Attched find an xml file "dc3.xml" that includes edits that allow 
accelleration on the main gear and relativly easy wheel landings.  With 
these changes, I can leave the tail wheel unlocked for take-off and 
landings.
Changes:
1.  Relaxed the stall width for both the wing and the hstab.  A dc3 
cannot possibly have worse stall characteristics than the c310.
2.  Added 'effectiveness="nnn"' to the flap0 for both the hstab and the 
vstab as well as 'effectiveness="nnn"' for both hstab and vstab.  As 
Andy Ross suggested, I could set the hstab effectiveness high and the 
hstab flap0 effectivness low to decrease the tendency to porpoise.  This 
really helped a lot!  See the file for the values.
3.  I moved the main gear back to 6.9 (from 6.02).  This had a very big 
effect and enables getting the tail up and accelerating on the mains. 
 Without this, no matter what I did, by the time the tail came up, I had 
already set up the porpoise.  Same on wheel landings.

With these changes and good rudder pedals, the yasim dc3 handles more 
like a real tail dragger.  At taxi speeds, you need differential brakes. 
 I have toe brakes on my CH Pro-Pedals.

Please fly it and then tell what you think.
Dave
<airplane mass="16865">

<approach speed="58" aoa="13">
  <control-setting axis="/controls/throttle[0]" value="0.4"/>
  <control-setting axis="/controls/throttle[1]" value="0.4"/>
  <control-setting axis="/controls/mixture[0]" value="1.0"/>
  <control-setting axis="/controls/mixture[1]" value="1.0"/>
  <control-setting axis="/controls/propeller-pitch[0]" value="0.5"/>
  <control-setting axis="/controls/propeller-pitch[1]" value="0.5"/>
  <control-setting axis="/controls/flaps" value="1.0"/>
  <control-setting axis="/controls/gear-down" value="1"/>
</approach>
<cruise speed="180" alt="23200">
  <control-setting axis="/controls/throttle[0]" value="1.0"/>
  <control-setting axis="/controls/throttle[1]" value="1.0"/>
  <control-setting axis="/controls/mixture[0]" value="1.0"/>
  <control-setting axis="/controls/mixture[1]" value="1.0"/>
  <control-setting axis="/controls/propeller-pitch[0]" value="1.0"/>
  <control-setting axis="/controls/propeller-pitch[1]" value="1.0"/>
	  <control-setting axis="/controls/boost[0]" value="1.0"/>
  <control-setting axis="/controls/boost[1]" value="1.0"/>
  <control-setting axis="/controls/flaps" value="0.0"/>
  <control-setting axis="/controls/gear-down" value="0"/>
</cruise>

<cockpit x="-1.63" y="0.41" z="0.76"/>

<fuselage ax="0" ay="0" az="0" bx="-19.75" by="0" bz="0"
          width="2" taper="0.5" midpoint="0.25"/>

<wing x="-7.02" y="1.09" z="0.95" length="11.58" camber="0.1"
      chord="4.77" taper=".286" sweep="19" dihedral="4">
  <stall aoa="14" width="6" peak="1.5"/>
  <flap0 start="0.04" end="0.38" lift="1.5" drag="1.2"/>
  <flap1 start="0.38" end="0.97" lift="1.2" drag="1.2"/>
  <control-input axis="/controls/flaps" control="FLAP0"/>
  <control-input axis="/controls/aileron" control="FLAP1" split="true"/>
  <control-input axis="/controls/aileron-trim" control="FLAP1" split="true"/>
  <control-output control="FLAP0" prop="/surface-positions/flap-pos-norm"/>
  <control-output control="FLAP1" side="left"
		  prop="/surface-positions/left-aileron-pos-norm"/>
  <control-output control="FLAP1" side="right"
		  prop="/surface-positions/right-aileron-pos-norm"/>
  <control-speed control="FLAP0" transition-time="5"/>
</wing>

<hstab x="-18.12" y="0.41" z="0.27" effectiveness="4.0" length="3.00"
       chord="3" taper=".545" sweep="15">
  <stall aoa="18" width="6" peak="1.5"/>
  <flap0 start="0" end="1" lift="1.5" drag="1.2" effectiveness="0.25"/>
  <control-input axis="/controls/elevator" control="FLAP0"/>
  <control-input axis="/controls/elevator-trim" control="FLAP0"/>
  <control-output control="FLAP0" prop="/surface-positions/elevator-pos-norm"/>
</hstab>

<vstab x="-18.12" y="0" z="0.95" effectiveness="2.0" length="2.72"
       chord="3.95" taper=".462" sweep="2">
  <stall aoa="14" width="4" peak="1.5"/>
  <flap0 start="0" end="1" lift="1.5" drag="1.2" effectiveness="2.0"/>
  <control-input axis="/controls/rudder" control="FLAP0" invert="true"/>
  <control-input axis="/controls/rudder-trim" control="FLAP0" invert="true"/>
  <control-output control="FLAP0" prop="/surface-positions/rudder-pos-norm"/>
</vstab>

<propeller x="-4.09" y="2.52" z="-0.95"
           mass="2000" moment="35" radius="1.4"
           eng-power="1200" eng-rpm="2700"
           turbo-mul="1.5"
           cruise-power="660" cruise-speed="195"
           cruise-rpm="2100" cruise-alt="20000"
           min-rpm="1600" max-rpm="2700">
  <actionpt x="-2.45" y="2.52" z="-0.95"/>
  <control-input axis="/controls/throttle[0]" control="THROTTLE"/>
  <control-input axis="/controls/starter[0]" control="STARTER"/>
  <control-input axis="/controls/magnetos[0]" control="MAGNETOS"/>
  <control-input axis="/controls/mixture[0]" control="MIXTURE"/>
  <control-input axis="/controls/propeller-pitch[0]" control="ADVANCE"/>
  <control-input axis="/controls/boost[0]" control="BOOST"/>
</propeller>

<propeller x="-4.09" y="-2.52" z="-0.95"
           mass="2000" moment="-35" radius="1.4"
           eng-power="1200" eng-rpm="2700"
           turbo-mul="1.5"
           cruise-power="660" cruise-speed="195"
           cruise-rpm="2100" cruise-alt="20000"
           min-rpm="1600" max-rpm="2700">
  <actionpt x="-2.45" y="-2.52" z="-0.95"/>
  <control-input axis="/controls/throttle[1]" control="THROTTLE"/>
  <control-input axis="/controls/starter[1]" control="STARTER"/>
  <control-input axis="/controls/magnetos[1]" control="MAGNETOS"/>
  <control-input axis="/controls/mixture[1]" control="MIXTURE"/>
  <control-input axis="/controls/propeller-pitch[1]" control="ADVANCE"/>
  <control-input axis="/controls/boost[1]" control="BOOST"/>
</propeller>

<!-- Tail wheel; has castering selectable by a wheel lock -->
<gear x="-17.3" y="0" z="-1.5" compression="0.2">
  <control-input axis="/controls/tailwheel-castering" control="CASTERING"/>
</gear>

<!-- Main wheels; note decreased compression -->
<gear x="-6.9" y="2.52" z="-3.49" compression="1.0" retract-time="7">
  <control-input axis="/controls/parking-brake" control="BRAKE"/>
  <control-input axis="/controls/brakes[0]" control="BRAKE"/>
  <control-input axis="/controls/gear-down" control="EXTEND"/>
  <control-speed control="EXTEND" transition-time="7"/>
  <control-output control="EXTEND" prop="/gear/gear[0]/position-norm"/>
</gear>

<gear x="-6.9" y="-2.52" z="-3.49" compression="1.0" retract-time="7">
  <control-input axis="/controls/parking-brake" control="BRAKE"/>
  <control-input axis="/controls/brakes[1]" control="BRAKE"/>
  <control-input axis="/controls/gear-down" control="EXTEND"/>
  <control-speed control="EXTEND" transition-time="7"/>
  <control-output control="EXTEND" prop="/gear/gear[1]/position-norm"/>
</gear>

<!-- From the type certificate: "Fuel capacity: 822 gals. (4 tanks in
     center section wing: 2 main including fuel system 210 gals. each
     (+48) and 2 aux. 201 gals. each (+83.5)" -->
<tank x="-7.02" y="0" z="0.95" capacity="4932"/>

</airplane>

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