"Well, I didn't have much time last time, and there were many more questions I wanted to ask you.

"I don't think we'll have enough time this time either. ......"

Elena and Arnold continued their conversation from the previous session.

"I know you had a bad time, Sienna, but I respect you.

"You said that the other day, I am very happy to hear it. There were very few people at that time who understood the greatness of your mother.

"Sienna's design philosophy is based on ......."

Your mother was ...... at the time.

"Then Elena was ......"

"Arnold was ......"

Their conversation heats up to the point that even an observer can tell that they are talking about the same thing.

Jin thought that it was not unreasonable since it was the first time he met someone with whom he could talk as much as he wanted, so he decided to let them do as they liked for a while.

However, Delphina, Rorona, and the other members of the rolled their eyes and looked a little surprised. .......

* * * *

The conversation between Arnold and Elena seemed to go on forever,

"Elena-sama, it is time for you to go.

Alietta Aeolial, one of the attendants, called out,

"Oh, I didn't know it was that time already. We've been talking so much.

Finally, the conversation came to an end.

"It's a pity. I would have liked to have talked with you longer.

Elena got up from her seat.

"Arnold, maybe some other time."

"Yes, another time, another time."

Elena then left the laboratory.

"......What is it that you came here for, Elena?"

Jin replied to Arnold.

"It's a little late for that, isn't it? <

"Oh, I see!"

"I explained it to Arrietta-san, Katya and I explained it to her.

I'm sorry. Thank you, Jin.

"I'm glad I listened to you earlier."

Jin laughed.

Jin smiled.

"Well, there are a few things I wanted to tell you while Jin is here.

"What is it?"

Arnold said, and former members of the Gor Institute, including Eira, Katya, and Gromma, as well as Zora Himmel, Ciel Azure, Lois Eisker, and other former members of the Aeronautical Research Institute, gathered around them.

Around them were other researchers, and in short, most of the members of the < gathered.

"The talk was about the operation of the rocket engine," he said.

"I thought you might be right."

"Yes, and I'd like to discuss the effective use of the wind shield.

I see.

The faster an aircraft tries to fly, the more the air resistance becomes negligible.

One solution to this problem is the wind shield.

"With this, I believe that speeds in excess of 1,000 kilometers per hour are not just a dream."

"Perhaps."

The aircraft on Horai Island have , so using <> will reduce the air intake efficiency.

Therefore, they use <> to generate sonic and supersonic speeds.

In other words, Arnold and his team, who are aiming for supersonic speed using only propulsion-type engines, are trying to go ahead of Horaijima in this respect.

"How the maximum speed will change depending on the shape of the <> is an issue for the future."

"I suppose so."

"But I also think that the shape of the aircraft itself is important.

I think so too.

Jin agrees with Arnold's opinion.

"Goh and Miss Rubina's was a sophisticated machine," he said.

"It's the delta wing that Rubina kept building."

"Yes. Continuity is important.

Arnold said he respects Rubina's work.

"I think the shape of the wing is a big factor when it comes to generating lift in flight."

Yes.

Stability and mobility are opposites.

"That's right."

Most of the aircraft on Horai Island are piloted by , so their maximum acceleration and maneuverability are literally of a different dimension than those for humans, so they cannot be used as a reference.

Even Jin's beloved aircraft < can be piloted by him since it is assisted by his magical brain.

Aside from that, the main purpose of <> is to develop airplanes for human passengers, so its direction is different from that of the aircraft in Horai Island.

"But I also think that it is our role to develop practical aircraft first."

"When you say practical ......, do you mean a speed range of around 400 kilometers?"

I agree with Jin.

The maximum speed is over 800 kilometers per hour, but it can be practical at much lower speeds.

Since it is not a jet engine, it does not need air intake. This means that there is no chance of something getting sucked into the air intake and clogging it up, which is a big advantage.

"Apart from Jin's and Lady Machina's , isn't the maximum speed of an ordinary airship about 200 km/h?"

"Yes."

The larger the air sacs, the greater the air resistance, and the higher the speed, the more deformation of the air sacs becomes a problem.

In this respect, an all-metal airplane has such a high speed limit.

"It's difficult. We haven't decided on a clear plan yet."

"You haven't?"

"Yes. ...... For example, I think there is a direction to build a very large airplane of about 50 meters in length and fly it at about 500 km/h. I think that's the way to go.

"I see."

That's the direction of the , Jin thought to himself.

"Or something with a capacity of about 10 passengers."

Jin thinks, "That's in the lineage of private jets or business jets.

"Or a two- to three-seater with a top speed of about 800 kilometers per hour."

Jin thinks, "It's a small aircraft of the fighter jet type.

"Well, which one do you think is best?"

"I'm not the one to ask. ......

Jin smiles wryly, but still, since he has been asked, he is willing to share his opinion.

"With that kind of speed for personal use, it would be for an airplane classified as an attack aircraft, wouldn't it?

"Yes, I see.

"The larger size would have runway problems and would compete with airships."

What do you mean?

I think we should start with a mid-size plane.

That's what you think?

I guess so. If I may add, it would be better if we could also develop an attack aircraft for the World Guard.

"That's very helpful, Jin. Thank you.

<.