying "Bad engineer! Bad engineer!" Someone in the background says "What a moron. Everybody knows you've got to catch them in the act."

 

[wuzak]

Name of book, please? I'd be happy to buy a copy.

P-51B Mustang: North American's Bastard Stepchild that Saved the Eighth Air Force : Marshall, James William "Bill", Ford, Lowell F., Gruenhagen, Col (Ret.) Robert W.: Amazon.com.au: Books

P-51B Mustang: North American's Bastard Stepchild that Saved the Eighth Air Force : Marshall, James William "Bill", Ford, Lowell F., Gruenhagen, Col (Ret.) Robert W.: Amazon.com.au: Books

www.amazon.com.au

 

[Thumpalumpacus]

P-51B Mustang: North American's Bastard Stepchild that Saved the Eighth Air Force : Marshall, James William "Bill", Ford, Lowell F., Gruenhagen, Col (Ret.) Robert W.: Amazon.com.au: Books

P-51B Mustang: North American's Bastard Stepchild that Saved the Eighth Air Force : Marshall, James William "Bill", Ford, Lowell F., Gruenhagen, Col (Ret.) Robert W.: Amazon.com.au: Books

www.amazon.com.au

Ordered, thanks!

 

[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.

It is not too small to matter it is to big to be taken seriously by anyone working in advanced science at the time. Your quoted date of 1893 is three years after Lord Rayleigh had done his experiment, which I did at school and I am sure many forum members did, dropping a droplet of camphor oil onto water covered in lycopodium powder, this typically estimates the size of a Camphor molecule as 1.7nanometers. As I remember my physics teacher telling me, the accuracy doesnt matter, at the time no one had any idea how big or small an atom or molecule was, if it is wrong by a factor of ten it was far too small for anyone to consider measuring with the methods they had in 1890. Johnson Matthey in London produced 30 bars of 90% platinum and 10% iridium and in 1889 bar number 6 was accepted as the closest to the prototype meter standard selected in 1799

The standard metre copy you describe when the USA took the metre standard was numbered copy bar no No 27, it deviated from the standard metre by 1.6 microns.

To summarise this part, while Angstrom was developing his Angstrom unit in the mid 1800s discussing measurements of 10 to the power minus 10 metres (10 to the power minus 7 mm) the world standards based on bars of metal couldn't produce reliable metal samples of a metre to better than 0.01mm, or 10 microns. In aerodynamics in the 1930s and 1940s companies like de Havilland and North American were discussing surface finish of 2 microns for polished aluminium and 5 microns for a good paint finish. Testing a paint surface for thickness and smoothness could induce irregularities or 1 to two microns. All of these measurements are below or in the ball park of the difference between the USA standard metre and the official standard held by in Paris by the Mètre des Archives).
As an inspector of 30 years working in metrology and other things I ca see the fundamental and unavoidable mistake made by the people concerned in the period 1799 and 1893, recognised by any person with a scientific background, can you?



Your point was made with respect to de Havilland ordering or supervising production of their Mosquito design in the USA. The Mosquito can stand beside the P-51 as being at the top of aircraft design. For choice of aerofoil, cooling drag regime and surface cleanliness and overall low drag design they are on par by their own route and path, they have almost nothing in common other than with the same engine both were approx. 30 MPH faster than a Spitfire with the same engine.
As a company de Havilland could build you an engine pre and post war, build you a metal or wooden aeroplane, they designed their own suspension for the Mosquito based on compressed rubber good enough to cope with massive overload on recon versions and also carrier landings. They manufactured propellers under license from Hamilton in USA, produced their own hydraulic and electrically actuated propellers even developed phenol-formaldehyde resins which were half the weight of aluminium for propeller blades. The notion that de Havilland could not cope with any metrology issues between USA and UK is just funny, in a very funny way. I really don't know where you get your ideas from.

 

[JDCAVE]

This is what the British 2,000lb AP looked like.

OP 1665 - British Ordnance; Part1 - Aircraft Bombs and Pyrotechnics; Chapter 6 - Semi-Armor-Piercing and Armor-Piercing Bombs: A.P. 2,000-lb. Mks I, II, III and IV (Service)

michaelhiske.de

It had a 9% charge to weight ratio.

Did the US have a 2,000lb AP bomb? I know they had the 1,600lb AP bomb.

How many 2,000lb bombs could the B-17 carry? From what I can tell, only 2 stations allow for 2,000lb GP bombs to be fitted internally, but they can load 2 x 1,000lb at the same time. These could be GP, or AP, or another 1,000lb bomb type.

But would you want the AP to fall after the GP bombs?

Up to 6 1,600lb AP could be carried. in overload condition. The two standard stations for the 1,600lb AP are lower than for the 2,000lb GP bomb, so you could put 1,000lb bombs in the same stations that are used when carrying the 2,000lb bombs.

If you do use AP bombs, won't they have less effect unless they are right on target?

AP bombs were typically used against shipping. I fail to see what use a bomb with a 9% charge to weight ratio would be against oil targets. Better to use HC bombs against such targets. 2, 4, 8, or 12,000 lb HC munitions were routinely dropped on oil targets. The charge to weight ratio was 71% for the 2,000lb bomb. Lots of these were dropped by Halifaxes during the war.

Jim