Originally, Wilhelm had intended to replicate the American B-17, but since the United States had started developing and test-flying the B-17 several years ago, he would be ridiculed if he produced an identical design.
After much contemplation, he recalled that Germany had its own heavy bomber, the He 177.
Due to limited oil and personnel resources, the German Air Force had always been a massive tactical force. Despite its large size, it remained at the tactical level.
Possibly influenced by Stuka's outstanding performance, the German Air Force's obsession with dive bombing reached a level of fanaticism.
Certainly, there was some reason behind this obsession. Due to the limitations of the era, the bombing accuracy of horizontal bombing was frustratingly low. Even Germany, renowned for its optical instruments, did not have a good solution for bombing precision.
During such times, dive bombers capable of precise destruction, especially of bridges or fortifications, became a kind of faith for the German Air Force.
Regardless of whether it was an obsession or a faith, requiring all bombers in the German Army to have dive-bombing capabilities was a bit excessive.
Driven by their preferences, the high command of the German Air Force demanded that all bombers equipped by the German Army must have dive-bombing capabilities! Ernst Udet, the then Director of the German Aeronautical Technical Bureau, even believed that bombers without dive-bombing capabilities were not worth producing.
Under this unreasonable demand, the He 177 bomber adopted a coupled twin-engine layout—installing two engines on one side of the wing but driving only one propeller. This made the four-engine heavy bomber look like a twin-engine medium bomber from its external appearance.
It's not hard to imagine how unreliable this coupled twin-engine arrangement was.
Firstly, the engine compartment space with coupled twin engines was already very small, and the hydraulic device of the landing gear had to be squeezed inside, resulting in hydraulic oil leaking out and igniting upon contact with the hot exhaust pipe. Secondly, the return oil pump was too large, causing oil to generate bubbles and foam when flying above 6000 meters, leading to lubrication failure. Thirdly, there were leaks in the high-pressure fuel injection pump. Additionally, the engine's position was too close to the fuselage, lacking sufficient space to install fire-resistant partitions. The proximity of various electrical circuits increased the risk of the engine catching fire in the air.
Among the 8 prototype aircraft manufactured by Henschel, 2 crashed due to engine fires (He 177V4 and He 177V5); others frequently experienced issues like mid-air fires or engine overheating. Therefore, people mockingly referred to the He 177 as the "airborne lighter". This terrible performance led to complaints from pilots, and few liked flying it into battle.
Even Field Marshal Göring had to admit, "Having a four-engine bomber dive is simply absurd!" However, despite the regret, Göring did not order a change in the design of the He 177; the entire German Air Force did not express a strong demand for heavy bombers. It can be seen that deeply rooted traditional thinking is not something that can be changed overnight.
However, Wilhelm had dismissed the short-sighted Ernst Udet early on, instructing the He 177 to adopt a separate four-engine structure similar to the American B-17, significantly improving engine reliability.
Moreover, he had secretly "invited" the chief designer of the Rolls-Royce "Merlin" aircraft engine from the British Empire several years ago. With everyone's collaborative efforts, the performance of German aircraft engines had now overcome the limitations of the original time and space.
As for various scarce resources limiting production, there had been significant improvements. Poland in later years became a world-class copper mining area; tungsten mines in Austria were already in operation; Libya's oil could enter large-scale production at any time; Romania was a veritable treasure trove, with nearly 80 types of minerals being mined, including iron, manganese, copper, uranium, gold, silver, molybdenum, and more. Even Hungary, with relatively poor natural resources, possessed a substantial amount of bauxite, ranking third in Europe in terms of reserves.
Adding various rare metal ores imported from Ming and the Soviet Union in recent years, Germany's current resource reserves, while not exactly abundant, are at least no longer a cause for worry.
With the engine issues resolved and a significant improvement in the overall performance of bombers, which was well-received by the Air Force, they have entered the mass production phase.
As mentioned earlier, while the battle in which German paratroopers parachuted onto the Eben-Emael Fortress was considered classic, Wilhelm decided to use a different approach this time.
He planned to use the last remaining Grand Slam to deal with the Eben-Emael Fortress.
Just breaking dawn, a He 177 bomber carrying a Grand Slam bomb, accompanied by four Stuka bombers, leisurely flew over the Eben-Emael Fortress under the protection of twelve Bf 109s.
Indeed, leisurely, because the Grand Slam bomb weighed a whopping ten tons, and the He 177 couldn't pick up speed even if it wanted to. To accommodate this giant, the He 177 underwent special modifications. The turrets on the aircraft's back and nose were removed, some armor was dismantled, the bomb bay door was eliminated, and a huge area was hollowed out in the belly to suspend the bomb, with the bomb rack being specially reinforced.
Not only the aircraft, but the Grand Slam bomb also underwent special modifications.
It's worth noting that there are many problems with high-altitude bombing. In theory, when a bomber drops a bomb, due to inertia, the bomb has an instantaneous forward speed identical to that of the bomber. Therefore, the trajectory of the bomb dropping resembles the trajectory of projectile motion, also known as a parabola.
However, various influencing factors exist during this process, such as the state of the carrier aircraft, the impact of aircraft vibrations on the initial state of the bomb, the effect of wind on the bomb during flight, and so on. The bomb's descent trajectory is by no means a complete parabola. When the bomb falls from several kilometers high, it's impossible to predict where it might deviate.
Therefore, before the advent of advanced computer-assisted systems and guided bombs in later years, carpet bombing was used to increase accuracy. When it seemed close to the target, a bomb was dropped every certain distance to carry out extensive blind bombing over the target area, turning the entire land in the target area like farmland.
However, for large bombs like the Grand Slam, it's impossible to use them for carpet bombing. Therefore, German engineers equipped this Grand Slam bomb with a control system, allowing the bomb to change its flight attitude in the air.
This wasn't Wilhelm's idea. Engineers from the original time and space of Germany had long studied precision-guided weapon systems and even developed two "smart bombs" called "Fritz X" and "Hs 293". The "Fritz X" bomb was equipped with the FuG-203 "Keel" III/FuG-230b "Strasbourg" type guidance components, featuring a unique gyroscopic stabilization. During combat, the carrier aircraft controlled it through radio signals to the electromagnetic-driven control surfaces mounted on the tail, achieving a hit rate of over 90% within a 30-meter radius of the target.
"Approaching the target, prepare to drop the bomb!"
The accompanying Stukas roared down, blasting the four anti-aircraft machine guns of the Eben-Emael Fortress to pieces.
Inside the He 177 cockpit, bombardier Daniel pressed his eyes against the eyepiece of the bomb sight, staring intently at the target below. As the target entered the bomb release reference point, he forcefully pulled the lever.
"Drop the bomb!"