Stall speed is too slow and your plane will drop out of the sky with a thud.
IE: For the Beaver stall speed is @ 50 knots..
Each plane has it's numbers.. from stall speed to over speed.
But there is also a process:
IE: The DHC2 Beaver: Typical or ideal approach/landing speed (depending on load) is @ 70 knots.
Process:
Descent
A good descent profile includes knowing where to start down from cruise altitude and planning ahead for the approach. Normal descent is done with no less than 20" of manifold pressure and 2,050 rpm. A good rule for determining when to start your descent is the 3-to-1 rule (three miles distance per thousand feet in altitude). Take your altitude in feet, drop the last three zeros, and multiply by 3.
For example, to descend from a cruise altitude of 10,000 feet (3,048 meters) to sea level:
10,000 minus the last three zeros is 10.
10x3=30
This means you should begin your descent 30 nautical miles from your destination, maintaining a speed of 135 mph (103 knots; it may not indicate this high until you descend into denser air) and a descent rate of 500 feet per minute. Add two extra miles for every 10 knots of tailwind.
In the Beaver, adjust thrust during descent to maintain 135 mph (use the joystick throttle or press F2 to decrease thrust, or press F3 to increase thrust). The propeller lever should remain at 1,900 rpm.
Approach
As you near the approach phase of flight, bring the power back and fly try to fly at @70 mph on downwind. When you intercept the glide slope or enter the downwind, set the flaps to Landing and put the landing gear down if landing on a hard-surface runway.
Turning base, go to full flaps. Over the fence you should reduce speed to 70 mph. In the full-flaps, high-drag configuration, you may need to use more power to maintain speed.
Landing
If landing on the water, make sure the landing gear are UP. If landing on a hard surface, make sure the landing gear are DOWN.
As you cross the threshold at around 50 feet (15 meters) AGL, the power should be as required and the prop should be full forward.
Raise the nose slightly to flare and slow the descent rate. Bring the power back to idle and hold some back pressure on the controls.
Once all of the wheels are on the runway (hard surface), apply the brakes to slow to taxi speed, exit the runway, and taxi to parking.
Once down on a water runway, lower the water rudders to taxi.
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All great in theory but it all takes practice. And still the force of touchdown may not be the ideal but if you're under -600 you're doing ok.
Like -200 for a small craft, under-400 for a medium sized and under -600 for a medium to larger is a nice to do but not always the case and weather, airplane load/weight etc all have a part of the dynamics and forces.
Norm