Written by Greg Gimlick Making the Nose of your Airplane Match the Fuselage As seen in the Summer 2018 issue of Park Pilot
Bonus Video
Drilling and mounting a fiberglass cowl can be a nerve-wracking process. We want them to be perfect and not messed up. The problem is drilling them in the right place to hit either a hard point in the fuselage or the side of the firewall. How do you find that when the cowl is in place? This method will walk you through a couple of easy steps to ensure that it’s perfect every time. 1. Place some tape on the side of the fuselage for drawing reference lines. I use low-tack painter’s tape so that I don’t damage the covering or paint. In this case, I want to drill exactly in the middle of the firewall, so I drew a line down the center of it.
From there, I measured back two inches, but the distance depends on how far the cowl will extend over the fuselage, so check that and adjust the distance accordingly. I placed a mark 2 inches back on the horizontal line. I use a line and not just a point because I want to ensure that I can measure back up to the exact intersection on the firewall tape line. 2. Place your cowl in position and temporarily install the spinner backplate and propeller. Adjust the cowl until you have it exactly where you want it. When you’re happy with the position, tape it firmly in place.
3. With the cowl securely taped, measure back up the line exactly 2 inches and place a mark on the cowl. This is where you will drill the mounting hole. Do this for each spot you need to drill. In this case, there are two screws on each side that will secure the cowl.
4. Remove the propeller, backplate, and cowl so that you can remove all of the tape. Enlarge the hole in the cowl, if necessary, so that the mounting screw doesn’t cut into it. Harden the holes in the firewall with CA adhesive. Slide the cowl back in place and secure it with the mounting screws. Everything should line up perfectly, just as when you test-fitted it. You’re done!
What if your fuselage is predrilled? No problem. Mount it the same way, but place your forward reference tape over the predrilled holes and mark the position of the hole. From there, draw your horizontal line back to the rear position and make your second mark. Test-fit the cowl, backplate, and propeller as discussed and tape them in position. When you measure forward on your reference line, you can make your mark on the cowl exactly over the top of the predrilled holes in the fuselage. Remove the cowl, drill the holes, and when you slide it into place, it should line up perfectly.
