When ready to fly, put on propellers by first putting on spacer that matches shaft. Make sure that you can read the numbers on the top of the propellers. Install the washer and then the nut. Tighten with pliers. (Figures 21A-D)
Figure 21A. Spacer to match shaft.
Figure 21B. Numbers (circled in red) should be visible
Figure 21C. Washer
Figure 21D. Nut should be tightened with pliers.
Turn the handheld transmitter ON by pressing and holding center button. To start motors, simultaneously take both switches down and to the center. (Figure 21E)