diff --git a/gpkitmodels/GP/aircraft/tail/empennage.py b/gpkitmodels/GP/aircraft/tail/empennage.py
index 0ba09422..7ec18ea0 100644
--- a/gpkitmodels/GP/aircraft/tail/empennage.py
+++ b/gpkitmodels/GP/aircraft/tail/empennage.py
@@ -4,7 +4,7 @@
 from .vertical_tail import VerticalTail
 from .tail_boom import TailBoom, TailBoomState
 
-#pylint: disable=attribute-defined-outside-init
+#pylint: disable=attribute-defined-outside-init, no-member
 class Empennage(Model):
     "empennage model, consisting of vertical, horizontal and tailboom"
     def setup(self):
@@ -12,9 +12,9 @@ def setup(self):
         W = Variable("W", "lbf", "empennage weight")
 
         self.htail = HorizontalTail()
-        self.htail.substitutions.update({"m_{fac}": 1.1})
+        self.htail.substitutions.update({self.htail.mfac: 1.1})
         self.vtail = VerticalTail()
-        self.vtail.substitutions.update({"m_{fac}": 1.1})
+        self.vtail.substitutions.update({self.vtail.mfac: 1.1})
         self.tailboom = TailBoom()
         self.components = [self.htail, self.vtail, self.tailboom]
 
diff --git a/gpkitmodels/GP/aircraft/wing/wing.py b/gpkitmodels/GP/aircraft/wing/wing.py
index b1a1d141..9548ecbe 100644
--- a/gpkitmodels/GP/aircraft/wing/wing.py
+++ b/gpkitmodels/GP/aircraft/wing/wing.py
@@ -137,12 +137,12 @@ def setup(self, static, state,
 
 class Wing(Model):
     """
-    Aicraft wing model for constant tapered wing
-    INPUTS
-    ------
-    N : int             number of sections
-    lam : float         taper ratio
-    hollow: boolean     True if wing is not hollow (filled with foam)
+    Wing Model
+
+    Variables
+    ---------
+    W                   [lbf]       wing weight
+    mfac        1.2     [-]         wing weight margin factor
     """
 
     sparModel = CapSpar
@@ -150,12 +150,10 @@ class Wing(Model):
     flight_model = WingAero
 
     def setup(self, N=5):
+        exec parse_variables(Wing.__doc__)
 
         self.N = N
 
-        W = Variable("W", "lbf", "wing weight")
-        mfac = Variable("m_{fac}", 1.2, "-", "wing weight margin factor")
-
         self.planform = Planform(N)
         self.skin = WingSkin(self.planform)
         self.components = [self.skin]