Question: How much deflection should I use for my Flaps? Can I overdo it?

Answer: We recommend using no more than 50% of the maximim deflection that the flap is capable of. Any more than that will likely due more harm than good.

Better Answer: If you overdo the flap deflection beyond 50% of the maximum deflection that the flap is capable of, you will get little additional flap effect but will substantially increase the drag and possibly make the model unstable. There is also a reduction in the effectiveness of the vertical stabilizer and the rudder when as flap deflection is increased. This loss of effectiveness can reduce the ability to counteract and control Yaw making it particuarly important to ensure that both flaps are deployed to the same degree at all times. Differential (non-equal) flap deflection can result in a crash due to roll and pitch changes that can be very difficult to overcome and control.

We suggest phasing in the amount of flap deflection, starting with very little and working up to the 50% max noted above. At each step, test your control over Yaw (using the rudder) and Roll (using the ailerons). If you can't maintain control over Yaw and/or Roll or the model is Pitching suddenly up or down, back off on the amount of flap deflection.