Brian DeFord's Adventure
Building a Cozy MK-IV

Chapter 13

Part 2:Nose Bottom, Sides, and Top

The nose bottoms are cut to size from 2-in thick urethane foam and bonded to NG-30, F-22 and F-0. After cure, the inside bottom pieces are glassed with BID. The nose sides are cut from 2-in thick urethane foam to size and dished out for the correct internal contour and glassed on the inside surfaces with a couple of inches of glass overhanging. While still wet they are laid on the nose bottom and the overhang is wet out onto the bottom pieces and allowed to cure.

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Nose sides in glass
Nose sides after fuselage attachment
Nose top

A local canard aircraft craftsman, Tom McNeilly, showed me a couple of installations of the landing light in the nose and since I have never liked the location of the landing light under the fuselage as the plans call for it, I decided to go that route. A few months ago, Marc Zeitlin installed two lights in the nose of his Mark IV project and I liked his installation quite a bit. I chose a slightly different mounting location for my lights, but in essence it is much like Marc's with the exception of the shape of the lenses. The lights were purchased from my local automotive parts store and are each 50 Watt add-on driving lights. I started by determining where the lights would best penetrate the nose cone and then cut out two holes in the F-0 bulkhead to allow the lights to be mounted on the NG-31's and shine through to the nose cone. This way I don't have to try to wrestle with the lights through the small nose cone access door, but have easy access through the nose top door. The mounting brackets supplied with the lights are bolted to the NG-31's and the lights can be adjusted up and down or left to right as required for the proper angle. These pictures show the location of the F-0 cutouts, mounting hardware and lights temporarily installed.

Landing light bulkhead cutouts
Landing lights

Next I drilled some 1/4" holes in the F-0 and F-22 bulkheads to run the pitot system. The system consists of 1/4" aluminum tubing that runs from the nose cone to a few inches aft of the F-22 bulkhead. The static line is 1/4" line embedded in the side of the fuselage about 10" below the top of the longeron and 8" forward of the instrument panel. The pitot tube is removable because it is made up of a 1/4" hose nipple with an 1/8"pipe thread. This connects to a threaded connector which in turn connects to a 45 degree adapter (1/8" thread to 1/4" tube). The aluminum tubing is then attached to this adapter. A plug is inserted into the nose when the nose gear is retracted to minimize damage on the ground but REMOVED PRIOR TO FLIGHT and replaced with the nipple (pitot tube). Here is the pitot line running along the left side of the nose and a view of the static port where it extends vertically on the side of the fuselage.

Pitot line
Static port line

I needed to finish the area ahead of F-0 in order to finish mounting the pitot line. This involved making a couple of braces from 1/4" plywood and foam glassed on each side and flox'd in place on F-0. I then finished the installation of the pitot by floxing it in place while making sure the nose cone would fit over the whole installation. Here is the final installation with the nose cone removed.

Pitot tubing in nose

I temporarily duct taped the nose cone in place so I could begin shaping the nose. I started on the bottom side and used a couple of tools for carving - my 3 foot sanding board, a hacksaw blade and a shaper. This was a slow, careful process. Eventually though, the nose started to take a pleasant rounded shape. Here are a couple of photo's taken during the process.

Nose bottom carving
Carved nose bottom

After finishing the carving, I turned to fabricating my landing light windows for the nose cone. I purchased the lexan for the windows at my local hardware store. It is .093 inches thick and is a variety that, according to the manufacturer, is 5 times stronger than regular acrylic. The shape of each is sort of triangular in that it is square on top and from the front and then it rounds up the sides. It is best described in this picture.

Landing light windows

I liked this shape, plus it gives me room to adjust the direction of the light. I drew this shape on my nose cone and then melted a 6"x6" piece of the lexan in my oven at ~300 degrees F. After about 5 minutes the material was very soft and pliable and I placed in over the nose cone and pressed it into shape while it cooled. Next I cut the openings out of the nose cone and trimmed the lexan to within 1/8" of this size and beveled the edges of the lexan and the nose cone cutouts. It was here that I made a big mistake. I masked off the windows so that they would not get scratched, but only on the outside. I flox'd and glassed the windows in place and let it cure. When I checked it later I realized that the epoxy had run onto the windows from the glass cloth and ruined both pieces. Aaaargghh!! I calmed down and tried to figure out what to do next since I didn't want to re-invest $70 into a new nose cone. I carefully cut the windows out with a jig saw and used my dremel tool grinding attachment to grind away the flox and fiberglass. I then used some duct tape to put the original nose cone cutouts back into place and flox'd the seams. After curing I sanded and filled the voids with micro until I had the nose cone back to its original condition. This time I made a female mold off of the nosecone to use as a form for the new windows and started the whole process again, except this time I masked BOTH sides of the windows prior to floxing it in place. After this cured, I spray painted the inside of the nose cone flat black to keep the glare down to a minimum. I also painted the forward face of F-0 and the nose cone support bulkheads. I pealed off the protective masking tape from the inside of the windows, gave them a good cleaning and flox'd the nose cone onto F-0. Here is the mold I made as well as the nose cone with windows temporarily mounted on F-0. The rough edges shown in the photo is masking tape that was eventually cleaned up before permanent mounting.

Landing light cover mold
Nose cone with light covers

With the nose cone completed, I masked off the landing light covers and completed the nose by glassing the underside. This is a two layer BID lay-up with an additional lay-up over the gear strut. One of the modifications I want to have is fully closing gear doors like conventional retractable gear aircraft. Because of this I didn't glass this lay-up directly onto the gear strut per the plans. I masked it off with posterboard covered with duct tape and then glassed directly over this. After cure I cut the posterboard free and left the opening for work on the gear doors at a later time - probably this winter. I turned the fuselage over so that it was right side up and carved the nose top. I made a three layer BID nose door per plans and laid it up on the foam for final cure to get the correct shape of the nose. After this cured, I sanded out an area for the door as well as an area at the top of the nose near F-22. This area will allow the canard assembly to sit flush when installed. I glassed the nose top with two plies of BID and let it cure. Afterward I cut the top off per plans! This was so I could carve the inside of the nose top to shape and glass it. After making the appropriate shape and cutting the nose access hole, I glassed the foam and let it cure. I then installed some nut plates to the inside of the nose top to secure the access door.

Inside view of the nose
Nose top carved with cover
Nose top glassed
Nose top
Nose top after cut