Below is a list of errors that myself and others have found in the instructions and plans of the Dumas DH-89 Dragon Rapide kit. Also included are some points of clarification.
Errors:
- Step 13 of the "Upper Wings" section - The 5/32" OD aluminum tubing inserted into the wings should only be cut to 2-5/8" long and inserted so that the inboard ends are flush with the wing root rib.
- Step 21 of the "Lower Wings" - See above.
- At no point in the building of the upper wing is direction given to glue A2 or the A6/A7 spar assembly to A3, A4, A16, and A17.
- At no point in the building of the upper wing is direction given to glue the trailing edge to A3 and A17.
- No aileron hinge locations are given on the plans.
- R1A is not labeled on the plans for the lower left wing.
- Step 7 of the "Lower Wings" section directs gluing R3A and R4A to the inboard trailing edge. This is incorrect, R3A and R4A do not attach to the inboard trailing edge and instead will get glued to WSBA in step 5 of "Landing Gear Assembly".
- Step 21 of the "Lower Wings" section - The 5/32" OD aluminum tubing inserted into the wings should only be cut to 2-5/8" long and inserted so that the inboard ends are flush with the wing root rib. At least that is what the plans show, but if you inserted the aileron servo trays per Tritle's design then you'll need the tubing to be more like 2-1/2" long.
- Sheet 3 of the plans shows a "right hand main gear strut" assembly that is actually the left one and the "Front View Left Motor Mount" shows the wheel axle pointing towards the wing root when it should point towards the wing tip. The view labeled "Bottom View Left Motor Mount" is correct. You'll know you have the landing gear strut assemblies on the correct wing when the holes in the plywood line up properly with the "U" shape of the wire. If in doubt reference this photo of Pat Tritle's landing gear.
Points of clarification and tips:
- The directions call for a 25A speed controller, but a 10 amp should be sufficient if using the suggested motor, prop, and battery.
- The plans may be stretched which could result in trouble building some of the wings and/or the wings on one side of the plane being longer than the other side. If you find your plans are stretched then build both wings to the same length, the laser cut parts help in this regard so don't glue anything in place till you are sure of the fit.
- The balsa sheet numbered 1815-9 should have 4 wing ribs numbered R10 as shown in the instructions, but it probably only has 3 of these ribs so use one as a pattern to cut a fourth rib.
- Parts A3, A4, A16, and A17 of the upper wing are labeled under the parts on the plan so mark the part number next to the part on the plan or write it on the part so you'll not be trying to figure out which parts they are later on.
- You only get 1/5 of the light plywood sheet 1815-10 that is shown in the directions.
- Step 11 of the lower wing assembly directs gluing the aileron servo tray flush with the top of A11 and parallel with the bottom of the wing. Just below it is a note from Dumas advising adding a slight tilt by dropping down the aft edge of the tray as shown in G-G and E-E. If you cut the aluminum tubing to the length shown on the plans it will stick past rib R3A and hit the servo tray before it can be fully inserted. In light of this you either need to cut the aluminum tube to 2-1/2" or follow the Dumas tip and tilt the servo tray at least enough to allow the aluminum tube to clear.
- Solder doesn't like to stick to smooth music wire so when soldering together the landing gear first scuff up the contact area with a little sandpaper. If using an electric soldering iron you'll want to use the biggest tip you've got so it has plenty of thermal energy to quickly heat the wires.
Please email me if anything needs to be added to or edited on this list.