When it comes to weight loss, that's Jiro Horikoshi's forte.

On the "Type 96" carrier-based fighter, he had already done it once.

In the spirit of "craftsmanship", the designers put forward every part.

No matter how small it is, as long as it is within the range of strength, it should be weakened and thinned as much as possible.

This time, of course, was no exception, and Jiro Horikoshi was a clear member of the design team.

"For each stressed part, the minimum range of strength necessary should be calculated as accurately as possible, and the weight calculation should be accurate to 1/100,000 of the fuselage."

The total amount of 12 test carrier-based fighters is estimated at 2,300 kilograms, in other words, to be accurate to 23 grams.

Surprisingly, Jiro Horikoshi's first goal turned out to be a naval design plan.

Traditionally, the fuselage load-bearing parts of naval fighters have been set to a strength factor of 1.8.

In other words, the component remains unbroken even at a maximum force of 1.8 times.

However, Jiro Horikoshi decided that it was unnecessary, and he changed the coefficient to 1.6.

Surprisingly, when the navy learned about this, it did not lash out.

I didn't invite Jiro Horikoshi to the gendarmerie for tea, and talked about long-term accommodation by the way.

After getting the tacit approval of the military, Jiro Horikoshi became more and more emboldened.

In line with the principle of "if there is weakness, there is no need to be strong", the design team tried to reduce and thin the parts as much as possible.

It used to take 10 rivets, but now it uses 8.

The diameter of the rivet is 3.5 cm, so change it to 3 cm.

If the thickness of the skin is 1 cm, then change it to 0.8 cm.

That's not all, Jiro Horikoshi still moved his hands and feet to the wings.

The spar needs to support the upper and lower skins of the wing, which requires considerable strength, and reducing the thickness of the material is certainly not an option.

After precise calculations, the R&D team made a number of round holes in the spar to reduce the overall weight of the wing.

But even so, the weight still can't be controlled at 2300 kg.

Just when Jiro Horikoshi was at a loss, he received good news.

Sumitomo Metal Corporation has developed a new generation of duralumin materials.

As early as around 34 years, the country was able to produce "dura aluminum" in China.

This was called "Super Aluminum Alloy" at the time, or "SDH" for short. The tensile strength is 45 kg/cm?.

At this time, Sumitomo Metal developed an aluminum alloy with higher strength, which is called "super super aluminum alloy" in China, referred to as "ESD", and the tensile strength can reach 60 kg/cm.

Jiro Horikoshi immediately used "ESD" on the spar, but he did not expect that the strength of this super duralumin alloy was really good, but it had a big disadvantage of "easy fatigue," which would cause a lot of trouble in the future.

But now, Horikoshi Jiro did not know that in order to increase the flight speed, the new aircraft abandoned the usual fixed landing gear and replaced it with a single-wheel landing gear that could be retracted, which was the first time in the history of the Japanese fighter jet.

On July 11, 1938, a full-scale wooden model of the "12 Test Carrier-based Fighter" was submitted to the Navy for acceptance.

The first impression of the test pilot was that it was actually big, and there were no other opinions.

In this way, the overall scheme of the "12 test carrier-based fighters" was successfully passed.

But just as the design team moved to the prototype manufacturing stage, the Navy jumped out to find trouble.

"The engine of the 12 test carrier-based fighter must be changed to the Rong 12 type of Nakajima Aircraft Company!"

The take-off power of the "Rong 12" engine is 940 horsepower, and the maximum power at an altitude of 4200 meters is 950 horsepower, which is a little better than the "Rising 13".

When the news came, Mitsubishi was in an uproar.

The whole design scheme was developed around the "Rising Star", and now suddenly there is a different engine, which requires a lot of changes to the scheme.

But the damn Naval Aviation Headquarters didn't make any prompts, isn't this a monkey game?

Jiro Horikoshi's design team finally has a deeper understanding of the arrogance of the Japanese military.

But in order to avoid being called into the gendarmerie, or wearing the hat of "non-national", they can only swallow their anger.

However, the military made some concessions for the first time.

Prototypes No. 1 and No. 2 could use the "Ruixing" engine, but on the No. 3 machine, in any case, the "Rong" engine would be used.

In fact, the navy of the Japanese country did not make a mistake this time.

The "Rong" series engines have excellent reliability, excellent maintenance and moderate output power, which ensures the flight performance of the "Zero Battle".

Until the second half of 1942, the "Rong" engine had a leading position, and it did not lag behind in the following year.

The real backwardness was in the second half of 1943, and the reason for this was the increasingly conservative style of the top brass of the Japanese Navy, which affected the research and development of the "Zero Battle" replacement aircraft.

On March 18, 1939, the No. 1 prototype of the "12 Test Carrier-based Fighter" was completed.

The empty weight of the aircraft was 1569.5 kg, which was slightly more than the calculated value, but this was the result of the addition of 55 kg of equipment.

It can be said that the calculation and manufacturing are already quite accurate.

On March 23, the No. 1 machine was dismantled and moved to the "ox cart", a vehicle with a long history.

With the accompaniment of "squeak and quack" all the way, I came to Kamubara Airport.

With a series of experiments, the "12 test carrier-based fighter" did meet the design requirements, so it received the official project designation "A6M1". ”

But in the following static tests, the plane had big problems.

At that time, the test methods were quite primitive, one was to rely on wind tunnel blowing to detect the problems that would occur when flying at high speeds.

The other is to use bags filled with lead pellets and pile them on the body to simulate the state of force until the parts break.

The tail of the Type 12 carrier-based fighter has sufficient strength, and it only breaks when it is 2.4 times.

The body part is terrible, and when the upward flexion reaches 0.8 times, the skin begins to fold and deform. 1 times is already overwhelmed.

At 1.6x, the wing undergoes severe deformation.

Even worse was the landing gear, where technicians hoisted the plane to a height of 40 centimeters and let it land directly.

The strong impact force instantly broke the ribs at the root of the left wing landing gear.

After the tinkering, a second test was taken.

The result was just as bad, and the other wing ribs were broken.

This incident caused a great controversy at the Naval Aviation Technology Factory of the Japanese Navy.

The technicians demanded that Mitsubishi should build another prototype for static testing.

However, Captain Toshio Kotani, who presided over the test, vetoed it.

"Where the strength is insufficient, strengthen it, first smash this one completely, and come up with a complete plan."

In this way, at the beginning of 1940, the "Type 12 carrier-based fighter" passed the tests of the Naval Aviation Technical Plant.

At this time, the item number was also changed to "A6M2." ”

Its performance fully meets the design requirements, and after it was delivered for trial, it was also well received.

The whole Mitsubishi company felt that the design was completed, and even Jiro Horikoshi took over the "Type 14 Local Fighter" project.

A sudden news, but it disrupted everyone's position.

Prototype No. 2 disintegrated in the air, test pilot died!