4- Glareshield

Translation by Christian Girardet


The glare-shield is called the “Cap” on French planes. It comprises the 3 blocks CPT-G, CEN-G and FO-G, attached to the Main Panel wooden blocks of corresponding names.

 

The dimensions will depend on the panels’ source and could change from supplier to supplier. In my case, Valerio “Captain Minch” gave me some FlightDeck Solutions spares he had. These panels are of excellent quality with the RAL paint of the latest A320 generation and are 9mm thick. The three panels CPT-EFIS, FCU and FO-EFIS are 263mm long and 89mm high. The smaller “wing” panels are 328mm long. The central panels are larger than the CEN block. The 3 blocks are also deeper and stick out above the Main Panel. The glare-shield’s cover sticks out an additional 55mm. It seems that when the pilot is normally seated, his vision axis is the bottom of the glare-shield and not the top; the glare-shield does not block his view of the instruments on the Main Panel.


Central CEN-G block.

 

This is a simple box made of particle board as seen in the plans here-under:

 

The bottom of the glare-shield is held by four 4x30mm wood screws onto the H rails of the CEN block. Two triangles are cut off to allow for the main panel lighting (be sure you cut them in the correct direction). Two or three powerful white LEDs are installed inside on a hinge, which helps to adjust the direction of the light beam. The triangle is closed with a piece of thin Plexi and a yellow gelatin filter which will soften the harsh LED lights beam. Make sure to paint the vertical sides of the Plexi to avoid light leaks.

 

The sides have to be done at the same time as their counterparts in the CPT-G and FO-G blocks as the upper cuts have the same angle. These two panels will be prepared together so as to drill two 6.3mm and a hole large enough for a 15 pins Sub-D connector to go through.

 

 

All sides are assembled with some L shape rails and 3x25mm metal screws. The dis-assembly is easier if you need to make some modifications later on. There is no back face. The top cover is somewhat more difficult to make as it a dual slope on the sides. The sloping part can be cut, its bevel angle refined with a wood plane and then glued. In this case, the board has to be a bit wider. Another option is to make a cut with a circular saw or a router leaving only about 2.5mm of the board thickness.

 

With a brush wet the bottom of the grove with water and wait 15 minutes. Without waiting for complete dryness, fill the grove with wood glue and saw dust. Stuff tightly, bend to the proper angle and let this dry overnight. The top cover will eventually be covered with a 2mm thick foam sheet, covered with black Skaï upholstery fabric glued with neoprene glue. The thickness of this fabric covering is the reason for the top cover width being less than that of the CEN-G block. The top cover will simply be supported by the block sides. There is little risk for it to move, unless you fly upside down… If you have a windshield, this top can be only removed by sliding it backward. You can install some lateral blocks to guide it while it slides, but do not put any lengthwise. Finally note that the top cover slot for the center post is somewhat larger that the center post itself; this extra space needed for the overhead’s wiring coming down the center-post.

 

All glare-shield blocks are painted white inside, dark marine blue outside. The top is covered with black Skaï fabric which could also be painted dark blue, like in the real A320. Acrylic paint holds very well onto Skaï and will not scratch or break when you install the fabric.

 

The FCU and EFIS ensemble is 575mm wide (see Chapter 6: FCU and EFIS). It comprises 3 panels and will be pushed and set between the glare-shield walls without brackets and/or screws as the EFIS components are nearly flush with the edges of the EFIS panels. To have brackets would require to make cuts in the walls of the glare-shield.


Side blocks CPT-G and FO-G

 

The center sidewalls were made at the same time we built the CEN-G block (see above). The outer sidewall will be 40mm high (small sidewall of the “Wing” block height plus 2mm for margin). This outer sidewall’s top is cut at the same angle than the center sidewall (to accommodate for the slope of the top cover) and will be cut longer than needed at 150mm: it will be brought to the right size later. The width of those glare-shield side blocks is theoretically 500mm. In practice, the exact dimension is the width of the three Main Panel wood blocks, minus 593mm and divided by two…

At this point you have to decide whether having a windshield or not, as this will have an impact on how to conduct the rest of the construction.

 


Windshield:

 

“To have or not to have” a windshield is an important question! The windshield and its lateral posts do not add to the rigidity of the overhead. As indicated earlier, the overhead displays a slight flexibility, which is not a big deal. The role of the windshield has to do with the “feeling” of the cockpit. In a completely open cockpit structure, you lose the sensation of being in a real plane. Just adding lateral posts will already improve the visuals as they frame the lateral vision. With the whole windshield in place, the feeling is completely different as the visual field is now focused on the projection screen. This is purely a trick as the 4 sides of our windshield do not mimic the real thing in terms of thickness or of location. Still, the result is worth the extra work.

 

Putting all this together is no easy task as the pieces will require compound angle cuts. As a consequence the cut cross section is diamond shaped, with unequal sides. In addition, we want to make easy it to disassemble… As much as possible, we will attempt to stay close to the real dimensions, but with some compromises: our cockpit does not have sides, which reduces the actual space we can play with. For instance in our case, looking at the windshield angle from the top, the backward tilt angle will be reduced from an actual 30 degrees to 22 degrees. The center post vertical angle is the proper 48 degrees, but as our Main Panel blocks are not as deep as in the real plane, the nearly horizontal roof section between the overhead and the windshield will be shorter than in the real plane. On the other hand, we will make sure that the vertical and horizontal sides of the windshield are f the same respective length to form a parallelogram onto which you could choose to affix a Plexi sheet.

 

The first step is to make a template. This will require every C clamp and trim pieces you have available!

 

After quite a bit of tweaking, here is the result:

 Some of the wood sticks on the picture are just temporary supports. The FO-G block top cover has been installed as it gives us the proper angle for the lower edge of the windshield, and therefore that of the top edge (as they are parallel).

This template is more about getting the correct angles than the exact length dimensions.

 

The construction starts from the rail/post installed in each of the stick side blocks. Each is composed of two 27x27mm cross section pieces of wood (A and B). These are cut at the proper angle, glued with strong wood glue. The connection is re-enforced with a 5x50TF screw. (5.1mm hole in B and 4mm pre-drill hole in A). Make sure the screw is as vertical as possible as otherwise its head may stick out in the extra length which will be cut and sanded at a later stage. So check your alignment with the A stick sides.

The vertical post A will be screwed later in the corresponding stick side block. For now, drill two 6.3 mm holes into it as it is easier to do it now with a press drill than inside the side block later on…

The A post must be placed exactly in the alignment of the glare-shield floor: a good thing we built the CEN-G block first…

 

 

The B post is inclined upward but also toward the inside of the cockpit. The final length will be 620mm. Start with a 750mm piece and we will adjust to proper length at the end of the construction. So where in the cockpit space does the upper end of the B stick (“P”) ends up when it is in place? Vertically at 1,335 mm from the floor and at 910mm from the center axis of the cockpit. From that end of the post, there is a horizontal rail “C” connecting to the overhead. We will deal with this after the windshield is in place.

 

At this point, when everything is in place, attach A inside the stick side block using C clamps, attach P, the upper end of the B piece, to some graduated stick which will give you the exact location of P as defined earlier (1,335mm and 910mm). Glue in place. Same process on the pilot side. If you did it right, the 2 B pieces are parallel with each other as well as to the windshield center post

 

 

Horizontal rails of the windshield

 

First, close the lateral blocks of the glare-shield with their cover top. This will give us the angle of the lower rail of the windshield. Don’t forget to account for the thickness of the Skaï fabric, i.e. 3mm (place some shims for now to simulate the Skaï thickness). One end of the windshield lower frame rail lands at the connection of the A and B sticks. The other will end slightly above the center post: place a wood piece there (with the proper angles) to fill-up the space. This should be done with a 13x28mm piece of dimensionally stable wood as pine has a tendency to warp. Similar support pieces will cut for all windshield’s frame parts. Once assembled they will make a frame simply resting onto the A/B post and on the front of the windshield center post. The two windshield sections are independent so that they can be taken apart easily for transport. Once the windshield lower rail is in place, make a mark 490mm up on the A/B and on the center post: this will be the location of the windshield upper rail. Gluing is no problem, but put a wood pin as reinforcement at each of the corners of the windshield for added strength. Note the 10x10mm piece of wood on the A/B post to which the windshield frame will be attached to. The support frames will be attached with Velcro or with some metal screws inserted into a brass tube, itself glued to the B rail. The two width of the support frame (28mm x 2) are larger than the windshield center post (43mm). This gap will be used later as a conduit for wiring.

 

All that is left to make the two “C” rails connecting the overhead to the “P” end of the “B” rail.

 

These C rails are not bearing and are mainly used to make the “roof”, i.e. the two small triangles between the top of the windshield and the overhead.

 

Their placement will be made by eyeballing: a piece of wood will be held at P and it other extremity will be placed against the overhead, making sure that the wood piece (our “C” rail) is visually parallel to the top of the Windshield. Mark the connection location on the overhead and the angle cut to make. Cut and trace the connection between C and B, then cut. Note than C is definitely not horizontal.

 

Prepare 2 steel brackets with the same type of 20mm steel perf bars we used for the Overhead frame. Fold to the right angle to connect C to the side of the overhead. Use wood screws to connect the bracket to C and 5 mm metal screws for the connection to the overhead. If at one point in the future, you need to take it apart for transportation, remove these metal screws.

 

At this point, line up B with the cut on the C rail and drill through both pieces at the same time. Push a 6mm interior diameter nylon tube (8mm external diam.). The hole in B is drilled at 6.3mm and countersunk for the screw head. Screw the two together. Remove the clamps in the stick side blocks and adjust the position of the A rail in the stick side block so that it can take its natural place, without bending or forcing it. Drill the side of the stick side block, through the holes we had made in A. Use two 6x50 TH screws to fasten. For transport, A and B will remain connected to the stick side blocks. C can remain connected to the Overhead or even better, remove the brackets connecting it to the overhead.

 

Remove the rulers we had used to place B in its position and note that the Overhead is now completely rigid in any direction. Cut off the extra length in the various rails as necessary.

 


The “roof”

The two triangles between the top of the windshield and the Overhead can be closed with a flat piece of board if C is actually in the same plane as the top of the windshield, without warping or bending.

 

We went with a lighter approach by stretching and gluing a piece of fabric on the upper rail of the windshield (cockpit side) and on the C rail. Skaï would look like the real A320 roof, but may be a bit heavy: overtime, the windshield upper rail may end up warping. The best choice is a piece of canvas fabric or burlap covered with a primer. This is readily available in any art supplies store. You need a piece 50cm long, painted navy blue inside the cockpit and gray or black outside, like the top of the overhead.

Once the paint on the fabric is dry, staple it onto the upper rail of the windshield. Use a band of strong cardboard to avoid creating wrinkles during the process:

Lay the fabric into place, tack it to check dimensions and cut the excess fabric.

 

From the inside of the cockpit, the staples are not too pleasing to the eye: cover them with another band of cardboard painted light grey.

 

Finally, the other end of the fabric piece will be stapled onto a length of wood, stretching the fabric pretty hard. That piece of wood is then screwed on the C rail:

 

The windshield is now completed. Remove the CPT-S and FO-S side blocks, as well as the two floor boards and cut the latter at an angle in the front, like shown on the plan:

At this time, we have a nearly completed glare-shield central block, the windshield and the beginning of the CPT and FO glare-shield blocks.

 

These blocks are a bit more difficult to make. One could choose to just finish the lateral “wings” like in the following picture, but on the right and on the left, there will be gaps between the glare-shield and the windshield’s A and B rails…This would not look too good.

 

Starting at the front edge of the “wing” face of the floor, there is a break and the floor dips downward. This “break” could be done with a router or with a circular saw as mentioned before. The glare-shield “floor” extends all the way to the windshield frame. The required cuts are clearly visible on the following picture:

Visually, the FO and CPT blocks seem to go through the FO-G’s floor: the latter was cut to make this possible. One could have chosen instead to cut the CPT and FO blocks’ outside walls 22mm shorter so to follow the slope of the glare-shield floor. With this option, there is a significant risk that one would end up with the top and the bottom exterior panels not being parallel. At this point it is possible to fill the space between these two with some extruded polystyrene (40mm thick). This will serve as a stiffener, as a front face (painted with marine blue acrylic paint) and as a rear face. The “roof” above this polystyrene piece does not need to be removable; only the part above the front face of the “wing” will be. Therefore we will make a cut with a saw at the end of the “wing” face and glue the rest on the polystyrene block with vinyl glue.

 

Finally, note that the “roof” of the block extends all the way to the “A” post, in a straight line without break. The “roof” of the central block is offset by 55 mm in regards to the front face of the instruments. This is reduced to 0 mm at the “A” post. This means that the “roof” is not parallel to the “floor”. Well this is much easier to build than to try to explain…

 

The polystyrene block
The polystyrene block
Gluing the top
Gluing the top
The F/O “wing” panel
The F/O “wing” panel

Loudspeakers’ “triangles”

 

… which actually are trapezoids. These are not easy pieces to make because of the various cuts at an angle. No need to provide a drawing as it is much easier to measure it directly or to make an actual template. Remember that if you want to be able to disassemble the blocks easily, the sides of the loudspeakers boxes cannot be screwed both on the FO and the FO-S blocks. This is even trickier if you want the air vents above the loudspeakers to be functional as this is the case in my cockpit. These vents are fed with small computer’s fans. Therefore the loudspeaker boxes should be as airtight as possible for the air to actually blow out of the vents and not out the side of the boxes!

 

Marking the loudspeaker box side.
Marking the loudspeaker box side.
Marking the loudspeaker box bottom side.
Marking the loudspeaker box bottom side.

 

The main side of the box is screwed into tapped holes on an aluminum L shaped profile using 3 or 4 mm screws (the profile is set on the bottom of the compartment) and into aluminum tapped brackets placed on the back of the glare-shield. In the event the glare-shield should have to be disconnected from the CPT block, these 2 screws would have to be removed. This setting will allow access to the inside of the loudspeaker box. The conduit for loudspeaker wires and for the wires powering the fans will be made airtight using some foam. Beware that there quite limited room and that some boxy loudspeakers could end up being too large for that space…

 

The loudspeakers area is painted dark marine blue.

 

The glare-shield is installed
The glare-shield is installed
The central section of the glare-shield can accommodate most of the IOCards.
The central section of the glare-shield can accommodate most of the IOCards.

 

Overall cockpit plan: main dimensions. The total length could be extended to 2meters if the two computers are placed in the front of the CPT and FO blocks.