diff --git a/Aircraft-yasim/yf23-yasim.xml b/Aircraft-yasim/yf23-yasim.xml
new file mode 100644
index 000000000..a3d3e37ea
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+++ b/Aircraft-yasim/yf23-yasim.xml
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+<!-- There weren't many YF23s - just the two prototypes - and I
+     couldn't find much 'hard' information so a lot of this fdm is
+     guess work (GW).
+-->
+<!-- Max take off weight is 64000lb so I'm allocating 4xAIM-9,
+     4x AIM-120, pilot and fuel and adding them as ballast entries
+     until I sort out correct weight entries.
+
+     GW figures for these are
+
+     Aim-9      200lb x 4 =  8000lb
+     AIM-120    400lb x 4 = 16000lb
+     Pilot      200lb x 1 =   200lb
+
+     Fuel     24000lb x 1 = 24000lb (from a web-site)
+-->
+<airplane mass="40000">
+
+<!-- Approach configuration -->
+<!-- From GW & photos -->
+ <approach speed="110" aoa="7">
+  <control-setting axis="/controls/throttle[0]" value="0.05"/>
+  <control-setting axis="/controls/throttle[1]" value="0.05"/>
+  <control-setting axis="/controls/flaps" value="0.7"/>
+<!--
+  <control-setting axis="/controls/slats" value="0.3"/>
+-->
+  <control-setting axis="/controls/gear-down" value="1"/>
+ </approach>
+
+<!-- Cruise configuration -->
+ <cruise speed="900" alt="35000">
+  <control-setting axis="/controls/throttle[0]" value="1.0"/>
+  <control-setting axis="/controls/flaps" value="0.0"/>
+<!--
+  <control-setting axis="/controls/slats" value="0.0"/>
+-->
+  <control-setting axis="/controls/gear-down" value="0"/>
+ </cruise>
+
+ <cockpit x="5.70" y="0.00" z="1.26"/>
+
+<!-- Fuselage entries for the fuselage proper and the two
+     engine housings.  The YF23 is basically a wing with
+     these three fuselage/housings, and the elevator.  For
+     this reason I've started the wings from the center-line.
+-->
+<!-- Fuselage proper -->
+ <fuselage ax="10.00" ay="0.00" az="0.00"
+          bx="-2.00" by="0.00" bz="0.00"
+          width="1.6" taper="0.1" midpoint="0.3"/>
+
+<!-- Left engine housing (Excl intakes) -->
+ <fuselage ax="-2.00" ay="1.80" az="0.00"
+          bx="-8.00" by="1.20" bz="0.60"
+          width="1.2" taper="0.1" midpoint="0.3"/>
+
+<!-- Right engine housing (Excl intakes) -->
+ <fuselage ax="-2.00" ay="-1.80" az="0.00"
+          bx="-8.00" by="-1.20" bz="0.60"
+          width="1.2" taper="0.1" midpoint="0.3"/>
+
+<!-- GW stall characteristics -->
+ <wing x="-2.00" y="0.00" z="0.25" length="6.66" chord="12.00"
+      taper="0.08" sweep="0" dihedral="0" camber="0.0">
+  <stall aoa="58" width="1" peak="1.3"/>
+  <flap0 start="0.36" end="0.63" lift="1.2" drag="1.4"/>
+  <flap1 start="0.63" end="0.89" lift="1.1" drag="1.1"/>
+<!--
+  <slat start="0.42" end="0.89" aoa="3" drag="1.1"/>
+-->
+  <control-input axis="/controls/flaps" control="FLAP0"/>
+  <control-input axis="/controls/aileron" control="FLAP1" split="true"/>
+<!--
+  <control-input axis="/controls/slats" control="SLAT"/>
+-->
+  <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-output control="SLAT" side="left"   prop="/surface-positions/left-slat-pos-norm"/>
+  <control-output control="SLAT" side="right"  prop="/surface-positions/right-slat-pos-norm"/>
+-->
+  <control-speed control="FLAP0" transition-time="10"/>
+  <control-speed control="FLAP1" transition-time="0.5"/>
+
+ </wing>
+
+ <hstab x="-8.60" y="2.40" z="0.36" length="3.30" chord="5.10"
+       taper="0.11" sweep="0" dihedral="40" effectiveness="-2.5">
+  <stall aoa="
+22
+" width="2" peak="1.3"/>
+  <flap0 start="0" end="1" lift="1.1" drag="1.2"/>
+
+  <control-input axis="/controls/elevator" control="FLAP0"/>
+  <control-input axis="/controls/elevator-trim" control="FLAP0"/>
+
+  <control-output control="FLAP0" side="left" prop="/surface-positions/left-elevator-pos-norm"/>
+  <control-output control="FLAP0" side="right" prop="/surface-positions/right-elevator-pos-norm"/>
+
+  <control-speed control="FLAP0" transition-time="0.5"/>
+ </hstab>
+
+<!-- The only figures I've found for the F119-PW-100L give 35000lb
+     'class' with afterburner.  The difference between the top speed
+     with and with out afterburner (mach 1.43 vs mach 2) suggests that
+     the afterburner ratio is << 2:1 so I've used a ratio suggested by
+     those mach speeds + plus a fudge factor = 0.7.  Also, the engine has
+     thrust vectoring but I've not worked that out yet.
+-->
+ <jet x="-6.26" y="1.20" z="0.60" mass="3000" thrust="24500" afterburner="35000">
+  <control-input axis="/controls/throttle[0]" control="THROTTLE"/>
+  <control-input axis="/controls/afterburner[0]" control="REHEAT"/>
+ </jet>
+
+ <jet x="-6.26" y="-1.20" z="0.60" mass="3000" thrust="24500" afterburner="35000">
+  <control-input axis="/controls/throttle[1]" control="THROTTLE"/>
+  <control-input axis="/controls/afterburner[1]" control="REHEAT"/>
+ </jet>
+
+<!-- Front -->
+ <gear x="5.25" y="0.00" z="-2.25" compression="0.65" spring="2.0">
+  <control-input axis="/controls/rudder" control="STEER" square="true"/>
+<!--
+  <control-input axis="/controls/brakes[0]" control="BRAKE"/>
+-->
+  <control-input axis="/controls/gear-down" control="EXTEND"/>
+  <control-output control="EXTEND" prop="/gear/gear[0]/position-norm"/>
+  <control-speed control="EXTEND" transition-time="4"/>
+  <control-output control="STEER" prop="/gear/gear[0]/steering-norm"/>
+ </gear>
+
+<!-- Left main -->
+<!--
+ <gear x="-2.20" y="1.92" z="-2.7" compression="1.2" spring="1.5">
+-->
+ <gear x="-2.20" y="1.92" z="-2.25" compression="0.65" spring="1.5">
+  <control-input axis="/controls/brakes[0]" control="BRAKE"/>
+  <control-input axis="/controls/gear-down" control="EXTEND"/>
+  <control-output control="EXTEND" prop="/gear/gear[1]/position-norm"/>
+  <control-speed control="EXTEND" transition-time="4"/>
+ </gear>
+
+<!-- Right main -->
+<!--
+ <gear x="-2.20" y="1.92" z="-2.7" compression="1.2" spring="1.5">
+-->
+ <gear x="-2.20" y="-1.92" z="-2.25" compression="0.65" spring="1.5">
+  <control-input axis="/controls/brakes[0]" control="BRAKE"/>
+  <control-input axis="/controls/gear-down" control="EXTEND"/>
+  <control-output control="EXTEND" prop="/gear/gear[2]/position-norm"/>
+  <control-speed control="EXTEND" transition-time="4"/>
+ </gear>
+
+<!-- Canopy -->
+ <gear x="4.1" y="0.0" z="1.05" retract-time="7" compression="0.6">
+  <control-input axis="/controls/parking-brake" control="EXTEND"/>
+  <control-speed control="EXTEND" transition-time="10"/>
+  <control-output control="EXTEND" prop="/canopy/position-norm"/>
+ </gear>
+
+<!-- The locations and capcities are GW. -->
+<!-- Fuselage tank -->
+ <tank x="1.5" y="0" z="0.68" jet="true" capacity="8000"/>
+<!-- Left wing tank -->
+ <tank x="-1.40" y="2" z="0.0" jet="true" capacity="8000"/>
+<!-- Right wing tank -->
+ <tank x="-1.40" y="-2" z="0.0" jet="true" capacity="8000"/>
+
+<!-- Avionics -->
+ <ballast x="4" y="0" z="0.6" mass="3000"/>
+
+<!-- Cockpit and radar -->
+ <ballast x="7" y="0" z="0.2" mass="1500"/>
+
+<!-- Pilot -->
+ <ballast x="5.8" y="0" z="0.6" mass="200"/>
+
+<!-- AIM-9 x 2 Left -->
+ <ballast x="-0.85" y="2.40" z="-0.23" mass="200"/>
+ <ballast x="-0.85" y="2.24" z="-0.46" mass="200"/>
+
+<!-- AIM-9 x 2 Right -->
+ <ballast x="-0.85" y="-2.40" z="-0.23" mass="200"/>
+ <ballast x="-0.85" y="-2.24" z="-0.46" mass="200"/>
+
+<!-- AIM-120 x 2 Left -->
+ <ballast x="-1.2" y="2.02" z="-0.52" mass="400"/>
+ <ballast x="-1.2" y="1.74" z="-0.52" mass="400"/>
+
+<!-- AIM-120 x 2 Left -->
+ <ballast x="-1.2" y="-2.02" z="-0.52" mass="400"/>
+ <ballast x="-1.2" y="-1.74" z="-0.52" mass="400"/>
+
+<!-- Trim ballast -->
+ <ballast x="6" y="0" z="0.0" mass="1000"/>
+
+</airplane>