Goh and Rubina were working on the specifications for the .

Let's start with the direction.

Let's start with a rough idea.

"Yes, let's start with a rough idea. As far as I'm concerned, I'm thinking of making a compact and maneuverable machine.

"That's fine.　It's not a fighter plane, so there's no need to put extra armament on it.

"That's right. I hope it will become popular among the general public.

Rubina said that she wanted to make a mild aircraft that could be owned by the general public.

Goh agreed.

"Then what about the crew?"

"Maybe three ....... Goh, you, me, and Mel on top of that.

"I guess so. ...... Hey, let's make it comfortable too."

"I'm all for it."

Looking at Merce's face, the two of them realized the importance of .

"...... So, how are you going to control it?"

"My idea is to make a plane that can be flown by me and Goh.

Rubina said, "I want it to be easy to fly, so that it doesn't need a dedicated pilot.

Goh, however, looked reluctant.

"Well, I understand what you mean. But I think it will be difficult for ordinary people to pilot it.

"Is that so?"

"Well, there is such a thing as a pilot, and people make mistakes."

"I see. ...... I was thinking of using an to assist in that regard."

The role that has been taken by golems and automata is now to be controlled by a computer.

We want to have a control brain that can correct us if we make a mistake, and in some cases, we want to leave it all to them," Rubina said.

"I think that's a good idea. But you can't do it out of the blue without accumulating data."

It would have to have a processing speed like Reiko's, Goh said.

"I see. ......"

This exchange of ideas led to the specification of the prototype ......, or rather a joint production machine.

"Shall we put two engines in it?"

"That will give us more room.

"Do you still want a delta wing?"

"I want to, but don't you want to use ......?

"No, I don't think so."

The specifications were almost finalized by 9:00 p.m. The next day, after breakfast, I immediately went to the office.

The next day, after breakfast, Goh and Rubyna decided to go to their respective bedrooms to start work immediately.

March 9.

March 9.

Rhodes and his team are conducting a survey of the Sitong River.

After finishing breakfast, Goh and Rubina went to the workshop and saw a pile of materials that Jin had prepared for them.

"What is this ......?"

"Jin-sama prepared this for me. ......"

"If we have this much material, we might be able to make three planes. ......

The most common type is light silver. In recent years, as smelting has become easier and the amount of silver in circulation has increased, the price has dropped to 20 tol (about 200 yen) per kilo.

Still,

"There's about ......5 tons of it."

Even though it is cheaper, 100,000 tons ...... are worth about one million Japanese yen.

There were also a few ingots of mithril silver, adamantite, aluminum, copper, zinc, magnesium, and tin.

"If Jin-sama expects us to do so well, we must do our best!

"Yes, that's right."

So the two began work on the framework of the fuselage.

Since it was a prototype, no monocoque or semi-monocoque structure was used. It would be too difficult to modify even with engineering magic.

The two build the framework using 64 light silver.

Ruby and Amezu, the five-colored golem maids, are assisting them, so they are able to do the heavy work efficiently.

Incidentally, the workshop is too small for them, so they are assembling the frame in the tent they have pitched in the garden.

"Wow, it's amazing.

"This is just a prototype, but when the final model is completed, the three of us will fly together!

"Yes, Ruby, Mr. Goh, I'm looking forward to it. Good luck!

"Thank you!"

Merce, who has been trained by Elsa in the etiquette of an aristocrat's daughter, occasionally visited the workshop during break time.

In response to their encouragement, the two completed the framework in the morning.

The aircraft is rather small, measuring 12 meters in length.

The overall width is 8 meters. It is a delta-wing aircraft, so it has plenty of wingspan.

"Yeah, it's good...we both made progress...I'd give it an 85."

When the framework was complete, Jin came over to do a general check.

There were no weak points or loose joints.

In fact, there were parts that were excessively sturdy, but Jin did not comment on them.

Jin-sama, where is the point you deducted?

"There are about 10 points because it is a prototype. But that's about the same as I would get if I did it myself.

But Jin-sama is a one-man team, and I'm sure his production speed is not as fast as ours.

That's true.

If the two of them were on the same level as Jin, Jin would have nothing to stand on.

He then told them that it was almost time for lunch.

* * * *

Lunch was sandwiches.

There were standard sandwiches such as ham, egg, and cheese sandwiches, as well as a few variations such as croquette, mixed vegetable, and bacon and egg sandwiches.

There were also fruit sandwiches, cream sandwiches ...... and desserts.

Some of them were made by Meltze.

"Can you guess which sandwiches I made?"

"Well, you'll know when you try ...... one."

"I guess so."

Before she could finish saying "Itadakimasu", Rubina put the cheese sandwich in her mouth.

And then,

"This is it."

Rubina said.

Meltze laughs and says, "That's the one.

Goh then ate a bacon and egg sandwich and said, "This must be the sandwich that Melze made, too.

Goh said, "You're right, too.

The rest of the sandwiches were made by Yenny.

The lunch was a harmonious scene.