Great post.
Could you elaborate on the above quoted excision? In my PPL VFR landing experience I have found generally less power solves many issues.
I know power does not necessarily equate to airspeed, and excess airspeed increases the odds of ballooning/bouncing/porpoising, so it is difficult to believe you are saying dragging it in by the prop fixes many landing issues. Hence, my request for clarification.
It may be my experience is a few standard deviations off the norm as my home drome is considered by some a short runway.
Thanks for your excellent observations. I've been to your website a couple of times and enjoyed it.
I'm not talking about the approach. It has been said often and correctly that a good approach is the key to a good landing. I'm talking about the time from the roundout/flare to the wheels touching. In this regime, and even if your approach was too fast you will eventually end up where you are operating "behind the power curve." This means that pitch is of virtually no use to you. By definition any change in pitch results in a loss of altitude. When you demonstrated min. controllable airspeed for you certificate it was not just to show that the airplane is mushy and slow to respond and you need gobs of right rudder, it is also to demonstrate that if you change pitch you lose altitude. The same applies in the latter stages of landing. So the cure is power.
Ex. 1: You approach a bit hot, or over control a bit in the initial pitch up, and the airplane balloons when you round out. You are now too high and airspeed is bleeding off quickly and you are, or soon will be behind the power curve. Eventually you'll get there. So you stop your flare and wait. Now you've bled off your airspeed and you are sinking again. At this point you are most likely behind the power curve and any pitch change will only make matters worse. If you pitch up you increase drag and your sink rate goes up. If you pitch down your sink rate goes up for all the usual reasons. You do not want to be there. High sink rate, nose either too high or too low. What to do? Add power. If the runway is long enough, re-establish level pitch and start the landing over. If it isn't long enough, go around. In addition the slipstream from the propeller re-energizes the flow over the elevator and rudder and you gain some controllability. Power is your friend.
Ex. 2: You bounce the landing and you are near the stall. Uh oh, now you are flailing around in an airplane with mushy controls, the stall horn is blaring and you are trying to keep it from landing on the nosewheel or slamming into the ground in a flat attitude. What to do? Add power. Lather, rinse, repeat. Re-establish a comfortable and controllable pitch attitude and start your landing over. Or, if you know you are still close to the ground hold the landing pitch attitude and keep feeding in the power until the mains touch. Remember while you are doing this that you'll need plenty of right rudder. A modest amount of power isn't going to make you go faster, it's just going to slow your descent. Remember you are behind the power curve and the only immediately effective control you have over your vertical component of flight is power. This is why you can't "pitch" your way through a windshear. Even if you are pitching up you need power. Power is your friend.
One thing I did not mention above is that
landings are nothing more than slow flight to the other end of the runway. Since the power is very low (usually idle) you won't get there, just keep flying the airplane and you'll touchdown eventually. Thinking of it this way refocuses your vision to the end of the runway where you are better able to judge important factors like height, drift and alignment. If you are over controlling in pitch as you get into the flare leave the power at 1200 -1500 rpm (training type aircraft). This effectively slows things down. You'll use more runway but you will have more time to make adjustments as you now have more time before the back side of the power curve comes to bite you. This is how you do wheel landings in tail draggers and glassy water landing is seaplanes.
The pilots who demonstrate extremely short landings fly behind the power curve during the final stages of the approach. They don't need to flare because it is power that is controlling the descent rate not pitch. They've set the pitch for the landing attitude. Now all they are doing is controlling the descent rate with power. Same thing with carrier landings. Watch the in cockpit videos of carrier approaches and you'll see the pilots are flying a fixed attitude and using power to control their descent rate and airspeed. Remember these are short field landings for keeps and they need to catch a wire. Pitch attitude matters, what keeps them from stalling? Power.
Bottom line, flying is all about energy management. Do I have enough energy in the system to do what I want to do? I personally don't think this is emphasized enough in flight training. Stalls are too little energy not too little speed. This why you can stall at high airspeeds, even though your speed is high your energy is insufficient to keep you flying. In flight training they call this an accelerated stall. "See you can stall at high airspeeds." If you have enough energy you can go straight up at zero airspeed -- see NASA. You can substitute speed for energy in certain flight regimes, just like Newtonian mechanics works in certain physical regimes, but for flight, if you want to understand the whole system, it is energy that matters, just like in physics you need the yet to be discovered unified theory.
Sorry, a bit long winded but I hope it helps someone.