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How I build my own cockpit ?

Courtesy light .

After the completion of the concealed space for the visual system. I was suddenly confronted with the fact that I didn't have enough light inside the cockpit to fly properly any more. I could barely read the text on the overhead panel and reading a map was almost impossible. So it became clear the we needed to tackle that problem. But how was a DC3 cockpit lit at that time?
So it was time again to go and visit the documentation centre of the aviation museum in Brussels to pit up my light. It was already quite a while ago that I made a visit to them. I was surprised. With the little manpower and money they have, they transformed the documentation centre in to a real library and put all the documents in second hand role cupboards. So they made some free space to put in new documents. I can assure you they still have so many documents that it will take them for ever to get it sorted out. And every year they receive tons of papers. So the amount of documents available is only the tip of the iceberg. I found no new technical information of the DC3 it was still the same technical info as before, but is more than adequate for me. We are drifting of here. Back to the point.
After some investigation in the parts manual I found a page with a technical drawing of the inside lightning system of a Dakota an no 1937. It exist out of 5 lamp holders wit a red filter and individual light regulator and three dome nuts for black-lights.
No, this black-light wasn't used for disco light or to create a more 'in the mood' atmosphere inside the cockpit. It was at that time on of the most sophisticated and efficient panel lighting you can imagine.
How does black-light work? Through the black fosfor coating of the lamp it spreads UV-A light, what is invisible for the human eye, together with a bluish violet light what you can see. When the UV-A light comes in to contact with a fluorescent surface it is turned in to white visible light. Big advantage of this system is , that you are not blinded by it and is invisible from the outside. Unless of course you put up a big smile and glow in the cockpit with a white shirt. For military purposes very useful, seen and not being seen. All faceplates and pointers of the analogue instruments were marked with fluorescent powder what perfectly lit up. It even stayed on glowing when everything was turned of.
Most of use only now black-light in the tubular form but it also exist as a glow lamp. Big disadvantage of the glow lamp is the worming up of the coating. Because the energy of the white light is being absorbed by the black fosfor coating and turned on in to heat, the lamp becomes so hot the she would only last for one hour on full power. There for the lamp is always used on half of its capacity and even then it becomes very hot. There fore they soon changed it to strip lights what is cooler light on its own. So fare for the theoretical part.

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Lamp holder:

Like usual the lamp holders I needed for the cockpit light are almost no where to find. So the only solution was to build them myself. First we started by making a technical drawing.

techlamp

 

 

 

 

 

 

Next we made the round hood for the back. We made this as follows. We started by making a tamper and a mould out of iron. In the mould we put in a pin that fitted in the hole of the tamper. By this the metal plate couldn't move in the mould when it was made. So we made every time a perfect copy of the mould.

lamp1

 

 

 

 

 

 

 

Afterwards the rounded plate is turned and a rim of 1.5 cm is welded on.
To make the lamp holder movable in all directions we have chosen to make a ball joint out of a round bar of 1 cm. The lamp is placed on a L shape thin metal plate of 8mm in inox where we have put on a MES socket. This is so placed that the lamp is positioned right in the centre. Over the lamp we then placed a tube made from a empty silicone cartridge.

lamp2

 

 

 

 

The tubes were cut into two lengths. Three tubes from 8cm and two from 6 cm.
This to ensure to have a better light bundling because the lights are positioned in different distances from the panels. In the front of the tubes we glued in a ring and put in a red filter. This was then all painted in black. It now looks like it has come right out of the factory of Mcdonald Douglas

lamp3 lamp4

 

 

 

 

 

Now the only thing we need to do is to put on the electrical wires and to make the electronic dimmer.
The dimmer is fairly simple in it self. It exist out of a small circuit that is build up out of a linear potentiometer with a fixed rod from 22K, a LM350T and a resistance of 3K3. This all is soldered on a print board. It is then connected with the 12V lamp and that's it. The pot meters are then mounted in the middle section of the overhead panel and a nice looking cap was put on top.

What the black-light is concerned, I'm still looking for 12V lamps. I first need to know how they look like before I can start making the lamp holders. As soon as I found the black-light and made the housing I let you now.

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© Verley Jan 2007-2017 original text from 2005 translation Jan Verley