Developed
by

Canadair CL-215 Water Bomber

by Andrew Curless

Fuselage The fuselage construction starts with having to build your formers F1 through F7 which is not quite as hard as it may look. Just lightly sand glue joints for a close fit and the naturally compressibility of the balsa will aid in getting nice tight glue joints. Then fit completed former over plan for finally sanding to shape. (Note: Fit and glue formers F4a to F4 and F6a to F6 at this point.)

Next pin both fuselage sides together and sand to required shape, then split apart and fit one over the plan and mark positions of all formers. Transfer positions to opposite fuselage side. Now fit all doublers and longerons to fuselage sides, remembering to make a left and a right side because it's a real bummer if you have two left sides! Next I began to fit formers F2, F3, F4 and F5 to one side of the fuselage making sure they were all square also fit wingmount plates WM1 and WM2 into position. After the glue joints have dried sand the tail post to the required wedge shape and fit the opposite fuselage side to all formers then glue in the tail area. Position fuselage over the plan to check for alignment and pin and tape until all glue joints have cured. (Upside down on plan.) Now fit formers F5a, F6, F7 and F8 into the rear of the fuselage. F1 now has to be fitted to the front of the fuselage this requires some skill to pull the nose of the fuselage from F2 into F1. I painted the balsa sides with cloudy ammonia to aid in the bending of the timber then with liberal glue added to the edges of F1,I pulled in both sides of the fuselage with the aid of masking tape and when satisfied, left to dry over night. Once all formers are fitted take a sanding block and sand bottom of formers to get a uniform finish. When satisfied, fit in the centre keel to the rear of F5 to the tail post and from F5 forward to just short of F1 where the hard wood nose gear block is to be fitted. Subsequently cut hard wood nose block to profile shown on the plan and fit into F1 butting up to the keel and aligning with the 3mm ply gusset. When complete take a sanding block and shape both keels to a triangle section ready for planking the bottom of the hull.

Turn the fuselage over, check shape and sand to requirements the top of all formers and fit 61/2 mm square stringers between F2 and F4 and between F6 and F8. Now plank the top of the fuselage between F2 and F4 and F6 to F8 with 3mm balsa sheet. From F8 to the tail post I fitted one piece of 10mm sheet then sanded to the profile required. Once happy with the tail shape temporarily fit the fin to the top of the fuselage cutting locating slots as required. (This is to determine location for flexible control rods to the rudder and elevator.) When happy with the control rod locations glue them into position and remove the fin from the fuselage. Now turn over the fuselage and make up the planking for the front of the fuselage bottom from F5 to F1. Sand to shape and glue into position. Now we can make up the nose pod and cabin area at the top of the fuselage, I made mine out of 1/2" balsa sheet. I copied the profile off the top view of the plan and made a series of horizontal horse-shoe shapes. Starting at the centre of the nose area, I layered the sheet one on top of the other to the full height of fuselage sides reducing in size as you build towards the extremities of the nose pod. (Note: It's better to be slightly oversize then undersized.) The cabin was built in a similar fashion using a solid block on the top of the cabin. When happy with basic outline construction it is time to sand to final shape, (I suggest outside on a windy day). I recommend a 6inch sanding disk in a 10mm pistol drill to quickly grind unwanted balsa away, (but be very careful, it’s easy to grind too much away). When close to the size required, change to a sanding block and complete hand shaping until happy with profile. By now you have a fairly wobbly fuselage which will not sit on your bench very well, a trip to your green grocery to pick up a foam fruit or vegetable box is a good idea as this can be quickly cut to fit the fuselage profile and make it much easy to work on your aeroplane. Glue in ply undercarriage plates, (FD), to the rear of F5 on inside of both sides of the fuselage. Mark and drill holes for undercarriage tubes, make up from scrap balsa with support packing for undercarriage tubes and fit and glue into position. In front of the wing saddle between the top of the fuselage planking and F4 fill with scrap balsa blocks and sand to shape. The same needs to the done at the rear of the wing saddle behind F6. This basically completes the fuselage construction except for the planking to the bottom of the fuselage behind F5, this will be done after the fin has been fitted to the fuselage and locked into place.

Assembly

I always start by fitting the wing to the fuselage first. Make sure the wing is sitting symmetrically on the fuselage. Then I triangulate the wing tips to the tail post, this guarantees a wing that is square to the fuselage centre line. Once in position pin then drill pilot holes for the bolts, remove wing and drill and tap wing mount plates. Enlarge holes in wing to correct size and re-fit wing to fuselage.

Now fit the fin into the tail of the fuselage, which is mostly a case of trial and error, until happy with the position of the fin to the centre line of the fuselage and 90∞ to the wing. The fin post extension protrudes over the keel at the bottom of the fuselage and because of the forward slope requires two packing pieces of balsa fitted between the fuselage sides and the front face of the fin post, this ties the fin post to the full depth of the fuselage and is the reason why the rear bottom planking was not fitted previously. Now the fin is fitted, the rear bottom planking can be cut and sanded to shape and glued into position. Next we have to fit the tail plane into the fin between R3 and R3a. Slide the tail plane into position, sanding R3 and R3a until the tail plane and the wing are level and square to each other and glue into position. Elevator and rudder can be hinged and fitted at this point, (but not glued yet).

This is also a good time to fiber glass the hull bottom from F5 to forward of F1 although if you are not planing to fly off water you could bypass this step.

Next fit your motors to the nacelles to determine the location of the access holes through the motor cowls for the motor heads, exhausts and needle valve.