Top 3 mistakes per country, in field of military aviation

[Hiromachi]

Nobody will deny that early war Bf 109 was hampered by limitation of it's armament. Spitfire received belt-fed cannons by mid/late 1941. The MG FFM and Hispano were with higher MV, so both could be used unison with LMGs installed, not the case for Zero's armament until 1943.
Lowe MV means that a seasoned flier/marksman is needed to use the cannon to the fullest, the seasoned pilots need to be looked after, and it will took time for green pilots to bacame good marksmen, that is if they live ling enough.

True, limitations of Type 99 existed. But it also had some advantages like very high reliability, something that could hardly be said about Hispano cannons.

Why making the exception of torpedoes and crews? Japanese torpedoes were far better than American until late war, meaning they could be launched at higher speed and altitude. That greatly improves bomber's chances to avoid interception/downing, either by fighers of AAA. Seasoned crew will make more hits than inexperienced under same circumstances. Low number of aircraft was attacking single CV, in one 'slice' of time. F4F was no great shakes in raw speed, it was even slower than Zero, and not all US fighters were concentrated over Yorktown when Kates arrived.
B5N was also a newer TB than Devastator.

Americans sent 22 Wildcats to intercept 16 attackers, 10 B5N2s and 6 Zeros. Despite radar directing, first four missed the bombers and had to chase them. Then two Wildcats attacked B5Ns only to be intercepted by Zeros. One Kate went down and both Wildcats were shot down. Then B5Ns managed to carry an attack at the speed approaching 200 knots, achieving two hits but in process Japanese lost Hiryu hikotaicho machine (Tomonaga), his wingman machine as well as other pair sent around.
So yes, not all Wildcats could intervene since they had to split between Tomonaga (whose chutai was wiped out) and Hashimoto. But they still had numerical advantage over the attackers and six Zeros really should not be a problem.

Yes, B5N was newer than TBD Devastator, but marginally. Sure, B5N2 had some upgrades over initial model but retained same aiframe and features. B5N was powered also by a slightly more powerful engine. But TBD interestingly had stronger defensive armament.

The story of US fighters doing escorts went better as war progressed, but at Midway they were not doing a good job. Including VF-6 (VT-6 is torpedo squadron), that lost sight of VT-8 Devastators as they started descend.

Yes, that was just a typo.
And true, they lost sight. But unlike Zeros they could fully take advantage of their radios.

Lack of engine power between sea level and 20000 ft meant Zero (and F4F for that matter) meant that interception of enemy aircraft above 15000 ft, like SBDs, let alone B-17s, will not be the easy task.

I think I already told you that Sakae 12 delivered over 810 HP at 6000 meters, which is 20 HP less than at Sea level.

That lack of engine power is a major fail. Disballanced weponry, at least in 1942, is another. We've also seen that, once even the small part of US fighter units (and F4F was never rated as equal to the Zero, let alone superior) got they act together, the Zeros went speechless. This is also where lack of protection was felt.
Reliable radios, for all the Zeroes? Really folding wings?

Point above. There was no lack of engine power at 20,000 feet.

With the armament I agree. Hence why I thought if there would any cooperation exist between IJN and IJA could take advantage of Ho-103 machine cannons. Those were interchangeable with Type 89 MGs so I see no problem in replacing with them Type 97s.
A6M2 carried 1360 rounds for 7.7 mm machine guns, which is 45 kg. 700 12.7 mm rounds could be easily taken increasing the weight by 10-11 kg, which is ... marginal.

I'd say that what you mean is tunnel vision. Too many Zeros tried to attack Thach and in fact they were interfering each other. That reminds me of those 15 Hellcats trying to shoot down Sakai over Iwo Jima. And as much as it was nice for F4Fs that also mean they were in total defensive, they could not help TBDs they were supposed to be protecting. Sure, they scored well on Zeros but at the same time allowed others to make passes on Devastators.
Thach wave is a defensive maneuver, it is very good maneuver, but an escort fighter that is in full defensive like this is not doing its job - providing the protection to the vulnerable bombers.

In regard to radios, at the very begging when I presented my points of 3 mistakes made by Japan I indicated a technological gap and little attention given to radios and radars. This indeed was a major lack.

Folding wings were not a requirement. They would greatly increase the weight (the folding mechanism) and require a full redesign of wing structure.

 

[tomo pauk]

True, limitations of Type 99 existed. But it also had some advantages like very high reliability, something that could hardly be said about Hispano cannons.

Depends on what time frame, platform type, and on type of installation. Hispanos in Hurricane and Typhoon were performing reliably, ditto for (belt fed type) on Beaufighter and Mosquito. Spitfire have it's share of problems, mostly early, with drum-fed cannons, and then mostly (due to insufficient heating capacity) on Mark Vc with 4 cannons.
Even the US Hispano, always indeed judged as unreliable, performed well aboard the P-38.

I think I already told you that Sakae 12 delivered over 810 HP at 6000 meters, which is 20 HP less than at Sea level.
...
Point above. There was no lack of engine power at 20,000 feet.

I'm not sure what is the problem here - for a light & well streamlined aircraft like Zero, Sakae decent power for the era, above 20000 ft. It was power under 20000 ft that was lacking.

With the armament I agree. Hence why I thought if there would any cooperation exist between IJN and IJA could take advantage of Ho-103 machine cannons. Those were interchangeable with Type 89 MGs so I see no problem in replacing with them Type 97s.
A6M2 carried 1360 rounds for 7.7 mm machine guns, which is 45 kg. 700 12.7 mm rounds could be easily taken increasing the weight by 10-11 kg, which is ... marginal.

Good idea.

Folding wings were not a requirement. They would greatly increase the weight (the folding mechanism) and require a full redesign of wing structure.

New aircraft needed

 

[Hiromachi]

Even the US Hispano, always indeed judged as unreliable, performed well aboard the P-38.

In field tests as late as in 1945 US Hispano was still found unreliable and prone to jamming under high G maneuvers. Gun was compared in tests with Ho-5 though. But I never heard any reliability issues related to Type 99 so could safely say it was similar in that.

I'm not sure what is the problem here - for a light & well streamlined aircraft like Zero, Sakae decent power for the era, above 20000 ft. It was power under 20000 ft that was lacking.

Ah,I understood it was 20,000 ft and above.

Anyway, below 20,000 ft Sakae 12 could be pushed to over 1000 HP (at 11,000 ft to be precise). That gives 0.19 hp/lb power-to-weight ratio. Bf 109 F-4 had something like 1.21 hp/lb, G-2 had 0.22. F4U had 0.17.
Power is always a relative thing. A6M could have engine of a greater output but price would be weight and drag.
Unless it would be like I proposed, aka going the Oscar way with Ha-115-II.

Good idea.

I actually tried to learn why the belt fed Type 99 arrived so late. Dr. Masaya Kawamura was working on the belt system. If that could be introduced earlier, it would help tremendously with the limited ammo supply.

 

[tomo pauk]

In general, the story of Hispano cannon in the US in ww2 was not a happy one, anyway. Not as bad as the story about torpedoes, though

...
Anyway, below 20,000 ft Sakae 12 could be pushed to over 1000 HP (at 11,000 ft to be precise). That gives 0.19 hp/lb power-to-weight ratio. Bf 109 F-4 had something like 1.21 hp/lb, G-2 had 0.22. F4U had 0.17.
Power is always a relative thing. A6M could have engine of a greater output but price would be weight and drag.
Unless it would be like I proposed, aka going the Oscar way with Ha-115-II.

In therms of speed of piston engined aircraft, it is power-to-drag ratio, or, better yet, the surplus power once the drag is overcome. This is where a fighter with 1000-1200 HP is in stark disandvantage vs. a fighter that has 1500-2000 HP under the hood, provided that drag (as force, not as coefficient) is not much greater. So the F4U or F6F will have hard time to climb with Zero (bad power-to-weight ratio), but it will outpace it easy (has more of surplus power once drag is 'beaten' than Zero). The lighter aircraft sacrified plenty to achiveve that power-to-weight ratio, though.

I actually tried to learn why the belt fed Type 99 arrived so late. Dr. Masaya Kawamura was working on the belt system. If that could be introduced earlier, it would help tremendously with the limited ammo supply.

The offspring of the Oerlikon FFL, the Type 99-2 (T. Williams says 99-4?), got belt feed. Type 99-1 was the license of FF (similar was the MG FF). The FFL (and Type 99-2) were designed around a more powerful ammo than the FF, but not so powerful as the FFS (and Hispano). The ammo for FFL was, IMO, perhaps the most ballanced 20 mm cartridge around for air fighting, until Soviet came out with 20mm for Shvak, and Germans for MG 151/20.

Why no earlier belt feed, or more ammo capacity? Perhaps due to doctrine - 6 carriers, with 25-30 Zeros each, means 300-360 cannons, 20000 of cannon shells (give or take) to provide the defense. Even 4 carriers (timing as conception of Zero) equals 12000 shells airborne.
Other than that, 60 rd drum was in vogue in late 1930s.

 

[Hiromachi]

One thing that could be improved without even touching engines would be propeller designs. If you take a notice of the table on page 4 and quotes from book, the propeller efficiency is quite low - 0.76
J2M1 -> 0.70
J2M2 -> 0.74
Based on my knowledge (limited though) it usually is around 0.79 at climb speed for 3 blade prop, 0.84-0.85 for 3 blades at max speed. ~0.84 at climb speed for 4 blades, 0.88-0.89 at max speed.
There is something really wrong with Sumitomo propellers.

 

[Shortround6]

Reliability of weapons is often anecdotal. Hard numbers are available for only a few weapons and reliability even for the same weapon varied with the installation and year (and in some cases the ammo.)

Anecdotal reports are often in relation to the other weapons mounted on a plane or in service at the same time/place.

For example the Japanese Navy may have had no complaints about the type 99-1 cannon in relation to the reliability of Type 97 machine gun but that isn't really saying a whole lot because the Type 97 was a licensed Vickers Class E machine gun. The British had given up on the Vickers Machine gun as an aircraft weapon in the late 20s/early 30s due to it's unreliability and cast around for something else which lead to adopting the Browning Machine gun in .303 (the British were never shy about adopting guns from outside of England if they worked). The British almost never mounted the Vickers where the pilot (or crewman) could not get at it, even if only to beat on it with a gloved fist. I would note that the Japanese seemed to follow that practice. Neither the type 97 or Army Type 89 seem to have been mounted in the wings to any great extent.

Early Hispanos in Spitfire wings that were drum feed and flopped on their sides seem to have trouble emptying a 60 round magazine without jamming. Late war belt feed guns may have gone around 700 rounds between malfunctions/jams. Over 1000rounds between major malfunctions/breakages have been reported. It also varied with their base/climate. Dirty airfields lead to greater jams.
Please note that I don't know the rate of jams/malfunctions of the Japanese weapons. But without such numbers just saying Gun x was considered reliable by AI Force (or Navy) Y doesn't tell us much.
Reliability should also not be confused with long life. The Hispano being originally designed for a gun life (not barrel) life of 10,000 rounds.

The Japanese army was without question several years out of date with it's armament. No other major power have adopted such a light armament as Ki 43 for a number of years (even if we count the standard armament as one 7.7 and one 12.7 and count the 12.7 as being equal to three 7.7mms). It required skilled, experienced pilots to use effectively.
The Navy was better but in the fall of 1941 the Zero's armament was already behind the times, let alone the summer of 1942.

 

[Shortround6]

One thing that could be improved without even touching engines would be propeller designs. If you take a notice of the table on page 4 and quotes from book, the propeller efficiency is quite low - 0.76
J2M1 -> 0.70
J2M2 -> 0.74
Based on my knowledge (limited though) it usually is around 0.79 at climb speed for 3 blade prop, 0.84-0.85 for 3 blades at max speed. ~0.84 at climb speed for 4 blades, 0.88-0.89 at max speed.
There is something really wrong with Sumitomo propellers.

Not really. Most props, wither 3 blade or 4 blade only averaged about .80
Many designers would have given their first born male child for a prop with 0.88% efficiency during WW II

edit: Something unknown in those tables may be the altitude. A propeller that shows very high efficiency at low altitude may not be very efficient at high altitude (20,000ft) where the air is 1/2 as dense or less as you go up. A large high altitude prop may not be the most efficient at low altitude as it is bigger in diameter and has more blade area causing more drag than needed at low altitude.

A few charts.

Please note the 2nd chart. In a time period when Turbo fans were in use the free propeller was still just under 90% and an awful lot had been learned about prop design and construction during the late 40s and 50s. The US was using some props in 1942/43 that didn't have the highest efficiency either, the tooth pick props on the early P-47 for example.
The Japanese props you show may not have been the best but really weren't that far off of what was know/possible at the time.

 

[parsifal]

ive read accounts that the hispano 20mm fitting into the spitfire had jamming issues initially, but that these were in part solved by simply turning the weapon on its side. belt feed also helped I understand.

As I understand it the type 99-1 cannon was drum fed, whilst the 99-2 and after were fitted with a belt feed mechanism. The 99-2 was not fitted until some way through the A6M-3 series, probably around the end of 1942. From what ive read, the drum feeds came in two types, a 60 round drum, which worked okay, but with only 60 rounds apiece was too small. There was a 100 round drum installation which had feed issues.

When did the allies start to fit belt feed into their cannon. I think its 1941 from memory. certainly the Mk IX spitfire featured a belt feeder mechanism from introduction, in mid - 1942.

Whatever the date, there is no comparison between a drum fed weapon and a belt feed one

 

[stona]

This is once again making Harris a scapegoat for British bombing policy.
On 14th February 1942 BEFORE Harris even assumed command of Bomber Command a new Directive was issued to the Command which cancelled the Transportation Directive of 13th July 1941. This new Directive listed as 'first priority' targets the industrial cities of the Ruhr-Rhineland area. The operations were to be

"focussed on the morale of the enemy civil population and, in particular, of the industrial workers."

This was not Harris' thesis or even his idea. It was the UK governments official bombing policy. Harris, as an officer serving in the RAF, hardly had a choice whether he carried it out or not..

I hesitate to quote myself, but I have come across the text of an Air Staff paper, dated 23rd September 1941, which predates the February 1942 Directive and on which that Directive is evidently based. The Air Staff paper was intended for a smaller circulation and does not mince words.

"The ultimate aim of the attack on a town area is to break the morale of the population which occupies it. To achieve this we must ensure two things; first, we must make the town physically uninhabitable and, secondly, we must make the people conscious of constant personal danger. The immediate aim, is therefore, twofold, namely, to produce (i) destruction, and (ii) the fear of death."

Harris didn't struggle hard to interpret what was required of him. He wrote.

"My primary authorised objective was therefore clear beyond doubt: to inflict the most severe material damage on German industrial cities."

In attempting to achieve his "authorised objective" he was carrying out the policy of the UK government. People today who have problems with this policy should apportion their blame to the UK government, not Harris or the men of Bomber Command. It is a disgraceful fact of British history that the immediate post war UK government(s) tacitly deflected the responsibility for its predecessors policies on bombing to Harris and Bomber Command, as if that organisation was somehow acting on its own. If you fling enough mud some of it will stick, and that is the case here.
The men of Bomber Command have from time to time been pilloried in the UK press and in some publications for their part in the campaign. Generally this now diminishing band have responded with great dignity to this disgraceful and ungrateful treatment. I, on the other hand, don't have to and will call it out for what it is at any opportunity.

Cheers

Steve

 

[stona]

The effects of the 'area' campaign.

There are a lot of whats, ifs and maybes in that graph (the Air Staff Memorandum circulated with Harris' 'Despatch' advises us to discount it) but it is easy to see why Harris was frustrated at being diverted to the pre-invasion campaigns and away from his city busting campaign in February 1944, just when he was starting to make a serious dent in Germany's production capacity. The index was flat lining for about eight months before the diversion. He would argue that the subsequent German recovery was at least partially due to him being obliged to release the pressure on the German cities and infrastructure.

Cheers

Steve

 

[Peter Gunn]

*SNIP*

The men of Bomber Command have from time to time been pilloried in the UK press and in some publications for their part in the campaign. Generally this now diminishing band have responded with great dignity to this disgraceful and ungrateful treatment. I, on the other hand, don't have to and will call it out for what it is at any opportunity.

Cheers

Steve

Perhaps I'm not enlightened enough but I have always failed to understand why present day nobs insist on passing judgment using 21st century ideals that have no bearing on a 1940's issue. How could anyone with two brain cells to rub together even begin to disrespect the men that fought and won WWII? While I believe atomic weapons are ghastly, I do not question the decision to use them in 1945, I wasn't there and have no frame of reference other than what I've read. And from what I've read, I'm glad I wasn't in on having to make that kind of decision.

 

[stona]

Perhaps I'm not enlightened enough but I have always failed to understand why present day nobs insist on passing judgment using 21st century ideals that have no bearing on a 1940's issue.

It's a very good point Peter. The fact that we won a war for national survival, and it was the men of Bomber Command among many others that won it, is what affords these people the luxury of expressing their views. They are absolutely entitled to do so, and I am entitled to rebut them.
Would I have bombed German cities, Tokyo, dropped the atomic bombs? Knowing what I do now and knowing what the decision makers knew then, yes to all three.
Whatever morals might have slipped in efforts to win the war, a far worse offence would have been losing to Nazism and allowing the world, in Churchill's words to "sink into the abyss of a new dark age made more sinister, and perhaps more protracted, by the lights of perverted science." The stakes were very high and it was not a game that could be lost under any circumstances. This is a fact not always grasped today.

Cheers

Steve

 

[Peter Gunn]

Totally agree Steve, well put.

I remember the end of "The Life and Death of Colonel Blimp" with Roger Livesay where he gets pulled from making his broadcast about fighting the war with honor and not stooping to the Nazis level or some such issue. I thought it very pointed when the radio exec explained that this war wasn't going to be played like a cricket match. I don't remember the words but the sentiment was it's a war to preserve civilization.

And I also agree, I'd say yes to the bombing issues you mentioned as well.

Just another movie quote for some reason that came to mind. In "Above and Beyond" about the A-Bomb, Robert Taylor as Col. Tibbets is handed a little cylinder with a button on it and a cord attached. The guy asks him, "If I said you could end the war by pushing that button would you do it?" Taylor does well because he's a good actor as he brightens to the idea, but then comes the "But if you do, 100,000 people will die" quote. YIKES! Taylor did a great job in that scene and I must admit from a small age, General Tibbets was a 10 foot tall hero to me.

 

[drgondog]

The effects of the 'area' campaign.

There are a lot of whats, ifs and maybes in that graph (the Air Staff Memorandum circulated with Harris' 'Despatch' advises us to discount it) but it is easy to see why Harris was frustrated at being diverted to the pre-invasion campaigns and away from his city busting campaign in February 1944, just when he was starting to make a serious dent in Germany's production capacity. The index was flat lining for about eight months before the diversion. He would argue that the subsequent German recovery was at least partially due to him being obliged to release the pressure on the German cities and infrastructure.

Cheers

Steve

Steve - it could be useful to note that 8th AF surpassed BC in tonnage dropped in December 1943 for the first time and the 15th would be on-line during Big Week Feb 20-25, 1944. It would, accordingly, be useful to point out that the Combined Bomber Offensive was conceived and ordered at Casablanca - and that the RAF night raids deep into Germany carried the primary load in eastern Germany until February, 1944

 

[stona]

The careful wording of the Anglo-American bombing directives always allowed Harris the latitude to interpret them to suit his methods.. Casablanca stated that the main object was
"the progressive destruction and dislocation of the German military, industrial and economic system and the undermining of the morale of the German people to a point where their capacity for armed resistance is fatally weakened."
That suited Harris just fine, it's what he had been doing for the last year. When Casablanca was revised in June, making the 'German Air Force' the main priority, followed by several other specific targets, these were assigned to the US 8th AF and Bomber Command was allowed to continue in its main aim, the 'general disorganisation of German industry.' The Command was supposed to operate in a way 'designed as far as practicable to be complimentary to the operations of the VIII U.S.A.A.F."
Harris wrote that in order to do this "the Command paid particular attention to the main industrial centres associated with aircraft production." Since all German industrial cities were associated to a greater or lesser extent with aircraft production he could carry on bombing what he wanted.
To this extent I've always considered the phrase 'combined Bomber Offensive', at this time, a bit of a misnomer as the two principle air forces involved were pursuing the same ultimate objective, the defeat of Germany, in very different ways and with only occasionally overlapping short term objectives and targets.
Later Harris would cooperate more fully, particularly with the Oil Plan, but he was not easily diverted from his original 1942 objective.

It is of note that the Air Staff, after the war, took exception to Harris' interpretation of his 1942 directives, arguing that Harris "tends to obscure the fact that the Air Staff intention was always to return to the bombing of precise targets as quickly as the tactical capabilities of the bomber force, and the improvement of night bombing technique, would permit."
What nonsense, no explanation of how a return to something that was never achieved in the first place might practically be realised, just a bunch of flannel about improved technique. Night bombing techniques never allowed for the bombing of precision targets, anymore than radar techniques could achieve precision by day in less than ideal conditions. Both the British and Americans were in some kind of denial about this, but at least the Americans had the decency not to stab the commanders carrying out their orders in the back.

Cheers

Steve

 

[tomo pauk]

For the USA, this might be the top 3 mistakes:

- For USAF - insisting that bombers will negate enemy air defenses when flying high, 'fast' and via the defensive guns. 'Knock on' effect was that no effort was invested in suitable escort doctrine and technology, despite having engines with good/great altitude power early on (R-2800 in 2-stage variant and turbo, the turbo V-1710, later the V-1650-1)
- For USN - not introducing a fighter designed around R-2800 early enough, say mid 1941.
- The torpedo scandal

 

[stona]

Tomo I agree with your first point, particularly as the US air forces had an extra couple of years to learn a lesson that the British and Germans had already learned the hard way. Simply looking at the performance of German fighters in 1940/41 should have shown them that their bombers were not going to fly high and fast enough in 1943 and the assumption that self supporting fields of defensive fire would be enough to defeat determined attackers was optimistic at the very least.

I can't really comment on the other two as what I know about US production planning and development you could write on a postage stamp

Cheers

Steve

 

[tomo pauk]

About the US torpedos, this is might be a start: U.S. Navy Torpedoes (part two)
About the R-2800 - in 1941 it was delivered in 1700+ examples, 1st hundred of those were delivered in March of 1941. Take off power 1850 HP, at ~1200 HP at 20000 ft. The 2000 HP version was delivered in ~250 pcs by Jan 1942; at 20000 ft power of ~1300 HP.
Granted, we won't have exactly Fw 190- or Typhoon type of performance (but we'd have relability, in contrast) in the early R-2800 powered naval fighter, but 370-380 mph might be realistic.

 

[Shortround6]

For the USA, this might be the top 3 mistakes:

- For USAF - insisting that bombers will negate enemy air defenses when flying high, 'fast' and via the defensive guns. 'Knock on' effect was that no effort was invested in suitable escort doctrine and technology, despite having engines with good/great altitude power early on (R-2800 in 2-stage variant and turbo, the turbo V-1710, later the V-1650-1)
- For USN - not introducing a fighter designed around R-2800 early enough, say mid 1941.

Both of these "mistakes" require an incredible amount of foresight in order to correct. Or in other words they require a time traveler to be able to make decisions at exactly the right time almost down the right day and even that is pushing things.
Please remember that it took 3-4 years to bring a plane from concept to service use (1st squadron, it took another 6-12 months to get 3-6 air groups). In the 1930s technology could change an awful lot in 3-4 years so that what looked like a good idea/concept at the start could end up not looking so good when planes went into service.
The US "bomber boys" had invested quite a bit of work and money on long range bombers, more than any other nation, during the 30s. The XB-15 was more a proof of concept aircraft than practical bomber but it started in 1934 with a desire for a 2000lb bomb load and a range of 5000 miles. The US "bomber boys" always thinking of greater ranges than European bomber advocates due the size of the US and the distance from any likely enemies. What they got was a plane that was late in flying (after the later B-17) and not reaching the goal/s. It did set a record of carrying a 4409lb payload 3107 miles at 166mph in 1938 and was rated at a range of 3400 miles while carrying a 2500lb bomb load. Obviously this range was well beyond the capability of any single engine fighter or even twin engine fighter. The Y1B-17s were ordered in 1936 and delivered in 1938. They had no turbos and their Cyclone 9 engines were rated at 930hp for take-off and 775hp at 14,000ft. Range in overload condition with 4000lbs of bombs was 2400 miles. Obviously this to was well beyond the capabilities of any fighter, single or twin engine, in 1938.
The Army funded and built the B-19 as another proof of concept aircraft and was funding the hyper engine project as the 'knowledge' of the time was that liquid cooled engines would stand up to turbo charging at high altitudes better than air cooling. (Makers of air cooled engines increase the amount of fins on each cylinder). The fitting of turbos to the B-17 increase the top speed by around 50mph and increased the ceiling by thousands of feet. The B-17C was ordered in 1939 and the first delivered in July 1940. With four .50 cal guns and single .30cal gun it makes the He 111 with three 7.9mm guns look rather badly armed.
Army (and Boeing, among others) had been working on successors to the B-17 with Boeing alone going through at least eight different 'paper' aircraft. Boeing designs 316, 322, 333A, 333B, 334, 334A, 341 and finally the 345 which was the basis for the B-29 and was submitted to the Army in May of 1940. After engineering studies, wind tunnel models and full size mock ups and prototypes ordered the Army orders 250 production B-29s in May of 1941, 4 months before the first single stage Merlin production engine is delivered by Packard. Back in Sept of 1940 (end of the daylight BoB?) The Army was ordering B-17Es with eight .50 cal guns and single .30. At high altitudes they could outrun and out climb Hurricane Is . And again with a nominal range of 2000 miles with a 4000lb bomb load there was no possible single engine fighter that could escort them when they started rolling off the production lines in Sept of 1941.
Now at some point the level of technology did get to a point where a single engine fighter could perform the escort mission but that wouldn't be until 1943.
The 2 stage mechanical supercharged R-2800 wasn't really the answer. It wasn't enough lighter or more compact compared to the turbo R-2800 used in the P-47 to make up for the 350-400 less hp at 22,000ft and up.

 

[stona]

The problem for the Americans was that their bombers could not outrun a Fw 190 or Bf 109 in 1943, particularly when the fighters were just the pointy end of a sophisticated air defence system, not unlike that developed by the British several years before the US even entered the war. I don't believe a crystal ball was needed to foresee this, just a careful analysis of campaigns that had already happened. They either needed a complete volte-face on daylight bombing or they needed to develop suitable escort fighters as a matter of priority. It took them far too long to even develop the drop tanks to extend the range of the fighters they already had.
Neither do I think a crystal ball was needed to anticipate the increase in the efficacy of flak. All the weapons and systems of control which would allow German flak to cause so much damage to the American bombers was in development (some even deployed in early forms) before the US entered the war.
What the Americans did was develop a concept or doctrine and then adhere rigidly to it, even in the face of evidence that it might not work as well as predicted. They were far from alone in this, in fact I can't think of any nation that didn't do the same somewhere. Whether they were right to persevere, eventually developing the escort fighters and tactics to mitigate losses to an acceptable level is a moot point. If you were one of the aircrew lost on one of the early 'proof of concept raids' concept it might not be so moot.
Cheers
Steve