diff --git a/aerodynamic_analysis/src/methods/semiEmpiricalHighLiftAdaption.cpp b/aerodynamic_analysis/src/methods/semiEmpiricalHighLiftAdaption.cpp
index d2a937d76882b39f30c6ffdc99aeb87a28627327..91a6468e73003a0e7f59ba2f7d747256950ee7ee 100644
--- a/aerodynamic_analysis/src/methods/semiEmpiricalHighLiftAdaption.cpp
+++ b/aerodynamic_analysis/src/methods/semiEmpiricalHighLiftAdaption.cpp
@@ -106,41 +106,37 @@ void semiEmpiricalHighLiftAdaption::processHighLiftDevices() {
         leadingEdgeHighLiftDevices.at(deviceID).innerSpan_abs = getHalfSpan(theMainWing) * fabs(leadingEdgeHighLiftDevices.at(deviceID).innerSpan_rel);
         leadingEdgeHighLiftDevices.at(deviceID).outerSpan_abs = getHalfSpan(theMainWing) * fabs(leadingEdgeHighLiftDevices.at(deviceID).outerSpan_rel);
         leadingEdgeHighLiftDevices.at(deviceID).span = fabs(leadingEdgeHighLiftDevices.at(deviceID).outerSpan_abs - leadingEdgeHighLiftDevices.at(deviceID).innerSpan_abs);
-        leadingEdgeHighLiftDevices.at(deviceID).c_rel_avg = 0.25 * (leadingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition
-                                                                + leadingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition
-                                                                + leadingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition
-                                                                + leadingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition);
+        leadingEdgeHighLiftDevices.at(deviceID).c_rel_avg = 0.5 * ((leadingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition
+                                                                    - leadingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition)
+                                                                   + (leadingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition
+                                                                    - leadingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition));
         double delta_x_rel_HL = 0.02;  // distance hinge line (apparently from Raymer..)
         leadingEdgeHighLiftDevices.at(deviceID).x_rel_hinge = leadingEdgeHighLiftDevices.at(deviceID).c_rel_avg - delta_x_rel_HL;
         leadingEdgeHighLiftDevices.at(deviceID).phiHL = getLocalSweep(theMainWing,
                                                             0.5 * (leadingEdgeHighLiftDevices.at(deviceID).innerSpan_abs + leadingEdgeHighLiftDevices.at(deviceID).outerSpan_abs),
                                                             leadingEdgeHighLiftDevices.at(deviceID).x_rel_hinge, "DEGREE");
-        double chordInboard = getLocalChordLength(theMainWing, leadingEdgeHighLiftDevices.at(deviceID).innerSpan_abs)
-                                    * fabs(leadingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition - leadingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition);
-        double chordOutboard = getLocalChordLength(theMainWing, leadingEdgeHighLiftDevices.at(deviceID).outerSpan_abs)
-                                    * fabs(leadingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition - leadingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition);
+        double chordInboardWing = getLocalChordLength(theMainWing, leadingEdgeHighLiftDevices.at(deviceID).innerSpan_abs);
+        double chordOutboardWing = getLocalChordLength(theMainWing, leadingEdgeHighLiftDevices.at(deviceID).outerSpan_abs);
         // area is calculated for both devices, because symmetry
-        leadingEdgeHighLiftDevices.at(deviceID).coveredA = leadingEdgeHighLiftDevices.at(deviceID).span * (chordInboard + chordOutboard);
+        leadingEdgeHighLiftDevices.at(deviceID).coveredA = leadingEdgeHighLiftDevices.at(deviceID).span * (chordInboardWing + chordOutboardWing);
     }
     for (size_t deviceID(0); deviceID < trailingEdgeHighLiftDevices.size(); ++deviceID) {
         trailingEdgeHighLiftDevices.at(deviceID).innerSpan_abs = getHalfSpan(theMainWing) * fabs(trailingEdgeHighLiftDevices.at(deviceID).innerSpan_rel);
         trailingEdgeHighLiftDevices.at(deviceID).outerSpan_abs = getHalfSpan(theMainWing) * fabs(trailingEdgeHighLiftDevices.at(deviceID).outerSpan_rel);
         trailingEdgeHighLiftDevices.at(deviceID).span = fabs(trailingEdgeHighLiftDevices.at(deviceID).outerSpan_abs - trailingEdgeHighLiftDevices.at(deviceID).innerSpan_abs);
-        trailingEdgeHighLiftDevices.at(deviceID).c_rel_avg = 0.25 * (trailingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition
-                                                                + trailingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition
-                                                                + trailingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition
-                                                                + trailingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition);
+        trailingEdgeHighLiftDevices.at(deviceID).c_rel_avg = 0.5 * ((trailingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition
+                                                                    - trailingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition)
+                                                                   + (trailingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition
+                                                                    -trailingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition));
         double delta_x_rel_HL = 0.02;  // distance hinge line (apparently from Raymer..)
         trailingEdgeHighLiftDevices.at(deviceID).x_rel_hinge = 1. - trailingEdgeHighLiftDevices.at(deviceID).c_rel_avg + delta_x_rel_HL;
         trailingEdgeHighLiftDevices.at(deviceID).phiHL = getLocalSweep(theMainWing,
                                                             0.5 * (trailingEdgeHighLiftDevices.at(deviceID).innerSpan_abs + trailingEdgeHighLiftDevices.at(deviceID).outerSpan_abs),
                                                             trailingEdgeHighLiftDevices.at(deviceID).x_rel_hinge, "DEGREE");
-        double chordInboard = getLocalChordLength(theMainWing, trailingEdgeHighLiftDevices.at(deviceID).innerSpan_abs)
-                                    * fabs(trailingEdgeHighLiftDevices.at(deviceID).innerRelAftChordPosition - trailingEdgeHighLiftDevices.at(deviceID).innerRelFwdChordPosition);
-        double chordOutboard = getLocalChordLength(theMainWing, trailingEdgeHighLiftDevices.at(deviceID).outerSpan_abs)
-                                    * fabs(trailingEdgeHighLiftDevices.at(deviceID).outerRelAftChordPosition - trailingEdgeHighLiftDevices.at(deviceID).outerRelFwdChordPosition);
+        double chordInboardWing = getLocalChordLength(theMainWing, trailingEdgeHighLiftDevices.at(deviceID).innerSpan_abs);
+        double chordOutboardWing = getLocalChordLength(theMainWing, trailingEdgeHighLiftDevices.at(deviceID).outerSpan_abs);
         // area is calculated for both devices, because symmetry
-        trailingEdgeHighLiftDevices.at(deviceID).coveredA = leadingEdgeHighLiftDevices.at(deviceID).span * (chordInboard + chordOutboard);
+        trailingEdgeHighLiftDevices.at(deviceID).coveredA = leadingEdgeHighLiftDevices.at(deviceID).span * (chordInboardWing + chordOutboardWing);
     }
 }