ORIGINAL: Villa
The point that I am trying to emphasize is that the human body ability to estimate the safe air speed of a model decreases drastically the closer the plane is to flying directly toward you. Many believe that your depth perception will help you. If you google Depth Perception you will find that it is about 17 feet. Yes, feet. When the plane is landing near to directly in front of you, left to right or right to left, you have the best view to help you estimate the safe air speed. I have stalled it into the ground HARD many times in my 39 years of flying RC, and have noticed that this usually happens when the plane is very far from me; the angle between my line if sight and the plane path is very small.
Agreed. I fly a final approach just like I would with a full size plane: trim the elevator for a desired final approach speed. This is an airspeed less than what most rc sport flyers trim their elevator for. And yes, elevator trim settings need to be moved for different flight conditions. Most rc sport fliers trim the elevator for full power level flight and never touch it again. Experiment with what this slower final approach speed is for your plane. Probably requiring 1/3 throttle. Now trim for level slow flight. Get used to flying the plane at this reduced power setting/slower airspeed. Limit your bank angle to approx. 30 degrees. Fly your downwind leg and base at this speed/power setting. Roll out on final and leave the elevator alone and reduce the power a few clicks. The plane should start to descent but maintain the same airspeed. Adjust the throttle until the descent rate appears to get you to your landing aim point. If it looks like you are going to land short, add a few clicks of power - not elevator. If you feel the landing is going to be long, reduce the power a few clicks. A strong headwind will require a few more clicks of power (to decrease your descent since your ground speed is going to be slower.) Don't reduce the power until your are ready to flare. If your landing speed is still too fast, repeat this entire procedure over with an even lower power setting. I can fly my stick around the pattern at approx. 1/4 power.
Just like Villa says, it is very hard to accurately perceive your airspeed when the plane is coming at you at a large distance. Instead, set the power and elevator trim to a known position which will determine your descent rate. Your descent rate will appear excessive in a headwind - so just add more power to reduce your descent rate as you fly to your aimpoint. And to piggyback on Villa's concept, I think many beginners get on final with a headwind, pull the power to idle, see the descent rate increase, so they pull back on the elevator and experience a stall.
As you might have noticed, THIS IS MY FAVORITE concept to discuss and teach, to both full scale pilots and rc fliers. It is much easier for the full scale pilots to figure it out SINCE they are SITTING in the PLANE.
Kurt
Kurt