Which aircraft would you cancel?

[Shortround6]

But would it be more troublesome than getting the licensed DB-601 into production? This could include avoiding the more extensive changes the Soviets made and remaining closer to the performance range the French managed with development of the 12Y (not 12Z) but possibly making further supercharger improvements or at least implementing 2-speed drive.

The French performance range is only good enough to get the pilots killed. You are down 10-20% in power from the DB-601. lets look at the Hispano 12Y again. (and please remember that the Russians were not happy with the 12Y's over haul life/reliability back in 1934 when they got the license. Lets also assume the French ignore what was going on in china and the threat to their own SE Asia Colonies and are greedy enough to sell the Japanese the latest versions.
Which runs right into another complication. HS had starting using superchargers designed by Szydlowski-Planiol which were much better than their own design. When HS licensed the 12Y-51 to Switzerland it was without the Szydlowski-Planiol supercharger and with the older HS unit. The -51 engine used bigger intake valves and had modifications that allowed it to run at 2500rpm. As built and used by the Swiss it gave 1020hp for take-off at 4.3lb boost and was good for 1030hp at 10,700ft (3250 meters) on 93 octane fuel. It weighed 1146lbs. The Swiss had a "B" version with quite possibly the the S-P supercharger and that engine was good for 1000hp at take-off and 1020hp at 12,300ft (3750meters).
Best engine before the -51 using a HS supercharger was the -37 with 1050hp for take-off and 960hp at 1250 meters (8.33 supercharger gear) and 7:1 compression in the cylinders. The -33 had a 10.0 supercharger gear, 7:1 compression in the cylinders and offered 960hp for take-off and 955hp at 2250 meters. This require 100 octane fuel.

Getting the license before that series of engines means getting the version/s without crankshaft dampers and with articulated connecting rods instead of the later concentric yolk rods.

Other than that, the Jumo 211 might have been easier to mass produce than the 601 (and the 211F would seem to line up with Ha-40/Ki-61 production) of course they wouldn't have been able to accommodate the Ho-3 in that case,

The question is why would you want to? the gun is heavy and slow firing and slightly less powerful than a Hispano round. Basically you get a rate of 2/3 that of a Hispano gun used in D. 520 83% of the ammo capacity for the same weight. Sticking a pair of them in a twin engine plane were the rear gunner could get to them to change magazines might have made a decent ground attack or light anti-shipping armament but a single gun in a single engine fighter is depending too much on the golden BB.

The Hispano engines seem better for a potential early/pre-war development as a direct follow-on for the earlier Ki-28 fighter design.

The Hispano engine was pretty much a dead end design without a major rework. It was a product of it's time, being sort of the first of a new breed of engine, sharing that with the Curtiss D-12 and RR Kestrel. It helped pioneer the cast block engine but then was caught in it's own success. It was a stretched/enlarged version of the 300hp Hispano V-8 engine and in fact the 12Y used the same bore spacing as the the old 300hp V8 and used some of the same production tooling. Having to design newer high powered versions of engines and yet use as much of the old legacy tooling as possible meant they were going to run into a wall at some point. A company with less money invested in production tooling could strike off in new directions easier.

 

[kool kitty89]

The French performance range is only good enough to get the pilots killed. You are down 10-20% in power from the DB-601. lets look at the Hispano 12Y again. (and please remember that the Russians were not happy with the 12Y's over haul life/reliability back in 1934 when they got the license. Lets also assume the French ignore what was going on in china and the threat to their own SE Asia Colonies and are greedy enough to sell the Japanese the latest versions.

I was thinking less as a proper alternative to the DB-601 (let alone on an aircraft of the same size/weight as the Ki-61) and more as a smaller, lighter, at least moderately more powerful replacement for the Ha-9. Then again, perhaps that's something Kawasaki should have been working on back with the Ki-10 even before the Ki-28 rather than continuing development of the old BMW-derived V-12.

Unless I'm completely mistaken and the Ha-9 was actually making more power at altitude than the 12Y engines of the mid 1930s. (except even there, with the weight and drag savings on a fighter -and potential for engine mounted cannon, the 12Y still had plenty of advantages)

Which runs right into another complication. HS had starting using superchargers designed by Szydlowski-Planiol which were much better than their own design.

Couldn't indigenous Japanese supercharger development displace the older Hispano unit too? (aside from just potentially adapting it to 2-speed drive)

Best engine before the -51 using a HS supercharger was the -37 with 1050hp for take-off and 960hp at 1250 meters (8.33 supercharger gear) and 7:1 compression in the cylinders. The -33 had a 10.0 supercharger gear, 7:1 compression in the cylinders and offered 960hp for take-off and 955hp at 2250 meters. This require 100 octane fuel.

Wiki lists the -33 as using a 5.8:1 CR. (the -36/37 is listed as 7:1)

The 28/29 with 7.2 CR and 920 hp at 3600 m seem to be the best altitude performing engines of the pre-SP supercharger models, though I'd assume required 100 octane fuel as well. (as with any of the higher CR engines)

Of the early engines, in the context of 2-speed driving using the same supercharger, the drs and drs2 altitude ratings seem like one of the better options.


Short of actively replacing the Ha 9 with 12Y derived engines (licensed or reversed engineered from captured examples), switching to Radial engines for follow-on developments from the Ki-28 would make more sense (along with later potential for the Jumo 211 being somewhat easier to manufacture than the 601).

In any case, the Ki-28 nearly managed the Ki-43-I's speed years earlier.

The question is why would you want to? the gun is heavy and slow firing and slightly less powerful than a Hispano round. Basically you get a rate of 2/3 that of a Hispano gun used in D. 520 83% of the ammo capacity for the same weight. Sticking a pair of them in a twin engine plane were the rear gunner could get to them to change magazines might have made a decent ground attack or light anti-shipping armament but a single gun in a single engine fighter is depending too much on the golden BB.

I was more just suggesting potential for what the IJA was already manufacturing. Getting the Ho-105 and Ho-5 into service sooner would have been far more useful. (adopting oerlikon FFF or FFL derived guns would probably be faster than the Browning derived 20 mm though) I suppose mounting larger numbers of 7.7 mm guns early-war would have been more effective too, but probably just better to replace those old, relatively slow firing Vickers derived LMGs as soon as possible. (of course the italians had a similar problem, but at least the IJA had a better replacement with the Ho 105 than the .50 Breda)

If the IJA (or Kawasaki themselves) were remotely interested in a centerline cannon armament pre-war, licensing one of the Oerlikon designs really seems like the quickest and more reliable direction to go.

 

[Shortround6]

I was thinking less as a proper alternative to the DB-601 (let alone on an aircraft of the same size/weight as the Ki-61) and more as a smaller, lighter, at least moderately more powerful replacement for the Ha-9.

Smaller may be correct, lighter may be debatable (at least from a practical standpoint). Moderately more powerful may also be debatable. There is not much information on the Ha-9 engine. we know the parent BMW engine went around 510KG which isn't that far off from the the later 12Y's. Now it is quite possible the Ha-9 porked up a bit over the base BMW but a 40-60kg difference isn't that much to get exited about.
The Ha-9IIb as used in the Ki-32 was listed at 850hp for take-off, 775hp at sea level and 950hp at 3,800 meters( 12,470ft) by Rene Francillon in "Japanese Aircraft of the Pacific War"
The Ha-9IIa as used in the Ki-10 and Ki-28 was listed at 850hp for take-off, 720hp at sea level and 800hp at 3,500 meters( 12,485ft) same source.

Then again, perhaps that's something Kawasaki should have been working on back with the Ki-10 even before the Ki-28 rather than continuing development of the old BMW-derived V-12.

Unless I'm completely mistaken and the Ha-9 was actually making more power at altitude than the 12Y engines of the mid 1930s. (except even there, with the weight and drag savings on a fighter -and potential for engine mounted cannon, the 12Y still had plenty of advantages)

Advantages seem small depending on which model 12Y, plus you have the cost/trouble of setting up production for an engine with a rather limited future. You can trace the 12Y back through the 12N and then to the 12Lb of 1927. It had already seen quite a bit of development. There was a reason the Allison and Merlin and Jumo 211 and DB 601 weighed several hundred pounds more than a 12Y. The 12Y wasn't strong enough to stand up to making much more power than it was. Both the crankshaft and crankcase were too light.

 

[GrauGeist]

I suppose the better question would be: would an alternate N1K-2 like design (but with the earlier Kasei engine) also be adaptable as a carrier based fighter? (wing loading/stall speed, wheel pressure, and performance with tail-hook equipped and CoG shifts addressed would all come into play)

The Shiden was perhaps one of the best performing, yet least known, fighters of WWII.

In it's land-based role, it would better serve Japan rather than being aboard carrier operations. It had suitable range (over 1,000 miles) and was able to engage Allied aircraft on it's own terms.

So keeping the N1K-J land-based and perhaps try to find a way to ramp-up the J2M for carrier ops and stay with those two as they were top-performers.

 

[kool kitty89]

Smaller may be correct, lighter may be debatable (at least from a practical standpoint). Moderately more powerful may also be debatable. There is not much information on the Ha-9 engine. we know the parent BMW engine went around 510KG which isn't that far off from the the later 12Y's. Now it is quite possible the Ha-9 porked up a bit over the base BMW but a 40-60kg difference isn't that much to get exited about.
The Ha-9IIb as used in the Ki-32 was listed at 850hp for take-off, 775hp at sea level and 950hp at 3,800 meters( 12,470ft) by Rene Francillon in "Japanese Aircraft of the Pacific War"
The Ha-9IIa as used in the Ki-10 and Ki-28 was listed at 850hp for take-off, 720hp at sea level and 800hp at 3,500 meters( 12,485ft) same source.

I had to dig around a bit but finally found this site again WarBirds
It came up years ago in this thread on Japanese engines: http://www.ww2aircraft.net/forum/engines/japanese-piston-engines-8450.html

The text encoding seems to have changed since 2008 though, there's an old archived version that seems more readable here:
航空機ã'¨ãƒ³ã'¸ãƒ³ä¸€è¦§ãƒ»æ—¥æœ¬è» (the Ha 9 would be listed under ハ９ there)

Hmm, it seems there's a good deal more on Japanese wikipedia too:
Google Translate

The stroke seems to have been shortened from 190 to 170 mm

The dry weights are listed as 560 kg for the Ha 9-I, 1000 kg Ha 9-II Ko (甲 = shell or carapace), 1000 kg Ha 9-II Otsu (乙), and 580 kg Ha 9-II Hei (丙).
But wiki omits those middle two values entirely while including the 560 and 580. (so perhaps those excessively high weights are in error?)

There's a few more mysterious V-12 engines listed there too. I believe at least one is a Junkers L88 or L55 derivative (same bore/stroke as the BMW VI) but the ハ２-２ (Ha 2-2) appears to be a Hispano 12Y derivative. (150/170 mm more/stroke, 36L displacement, CR of 6.2:1, T/O power 940 hp at 2300 rpm, 900 hp at 2400 m 2300 rpm listed with a question mark) Given the added weight, lower RPM and the 6.2:1 CR, perhaps it's a development of the HS 12N independent of the 12Y.

No idea what the ハ４ (Ha 4) is, listed as a 41L V12 with 160/170 mm bore/stroke, 1100 hp at 3000 m at 2300 rpm. (also the Ha 21 and Ha 46, and at a real stretch, one or both of those might be related to the Fiat A.30)


The Ha 9-1 seems to fare worse than the 12Y in all categories, but the 3 Ha 9-2 models seem more competitive, if still at very least moderately heavier and significantly bulkier. (ignoring the 1000 kg figures and assuming all are in the 560-580 kg range or slightly heavier) That 950 hp at 3800 m figure for the Ha 9-IIb (or Otsu) also lines up with your information. The Ha 9-II Ko (which should be the IIa) used on the Ki 28 is listed as having 850 hp take-off (2350 rpm), 900 hp at 3170 m (2200 rpm) and 890 hp at 4500 m (2200 rpm), which doesn't match you figures. (which instead seem to line up with the Ha 9-I which that chart does indeed list as 800 hp at 3500 m)

At a rough guess, the 580 kg dry weight for the Ha 9-II Hei (IIc in other nomenclature, I assume) is at least reasonably representative of the other engines (that 1000 kg figures makes no sense as the dry weight) that's still roughly 100 kg in weight over the 12Y, more or less depending on the model. (though, if we're to take that chart as accurate, the possibly 12Y derived Ha 2-2 weighs some 550 kg) The frontal area on the Ha 9 is definitely considerably larger than the 12Y in any case, and the engine is also considerably longer.

The modest savings in weight combined with drag reduction might more than make up for the power losses over the Ha 9, at least for a fighter (not so much for the Ki 32) Going with the older 1934 vintage 12Ycrs at 470 kg, 835 hp take-off and 860 hp at 4000 m.

Advantages seem small depending on which model 12Y, plus you have the cost/trouble of setting up production for an engine with a rather limited future. You can trace the 12Y back through the 12N and then to the 12Lb of 1927. It had already seen quite a bit of development. There was a reason the Allison and Merlin and Jumo 211 and DB 601 weighed several hundred pounds more than a 12Y. The 12Y wasn't strong enough to stand up to making much more power than it was. Both the crankshaft and crankcase were too light.

It seems like adopting the 12Y back in the early 1930s in place of continued BMW VI/IX development might have been better for the likes of the Ki-10 and Ki-28. Then again, it seems like Kawasaki got a fair bit out of the old BMW design as it was. (compared to Mikulin taking the same bore/stroke/displacement and asymmetrical stroke piston with articulated connecting rod arrangement with the cast-block AM34 and ran with that instead -the Ha 9 seems to have managed pretty decent power and altitude performance -if these figures are accurate- while keeping weight much lower than the Mikulin designs)


In any case, it doesn't change that the Ki-28 (with its existing Ha-9 engine) seems to be a superior design to the Ki-27, would have aged much better, likely would have given the Flying Tigers a tougher fight than the Ki-27, and could better pave the way for a replacement better than the Ki-43. (or just going the Ki-61 to Ki-100 route and mating the Ki-28 airframe to a Sakae or possibly Zuisei engine) Actually, a redesign including retractable landing gear might be enough to push speed beyond that of the early Ki-43. (the Ha 102 model of Zuisei, based on that same chart, was rated for 1080 hp at 2700 rpm take-off, 1055 hp at 2800 m 2600 rpm,
950 hp at 5800 m 2600 rpm, weighs 565 kg, and is 1118 mm in diameter) Any of several early-war variants of the Sakae would seem fitting too, if slightly wider and heavier. (the added power would probably cope better with increased weight from armor and armament, etc -though you'd inevitably lose range of need a fuel capacity increase as well)

Beyond that you'd need a new airframe, either with one of the 12~1500 hp class radials, or maybe the Jumo 211. (again, assuming that avoids most of the trouble seen with the DB 601 -if nothing else, the fact the Germans seemed to have more trouble with the DB-600, 601, and 605 compared to the contemporary 211s points to the Jumo engine's favor)


Come to think of it, with the likely added weight of a wing including retractable gear, the added power of the Ha 9-II would probably make things better off than the early 12Y. (better compromise between power/weight/drag ... granted)

So keeping the N1K-J land-based and perhaps try to find a way to ramp-up the J2M for carrier ops and stay with those two as they were top-performers.

The J2M seems nowhere remotely close to making sense as a carrier based fighter and would be competing with similar engines as the N1K (with both Kasei and Homare being useful on the N1K) so even if the N1K sticks to land only, making more of those over some J2Ms seems a lot more sensible. (a simplified J2M might get into service sooner than any N1K derivative though, but the short range makes it mostly useful for interceptor defense work and possibly close support)

An upgraded/refined A6M with greater emphasis on armament, engine power (ie Kinsei) structural strength, and armor/protection by 1940/41 would be important. A Zuisei powered A5M derivative might work better earlier. Given its earlier availability, having the A6M target the Kinsei from the start would make more sense too.

 

[Shortround6]

I am not sure why the fascination with the Hispano Suiza engine. It was good and perhaps excellent engine in it's day but it's day was in the late 20s and early 30s. By the late 30s you are flogging a dying horse. It started out in 1924 as a 12 cylinder development of the older large V-8 engine (the was also a 12 cylinder W engine using the same cylinders). This engine was a nominal 450hp engine (max continuous) and could reach 582hp with a 6:1 compression ratio. It weighed 420kg dry but the early ones had no supercharger and no reduction gear. The cylinders were 140mm X 150mm. Over the years they increased the stroke to 170mm (and made the engine 24mm taller) and by changing from dry liners to wet liners found the room for the 150mm bore without changing the cylinder spacing (got to keep that production tooling). They added reduction gears and turned higher RPM and added the supercharger/s ( different impeller sizes for different duties). They did get it up to over 1100hp and that would work out to a theoretical 1400-1500hp at sea level IF you could open the throttle that far without blowing the engine up. And that brings us to it's main problem as a late 1930s engine. Without a total redesign it had reached it's limit/s. If the Japanese had gotten a licence in 1933/34 like the Russians did and spent a large sum of money tooling up for mass production (really massive like the Russians) then maybe sticking with it and trying to upgrade it make sense. Buying it in 1938-39 is an act of pure desperation as several engines, if not actually on the open market, have shown how out of date the Hispano-Suiza is.

Wright took the R-1820 Cyclone from 575hp to 1525hp over around 20 years but at several times threw out everything but the bore and stroke. Changing to forged steel crankcases from Aluminium meant new foundry equipment. (and there were at least 3 different steel crankcases) changing the way the cylinder fins were made required a massive investment in new tooling, Cylinder heads changed from cast to forged and so on.

Japanese went withe DB-601 in an attempt to get a "modern" engine pretty much 'of the box' and and not a collection of parts that needed extensive modification and substitution to bring it up even close to modern standards.

A Zuisei powered A5M sounds neat but hte Japanese had a real shortage of engineers, the more time spent on updating really obsolete designs like the A5M and K-27 (or Ki 28) is less time they could have used to build more modern/useful planes.

The Japanese were 1-2 years behind the west as it was. Think Zero or Ki-43 over the English channel in the Spring/summer of 1942. They, like the Germans, needed planes the 'average' pilot could use to effect. Not planes that needed great skill (even if they rewarded that skill) to get kills with.


View: https://www.youtube.com/watch?v=4DzcOCyHDqc

 

[GrauGeist]

The J2M seems nowhere remotely close to making sense as a carrier based fighter and would be competing with similar engines as the N1K (with both Kasei and Homare being useful on the N1K) so even if the N1K sticks to land only, making more of those over some J2Ms seems a lot more sensible. (a simplified J2M might get into service sooner than any N1K derivative though, but the short range makes it mostly useful for interceptor defense work and possibly close support)

An upgraded/refined A6M with greater emphasis on armament, engine power (ie Kinsei) structural strength, and armor/protection by 1940/41 would be important. A Zuisei powered A5M derivative might work better earlier. Given its earlier availability, having the A6M target the Kinsei from the start would make more sense too.

But herein lies the problem:
The N1K-J in it's historical form was heavily armed, fast, long range and capable of not only keeping 1 to 1 with ANY Allied fighter, but in many cases, outperforming them. This proves it's value alone. So why change it?

As for the J2M, it was also a deadly adversary and was already navalized. It's short range may have been seen as a detraction, however, by the time it was in service, the Japanese carrier fleet was no longer in a position to launch long-range attacks, but rather more of a defensive role. You don't need long range to protect the fleet.

If the Japanese were able to ramp up their manufacturing output and produce more Shidens, then perhaps take the time to modify it's airframe for naval service. But now you're losing precious time with modifications.

 

[tomo pauk]

Dave - the J2M was not navalized, though it was ordered and used by the Navy. The Shinden ('normal' one, not the pusher) with the wing relocated down ASAP should be indeed a fine fighter, but the Homare of 1944 was not the Homare of 1945?

Agreed with SR6 re. Hispano engine - once the DB 601A/Aa is available for the Japanese, the 12Y lost most if all of it's appeal. The Ki-61/DB 605A should be another fine fighter, BTW.

 

[Milosh]

tomo

Shinden ("Magnificent Lightning") - Kyushu J7W

Shiden ("Violet Lightning") - Kawanishi N1K

 

[tomo pauk]

Whoops -thank you

 

[kool kitty89]

Without a total redesign it had reached it's limit/s. If the Japanese had gotten a licence in 1933/34 like the Russians did and spent a large sum of money tooling up for mass production (really massive like the Russians) then maybe sticking with it and trying to upgrade it make sense. Buying it in 1938-39 is an act of pure desperation as several engines, if not actually on the open market, have shown how out of date the Hispano-Suiza is.

Yes, after thinking on it more (and as I shifted towards in the conclusion of my previous post), what Kawasaki managed with the Ha 9 was probably good enough to not merit bothering with the HS engine. (licensing and developing that older design may have been more cost effective for them too, and easier to adapt to the mid 1930s Japanese engine manufacturing industry)

On that thought, it might have also been a bit of a waste for the Soviets to invest so much in the Klimov engines rather than expanding development and manufacturing of the Mikulin types. (2-speed drive and/or an intermediate supercharger setting compared to the AM35 and AM38 should have allowed 1.3~1.4x the power at similar altitude ratings to the Klimov engines, and a greater emphasis on larger/heavier fighters and bombers as well as potential higher powered small interceptors) Admittedly, they'd lose the advantage of the spacious Hispano type hub cannon placement. (and the Mikulin never fielded a hub cannon in combat, though I'd think the large size of the engine would at least allow similar tolerances to the DB 603's arrangement -the Il-2's radiator and armor placement might have mitigated practical installation potential of large cannon in the nose as well)

Wright took the R-1820 Cyclone from 575hp to 1525hp over around 20 years but at several times threw out everything but the bore and stroke. Changing to forged steel crankcases from Aluminium meant new foundry equipment. (and there were at least 3 different steel crankcases) changing the way the cylinder fins were made required a massive investment in new tooling, Cylinder heads changed from cast to forged and so on.

Indeed, several engines did similarly (the 'C' series R-2800 shares relatively little other than bore/stroke and external dimensions the the earlier models). Really, it's not that unlike the transition the Russians made going from the M17 to AM34. (similar bore/stroke/displacement and assymetric cylinder configuration, but a totally new engine)

Japanese went withe DB-601 in an attempt to get a "modern" engine pretty much 'of the box' and and not a collection of parts that needed extensive modification and substitution to bring it up even close to modern standards.

Yes, and in that context I still think the Jumo 211 would be the more interesting alternative to consider.

A Zuisei powered A5M sounds neat but hte Japanese had a real shortage of engineers, the more time spent on updating really obsolete designs like the A5M and K-27 (or Ki 28) is less time they could have used to build more modern/useful planes.

Of those, the Ki 28 seems the most worth the upgrade, but if the modifications were too extensive, it may have been better to just focus on a new design entirely, but stemming from the same emphasis on speed and streamlining. (granted, raw engine power seems to have been an interest too, and certainly an area the Ki 28 had an edge over the Ki 27 and Ki 33 or A5M) Retractable or semi-retractable gear combined with the existing Ha 9 (or another Ha 9 model) might be useful if implemented early enough.

On Mitsubishi's end, putting development emphasis on the A6M would indeed make the most sense and with limited engine production resources, perhaps the Kinsei (and the larger Kasei) should have received higher priority over the Zuisei, and the Ha41/109 over the Sakae (and Homare) on Nakajima's end.

The Japanese were 1-2 years behind the west as it was. Think Zero or Ki-43 over the English channel in the Spring/summer of 1942. They, like the Germans, needed planes the 'average' pilot could use to effect. Not planes that needed great skill (even if they rewarded that skill) to get kills with.

Not to mention planes where average or exceptional pilots could have a better chance of surviving being shot down (be it bailing out or crash landing -or limping home with extensive damage), especially significant over friendly territory where returning to combat duty would be rather straightforward, or near enough to the front lines of having a chance of evading capture. (even with the ... issues with Imperial Japanese doctrine and sense of honor, there's still a big difference between living to fight another day and living to be captured by the enemy)

That and having enough structural strength in fighters to perform high G maneuvers and manage high speed dives. (maintaining control in high speed dives -particularly ailerons- seemed to be a common, if sporadic problem on several of the aircraft that could withstand dives in the 400-500 mph range too)

An earlier Ki 44 with larger wing and more fuel (a sort of pre-Ki 84 as you suggest) would make plenty of sense as well. (or just a Ki 43 with stronger airframe and Ha41 or Kinsei -with the wing size, you might end up with something closer to the P-36 there though, probably a bit lighter and better power and altitude performance than the contemporary P-36)

Dave - the J2M was not navalized, though it was ordered and used by the Navy. The Shinden ('normal' one, not the pusher) with the wing relocated down ASAP should be indeed a fine fighter, but the Homare of 1944 was not the Homare of 1945?

Using the bulkier Kasei should still make reasonable sense too, with later introduction of the Homare and limited production and availability all around. Performance would be somewhat reduced earlier in the war with earlier engine variants, but so would the opponents.

Given the original floatplane N1K and J2M had almost parallel development timelines, there might not have been an advantage to the J2M in production at all either (at least had the N1K been designed as land based from the start). Having

Agreed with SR6 re. Hispano engine - once the DB 601A/Aa is available for the Japanese, the 12Y lost most if all of it's appeal. The Ki-61/DB 605A should be another fine fighter, BTW.

Again, the Jumo 211 seems an interesting option, and would you at least agree that production of that engine likely would have gone more smoothly than the DB designs?

I suggested starting straight off with the more advanced Jumo 211F given historical timing for the Ha 40, but the earlier B/C/D might have been useful if tooling started a bit earlier. (with the more primitive early 211 models, tooling and quality control might have been a bit easier to transition to from the Ha 9, though upgrading to the 211F later on might be problematic/wasteful compared to targeting that engine from the start) In any case, given the size and weight of the 211 engines, transitioning some existing Ha 9 based developments to that engine might also have been fairly straightforward. (or at least close enough to begin prototyping with the Ha 9 with specific planning/provisions made for introduction of the newer engine later)

 

[GrauGeist]

Dave - the J2M was not navalized, though it was ordered and used by the Navy. The Shinden ('normal' one, not the pusher) with the wing relocated down ASAP should be indeed a fine fighter, but the Homare of 1944 was not the Homare of 1945?

Agreed with SR6 re. Hispano engine - once the DB 601A/Aa is available for the Japanese, the 12Y lost most if all of it's appeal. The Ki-61/DB 605A should be another fine fighter, BTW.

Ahh Tomo, yes, you're correct...I messed my post up because the ipad hates this server.

The intention was to say that the J2M was in development longer and could have been navalized during that time.

The first flight by the J2M was in spring of 1942, making it a possible candidate to replace the A6M as the Raiden was a superior performer despite it's shorter range.

 

[kool kitty89]

The intention was to say that the J2M was in development longer and could have been navalized during that time.

The first flight by the J2M was in spring of 1942, making it a possible candidate to replace the A6M as the Raiden was a superior performer despite it's shorter range.

With the existing J2M and N1K, it really seems like the latter is far closer to being a practical carrier borne fighter (and the superior land based fighter) while also likely performing better on the whole even if using the same engine. (if not quite as fast, at least having better range and handling)

Now, if you want to change the scenario entirely and nix J2M development in favor of a Kasei powered direct successor to the A6M, then that certainly might have merit too. (except it may have been better to focus Mitsubishi's resources on developing a superior Kinsei powered A6M rather than diverting resources to developing yet another Mitsubishi fighter -it wouldn't be on the level of the late war A6M8 prototype, but something more akin to the A6M5 using an earlier less powerful Kinsei model would be more plausible -more or less with the same sorts of modifications the likes of the F2A, F4F, and P-40 were getting in 1940 -except the Zero also needed further strengthening and thicker skin)

 

[stona]

Way back I said the Halifax should have been cancelled at the earliest opportunity and have just stumbled across some interesting statistics compiled in a report entitled 'Comparison of Aircraft Types'.

Aircraft. Casualty Rate. Bomb Load/Sortie. Bombs Dropped/Missing Aircraft. 'Cost'

Lancaster 3.5% 3.95 tons 112.6 tons 20 man months/ton bombs dropped

Halifax 5.4% 2.20 tons 45.4 tons 60 man months/ton bombs dropped

Mosquito 2.3% 0.68 tons 29.8 tons 20 man months/ton bombs dropped.

Based on all operational sorties from 1st June to 15th September 1943 and a Mosquito bomb load of 4,000lbs.

It's hardly surprising that Harris wanted to ditch the Halifax and shoot Handley Page

Cheers

Steve

 

[pbehn]

It's hardly surprising that Harris wanted to ditch the Halifax and shoot Handley Page

That is only revealed by statistics, many crews liked the Halifax as it was obviously easier to get out of, they weren't immediately aware how much more likely they would need to.

 

[fastmongrel]

Way back I said the Halifax should have been cancelled at the earliest opportunity and have just stumbled across some interesting statistics compiled in a report entitled 'Comparison of Aircraft Types'.

Aircraft. Casualty Rate. Bomb Load/Sortie. Bombs Dropped/Missing Aircraft. 'Cost'

Lancaster 3.5% 3.95 tons 112.6 tons 20 man months/ton bombs dropped

Halifax 5.4% 2.20 tons 45.4 tons 60 man months/ton bombs dropped

Mosquito 2.3% 0.68 tons 29.8 tons 20 man months/ton bombs dropped.

Based on all operational sorties from 1st June to 15th September 1943 and a Mosquito bomb load of 4,000lbs.

It's hardly surprising that Harris wanted to ditch the Halifax and shoot Handley Page

Cheers

Steve

How often did the Mossie carry 4,000 pounds in 43.

 

[stona]

That is only revealed by statistics, many crews liked the Halifax as it was obviously easier to get out of, they weren't immediately aware how much more likely they would need to.

The problems associated with escaping from all aircraft exercised the minds of many senior officers in Bomber Command and the Air Ministry following ORS reports on the increase in crew losses in 1 Group following its conversion to Lancasters.
Survival rates for the Lancaster were estimated at 10.9%, for the Halifax 29.4%. Of course you were much more likely to be shot down in a Halifax.
Harris immediately wrote to Saundby in September 1943, asking him to,
'write officially drawing attention to urgent need of improvement in escape hatches etc. Far too few crews are getting away with it and bad hatches etc. are the reason."
Saundby now turned to the scientists, asking Dickins to look into this. He was told it would take '2 or 3 weeks' for the investigation but in fact it took four months. A detailed study was released in January 1944. It concluded that there was
'no doubt that the chances of survival in a Lancaster are significantly lower than in a Halifax and this is thought to be primarily due to the more restricted space within the aircraft and to the poor rear escape hatch'.
There were other reasons. All escape hatches on both aircraft tended to jam. The Lancaster had a greater tendency to break up in flight and this contributed to the relative lack of survivors (though a very few survived because of this). It was also noted that training for abandoning the aircraft needed improvement.
As a result training for abandoning aircraft was increased. Practice parachute jumps were not adopted as ORS reports already showed that crews abandoning aircraft under control (as in fuel shortage or U/C failure) had good results.
The adoption of engine fire warning lights was thought to give crews a better chance of abandoning an aircraft whilst still under control and before the fires got 'out of hand'
Escape hatches should open outwards. This was considered an impractical modification for aircraft in service, but was adopted on the late Marks of aircraft due to be introduced.
The RAE looked at self sealing fuel tanks for the Lancaster, but the 1000lb weight penalty was deemed too great. It also investigated sub-dividing the large wing root tanks on the Lancaster but I haven't been able to find out if this ever happened.
The much maligned forward escape hatch in the Lancaster was never enlarged but, interestingly, this was not identified as a primary cause of losses in Lancasters in these reports.

The Halifax shouldn't have been maintained or cancelled due to crew survival rates, it should have been cancelled because, compared to the Lancaster, it was an expensive and inefficient means of carrying out the strategic bombing offensive.

Cheers

Steve

 

[gjs238]

The RAE looked at self sealing fuel tanks for the Lancaster, but the 1000lb weight penalty was deemed too great. It also investigated sub-dividing the large wing root tanks on the Lancaster but I haven't been able to find out if this ever happened.

Did B-17's and B-24's have self-sealing fuel tanks?
What about the medium bombers?

 

[Greyman]

The RAE looked at self sealing fuel tanks for the Lancaster, but the 1000lb weight penalty was deemed too great. It also investigated sub-dividing the large wing root tanks on the Lancaster but I haven't been able to find out if this ever happened.

I'm fairly certain all of the Lancaster's six inter-spar tanks were self-sealing (830 lb. of CIMA 397H I believe).

Oil tanks as well.

 

[GrauGeist]

Did B-17's and B-24's have self-sealing fuel tanks?
What about the medium bombers?

The B-26 was the first U.S. combat aircraft to have self sealing tanks as a standard feature (1936 - called "Merang cells")
Late B-25A models onward
XB-24B onward
Late B-17C onward
A-20C onward
A-26 production (all post "X" airframes) onward
XB-29 onward

So yes, they did