Improve That Design: How Aircraft Could Have Been Made Better

[Glider]

I know it sounds obvious but there have been a few postings about having more effective nightfighters earlier in the war. It doesn't matter what the performance of the aircraft, the key ingredient is the radar. The time and effort invested, and achievements made were remarkable. Developing what was a brand new technology to fit, work and be reliable in a small vibrating aircraft must have been the hardest task in the early years probably only matched by code breaking and couldn't have been achieved any quicker. The fact that the Beaufighter entered production at more or less the same time was a match made in heaven.
With the mk IV radar the Beaufighter became the first true nightfighter with speed, range, firepower plus of course radar. It could not have been brought forward any earlier.

 

[Shortround6]

The Blenheims and their crews pioneered the way but the early radars just weren't good enough, or the Blenheim fast enough or heavily armed enough to show decisive results.
They certainly showed the concept had possibilities.

The British then threw away an opportunity when they failed to use some of the Early Douglas Bostons as true night fighters, with either 8 gun or 12 gun noses and their higher speed they would have covered two of the conditions of a better night fighter but if equipped with the older radar might not have showed significantly better results. Some were used as intruders (without radar?) over France during the Blitz to shoot down returning german bombers.

British then used up a number of the Douglas aircraft (about 70) on the far from successful turbine light scheme. Most of these were equipped with the MK IV radar in the early days to no effective purpose, as the accompanying Hurricanes were never (or once?) able to turn a contact/illumination into a kill.
Some sources do say that the First radar equipped Hovacs ( with MK IV radar) weren't issued to a squadron until late April of 1941 which is too late to have any significant impact on the Night Blitz. So yes the Beaufighter was by far the plane that truely introduced successful night fighting.

The British may still have been suffering from a shortage of "Dixon" incendiary rounds during the night blitz reducing the effectiveness of the .303 batteries?

 

[tomo pauk]

Trying to come up with a few ideas,

for the Germans, leave some sort of wing guns in the 109F even if it just a MG17 in each wing. this roughly doubles the firepower of the F-0 when the 55-60 rounds in the MG/FFM run out. Leaves an option for the 109G to have one 20mm and four MG 131s? Not B-17 killing armament but something better than hanging guns under the wing.

Bf 109F-0 was a rather rare bird? Granted, it could've used more firepower - 2 HMGs + MG FFMs, or just 3 MG FFMs each with a 90 rd drum (otherwise used 1st from late 1942?). A belt-fed MG FF(M) was no rocket science, after all, however it was developed even later than MG 151/20, and used probably only at Do 217 NFs.

AS mentioned before for the Ju-87, double the number of MG 17s, you can carry bombs and strafe(somewhat) without hanging gun pods on the under wing racks.

How about a dedicated tank-buster version with 2x MK 101s for 1941/42?

Germans actual develop a full power turret with two MG 17s or MG 131s and stick it on top of the HE 111. And put up to date engines in the He 111 after 1940.

Hopefully Germans can make a better bomber than it was the venerable He 111? But yes, the 111 will need improvement of defensive firepower.

Some are operational, you don't have to give up bombing Germany until 1942 in order to give Coastal Command 100-200 Blenheims in 1939/40. The MK IV Blenheinm was a designed as quick and dirty modification of the MK I Blenheim to suit a Canadian requirement for a maritime recon aircraft. It was originally called the Bolingbroke. Not as good as the Beaufort but it could have been available in numbers (half dozen squadrons anyway) when the Beaufort was still entering production.

Bolingbroke was the Mk.V.
Mk.IV was about the furthest the basic Benheim design need to be pushed?

The Americans are in pretty good shape in regards to engines and propellers. Now just beat somebody over the head until they agree that sticking 800-1000lbs worth of guns and ammo in 1200hp airplanes isn't really a good idea

They might also need some convincing in 1939-41 that drop tanks are not work of the devil.

DB seemed to be a bit late (chronically?) in delivering either the number of engines or engines that delivered the promised power. Maybe it was not their fault but the change over to DB 601s from Jumo 210s and DB 600s seems to have been later than desired.

Granted, the 601N was a not a paramount of reliability, the 601E was fully rated after 6-7 months, the 605A after more than a year (managing to kill Marseille in process), while 603A was trying to replicate problems of early BMW 801s and Sabres in 1943.

 

[Kevin J]

IIRC Molders rigged up a Bf-109F-1 with two cannon in the wings, I've seen the photo somewhere. Don't know what the effect on performance was.

 

[Zipper730]

Both North American and Martin had designs and were building prototypes for high altitude bombers.

While this might be a redundant reply, it's basically aimed in response to information that I stumbled across: I don't know exactly when the XB-27 began design work, but the XB-28 was ordered after the B-26 began design.

A two-speed supercharger would theoretically give around 19000 - 21500 feet (based on the F4U-1 figures) without ram. If I recall, the design estimates called for the presumption of an ACA 2000'-3000 feet higher with ram. This would yield 21000-23500 feet on the low end and 22000-24500 feet on the upper end. The F4U-1 was generally able to do around 23800 feet ACA.

Until about 1940 the US .50 cal ammo used a 753 grain bullet at about 2500fps velocity.

So we started using the faster rounds around 1940 and after?

The short, symmetrical wing was chosen because that met the Army's requirements for high speed, but at the cost of higher stall speeds, longer take offs.

From what I remember the real problem with the B-26 was not so much high takeoff and landing speeds, but the controllability speed with one engine dead. From what I remember, it was pretty high, and without proper training, or bad luck (engine cuts out as you're low to the ground), you'll go out of control and crash.

In a way the B-26 tried to meet as many expectations of the Army's requirement as physically possible, using the technology available at that time, but sacrificed much to achieve it.

I wonder why they didn't decide to use the fowler-flap design.

The existence of the A-26 is the reason that many proposed improvements were not made to the B-26. The Army froze development on the B-26 and cancelled contracts as the A-26 neared gestation.

Are you sure about that, according to this, the design did't begin until the fall of 1940, at which point the B-26 was nearing its first flight, and the proposal wasn't formally proposed until January 1941.

That said, it was designed to replace the A-20 Havoc, the B-25 Mitchell, and B-26 Marauders (which is pretty amazing that you're basically designing a successor before the predecessor flew).

That said, imagine an A-26 with an R-2800 with a two-stage supercharger?

1943.

Okay, so radar additions would not have been available until then. I would assume you'd mount it behind the bomb-bay on the lower fuselage like how it was done on the Avro Lancaster?

 

[Shortround6]

Bf 109F-0 was a rather rare bird? Granted, it could've used more firepower - 2 HMGs + MG FFMs, or just 3 MG FFMs each with a 90 rd drum (otherwise used 1st from late 1942?). A belt-fed MG FF(M) was no rocket science, after all, however it was developed even later than MG 151/20, and used probably only at Do 217 NFs.

This kind of goes with using existing guns/technology or speeding up development of some guns or it could have been built?
When did the 90 round drums show up? and will they fit in a 109 wing?
By the time the Japanese had belt fed Oerlikons the Germans were using the MG 151 making the point rather moot.
In any case even with the 15mm MG 151 a bit more firepower wouldn't hurt. ANd with the DB 601 engine situation the way if was (DB 601N engine good for 1175 hp at 4800 meters) it iis going to be a careful balance between firepower and performance.

How about a dedicated tank-buster version with 2x MK 101s for 1941/42?

one source says they only built about 180. That could be solved (put back into production) but in 1942 the MK 101 is too light a gun. And it only fires about 50% faster than the 37mm gun. One or two more shots per barrel per attack?
For attacking soft targets four MG 17s seems to be a decent change even if not spectacular.

Hopefully Germans can make a better bomber than it was the venerable He 111? But yes, the 111 will need improvement of defensive firepower.

I have a bit of a soft spot for the old He 111, it was supposed to be replaced several times but it never happened and in the meantime they kept using it with pretty much 1940 defensive guns and pretty much 1940/early 1941 engines. It didn't get an MG 131 in the dorsal position until 1942 (He 111H-11?) The power turret, which was power only in traverse(?) came later, a modification kit to the H-16. granted it was never going to fight it's way into a a target but better defence might have helped the loss rate. Same with the engines, a bit more speed or more speed and altitude when flying on one engine?

Bolingbroke was the Mk.V.

The Bolingbroke name was re-used several times in the Blenheim history. You are correct in that in end the MK V was known as the Bolingbroke. earlier the name would come up and then be dropped as it was felt there either wasn't enough change in the aircraft and/or it would cause confusion.

They might also need some convincing in 1939-41 that drop tanks are not work of the devil.

This one is really curious as most of the early 1930s fighter (biplanes) and attack planes carried drop tanks or jettisonable tanks. I have never heard of any problems but that seems a rather sort period of time to forget about them unless there were problems.

Granted, the 601N was a not a paramount of reliability, the 601E was fully rated after 6-7 months, the 605A after more than a year (managing to kill Marseille in process), while 603A was trying to replicate problems of early BMW 801s and Sabres in 1943.

I am thinking even earlier when around 25% or more of the Bf 110s that attacked Poland used Jumo 210 engines and the large number of 109Ds that were built using Jumo 210s after the DB engines were used in air races in Switzerland.
I don't know if DB was starved for funds or what was going on but even the He 111 went from using DB 601s on the P to Jumo 211s on the H (which actually came later)

If you do have an extra DB engines floating around perhaps a better use for them than a DB powered FW 190 would be more Do 215 bombers? It was a close to German Mosquito as you were going to get early in the war.

 

[Ivan1GFP]

Zipper730,
The short, symmetrical wing was chosen because that met the Army's requirements for high speed, but at the cost of higher stall speeds, longer take offs. The B-25 used a more conventional airfoil and though it cost speed, it improved low speed handling, improved take off performance.
In a way the B-26 tried to meet as many expectations of the Army's requirement as physically possible, using the technology available at that time, but sacrificed much to achieve it.

Hello Greg Boeser,
That WAS the explanation for the symmetrical airfoil, but the really interesting thing is that even with more power, the Marauder wasn't substantially faster than the Mitchell even in the early versions and in the war time versions, they were nearly identical in level speed.
I had always wondered why anyone would use a symmetrical airfoil in an aircraft that was not intended to spend any time flying inverted. Eventually I came across an article that quoted Peyton Magruder as stating that the symmetrical airfoil was probably a mistake.

The Americans are in pretty good shape in regards to engines and propellers. Now just beat somebody over the head until they agree that sticking 800-1000lbs worth of guns and ammo in 1200hp airplanes isn't really a good idea

Hello Shortround6,
This comment surprises me a bit.
The lack of development of a two stage or even a two speed supercharger seems like a serious mistake.
The theory was that Turbochargers would be used when needed for high altitude performance but that doesn't seem to have worked well with the smaller aircraft.

IIRC Molders rigged up a Bf-109F-1 with two cannon in the wings, I've seen the photo somewhere. Don't know what the effect on performance was.

Hello Kevin J,
I believe those were Adolf Galland's aircraft.

- Ivan.

 

[Ivan1GFP]

Power adders for BMW 801 were not a happy story, DB 605s were much better in that regard. Granted, the fully-rated BMW 801 will have 1700 PS for take off, but for the fighters the altitude power was a much more important thing. We know that P-40s and P-39s with 1600 HP at 2500 ft were nothing fancy above 15000 ft.

Hello Tomo Pauk,
Eventually the BMW 801D-2 became pretty reasonable with C-3 injection and even made some pretty impressive power without any power adders. It certainly was heavy for the amount of power though.
It is hard to disagree that the DB 605 was a better engine in the long run, but early versions were not just derated, they were unreliable.
As for a comparison with the single speed V-1710 engines, there is a pretty big difference between a critical altitude of 13,000 feet and one that is pretty close to 20,000 feet.

We can also make a speculation how interested was Germany in investing money in a private compaby that DB was, vs. in the government-owned Jumo in the time Germany beliveed that the've won the war? For whatever the reason, production of DB engines stayed about the same from late 1939 to late 1940, while production of Jumo engines doubled in the same time.
Note that I don't advocate cancelling the BMW 801s, they can come in handy on Ju-88s, a small Ju 288, and later, f/b versions of Fw 190. What I'd cancel is the Bf 110 and subsequent 210 programe by winter of 1940/41.

I believe Kurt Tank was also of the opinion that the ultimate FW 190 would be powered by a Daimler Benz engine but was told that while he could experiment as much as he wanted, there simply would not be production quantities of those engines available to him.
Those early JuMo engines of that period were not really suited to use in fighters.
Without a pressurized cooling system, the radiators tended to be much larger because of lower efficiency.
As a general observation, the organizations within the Axis powers did not appear to work well together and seemed reluctant to share information with each other.

- Ivan.

 

[Shortround6]

Hello Shortround6,
This comment surprises me a bit.
The lack of development of a two stage or even a two speed supercharger seems like a serious mistake.
The theory was that Turbochargers would be used when needed for high altitude performance but that doesn't seem to have worked well with the smaller aircraft.

As with all generalities there are some holes. However:
Who else in 1940 had a 1600hp radial engine in production (over 1900 built in 1940) ? with a two speed supercharger?
Who else was working on a 1700hp radial that would enter production in 1941?
Who else had an 1850hp engine going into production at the end of 1940 (2 speed)?
Who else had a two stage engine in production in 1940?
Wright was offering two speed engines in 1938.
Who else had turbo superchargers in production in 1940?

So I would say that the US was in pretty good shape in regards to engines compared to the rest of the world in the 1939-41 time period.

Granted the US had a few clangers, or more than few, The Wright Tornado and early R-3350s come to mind. But the US had enough different engines that proved powerful and reliable to supply power for most of their needs. The French, Italians, Russians and Japanese weren't even in the same league (in part due to fuel but two row radials without a center bearing weren't going anywhere) and it took the Germans several years to get a radial up to the power of the early US radials (R-2600 A series).

 

[wuzak]

When did H2S & H2X become first available for night-bombing operations?

1943.

Okay, so radar additions would not have been available until then. I would assume you'd mount it behind the bomb-bay on the lower fuselage like how it was done on the Avro Lancaster?

I should clarify.

H2S Mk.I was used, in small numbers, in January 1943. The Mk.I was essentially the pre-production version of the Mk.II, which came into widespread service ~July 1943.

H2S Mk.III, which had better resolution due to using a shorter wavelength and was equivalent to the H2X, began use in December 1943.

H2X was first used in combat in November 1943.


Initially H2X was fitted behind the chin turret on B-17Gs. Most were fitted in place of the ball turret.

http://www.482nd.org/sites/default/files/2016-09/B-17-23511.jpg
How H2X "Mickey" – Got its name | 482nd Bombardment Group (P)


Lancasters had them in the rear fuselage (where the under turret was fitted on some Manchesters).

For the Mosquito it took up the bomb bay!
Royal Air Force RAF de Havilland Dh-98 Mosquito B-16 'H2S' Radar Scanner Fitted in the...

Probably why they didn't use Mosquitoes with H2S.

 

[davparlr]

Zipper730,
The short, symmetrical wing was chosen because that met the Army's requirements for high speed, but at the cost of higher stall speeds, longer take offs. The B-25 used a more conventional airfoil and though it cost speed, it improved low speed handling, improved take off performance.
In a way the B-26 tried to meet as many expectations of the Army's requirement as physically possible, using the technology available at that time, but sacrificed much to achieve it.
The A-26, which began design just a year later, exceeded the B-26 in virtually every category. But it was designed under a different set of requirements.
The existence of the A-26 is the reason that many proposed improvements were not made to the B-26. The Army froze development on the B-26 and cancelled contracts as the A-26 neared gestation. The B-26 was costly to build, and the A-26 promised to be an improvement at a similar cost, so why invest more $$$ into an obsolescent design? The B-25 continued in production because it was cheaper and a tamer handler.

To beat an old drum of mine, putting the big wing on the B-26 was the error. Instead, the AAF, and Navy should have started addressing adapting to faster flying, and landing, aircraft, which was the future. This adaptation must include pilot training and, also, launch and landing platforms, that is, runways and aircraft carriers (the Navy was ill-adapted to deal with the fast flying air battles of the Korean War, only five years after WW2).
Given that, I think many lives would have been saved over Germany in 1943 if the AAF had built the XB-33A, only with R-2800 engines instead of the R-2600 and maybe with the P-47B turbochargers. This plane would be well over 250 mph cruise and 350 mph dash speed at 25000 ft. (I wouldn't sweat the pressurization, I would design to it but not press meeting it. Get the planes into the air!). In order to provide engines and manufacturing facilities, cancel my beloved B-26s.

 

[BiffF15]

Okay, my input is simple.

Have a Rolls-Royce design a supercharger for the V1710, then update it it regularly as they made advances on the Merlin.

Faster and better performing P-40s, P38s, P-39s and P-51As...

The follow up would be what could you do performance wise with Merlin type power at altitude with those aircraft?

 

[Zipper730]

Okay, my input is simple.

Have a Rolls-Royce design a supercharger for the V1710, then update it it regularly as they made advances on the Merlin.

Would that be feasible?

 

[GrauGeist]

Okay, my input is simple.

Have a Rolls-Royce design a supercharger for the V1710, then update it it regularly as they made advances on the Merlin.

Faster and better performing P-40s, P38s, P-39s and P-51As...

The follow up would be what could you do performance wise with Merlin type power at altitude with those aircraft?

The question is, how long would that take to go from concept to production and what changes in the V-1710 would need to be made in order to accept the add-on?

And, would those changes slow existing production?

 

[Greg Boeser]

I find it interesting that the early (pre-war) users of the B-26 didn't have that much trouble with them. It was the first generation expansion pilots that were killing themselves with abandon in 1942. By 1943 the accident curve had swung way down, but by that time the decision had been made to kill the program.
Another point that is often overlooked when talking about the "Widowmaker" is that it had a far better accident rate than the A-20 or A-26, though I suspect that as the A-26 matured it's accident rate curved down as well.

 

[wuzak]

Okay, my input is simple.

Have a Rolls-Royce design a supercharger for the V1710, then update it it regularly as they made advances on the Merlin.

Faster and better performing P-40s, P38s, P-39s and P-51As...

The follow up would be what could you do performance wise with Merlin type power at altitude with those aircraft?

Would that be feasible?

Allison tested a V-1710 with a Merlin 2 stage supercharger, but not directly connected. The performance was very much the same as the Merlin.

The Merlin supercharger could have been fitted - but the extent of the modifications to the engine and supercharger may be too much.

 

[wuzak]

I should also mention that the supercharger bearings failed due to operating under different conditions than it would on the Merlin.

 

[tomo pauk]

This kind of goes with using existing guns/technology or speeding up development of some guns or it could have been built?
When did the 90 round drums show up? and will they fit in a 109 wing?
By the time the Japanese had belt fed Oerlikons the Germans were using the MG 151 making the point rather moot.
In any case even with the 15mm MG 151 a bit more firepower wouldn't hurt. ANd with the DB 601 engine situation the way if was (DB 601N engine good for 1175 hp at 4800 meters) it iis going to be a careful balance between firepower and performance.

Thing with MG 151 is that it will be a very problematic fit (will not say impossible) within the confines of the wing of Bf 109, having a bigger receiver, and using bigger ammo.
The 90 rd drum was probably of early 1943 vintage? German take on belt-feed MG FFM involved electrical motor, vs. Japanese cannons belt feed being powered by gun operation itself. MG FFM being a pretty light cannon will help out here - for example, three of those will weight less than two MG 151s (two FFMs will weight like one Hispano II), and will have lighter and more slender ammo. Granted, I'm trying to solve the problem of 1939/40 with a cure from 1943 here. Unlike Anglo-American fighters, German fighters were small & mostly light, so the 601N and early 601E will cut it here for 1941, even for 1942.

one source says they only built about 180. That could be solved (put back into production) but in 1942 the MK 101 is too light a gun. And it only fires about 50% faster than the 37mm gun. One or two more shots per barrel per attack?
For attacking soft targets four MG 17s seems to be a decent change even if not spectacular.

Yes, adding an extra pair of MG 17s does not tip the scales, but it doubles the rate of fire.
Two MK 101s beat a single MK 101 carried by early Hs 129Bs Granted, by 1942/43 something bigger can/need to be added, 37mm is a good choice.

I have a bit of a soft spot for the old He 111, it was supposed to be replaced several times but it never happened and in the meantime they kept using it with pretty much 1940 defensive guns and pretty much 1940/early 1941 engines. It didn't get an MG 131 in the dorsal position until 1942 (He 111H-11?) The power turret, which was power only in traverse(?) came later, a modification kit to the H-16. granted it was never going to fight it's way into a a target but better defence might have helped the loss rate. Same with the engines, a bit more speed or more speed and altitude when flying on one engine?

He 111 really deserves the BMW 801s (or something better, that either didn't materialized, or materialized too late). The 801A that powered early Do 217s was a reasonably reliable engine (probably due to not having 'option' for Notleistung?). One MG 131 will not cut it in dorsal position, have two there at least? Or, let's steal the idea from the British and have a 4-gun turret with MG 17s?

This one is really curious as most of the early 1930s fighter (biplanes) and attack planes carried drop tanks or jettisonable tanks. I have never heard of any problems but that seems a rather sort period of time to forget about them unless there were problems.

Looking at the pics at the AHT, seems like mostly USN fighters were carrying drop tanks - making the drop tanks look indeed like the work of devil in the eyes of the USAAC/AAF

I am thinking even earlier when around 25% or more of the Bf 110s that attacked Poland used Jumo 210 engines and the large number of 109Ds that were built using Jumo 210s after the DB engines were used in air races in Switzerland.
I don't know if DB was starved for funds or what was going on but even the He 111 went from using DB 601s on the P to Jumo 211s on the H (which actually came later)

Okay, got it now.
My cunning plan does not involve Daimlerized Fw 190s fighting in Poland, but Fw 190s in early 1941 that don't burn due to engines, while having much better range/radius than Bf 109, as well as better rate of roll, cockpit, landing gear and armament.

If you do have an extra DB engines floating around perhaps a better use for them than a DB powered FW 190 would be more Do 215 bombers? It was a close to German Mosquito as you were going to get early in the war.

Nah, I don't rate the Do 215 as close to even early Mosquito - no speed, you know We might as well bomb-up Bf 110Cs.

 

[tomo pauk]

Hello Tomo Pauk,
Eventually the BMW 801D-2 became pretty reasonable with C-3 injection and even made some pretty impressive power without any power adders. It certainly was heavy for the amount of power though.
It is hard to disagree that the DB 605 was a better engine in the long run, but early versions were not just derated, they were unreliable.
As for a comparison with the single speed V-1710 engines, there is a pretty big difference between a critical altitude of 13,000 feet and one that is pretty close to 20,000 feet.

If only there was a 1-stage V-1710 with the critical altitude of 20000 ft - the best in-service version went to 15500 ft (for 1125 HP) by late 1943/early 1944.
Thing with C3 injection was that it worked under 1.5 km of altitude. What BMW 801D needed, apart from reliability in 1st 6 months of service use, was a better supercharger from mid-1943, that eventually was in service by late 1944 with 801S - too late, that is.
The (un)reliability of DB 605As was not so acute as with BMW 801s in the first ~15 months of service with Fw 190s, that acute that it almost killed the whole Fw 190 program with engine itself. Let's note that DB 605A still have had no restrictions on 30-min regime, or any other lower regime, while restrictions on the BMW 801D were applied for all regimes.

I believe Kurt Tank was also of the opinion that the ultimate FW 190 would be powered by a Daimler Benz engine but was told that while he could experiment as much as he wanted, there simply would not be production quantities of those engines available to him.
Those early JuMo engines of that period were not really suited to use in fighters.
Without a pressurized cooling system, the radiators tended to be much larger because of lower efficiency.
As a general observation, the organizations within the Axis powers did not appear to work well together and seemed reluctant to share information with each other.
- Ivan.

The people at RLM tried to install the DB 603s into the war-winning Me 410 - whoops...
Nobody used open cooling system on liquid-cooled engines from some time of 1930s? Granted, the over-pressure cooling systems, like what was introduced with DB 601E and Jumo 211F will enable for no increase of radiator size despite the increase of power.
The internal (in)efficiencies of within Axis powers are story for itself.

 

[Shortround6]

Thing with MG 151 is that it will be a very problematic fit (will not say impossible) within the confines of the wing of Bf 109, having a bigger receiver, and using bigger ammo.
The 90 rd drum was probably of early 1943 vintage? German take on belt-feed MG FFM involved electrical motor, vs. Japanese cannons belt feed being powered by gun operation itself. MG FFM being a pretty light cannon will help out here - for example, three of those will weight less than two MG 151s (two FFMs will weight like one Hispano II),.

I don't know how big a difference there was in the thickness of the wings on th e109 and Zero where the guns (and ammo) were located. I mean actual thickness, not percentage as the Zeros wing was a lot bigger. Even a few inches might make a difference.
The MG FF and FF/M had the dual problems of low rate of fire and poor velocity. You need more than two to get a large number of shells in the air, and you have to get close or use angles of fire with little deflection. The long time of flight making deflection shooting difficult.

Two MK 101s beat a single MK 101 carried by early Hs 129Bs

Ah, but one in/on the fuselage is worth two in the wings..... or so we are told

He 111 really deserves the BMW 801s (or something better, that either didn't materialized, or materialized too late). The 801A that powered early Do 217s was a reasonably reliable engine (probably due to not having 'option' for Notleistung?). One MG 131 will not cut it in dorsal position, have two there at least? Or, let's steal the idea from the British and have a 4-gun turret with MG 17s?

They did manage to power some of them with Jumo 213s once they stopped making 211s so it seems like there was no insurmountable difficulty in using more powerful engines.

A manned turret with two MG 131s with power traverse and power elevation (both with fine control and not just rough slew) might have done wonders for a number of large german planes. In 1941 even a pair of MG 81s (not necessarily the MG 81Z) is going to beat the heck out of a MG 15.

Nah, I don't rate the Do 215 as close to even early Mosquito - no speed, you know We might as well bomb-up Bf 110Cs.

Well, the Do 215 was rated at just about 500kph. Since the bombs are carried inside it doesn't take the performance hit that strapping bombs to the bottom of the 110 would cause so the actual attack speeds (30 minute rating?) would be a lot closer. Get rid of the "bug-eye" nose and put on something like the night fighter nose. Use DB 601N or E engines (mainly to get the altitude up higher than the DB601A and DB601Aa. You also have a more range than the 110. Possibility of trading bomb bay space for more fuel. Just do something about the idiotic gun array at the rear of the canopy.

It will never equal the Mosquito but since you could have them almost 2 years before the Mosquito shows up in any numbers it doesn't have to be quite as good.
The JU-88 was never going to equal the Mosquito either as by the time you get to the A-4 (very late 1940/early 41) you have plane weighing thousands of pounds more.