On April 9, Jin left the laboratory without breakfast to conduct a test flight of the <>.
"Father, I'd like to be the test pilot.
Reiko insisted.
"Okay, please."
"Yes!"
Jin then called Hope,
"Hope, you fly the TAUBE Kai. I'll get in."
"Yes, sir."
I'm going to follow <> with <> and observe its subtle behavior.
This is possible only with a <> which flies at a low speed.
* * * * * * * * * * *
Jin's <> is waiting in the air.
Reiko then sends a message via manacam.
"Okay, go!"
< lifts off the water.
<
"Looks that way."
Observations from the air show no behavior that would cause any problems, and the < shows a stable takeoff.
"I don't see any instability on takeoff."
The Taube, Taube Kai and Taube Kai 2 have the same circular wings, but their curvature is different.
While the Taube and Taube Kai are convex at the top, the Taube Kai 2 is almost flat. Therefore, there is more loss in the airflow for lifting.
Jin increased the output power of the < for lifting.
<>
"Okay, go!"
After gaining about 50 meters of altitude, the < takes off and flies horizontally.
"Yeah, that feels good."
This is where the effect of the flatness of the circular blades comes into play.
< or is the circular wing, which is the main wing.
The speed was increased by making the wings almost flat.
The propulsion engine was the same, but the speed was increased by more than 40%.
Reiko then starts to test the mobility of the boat.
"Oh, it's quite maneuverable, isn't it?
The half of the fuselage that also serves as a vertical stabilizing plate has been made movable, and the effect of having it also serve as a rudder has been realized.
But....
As I was testing how small a turn I could make, the <> suddenly lost its attitude.
"Looks like. "Well, it looks like it stalled when it tilted its circular wing for a turn.
Jin felt a little disappointed that the emphasis on maneuverability had resulted in a considerable sacrifice of stability.
Then, after checking all the maneuverability,
"Okay, let's land for now."
That was the end of the test flight.
The <> and <> landed in the plaza in front of the laboratory.
"Well, I think this is the limit for this shape. ......"
Jin reflected that he had changed the shape of the aircraft to make it more peaky, but it seemed to have become a difficult aircraft to handle.
"I guess that's one way to look at it."
Jin's face was difficult to see, as it did not seem to have the performance that he had aimed for.
It was because it did not turn out as he had expected.
"Father, didn't you like it?"
Reiko was also a little disappointed.
"No, it's not your fault. It's a design problem.
So Jin consoled her.
"It's good for competitions, but not for daily use.
<.
* * * * * * * * * * * * *
"Hmmm, let's try another idea then: ......"
Jin had been working on an idea for a that was not a .
It is a <> with four circular wings, front, back, left and right.
The front and rear circular wings are small and the left and right circular wings are large.
The < built by Jin had <> for levitation at both ends of the main wings, which also had front and rear wings.
It is similar to what is called a < in modern Japan, but is oriented 45 degrees differently from the direction of travel.
The circular wings in the front and rear were intended to change the vertical angle, and the circular wings on the left and right were intended to change the horizontal angle for turning.
The short fuselage and cockpit are placed in the center connecting the left and right circular wings.
The total area of the four circular wings is about the same as that of a conventional <> or <>.
So, the exclusive area of the aircraft will be larger.
Since there is still time for lunch, Jin decides to make a prototype along these lines.
"Reiko, help me."
"Yes, father."
Jin asked Reiko to assist him and also called in a craftsman, and in about an hour his idea took shape.
This time, the circular wing is curved so that it is convex at the top.
After checking everything, Jin said, "It's still 30 minutes before lunchtime,
"We still have about 30 minutes before lunch, so let's do a quick test.
He said, "There is still about 30 minutes before lunchtime. After all, he wanted to try out what he had made as soon as possible.
"Well, I'll do it."
"Yes, I'll take care of it.
Reiko again stood for the position, and Hitoshi decided to leave it to her.
"When turning, change the output of the left and right blow engines. The lift and descent are done back and forth."
"Yes, that's fine."
Since the maneuvering and control of the boat was still unknown to them, they relied on Reiko's reaction time. This is an area where Hope is not comfortable.
"Be careful."
"Yes, Father."
The new attitude control system is unprecedented, so we have to be very careful. Jin calls in 50 craftsmen to set up shock-absorbing wards in case of a crash.
It was the same as the one he had put up during the air race.
"Okay, let's go!"
Reiko, let's go!
The prototype's roared to life and the aircraft began its slow ascent. .......