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18.04.2019

Canopy Windows

After installing the projection system, I stopped using the canopy for a while. It’s main function had been to block the pilot’s view to the left and right. In V.2 of the cockpit, the forward canopy structure connected to and enclosed the three monitors used for outside views. The use of beamers made the monitors obsolete, hence the decision to remove the canopy.

But the sensation of flying in the open cockpit was strange: not only could I see the room around me – distracting me from the the task of flying my virtual 737 – but the lack of enclosure made me feel like I was sitting on a flying carpet (equipped with rather advanced avionics, though). Enclosure is good for immersion, so I began to toy with the idea of rebuilding the canopy – but this time with real windows. The existing aft section – i.e. the part that openes – was re-usable without much modification. The front section would be all new.

Here is a description of the building process:

For once, the design process did not start with Corel Draw, but on a simple sheet of paper.

My idea was to place the windows in such a manner that their frames would not only block the view into my simulator room, but also hide the borders of the projection screens themselves. Even when moving the head left or right, the pilot should not see the screen borders, but simply more of the projected outside world. I hoped that this fact would significantly strengthen the feeling of immersion during flight.

Besides the basic idea for the windows, the sketch contains some additional design and construction ideas. Some of these made it into the final product, others didn’t.

This picture shows the first tentative steps of defining the size and shape of the windows – and to integrate these new elements into the existing structure of the cockpit shell and canopy.

I fixed the first battons temporarily with screws, sat in the cockpit to test the result, than modified the angles and tried again. Patience during this phase is essential for getting things right. As the following pictures show, the final shape of the windows is rather strange – the result from many rounds of trial and error.

A close-up, also taken during the initial building phase.

Note the new front section of the moving canopy (which formerly contained day and night lighing). It was modified to hold overhead panels.

This shot evidences a known fact: A fighter cockpit is a crammed place! Even though the avionics and main systems of my simulator mimmick a Boeing 737, there will be no flight attendant to serve coffee after reaching cruizing altitude…

In case anyone is interested: The bulge on the left is a custom made plastic piece that had to be added to give my joystick enough room. As opposed to the real stick, the Thrustmaster Cougar FCS has quite a bit of travel, so during a bank the top hit the wall of the original shell.

Construction is coming along nicely! Slowly, the final shape of the canopy structure is emerging.

In order to keep the side walls’ weight down yet make them strong enough, I decided to employ the same building technique as for the moving part of the canopy. The basic structure is defined by batens and bulkheads, covered on outside and inside with thin plywood. This makes the building process painstakingly slow, but it allows for round, 3-dimensional shapes that are pleasant to the eye.

The windows are ment to mask everything but the screen, hence their rather irregular shape.

The small size of the windows also demonstrates clearly how little we actually see of the outside world – even when a big projection system is employed. An F-16 pilot would see at least ten times more sky through his huge bubble canopy. Even the windows of the 737 cockpit offer a far bigger field of vision!

When building the window frames I decided it was finally time to give the front panel case a more three-dimensional look.

Not only does this part of the cockpit now look much better, but the case made the from panel more stable. Now I can push a button on the MCP without the panel moving under my fingers.

After completion of the canopy structure there was a rather ungainly space in the front section, where the fiberglas shell extends beyond the window frames. The solution to this problem was a plywood hood. It made the front end look much nicer. At the same time it provides space for the installation of two fans. With the full enclosure I expected the need for some form of air conditioning.

The last step was to cut the windows from acrylic glass sheets. I decided to use 4mm acrylic for the side windows and – because of its larger surface – 5mm for the front window.

First I made samples from medium thick carboard. Once I was sure of the samples’ precise fit into the frames, I fixed the carboard to the acylic with Scotch tape and than just cut along the edges with a motor saw (equipped with a special blade for acrylic glas). That system worked beautifully: The acrylic windows were a perfect fit. I simply pressed them into the frames – without using any messy glue.

It’ a bird… it’s a plane… it’s my Boeing-737-Jet-Fighter contraption!

When I first tried out the simulator with the new canopy, I was amazed at how much of a difference the windows make. There is now a clear separation between the inside of the cockpit and the outside world, full 9 ft away on the big screen. Tiny, moving reflections on the windows add to the illusion of actually flying. The effect is best during take off and landing, in slow turns at low altitude or when passing over a ridge.

It quickly became clear that the two fans are no gadgets, but an absolute necessaty. Without them, it gets steamy in the cockpit just minutes after the canopy is closed. And the canopy needs to stay closed during flight – in the open position it blocks the image from the center beamer.

From this angle, the cockpit now looks rather mean. Because of the angular shape of the windows it reminds me of the SR-71 Blackbird or the F-117 Nighthawk.

Getting into the simulator is still easy, as long as you know the right sequence of movements. When I have guests I usually see them struggeling, even though I had just explained exactly where to step, what to grab and how to slide into the seat.

Well, this certainly ain’t no Boeing cockpit!

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