diff --git a/gpkitmodels/SP/SimPleAC/SimPleAC.py b/gpkitmodels/SP/SimPleAC/SimPleAC.py
index c53f093f..67971bb5 100644
--- a/gpkitmodels/SP/SimPleAC/SimPleAC.py
+++ b/gpkitmodels/SP/SimPleAC/SimPleAC.py
@@ -17,9 +17,9 @@ def SimPleAC():
     S_wetratio = Variable("(\\frac{S}{S_{wet}})", 2.075, "-", "wetted area ratio", pr=3.)
     tau        = Variable("\\tau", 0.12, "-", "airfoil thickness to chord ratio", pr=10.)
     W_W_coeff1 = Variable("W_{W_{coeff1}}", 2e-5, "1/m",
-                          "Wing Weight Coefficent 1", pr= 30.) #orig  12e-5
+                          "wing weight coefficent 1", pr= 30.) #orig  12e-5
     W_W_coeff2 = Variable("W_{W_{coeff2}}", 60., "Pa",
-                          "Wing Weight Coefficent 2", pr=10.)
+                          "wing weight coefficent 2", pr=10.)
     p_labor = Variable('p_{labor}',1.,'1/min','cost of labor', pr = 20.)
 
     # Dimensional constants
@@ -63,13 +63,12 @@ def SimPleAC():
 
     with SignomialsEnabled():
             # Wing weight model
-            #NOTE: This is a signomial constraint that has been GPified. Could revert back to signomial?
         constraints += [W_w >= W_w_surf + W_w_strc,
                         # W_w_strc >= W_W_coeff1 * (N_ult * A ** 1.5 * ((W_0+V_f_fuse*g*rho_f) * W * S) ** 0.5) / tau, #[GP]
                         W_w_strc**2. >= W_W_coeff1**2. * (N_ult**2. * A ** 3. * ((W_0+V_f_fuse*g*rho_f) * W * S)) / tau**2.,
                         W_w_surf >= W_W_coeff2 * S]
 
-    # and the rest of the models
+            # Weight and aerodynamics model
         constraints += [LoD == C_L/C_D,
                     D >= 0.5 * rho * S * C_D * V ** 2,
                     Re <= (rho / mu) * V * (S / A) ** 0.5,
@@ -77,17 +76,18 @@ def SimPleAC():
                     T_flight >= Range / V,
                     W_0 + W_w + 0.5 * W_f <= 0.5 * rho * S * C_L * V ** 2,
                     W <= 0.5 * rho * S * C_Lmax * V_min ** 2,
-                    W >= W_0 + W_w + W_f,
-                    V_f == W_f / g / rho_f,
+                    W >= W_0 + W_w + W_f]
+            # Fuel volume model 
+        constraints +=[V_f == W_f / g / rho_f,
                     V_f_avail <= V_f_wing + V_f_fuse, #[SP]
-                    V_f_wing**2 <= 0.0009*S**3/A*tau**2, #linear with b and tau, quadratic with chord!
+                    V_f_wing**2 <= 0.0009*S**3/A*tau**2, # linear with b and tau, quadratic with chord
                     V_f_fuse <= 10*units('m')*CDA0,
                         #TODO: Reduce volume available by the structure!
                     V_f_avail >= V_f,
                     W_f >= TSFC * T_flight * D]
 
     # return Model(W_f/LoD, constraints)
-    #return Model(D, constraints)
+    # return Model(D, constraints)
     return Model(W_f, constraints)
     # return Model(W,constraints)
     # return Model(W_f*T_flight,constraints)