From 626d78132db5c25562d132ac09f235c961bc1bed Mon Sep 17 00:00:00 2001
From: david <david>
Date: Thu, 15 Aug 2002 22:02:57 +0000
Subject: [PATCH] YASim aero model for a Piper J3 Cub.

---
 Aircraft-yasim/j3cub.xml     | 138 +++++++++++++++++++++++++++++++++++
 Aircraft/j3cub-yasim-set.xml |  63 ++++++++++++++++
 2 files changed, 201 insertions(+)
 create mode 100644 Aircraft-yasim/j3cub.xml
 create mode 100644 Aircraft/j3cub-yasim-set.xml

diff --git a/Aircraft-yasim/j3cub.xml b/Aircraft-yasim/j3cub.xml
new file mode 100644
index 000000000..d48b12d5c
--- /dev/null
+++ b/Aircraft-yasim/j3cub.xml
@@ -0,0 +1,138 @@
+<?xml version="1.0"?>
+
+<!--
+************************************************************************
+YASim aerodynamic model for a Piper J3 Cub.
+Started 2002-08-15 by David Megginson.
+
+This aerodynamic model is based on three-views, unauthoritative
+performance data, and wild guesses.  These sites provided particularly
+useful information or were simply fun to visit:
+
+Performance data:
+  http://www.marss.com/cub.htm
+Weight and balance:
+  http://www.danford.net/balance.htm
+Three-view:
+  http://www.fiddlersgreen.net/aircraft/private/j3cub/j3cub_info/j3_info.htm
+Useless but fun free paper model:
+  http://www.fiddlersgreen.net/aircraft/private/j3cub/j3cub.htm
+Useless but fun 1945 Piper Cub add from FLYING:
+  http://www.fiddlersgreen.net/aircraft/private/j3cub/j3cub_info/piperad.jpg
+
+The reference datum for measurements is the leading edge of the wing,
+since it is what the weight-and-balance site above uses.
+************************************************************************
+-->
+
+<!-- 
+  680lb empty weight less 200lb for engine (wild guess)
+  + 340 for pilot and passenger
+ -->
+<airplane mass="820">
+
+<!-- Approach configuration (actually touchdown, I think) -->
+<approach speed="25" aoa="16">
+  <control-setting axis="/controls/throttle[0]" value="0.3"/>
+  <control-setting axis="/controls/mixture[0]" value="1.0"/>
+</approach>
+
+<!-- Cruise configuration -->
+<cruise speed="67" alt="8000">
+  <control-setting axis="/controls/throttle[0]" value="1.0"/>
+  <control-setting axis="/controls/mixture[0]" value="1.0"/>
+</cruise>
+
+<!-- pilot's eyepoint -->
+<cockpit x="-0.23" y="0" z="-0.30"/>
+
+<!-- FIXME: midpoint (I don't understand it) -->
+<!-- FIXME: taper (I just left in the C172 value) -->
+<fuselage ax="1.37" ay="0" az="-0.71" bx="-4.81" by="0" bz="-0.65"
+          width="0.71" taper="0.16" midpoint="0.83"/>
+
+<!--
+  I treat it as a perfectly rectangular wing for now.  Note that
+  the dihedral is exaggerated to simulate hull-interference effects
+  on a high-wing aircraft; once YASim models that properly, the
+  angle should be reduced to something like 2 degrees.
+
+  Note that the J3 Cub has no flaps.  With a stall speed of 25kt, who
+  needs them?  From what I've read, the ailerons add lots of drag.
+-->
+<!-- FIXME: camber (used the C172 value) -->
+<wing x="-0.80" y="0.42" z="0.0" taper="0.0"
+      length="4.87" chord="1.60" sweep="0" dihedral="5" camber="0.1">
+  <stall aoa="16" width="6" peak="1.5"/>
+  <flap0 start=".31" end="0.85" lift="1.5" drag="1.4"/>
+  <control-input axis="/controls/aileron" control="FLAP0" split="true"/>
+  <control-input axis="/controls/aileron-trim" control="FLAP0" split="true"/>
+  <control-output control="FLAP0" side="left"
+		  prop="/surface-positions/left-aileron-pos-norm"/>
+  <control-output control="FLAP0" side="right"
+		  prop="/surface-positions/right-aileron-pos-norm"/>
+</wing>
+
+<!-- FIXME: taper (used the C172 value) -->
+<hstab x="-4.87" y="0.05" z="-0.42" taper="0.5"
+       length="1.49" chord="1.13" sweep="0">
+  <stall aoa="16" width="4" peak="1.5"/>
+  <flap0 start="0" end="1" lift="1.7" drag="1.2"/>
+  <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>
+
+<!-- FIXME: taper (used the C172 value) -->
+<!-- rudder has to be able to counteract aileron drag -->
+<vstab x="-4.87" y="0" z="-0.65" taper="0.38"
+       length="1.31" chord="1.37" sweep="0">
+  <stall aoa="16" width="4" peak="1.5"/>
+  <flap0 start="0" end="1" lift="1.5" drag="1.2"/>
+  <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"
+		  min="1" max="-1"/>
+</vstab>
+
+<!-- FIXME: engine mass (just a guess; it's a small engine) -->
+<!-- Assume 75% power at 8000ft -->
+<propeller radius="0.95"
+	   cruise-speed="60" cruise-rpm="2300"
+           cruise-alt="8000" cruise-power="48"
+           takeoff-power="60" takeoff-rpm="2300"
+           eng-power="65" eng-rpm="2700"
+           x="0.71" y="0" z="-0.65" mass="200" moment="8">
+  <actionpt x="1.31" y="0" z="-0.65"/>
+  <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"/>
+</propeller>
+
+<!-- FIXME: the J3 Cub may not actually have a tail-wheel lock -->
+<gear x="-5.17" y="0" z="-0.71" compression="0.2">
+  <control-input axis="/controls/tailwheel-castering" control="CASTERING"/>
+</gear>
+
+<gear x="0" y="0.89" z="-1.96" compression=".3"> <!-- left main -->
+  <control-input axis="/controls/brakes[0]" control="BRAKE" split="true"/>
+  <control-input axis="/controls/parking-brake" control="BRAKE" split="true"/>
+</gear>
+
+<gear x="0" y="-0.89" z="-1.96" compression=".3"> <!-- right main -->
+  <control-input axis="/controls/brakes[1]" control="BRAKE" split="true"/>
+  <control-input axis="/controls/parking-brake" control="BRAKE" split="true"/>
+</gear>
+
+<!-- There's just one 12-gallon tank, right behind the engine (!!!) -->
+<tank x="-0.45" y="0" z="-0.89" capacity="72"/> 
+
+<!--
+  Note the tandem seating; the x values (arms) come from the
+  weight-and-balance page cited at the start.
+-->
+<ballast x="-0.23" y="0" z="-0.70" mass="170"/> <!-- pilot -->
+<ballast x="-0.91" y="0" z="-0.70" mass="170"/> <!-- passenger -->
+
+</airplane>
diff --git a/Aircraft/j3cub-yasim-set.xml b/Aircraft/j3cub-yasim-set.xml
new file mode 100644
index 000000000..b5fc7abbb
--- /dev/null
+++ b/Aircraft/j3cub-yasim-set.xml
@@ -0,0 +1,63 @@
+<?xml version="1.0"?>
+<!--
+************************************************************************
+Piper J3 Cub simulation config. This files ties together all the components
+used by FGFS to represent the J3 Cub. Components include the flight data 
+model, instrument panel, and external 3D model.
+3D models can be downloaded from http://home.t-online.de/home/Wolfram.Kuss/
+************************************************************************
+-->
+
+<PropertyList>
+ <sim>
+  <flight-model>yasim</flight-model>
+  <aero>j3cub</aero>
+  <fuel-fraction>0.8</fuel-fraction>
+
+  <sound>
+   <audible>true</audible>
+   <path>Aircraft/c172/c172-sound.xml</path>
+  </sound>
+
+  <panel>
+   <visibility archive="n">false</visibility>
+  </panel>
+
+  <model>
+   <path archive="y">Aircraft/c172/Models/c172-dpm.xml</path>
+  </model>
+
+  <view>
+   <internal archive="y">true</internal>
+   <config>
+     <x-offset-m archive="y">-0.25</x-offset-m>
+     <y-offset-m archive="y">0.20</y-offset-m>
+     <z-offset-m archive="y">0.66</z-offset-m>
+   </config>
+  </view>
+
+  <current-view>
+   <pitch-offset-deg>-13</pitch-offset-deg>
+  </current-view>
+
+ </sim>
+
+ <controls>
+  <magnetos>3</magnetos>
+ </controls>
+
+ <!-- An autopilot on a Cub??? -->  
+ <autopilot>
+   <config>
+     <min-climb-speed-kt type="float">48.0</min-climb-speed-kt>
+     <best-climb-speed-kt type="float">56.0</best-climb-speed-kt>
+     <target-climb-rate-fpm type="float">400.0</target-climb-rate-fpm>
+     <target-descent-rate-fpm type="float">1000.0</target-descent-rate-fpm>
+     <elevator-adj-factor type="float">6000.0</elevator-adj-factor>
+     <integral-contribution type="float">0.008</integral-contribution> 
+     <zero-pitch-throttle type="float">0.35</zero-pitch-throttle>
+     <zero-pitch-trim-full-throttle type="float">0.001</zero-pitch-trim-full-throttle>
+   </config>
+ </autopilot>
+
+</PropertyList>