Dive brake indicator on D3A1 Val

[JOVE23]

Hello everyone,

This is an excerpt from a much larger photo taken by the Navy of the Val that was recovered from Middle Loch after the Pearl Harbor attack.

I am trying to build a 3d model of this plane (cockpit included), but this dive brake indicator has me stumped. How does it work? Is there another one still in existence somewhere in better condition that might show me what the indicators look like? I'm 95% sure they are not lights but some sort of insert that moves into/out of position depending on the position of the dive brakes but if someone has more insight I'd love to hear it.

Thanks!

 

[VERSUCH]

I brightened your picture, so you can decide..

Regards Mike

 

[Shinpachi]

This is D3A's hydraulic system for the flap & dive brake introduced in Mechanic of World Aircraft.

 

[JOVE23]

Arigatou Shinpachi san! Have you found any images of the indicator mechanism? I would like to know how the display works, whether it is by lights or by mechanical indicators. I'd also like to determine the purpose of the little tabs by each set of cutouts.

 

[Shinpachi]

No more data available at the moment but a fact that pilots were nervous about the simpler indication of the dive brake angle on the indicator as well as brighter pilot lamps. This is why the dive brake indicator was changed to the analog scale type for the D3A2 from the initial 'digital' on-off (on=90°, off=0°) type for the D3A1.

This is just my guess but the additional plate which holds 4 square holes and 2 tabs on the dive brake indicator of your photo would be a sort of color filter to reduce the light bulb brightness with red for 'on' and blue for 'off'.

 

[JOVE23]

Arigatou! Would you consider it to be red lights up top and blue lights on the bottom? or should it be reversed?

 

[Shinpachi]

Yes. It ought to be red lights up top and blue lights on the bottom as an IJN's rule.

 

[JOVE23]

And would it be an actual blue light or just blue light covers and yellow light bulbs to make green ish light?

 

[Shinpachi]

This is IJN's original blue. Light bulb has no color as we call it a 'white' bulb even though it may look yellowish.

 

[JOVE23]

Ohh, so the port and starboard wing tip lights and red and blue and not red and green like US?

 

[Shinpachi]

Strictly saying, it should be blue for the old Japanese aircraft but it is no wonder even though a green filter was applied because the Japanese word "Ao (青)" involves both blue and green traditionally. You will find two versions of "Ao" for the traffic lights in Japan even today. I don't mind whichever, though .

Tachikawa Ki-54's original color filter

Source: 翼端灯 一式双発高等練習機 | Summer Snow

Traffic lights in Japan

Source:

信号機の色はなぜ「赤・青・黄」？なぜ緑ではなく青と呼ぶの？の写真（1枚目） by 車選びドットコム

信号機の色はどうして「赤・青・黄」なのか。そしてなぜ青信号は緑色となっているのか。当たり前の様に普段目にする信号機ですが、違う色の信号があってもいいと思ったことはありませんか？今回は、普段当たり前としていた何気ない疑問を解決します。の写真（1枚目）

car-me.jp

交通信号機　左から「青色、黄色、赤色」の配列や順番の理由、緑なのになぜ「青」という？

日本では横型の信号機の場合、いずれも左から青、黄、赤の順になっています。縦型は上から赤、黄、青の配列。この配列や点灯の順番は、何が根拠になっているのでしょうか。

bike-news.jp

 

[JOVE23]

Thank you!

 

[Maty12]

Strictly saying, it should be blue for the old Japanese aircraft but it is no wonder even though a green filter was applied because the Japanese word "Ao (青)" involves both blue and green traditionally. You will find two versions of "Ao" for the traffic lights in Japan even today. I don't mind whichever, though .

Fascinating stuff! I had heard from an old Tom Scott video on linguistics that a lot of cultures consider green and blue to be different shades of the same color, but never thought about how Japan or their aircraft might factor into this.