Empire Conquest

Chapter 555 - 551: The Super Bomber

Early the next morning, Li Yunxiang came to wake Bai Zhizhan and then took him to the airfield.

When Bai Zhizhan saw those towering Heavy Bomber-5 bombers, he initially did not react until he approached the bombers. Only after he fully appreciated their immense size did he suddenly realize that he was looking at the largest aircraft he had ever seen, at least in terms of wing span and length.

Although they also had only four engines, these were evidently larger than the four-engine bombers of the past.

"Is this the ’Divine Eagle’?" Bai Zhizhan asked.

After Bai Zhizhan posed his question, Li Yunxiang simply nodded without further explanation.

Indeed, this was the "Divine Eagle" Heavy Bomber-5, the third model of four-engine heavy bombers obtained by the Empire’s Army Air Force during the great war.

Bai Zhizhan was well aware of this type of bomber.

The development work for the "Divine Eagle" had started before the outbreak of the war, and it was funded entirely by He Pengfei’s company, which took on all the risks.

Among those who had urged He Pengfei to finance the development of the "Divine Eagle" was Bai Zhizhan himself!

In order to win the Army’s favor and secure a mass production order, as well as to attract attention, the performance specifications set for the "Divine Eagle" at the start of the project were outrageously ambitious. For instance, the payload had to be at least 9 tons, the combat radius at least 3,000 kilometers, the maximum flying altitude over 10,000 meters, the flight speed over 500 kilometers per hour, equipped with several 20-millimeter machine guns, and armored plating had to be placed in critical areas such as the cockpit.

Such an advanced bomber, say nothing of that time, might still be beyond production capabilities even now.

The first issue to tackle was the engines.

In fact, during the initial stages or rather the concept design phase, the primary challenge was the lack of suitable engines.

In the first few design versions, six engines were used!

The reason was straightforward: even if the still-in-development 2,000 horsepower air-cooled engines, whose production timeline was unknown, were used, six would be required to meet the main design specifications of the "Divine Eagle." Using only four engines would necessitate a reduction in payload or a shorter range.

Before the war erupted, the Land Air Force certainly could not accept a bomber with six engines.

In fact, even after the outbreak of the war, the Land Air Force was not particularly keen on six-engine bombers.

Though theoretically, six engines could provide greater safety redundancy, it also meant increased complexity and a lower operational readiness rate for the bombers.

Additionally, the procurement price and maintenance costs had to be considered.

The cost of producing a six-engine heavy bomber was at least 40% more than that of a four-engine bomber, while the combat efficiency was usually comparable to that of a four-engine bomber.

The key issue was that only less than 10% of the ultra-long-range bombing missions could not be performed by four-engine bombers.

In summary, the cost-effectiveness ratio of six-engine bombers was too low.

Even if budget was not an issue during wartime, the overall costs had to be taken into account.

Excessive manufacturing costs, or high maintenance and operational expenses, meant that mass production was not feasible.

Because of this, after the outbreak of the war and obtaining military investment, the primary design direction for the "Divine Eagle" was established.

With only four engines in use, the first priority was to ensure a 3,000-kilometer combat radius, and the second was to guarantee a normal payload of at least 6 tons.

As for other performance specifications, there was room for negotiation.

Even at this point, the crux of the issue still lay with the engines.

When the main performance indicators were set, the best available air-cooled engine only produced 2000 horsepower, and its production was scant, plus it had to prioritize the needs of the Navy’s ship-borne aircraft. The key issue was that this type of air-cooled radial engine, specifically developed for ship-borne aircraft, wasn’t strong enough and had a fatal flaw for bombers, as its power output rapidly decreased with altitude, which made it unsuitable for long-duration high-altitude flights.

At that time, what could actually be obtained was a dated 1800 horsepower engine.

Clearly, if only the 1800 horsepower engine was used, then the "Divine Eagle" could not possibly achieve a combat radius of 3000 kilometers while carrying a 6-ton payload no matter what.

Even adopting an all-aluminum structure would yield performance that was only slightly better than the previous model of heavy bomber, nicknamed "Pegasus," the Heavy Bomber-4. There wouldn’t be a substantial improvement, and because the cost definitely couldn’t be reduced, it was unlikely to replace "Pegasus" and secure large-scale production opportunities.

Don’t forget, electrolytic aluminum isn’t cheap, and bombers using an aluminum structure would definitely be very expensive.

As such, for over a year after the outbreak of the war, or rather around one year after obtaining military funding and officially becoming a military equipment project, the "Divine Eagle" remained in the conceptual development stage, mainly waiting for engines and trying to reduce production costs.

Some design variants even used wood to replace aluminum!

Considering the Bulan Royal Air Force’s several wooden aircraft models, their main performance wasn’t too bad while significantly reducing costs.

As for high-quality timber, it was not a problem at all for the vast Empire.

Not to mention anything else, the Extreme North region of the Empire was almost entirely primal forest.

Of course, the fundamental solution still involved working on the engines.

Until now, the Empire’s large air-cooled engines had not entered the mass production phase.

According to the plan, the specifically developed 2400 horsepower twin-supercharged air-cooled engine for the "Divine Eagle" was set to enter mass production in the fourth quarter of the New Calendar year 103.

Fortunately, a replacement for the engine problem was found in the Tiaoman Empire.

The Tiaoman Empire had a type of engine that reached close to 3000 horsepower, namely the DB610 series used in the He-177 twin-engine bombers.

This compound supercharged liquid-cooled engine had many problems, such as extremely poor reliability.

Because of this, the production volume of He-177 had always been low, and its operational range was severely limited.

However, the Land Air Force had no better choice.

When introducing this engine, upon the military’s request, the manufacturer taking on the production made some adjustments, mainly removing the second-stage supercharging system to improve engine stability. As a result, the engine’s power output dropped directly to 2200 horsepower, and its high-altitude performance was very poor, which also limited the service ceiling of the heavy bombers that used this type of engine.

However, a gap of 200 horsepower and significantly weaker high-altitude performance actually weren’t issues.

At least, this was a high-power engine that could be acquired immediately and for the time being only compatible with the "Divine Eagle."

Another key point was that the production was undertaken by small manufacturers.

Because the application range of large liquid-cooled engines was extremely narrow, when the decision to introduce a license was made, domestic large engine factories refused the collaboration invitations on the grounds of saturated capacity. Therefore, the military had to step in and organize several small manufacturers to undertake joint production.

To this end, the military even dispatched experts to provide technical support for the manufacturers.

The benefit was that there was no need to compete for production lines with other engines.

Because of this, in June, the "Divine Eagle" received approval from the Land Air Force to officially enter the mass production stage, with an initial order quantity of 500 units.

To ensure production speed, the first batch of 500 units were not prepared for future retrofitting.

If additional orders were needed, starting from the 501st unit, adjustments would have to be made to the engine attachment points on the wings to facilitate the replacement with the 2400 horsepower air-cooled engines in the future.

Now, the 20 units that have been delivered are all in Sri Lanka.