Four Engined He 177 w/ Level-Headed Specs

[Zipper730]

I've read a bit about the He 177: It's one of those completely absurd designs that leave you scratching your head. While many unorthodox designs have been proposed: Most are weeded out before they ever fly. While there are others that manage to proceed, there are the very small number that make the unorthodox work (such as the de Havilland Mosquito); most, however, are heavily-modified in either, the design-stage, or the flight-test phase.

While some of it's specifications weren't all that unreasonable, the requirement for moderate-angle (40-50 degree) dive-bombing attacks was a rather unusual feature. It would require considerable strengthening to the fuselage, as it would require stronger wings and fuselage, as well as the ability to tolerate higher maximum airspeeds than normally required for a heavy-bomber; while, I'd almost swear, I heard that the Royal Air Ministry's P.13/36 specification (gave rise to the Avro Manchester) demanded some steep diving requirements too, they were reduced to a more reasonable 25-30-degrees (still impressive for a heavy-bomber): The RLM actually demand these requirements to be increased to 60-degrees, something that required dive-brakes, an additional degree of strength (and weight), and reduced overall range (even with additional fuel), and a more complicated main landing-gear arrangement to support it (that said, I'm not sure if it posed any reliability issues).

That said, some of the design features weren't entirely the fault of the RLM. Some were Heinkel's fault as well, either through personal preferences, or responses to the changing requirements. For starters, they had a strong predilection to the idea of surface evaporative cooling (something which works well for race-planes, but not combat aircraft), and also chose the DB606 (which wasn't an RLM requirement) with the hope of reducing installation drag by 3%.

While the DB606 wasn't intrinsically flawed (it worked on the He 119 and Me 261), the idea of using surface cooling on the DB601 was impractical (it'd work, but the plane could be easily incapacitated by a few well-placed rounds). With the DB606, it was damned-near impossible. In an effort to keep cooling drag down, they used a tight-cowl, which made sense, but the engine ran quite hot, and tight cowls tend to produce inadequate cooling at certain speeds. Given that a hotter engine produces hotter exhaust, and the DB606's inner exhaust ducts run close to each other, have less ambient air flowing around them, they produce high temperatures and deposit soot, which can ignite.

The increases in weight resulted in the engine installation being recessed further back inside the wings without a firewall. The oil pump was badly designed, and the position of the electrical harnesses and oil lines, all served to make fires occur easily. Without a firewall installed, the airplane could quickly go up.

It's pretty obvious with 20/20 hindsight (or the properly calibrated crystal-ball -- thanks, X XBe02Drvr -- that's become one of my favorite expressions) that the Lotfernohr 7 bombsight would come online in 1941, and the dive bombing requirement would be lifted in 1942: The fact is that the Do 17/215 & Ju 88 were predominantly level-bombers that could do dive-bombing if need be. The moderate-angle dive requirement prior to late 1937 was probably already overkill, but it might have been easier to achieve weight and range requirements.

It seems 4 x DB601 would be the best choice because it'd have a smaller propeller diameter, and that'd simplify the landing-gear. I remember hearing that drag difference would be all of 3%, and that could be covered by some aerodynamic refinement.

 

[tomo pauk]

The 'classic', no-dive-bomb 4-engined take on He 177 is a very good proposal IMO, at least from the technical side. From operational & logistical side, we might see the earlier cut of the He 111 production at Heinkel and service introduction of "ALT He 177" earlier and with less problems. That in return should allow Luftwaffe to conduct some meaningful strategic bombing of Soviet targets by early 1943?
Granted, the bombers could use escort, and Soviets will be fielding aircraft more suited for 5-6 km altitude (Spirfires, perhaps La-5, what is left of MiG-3) as means to stop the bombers.

 

[Zipper730]

The 'classic', no-dive-bomb 4-engined take on He 177 is a very good proposal IMO, at least from the technical side. From operational & logistical side, we might see the earlier cut of the He 111 production at Heinkel and service introduction of "ALT He 177" earlier and with less problems.

I actually didn't consider that possibility, but the He 111 was getting a bit long in the tooth by the end of the war.

That in return should allow Luftwaffe to conduct some meaningful strategic bombing of Soviet targets by early 1943?
Granted, the bombers could use escort, and Soviets will be fielding aircraft more suited for 5-6 km altitude (Spirfires, perhaps La-5, what is left of MiG-3) as means to stop the bombers.

Actually, I'm not sure how long it would have taken for a more conventional He 177 design to have entered service, some of the delays were caused because of the dive-bombing requirements.

 

[Shortround6]

Four propeller he 177s are nice what ifs but would have had little effect on the war.

If you introduce the plane earlier than the real He 177 you have the same or worse defensive armament than the early 177s, depending on how early you may have less total power.
Since you can easily outrange any escort the defensive armament takes over some importance. German 1941-42 defensive armament setups were pretty poor.

Then you have the question of what strategic targets were actually in range. Not everything got evacuated to the Urals but the number of suitable targets are limited. Any trips to Urals are one way unless the bomb load is pitifully small. ( a few Grenades out the window?)

I am not sure if the He 177 was actually the result of an actual stratic need or a case of "bomber envy". Everybody else got big bombers so we need one too?

 

[tomo pauk]

...
I am not sure if the He 177 was actually the result of an actual stratic need or a case of "bomber envy". Everybody else got big bombers so we need one too?

4-engined bombers do offer better payload/HP and payload/crew ratios (assuming the same engines are used).
IOW, a force of 100 4-engined bombers will be carrying more to the same distance (or same bomb-load farther) than a force of 200 2-engined bombers, and will need far less crew to do it. Less radios and radars (when available) are needed, half of bomb sights. A more efficient defensive armament can be installed in a bigger aircraft. Big aircraft can carry big bombs easily in a bomb bay, big bombs are better in damaging buildings etc.
Or, if a target X is at 700 km, the force of 4-engined bombers will still deliver a meaningful bomb load to hit the target, the 2-engined bombers might not.

Germany have had enough of engineers and wherewithal to figure the same thing the British, US or Soviets figured out.

 

[stona]

This is all pie in the sky.

The Luftwaffe could not support the bombing forces it had, and they were continually cut back.

As early as July 1942 Luftwaffe training was cut to the point that only 20% of bomber crew replacements could be provided.

By January 1943 the OKL was seriously discussing cutting the number of bomber Gruppen from 17 to 4 or 5. According to the notes of a situation briefing of 16th January 1943, "The majority [of bomber Gruppen] existed only on paper as far as striking power was concerned, with the youngest Lieutenants acting as squadron commanders."

January 1943.

Where is the materiel to build a strategic bomber capability going to come from? If you build bombers you will have to build less of something else. When fighting a defensive war to protect your own air space do you really want to cut fighter production?

If you build the bombers, who is going to crew them?

 

[Shortround6]

4-engined bombers do offer better payload/HP and payload/crew ratios (assuming the same engines are used).
IOW, a force of 100 4-engined bombers will be carrying more to the same distance (or same bomb-load farther) than a force of 200 2-engined bombers, and will need far less crew to do it. Less radios and radars (when available) are needed, half of bomb sights. A more efficient defensive armament can be installed in a bigger aircraft. Big aircraft can carry big bombs easily in a bomb bay, big bombs are better in damaging buildings etc.
Or, if a target X is at 700 km, the force of 4-engined bombers will still deliver a meaningful bomb load to hit the target, the 2-engined bombers might not.

Germany have had enough of engineers and wherewithal to figure the same thing the British, US or Soviets figured out.

We have been over this a bunch of times. A lot depends on timing. Many of these threads call for the He 177 to enter service earlier, as a guideline it flew one month after the HP Halifax.
Except the He 177 needed a lot more fixing (not claiming the Halifax was all that good to start with) and a lot of the fixing had nothing to do with the dive bomber requirement.
The He 177 defence had been planned around speed (failed)and remote control gun barbettes (also failed). In part the speed failed because they decided not to use the surface evaporation cooling system and the drag of the radiators cost quite a bit of speed. The remote control barbettes were nowhere near ready and early prototypes used manned guns. However the V1 never had guns fitted. The V2-V4 were supposed to have three 13mm MG 131s fitted (with a four man crew, very busy boys) but the V5 used four 7.9mm MG 15s.
The V6 got 2700hp engines vs the 2600hp engines used in the first 5 planes.
The V6 and V7 don't get to Bordeaux-Merignac until Aug 2nd 1941, the V7 has a couple of Mg 131s and 20mm MG FF in the front of the gondola and in some sort ot turret on top.
The V8 keeps it's mg 131 in the tail but goes back to all MG 15s in the other positions. Self defense using this suite of guns is pretty much a bad joke in 1941.

As far as actually building these things. The order for 30 of A-0 series goes, it was split between 3 different factories, inpart due to limited capacity and in part to get other production sources ready. Now think of the cost in tooling already committed to this program. You also have the ussual German problem of a 5 man crew trying to use weapons in five different locations and since the pilot is flying the plane and the guy on the tail gun is meters away from any other gun you again have a couple of very busy crewmen athletically jumping around in the fuselage. The guns are nowhere near as close together as the guns in the Ju-88 or DO 17 and they bad enough.

Going to the 4 engine layout solves the engine problems of catching fire. Getting rid of the 60 degree dive helps out and makes the plane a bit lighter.
But this thing is not fast enough or well defended enough to be a day bomber in 1941/42.

BTW the He 11 could carry a rather decent payload to 700km

 

[tomo pauk]

We have been over this a bunch of times. A lot depends on timing. Many of these threads call for the He 177 to enter service earlier, as a guideline it flew one month after the HP Halifax.
Except the He 177 needed a lot more fixing (not claiming the Halifax was all that good to start with) and a lot of the fixing had nothing to do with the dive bomber requirement.
The He 177 defence had been planned around speed (failed)and remote control gun barbettes (also failed). In part the speed failed because they decided not to use the surface evaporation cooling system and the drag of the radiators cost quite a bit of speed. The remote control barbettes were nowhere near ready and early prototypes used manned guns. However the V1 never had guns fitted. The V2-V4 were supposed to have three 13mm MG 131s fitted (with a four man crew, very busy boys) but the V5 used four 7.9mm MG 15s.
The V6 got 2700hp engines vs the 2600hp engines used in the first 5 planes.
The V6 and V7 don't get to Bordeaux-Merignac until Aug 2nd 1941, the V7 has a couple of Mg 131s and 20mm MG FF in the front of the gondola and in some sort ot turret on top.
The V8 keeps it's mg 131 in the tail but goes back to all MG 15s in the other positions. Self defense using this suite of guns is pretty much a bad joke in 1941.

As far as actually building these things. The order for 30 of A-0 series goes, it was split between 3 different factories, inpart due to limited capacity and in part to get other production sources ready. Now think of the cost in tooling already committed to this program. You also have the ussual German problem of a 5 man crew trying to use weapons in five different locations and since the pilot is flying the plane and the guy on the tail gun is meters away from any other gun you again have a couple of very busy crewmen athletically jumping around in the fuselage. The guns are nowhere near as close together as the guns in the Ju-88 or DO 17 and they bad enough.

Thank you for the effort to find out and type out the details.
The He 177 needs to be designed around 4 separate engines from get go.

Going to the 4 engine layout solves the engine problems of catching fire. Getting rid of the 60 degree dive helps out and makes the plane a bit lighter.
But this thing is not fast enough or well defended enough to be a day bomber in 1941/42.

Same holds true for any bomber of the era.

BTW the He 111 could carry a rather decent payload to 700km

700 km towards the target with bomb, 700 km back - a 2200 lb bomb for the H-16.
4500 lb bomb - half of 1230 km.
If 550 lb bombs make sense to attack a factory, it can lug 8 of them (4400 lb) to half of 1885 km.
Wellignon IC (1000 Hp Pegasus engines) - 4500 lbs (9x500 lb) at distance that is half of 1930 km (1200 miles) range.
The worst Halifax there was, 4 x 1130 HP - 13000 lbs to the target 800 km away, if we believe RAF's sheet.
British figures have allowances. Neither sheet includes wind that can be less than cooperative, of navigator's faults.

 

[Zipper730]

Four propeller he 177s are nice what ifs but would have had little effect on the war. . . . If you introduce the plane earlier than the real He 177 you have the same or worse defensive armament than the early 177s

I merely figured it'd enter service earlier if the dive-bombing requirements weren't getting in the way of the design.

Then you have the question of what strategic targets were actually in range. Not everything got evacuated to the Urals but the number of suitable targets are limited. Any trips to Urals are one way unless the bomb load is pitifully small.

Poland was under German control, and that would make it possible to hit the Urals and come back. The requirements called for 5000 km with a 1000 kg load. I wouldn't want to be in a city that'd see a few squadrons worth of aircraft, each dropping roughly a metric ton apiece on.

We have been over this a bunch of times. A lot depends on timing. Many of these threads call for the He 177 to enter service earlier, as a guideline it flew one month after the HP Halifax.
Except the He 177 needed a lot more fixing (not claiming the Halifax was all that good to start with) and a lot of the fixing had nothing to do with the dive bomber requirement.
The He 177 defence had been planned around speed (failed)and remote control gun barbettes (also failed). In part the speed failed because they decided not to use the surface evaporation cooling system and the drag of the radiators cost quite a bit of speed. The remote control barbettes were nowhere near ready and early prototypes used manned guns. However the V1 never had guns fitted. The V2-V4 were supposed to have three 13mm MG 131s fitted (with a four man crew, very busy boys) but the V5 used four 7.9mm MG 15s.
The V6 got 2700hp engines vs the 2600hp engines used in the first 5 planes.
The V6 and V7 don't get to Bordeaux-Merignac until Aug 2nd 1941, the V7 has a couple of Mg 131s and 20mm MG FF in the front of the gondola and in some sort ot turret on top.
The V8 keeps it's mg 131 in the tail but goes back to all MG 15s in the other positions. Self defense using this suite of guns is pretty much a bad joke in 1941.

Now this is an interesting discussion -- I thought most all the problem revolved around the dive-bombing requirements (and the engines catching fire).

The problems seem to revolve around propulsion and armament: I had never really considered the armament up until this point, but it's a valid issue. While, as far as I'm aware, the upper turret was remotely controlled, the aircraft wouldn't be adequately armed without a tail-gun, even if it had an upper/lower turret.

The propulsion system was fairly obvious: While the DB606 wasn't intrinsically flawed (or, more accurately, it wasn't guaranteed to turn every plane which used it into a fireball). The installation was the problem. They wanted to use surface evaporative cooling to eliminate cooling-drag (similar to the He 100), which would work on a DB601, but not on the DB606 (the He 119 couldn't make it work either, they needed a semi-retracting system), since they couldn't make it work: They ended up using a tight-cowling to recover as much performance as they could (something which succeeded in making the engine run fairly hot, which combined with the inner cylinder banks, produced a fire-hazard). The nacelle was placed further back in the wing, which left little room for a well-designed oil-pump (which caused foaming and inadequate lubrication), and the desire to trim weight left little room for a firewall (which resulted in fires that would spread everywhere).

With 4 x DB601, the surface evaporative cooling system could probably have been made to work (that said, it'd probably require a retracting radiator like the He 110 did) at high speeds. With a loss of performance of 3% that would reduce top speed from 550 km/h (341.8 mph) to 534 km/h (331.8 mph).

As far as actually building these things. The order for 30 of A-0 series goes, it was split between 3 different factories, inpart due to limited capacity and in part to get other production sources ready. Now think of the cost in tooling already committed to this program. You also have the ussual German problem of a 5 man crew trying to use weapons in five different locations and since the pilot is flying the plane and the guy on the tail gun is meters away from any other gun you again have a couple of very busy crewmen athletically jumping around in the fuselage. The guns are nowhere near as close together as the guns in the Ju-88 or DO 17 and they bad enough.

Going to the 4 engine layout solves the engine problems of catching fire. Getting rid of the 60 degree dive helps out and makes the plane a bit lighter.
But this thing is not fast enough or well defended enough to be a day bomber in 1941/42.

I figure the cost allocated to the design would solely be the function of resources required to build it. If it was designed with 4 x DB601 from the start, there wouldn't have been a need for massive-redesign, except for the tail-gun.

As for armament and crew-complement: I'm not sure, what the RLM would have tolerated. There were other competitors in the design, far as I know. That said, the Boeing Model 299 didn't start with that many guns, but ended up with 8 x 0.50 spread across 4 x turrets, with 5 x 0.50 in single-mounts comprising the two waist-positions, the central-gunner, and two in the nose. Somehow the design managed to adapt. Even by the time the B-17E, the plane was still holding a top speed of 317-318 mph with one less turret (the chin turret), and 4 x 0.30" in the nose.

4-engined bombers do offer better payload/HP and payload/crew ratios (assuming the same engines are used). . . a force of 100 4-engined bombers will be carrying more to the same distance (or same bomb-load farther) than a force of 200 2-engined bombers, and will need far less crew to do it. Less radios and radars (when available) are needed, half of bomb sights. A more efficient defensive armament can be installed in a bigger aircraft. Big aircraft can carry big bombs easily in a bomb bay, big bombs are better in damaging buildings etc.

Correct. I'm surprised the Germans never realized that -- they were quite adept at matters of engineering and stuff...

This is all pie in the sky

Well yeah, it's a fictional discussion on an online aviation forum. When did the Germans start having cut-backs in bomber-training?

 

[pbehn]

The He 177 was a four engine bomber but the engines were paired in each wing for aerodynamic efficiency driving a single prop. By the same metric the B-29 was an eight engine bomber, with engines paired one behind the other.

 

[pbehn]

The He 177 was a four engine bomber but the engines were paired in each wing for aerodynamic efficiency driving a single prop. By the same metric the B-29 was an eight engine bomber, with engines paired one behind the other.

I was trying to be serious Shortround (maybe a bit extreme), it all seems to be a calculation of cylinders per wing, air or water cooled. The Manchester Lancaster and He 177 had the same number of cylinders in their plane designs, the B-29 had fewer still but bigger and air cooled.

 

[Shortround6]

I merely figured it'd enter service earlier if the dive-bombing requirements weren't getting in the way of the design.

And everybody that wants it to enter service earlier wants it to go into service using 1942/43 engines and guns. If you want a somewhat historical what if it would go into service in 1941 (pick a month) with whatever engines and guns were in the Luftwaffe inventory or being introduced in that month.

Poland was under German control, and that would make it possible to hit the Urals and come back. The requirements called for 5000 km with a 1000 kg load. I wouldn't want to be in a city that'd see a few squadrons worth of aircraft, each dropping roughly a metric ton apiece on.

Well, we have the requirement and we have reality. It is 2167 km from Minsk to the City known as Tankograd (Chelyabinsk). 2640KM from Warsaw.
I wouldn't want to be in the city either but remember, an He 111 could get two metric tons to most of England. So it is going to take more than a few squadrons to really damage any Russian industrial complex. Assuming they could even find it. The beam navigation systems used over England won't work, the distances are too great. How much of the year can you depend on 9-10 hours of darkness for these missions? Because daylight is going to make the 8th Air force in 1943 look like a walk in the Park.

The problems seem to revolve around propulsion and armament: I had never really considered the armament up until this point, but it's a valid issue. While, as far as I'm aware, the upper turret was remotely controlled, the aircraft wouldn't be adequately armed without a tail-gun, even if it had an upper/lower turret.

The remote controlled upper turret with a single MG 131 shows up with the A-1 in March of 1942, This is pretty pathetic considering the rest of the guns. But the Germans do try changing things as soon as possible. However the rest of the A-1 guns are a 7.7mm MG 81 in the nose, a 20mm MG FF in the front of the ventral gondola, two 7.9mm MG 81s in the rear of Gondola and a single gimbal mounted (hand aimed) 13mm MG 131 out the tail fired by a man laying on his stomach. Later versions got a single remote controlled turret with 13mm MG 131 under the fuselage but it was aimed from the rear of gondola so if th egunner theri was controlling the remote turret was he aiming and firing the gun/s in the rear of the gondola (changed from the pair of MG 81s to a single MG 131).

Just about all He 177 had a tail gun, some just had better setups than others. Allowing the gunner to sit allows him to use his whole upper body to aim the gun rather than just his arms as is the case laying prone.

If you add guns and gunners the weight and drag go up and the speed/range go down. The Germans were late with powered operated mounts and let's face it, the MG 131 wasn't that good a defensive gun, especially in a single mount.

 

[Shortround6]

I was trying to be serious Shortround (maybe a bit extreme), it all seems to be a calculation of cylinders per wing, air or water cooled. The Manchester Lancaster and He 177 had the same number of cylinders in their plane designs, the B-29 had fewer still but bigger and air cooled.

Sorry, there isn't a really good emoji for what I meant. Yes the B-29 was using eight slightly shrunk R-1820 Cyclones. (R-1675s).

Weirdly enough, the B-29, as we all know, suffered from overheating and engine fires.

 

[Zipper730]

And everybody that wants it to enter service earlier wants it to go into service using 1942/43 engines and guns.

Frankly, I just figured it would be in service earlier.

Well, we have the requirement and we have reality. It is 2167 km from Minsk to the City known as Tankograd (Chelyabinsk). 2640KM from Warsaw.
I wouldn't want to be in the city either but remember, an He 111 could get two metric tons to most of England. So it is going to take more than a few squadrons to really damage any Russian industrial complex. Assuming they could even find it. The beam navigation systems used over England won't work, the distances are too great. How much of the year can you depend on 9-10 hours of darkness for these missions? Because daylight is going to make the 8th Air force in 1943 look like a walk in the Park.

I didn't know the Germans had control over Minsk, but that would put it inside the 5000 km radius of action.

As for the He 177's performance, they were said to be difficult for the Soviet Union to intercept. I figure with a top speed going from around 280-290 mph to 330 would make things greatly harder.

The remote controlled upper turret with a single MG 131 shows up with the A-1 in March of 1942, This is pretty pathetic considering the rest of the guns. But the Germans do try changing things as soon as possible. However the rest of the A-1 guns are a 7.7mm MG 81 in the nose, a 20mm MG FF in the front of the ventral gondola, two 7.9mm MG 81s in the rear of Gondola and a single gimbal mounted (hand aimed) 13mm MG 131 out the tail fired by a man laying on his stomach. Later versions got a single remote controlled turret with 13mm MG 131 under the fuselage but it was aimed from the rear of gondola so if th egunner theri was controlling the remote turret was he aiming and firing the gun/s in the rear of the gondola (changed from the pair of MG 81s to a single MG 131).

I'm guessing they went with MG 81's for the same reasons the RAF went with the Browning 0.303?

I am surprised the Luftwaffe would be late to the party with the powered turrets. I'd figure we'd be the latest arrivals, and by 1941/2 we had them in our B-17's & B-24's.

If you add guns and gunners the weight and drag go up and the speed/range go down.

Of course, that said: I'm not sure if the range would have been limited as much as it really was. Consider they wanted the range brought up to 6700 km -- I doubt they could have done that. That said, a lighter plane would make it easier to get closer to that, or at least keep the range around 5000 km.

 

[tomo pauk]

...
Correct. I'm surprised the Germans never realized that -- they were quite adept at matters of engineering and stuff...
...

They certainly realized that. Problem was that execution of the idea was flawed.

 

[stona]

Well yeah, it's a fictional discussion on an online aviation forum. When did the Germans start having cut-backs in bomber-training?

At a conference with Keitel at Romintem on 10th July 1942, Goering made it clear that the events of the previous winter, with the increased deployment of transport aircraft and even training aircraft on behalf of the Army had materially reduced the supply of aviation fuels available. Goering stated that the resulting reduction in fuel allotments to the training programme had resulted in a reduction in the numbers of trained crews available as replacement personnel. Based on the numbers authorised only 20% of bomber and 40% of fighter crews could be produced. He went on to state that Hitler's order to increase aircraft production was pointless as there would be nobody to fly them.

This was in July 1942, before the He 177 even entered service. Erprobungsstaffel 177 had been formed at Rechlin-Larz, it had just eight A-0s by the end of August.

The average monthly allotment of aviation fuel to training prgrammes was 27,000 tonnes in 1941. In 1942 it was just 15,000 tonnes. On 1st September 1942 an allotment of just 5,000 tonnes for the five week period beginning that month was made, and Luftwaffe training effectively came to a temporary halt.

 

[Shortround6]

Frankly, I just figured it would be in service earlier.

You might get the airframe into service earlier, but a heavy bomber is often a combination of airframe, engines, weapons, bombsight/electronics. Primitive as the electronics were then. A lot of things were evolving/developing at the same time.

I didn't know the Germans had control over Minsk, but that would put it inside the 5000 km radius of action.

The Germans did not have control over Minsk in 1939 but it does show the absurdity of these per war Ural bomber schemes. For operational use you want somewhere between 10-20% of the "book/brochure" range as a reserve unless you want a really high attrition rate of planes running out of fuel. Once you figure in about 1 to 1 1/2 hours worth of reserve fuel for the 177 you can't reach the Urals and return from Germany and you can't even do it from Poland. You have to capture Russian territory to base the bombers in. A rather iffy proposition in the planning stages of a bomber?

As for the He 177's performance, they were said to be difficult for the Soviet Union to intercept. I figure with a top speed going from around 280-290 mph to 330 would make things greatly harder.

The only way you were going to get a He 177 up to 330mph is by putting rocket engines in it. He 177s did perform a number of missions by climbing and then going into a long shallow dive approaching the target area and continuing losing altitude on the escape route. Works over England or for targets close to contested airspace where you are close (or only minutes away) from friendly fighters. Now try a 10-12 flight to urals? You can't use the shallow dive trick, You have no element of surprise, on the return trip the fighters have hours to get ready for you.

I'm guessing they went with MG 81's for the same reasons the RAF went with the Browning 0.303?

Pretty much, nothing else available. The MG 131 took a while longer to sort out and get into production than they planned. They started work in 1937/38(?) but it wasn't being fitted to planes in large numbers until 1942.

I am surprised the Luftwaffe would be late to the party with the powered turrets. I'd figure we'd be the latest arrivals, and by 1941/2 we had them in our B-17's & B-24's.

And B-25s and B-26s. And at least one of the German power turrets was crap, The one used on the Do-217 and He 111 held one MG 131 and used power traverse for gross changes in turret traverse, fine aim , if you can call it that, was done by manually moving the gun in the mount with the turret stationary and the elevation was entirely manual. Too much time being spent on the remote control gun systems?

Of course, that said: I'm not sure if the range would have been limited as much as it really was. Consider they wanted the range brought up to 6700 km -- I doubt they could have done that. That said, a lighter plane would make it easier to get closer to that, or at least keep the range around 5000 km.

I would be very interested to see the long range cruise speed/s of the He 177 as I suspect they are a lot different than what Wiki or many books post as the Cruising speed. Old Book by William Green has the long range cruise speed of the He 177A-5/R2 (external loads?) as 210mph at 20,000ft.

 

[Zipper730]

They certainly realized that. Problem was that execution of the idea was flawed.

Tell me about it! It seems that our saving grace in WWII was that the Germans made loads of bone-headed mistakes...

You might get the airframe into service earlier, but a heavy bomber is often a combination of airframe, engines, weapons, bombsight/electronics. Primitive as the electronics were then. A lot of things were evolving/developing at the same time.

That's a valid point.

Looking at the armament requirements: They seemed mostly interested in keeping crew complement as low as possible (apparently under the hope that the two-guns could cover all hemispheres). A requirement for a tail-gun was issued in 1937, which was quite a bit before the airplane flew; As for the the initial armament: It called for the MG81 but they couldn't guarantee they'd be ready, so they looked at the MG15 as an interim, and the MG131 as an alternate (and it seems like a better choice, as it's more potent).

As for powered-turrets, I'm surprised that they'd have trouble with them if they developed remote-controlled systems, since an R/C turret seems more complicated.

The Germans did not have control over Minsk in 1939 but it does show the absurdity of these per war Ural bomber schemes. For operational use you want somewhere between 10-20% of the "book/brochure" range as a reserve unless you want a really high attrition rate of planes running out of fuel. Once you figure in about 1 to 1 1/2 hours worth of reserve fuel for the 177 you can't reach the Urals and return from Germany and you can't even do it from Poland. You have to capture Russian territory to base the bombers in. A rather iffy proposition in the planning stages of a bomber?

The only way you were going to get a He 177 up to 330mph is by putting rocket engines in it. He 177s did perform a number of missions by climbing and then going into a long shallow dive approaching the target area and continuing losing altitude on the escape route. Works over England or for targets close to contested airspace where you are close (or only minutes away) from friendly fighters. Now try a 10-12 flight to urals? You can't use the shallow dive trick, You have no element of surprise, on the return trip the fighters have hours to get ready for you.

Considering the range stipulated the ability to carry 1000 kg of bombs 5000 km, I figured that was a combat-range figure. As for basing, the Germans might not have had Minsk, but they did have a location called Zaporozhye (which is now called Zaporizhia) which, aside from starting out as a giant snowdrift, wasn't too far from Moscow or Sverdlovsk (well inside 1500 km).

Regarding performance: I was basing the top speed of the plane on the requirement (500 km/h top speed), Heinkel's submission that called for a top speed of 550 km/h, as well as claims that the doubled-up engines reduced drag by 3% (550/1.03). The aircraft was greatly slower, owing to all the structural modifications made to either meet the dive-bombing requirements, remedy structural deficiencies (If I recall, the wings needed additional strengthening), redesign the radiator (first by removing the surface evaporative cooling system, and adding a more traditional cowling, then redesigning the cowling further), add an extra gunner and 2 crew members (the design originally called for a 3-man crew, which was increased to 4 when the tail-gun was added), and increase fuel capacity. If I recall, it managed to top out somewhere between 248-273 mph.

While the aircraft might not have been able to execute shallow dives to bomb the USSR, the ability to drop the nose and pick up speed real fast was an effective evasion tactic from enemy fighter planes. Even if they were operating over short ranges like in Steinbock, they would be facing far nastier anti-aircraft artillery (according to Richard Overy's The Bombing War).

 

[Zipper730]

I assume that aircraft designed around 4 x DB601 would probably longer wingspan than an aircraft designed around 2 x DB606, correct?

 

[taly01]

Not necessarily as the props would be smaller with 4xDB601 variants, the error IMHO was not running a parallel prototype program of 2xDB606 alongside 4xDB601. ie. a safer vs possibly better advanced design.

There are meant to be advantages in long range economy/efficiency with 4 prop planes but it beyond my knowledge Certainly the safety aspect of 4 reliable engines vs 2 unreliable firecans I can understand.