Thanks, Kurfurst. You make good points. Actually, I knew Germany had a four engine bomber but that it had tremendous engine problems. I did not know that Germany produced 1500 of them, however and don't recollect reading about their service. Where were they used?
The He 177s were used in almost all theatres I believe, but they could never replace the older types because of the small numbers produced.
Some were used for recconnaisance (sp? dang French word, LOL) over England in 1943, taking off from West-German air bases, and penetrating the British air space at high altitude and high speed (the Greif was quite fast, at 565 km/h!) at 30 000 ft, occasionally carrying a pair of 1 ton bombs for nuisance raids. This profile presented difficulties intercepting them, as climbing to their altitude took a lot of time. Since the climb speeds are generally very low for fighters, He 177 tactics were simply to put the big birdie into a shallow dive in which it reached 400 mph and get of of trouble while the fighter was trying to get to 30 000 feet at 170 mph indicated. I believe they were quite successfull at that for some time. Later on they were used in the West in the 1944 'Baby Blitz' in the noctural night bomber role, but flying loaded and at normal altitudes, they were much more vulnerable to night fighters.
The other major operational areas were maritime patrols chiefly against the Murmansk convoys, in which they were equipped with guided glide bombs and were employed against merchant shipping, and I recall some operations in the Med - there was a sinking of a heavily laden US troop ship by one of these with a large loss of life.
They were also used in the Eastern front in conventional daylight bombing roles (a few of the initial batch were used at Stalingrad for transport, a task it was not really suited, being a bomber with limited storage volume rather than a true transport), en masse in large formations composed of 100 bombers in 1944, but it was soon ended due to the lack of fuel. Some were used as tank destroyers(!!!) fitted with large calibre AT guns, but were generally unsuccessfull due to the sheer target surface the plane represented to ground AA - a rather silly idea, whoever come up with it
The problem was that by the time it's teething troubles were fixed, aggrevated by the sheer size of the aircraft calling for much more serious infrastructure, and the production was starting to speed up, ie. by 1944, the Allied offesive on Axis oil production was severly felt, and a result in the second half of 1944 most bomber units were grounded, and the fuel was used by the daylight fighters, since a bomber sortie was taking 10 to 20 times the volume of fuel to fly a single sortie of a fighter...
Still, the point of what I wrote earlier is that the Germans had the wrong sort of air force to attack England with. Even Fighter Command, when stretched to the limit, still had a number of squadrons in reserve in the north of England.
If memory serves, the Germans used the STUKA just one time in an attack on England before withdrawing it because it was a sitting duck to Hurricanes and Spitfires. The Germans had the right close support air force for Blitzkrieg, but not a strategic air force.
That's a bit of an old myth that dies hard.
The Luftwaffe's image is definied by the Stuka dive bomber, which was indeed a small tactical support bomber. The Stukas however amounted only a small fraction (about 20%) of the German bomber force of about 2000-2100 at the start of the French campaign, (and indeed dive bombers were rather uniquely a Luftwaffe-thing in the ETO). The vast majority was made up by conventional medium level bombers, predominantly the He 111 in 1939-40. These operated very much like the RAF's most common (and rather comparable) bomber of the time, the Wellington medium level bombers, or US B25s or B-26s.
It may be argued wheter the Germans would have been better of with heavy four engined bombers in 1940, but I doubt it. A heavy bomber's primary advantage that it can deliver effective bombload to even long ranges (as a bombers useful load is always a compromise between fuel and bombs). For short range of course the avarage heavy bomber would carry about twice the bombload as an avarage medium, but given that a single heavy bomber costs about 2-3 times as much as a single medium, requires about the same amount of crew as two mediums.
OTOH it needs a much more serious technical background, or supply 'tail', larger and better equipped airfields - frankly I doubt they would be able to re-deploy and operate these from French forward air bases as they did with the much smaller He 111 in 1940 - and of course a single heavy is easier to shot down than two mediums, so I think for the short range missions (a couple of hundred kilometers from the bomber bases at best) the Luftwaffe had in BoB, heavies would not constitute a really appricable advantage. If the same amount of resources would have been put into heavy bombers, they'd probably have 1/2 to 1/3 the number of heavies instead of mediums. In any case, nobody had heavyh bombers in meaningful numbers early in the war anyway. Heavies made a lot more sense for the US and UK later during the war (because of the range/load noted above), given that their targets were much further away in Germany, as compared to the Luftwaffe only having to literally hop over the channel to bomb targets, and it concentrated on troop marshalling yards in the Eastern Front with medium bombers, as in previous campaigns. The Soviet industry behind the Ural would have been beyond the range of any contemporary heavy bomber in any case, save perhaps the B-29, but that one was something like twice as big as the B-17, Lancaster or He 177.