A large aircraft for <>.

Jin's idea was also an airship.

Elsa and Hannah heard his mutterings.

"You like airships, don't you?

"Why, you were making airplanes at first...?"

They both asked if Jin's tastes had changed.

"Oh, no, I don't."

Jin shook his head in denial.

"In the first place, <> can only be used in the air, and they don't generate lift if they are stationary. In other words, it can only fly if it is constantly moving.

"Right."

"Yes, that's right."

"In the early days, we built airplanes that used the Magijet engine as a propulsion system, but after we learned about gravity magic, we were able to separate from ."

"Oh, so that's how it is. In your world, there was no magic, so you needed a balloon or an air sac to float, but with magic, you can float more easily."

"That's what I meant."

"...... and the air resistance is not so much about the shape as it is about the <>."

Both Hannah and Elsa seemed to understand what Jin meant.

"Besides, wings are necessary to float, but they also create air resistance. ...... If you make them smaller, stability at low speeds will deteriorate. ...... Or rather, they won't be able to fly."

"Indeed . If you make it bigger, it will be more aerodynamic and heavier."

"......Well, I know only the rudiments of aerodynamics, so I'm not sure what the aircraft researchers might say about that."

"I get it."

"So that's what you meant."

The two nodded in satisfaction.

* * * * * * * * * * * * * * *

"...... So, I'm going to build a medium-sized airship-type plane.

In his workshop (dock), Jin presented his concept.

The operational image is that of a sightseeing bus.

"It will seat up to 30 passengers. < and some guests who may or may not show up."

"Hmm."

Elsa, Hannah, and Reiko are listening to the conversation, along with the 1 to 3.

"It's 30 meters long. Diameter is 6 meters. <

The shape is cigar-shaped. The cabin is shared with the main body, so it does not protrude downward.

It is completely airtight and watertight, so it can dive underwater and go into space.

"The propulsion system is a . The levitator is a . It is equipped with a retractable stabilizing plate for use in the atmosphere and underwater."

At this point, Erza asks a question.

"Is it safe?"

"Yes. I'm thinking of two warp gates with independent and two transfer magic circle.

The magic circle is activated stand-alone and does not need to be supplied with magic power.

"We will also carry ."

I'm also thinking of adding a parachute and hang glider for personal use," Jin concluded.

"I see."

You are very thorough.

"I'm going to focus on safety as much as possible."

And the materials.

"The main material is 64 light silver, since it is an aircraft. The key areas are reinforced with magi adamantite."

The transparent part is made of laminated corundum and ground spider resin (GSP).

The interior is based on a spaceship.

"...... is what it looks like."

After explaining the detailed specifications, Jin started to create a <>.

* * * *

<> is, in essence, a blueprint for engineering magic and data for processing.

The image is a three-dimensional blueprint with annotations such as processing methods and magical processing to be given.

All Golem automata created by Jin and Jin are compatible with this format and can read them.

In other words, on Horai Island, as long as you have this <, you can mass-produce as many of the same thing as you want.

Since this time is half of Jin's hobby time, he is going to make it slowly and carefully.

However, the engineering magic that Jin uses is out of the ordinary.

He is able to transform a 30 meter long piece of material into a given shape by < at once.

And since this is a dedicated workshop (dock), it is equipped with cranes and lifters that use gravity magic, allowing it to be lifted and assembled with ease.

This time, however, > and Reiko were doing the assembly, so Jin was able to concentrate on the machining.

"You're a good girl as always, aren't you?"

"Hmm."

Elsa and Hannah like to watch Jin making things.

Hannah has been doing it since she was in Kaina Village, and Elsa since she started learning engineering magic on Horai Island.

It's just, you know...

huh?

Both of them know that Jin tends to forget to eat and sleep when he is absorbed in making things.

So..,

"Brother Jin, it's time for lunch."

"Onii-chan, stop for a while!"

(Reiko is in charge when they are not together).

"Oh, is it that time already?"

Jin, too, would stop at the end of the day when he heard such a call.

* * * *

Today's lunch was soaked in hot water.

The leftover cold rice is put together and heated in an earthenware pot with water.

It is almost porridge.

It is easy to digest, which is good in the cold season.

In Horai Island, however, the lowest temperature rarely drops below 15 degrees Celsius even in winter.

The food is served with tsukudani (food boiled in soy sauce), oshinko (pickles), furikake (sprinkled on rice), etc., according to one's preference.

Jin prefers wasabi-flavored furikake.

Erza likes tsukudani of kelp and Hannah likes takuan.

Since Reinhardt has gone to Hale, the three of us are the only ones on Horai Island now, and we have a quiet lunch.

* * * * * *

"By the way, what color are you going to wear?"

Hannah asked over a cup of tea.

The exterior is made of 64 light silver, so the color can be changed freely by the oxide film.

"I hadn't thought of that. ...... Can't we just use silver?"

"I don't think so."

"What about the name, Brother Jin?　I guess it depends on that.

"Oh, I see. ...... name or ...... name."

Jin thought for a moment and then said,

"How about <>?"

Jin thought for a moment and then said, "How about <>?

He came up with this name because the airship-type aircraft in Ars is a <>.

"It means a storm or a tempest," he said.

<> also means the same thing (a tropical storm that occurs in a particular place).

"Hmm, not bad, maybe."

"Then the color is ...... difficult."

"Hmm, sure."

The three of us pondered.

It was a peaceful moment.