diff --git a/conf/airframes/CDW/ChimuLisaFw.xml b/conf/airframes/CDW/ChimuLisaFw.xml
index 913735d4dc..8311664aaf 100644
--- a/conf/airframes/CDW/ChimuLisaFw.xml
+++ b/conf/airframes/CDW/ChimuLisaFw.xml
@@ -69,7 +69,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/CDW/ChimuTinyFw.xml b/conf/airframes/CDW/ChimuTinyFw.xml
index 64fe437952..6b78fd2800 100644
--- a/conf/airframes/CDW/ChimuTinyFw.xml
+++ b/conf/airframes/CDW/ChimuTinyFw.xml
@@ -93,7 +93,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/CDW/ChimuTinyFwSpi.xml b/conf/airframes/CDW/ChimuTinyFwSpi.xml
index f025bdb22f..430e959fde 100644
--- a/conf/airframes/CDW/ChimuTinyFwSpi.xml
+++ b/conf/airframes/CDW/ChimuTinyFwSpi.xml
@@ -93,7 +93,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/firestorm.xml b/conf/airframes/ENAC/fixed-wing/firestorm.xml
index 58de7bf5ff..fff31ef897 100644
--- a/conf/airframes/ENAC/fixed-wing/firestorm.xml
+++ b/conf/airframes/ENAC/fixed-wing/firestorm.xml
@@ -149,7 +149,7 @@
 
     <!-- define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/ -->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/funjet2.xml b/conf/airframes/ENAC/fixed-wing/funjet2.xml
index d08f05c4d3..4bcde918ba 100644
--- a/conf/airframes/ENAC/fixed-wing/funjet2.xml
+++ b/conf/airframes/ENAC/fixed-wing/funjet2.xml
@@ -144,7 +144,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/funjet2_nc.xml b/conf/airframes/ENAC/fixed-wing/funjet2_nc.xml
index 00b9fc079c..fb72b8de8e 100644
--- a/conf/airframes/ENAC/fixed-wing/funjet2_nc.xml
+++ b/conf/airframes/ENAC/fixed-wing/funjet2_nc.xml
@@ -149,7 +149,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/funjet2_new.xml b/conf/airframes/ENAC/fixed-wing/funjet2_new.xml
index fa923d7b4d..7cee529be2 100644
--- a/conf/airframes/ENAC/fixed-wing/funjet2_new.xml
+++ b/conf/airframes/ENAC/fixed-wing/funjet2_new.xml
@@ -149,7 +149,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/funjet3.xml b/conf/airframes/ENAC/fixed-wing/funjet3.xml
index 4d63332ab4..ce2050fdd1 100644
--- a/conf/airframes/ENAC/fixed-wing/funjet3.xml
+++ b/conf/airframes/ENAC/fixed-wing/funjet3.xml
@@ -120,7 +120,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.159999996424"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.159999996424"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="5."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/merlin.xml b/conf/airframes/ENAC/fixed-wing/merlin.xml
index 0e14f89944..d2628cb7a1 100644
--- a/conf/airframes/ENAC/fixed-wing/merlin.xml
+++ b/conf/airframes/ENAC/fixed-wing/merlin.xml
@@ -119,7 +119,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/minimag1.xml b/conf/airframes/ENAC/fixed-wing/minimag1.xml
index dd064f520f..e61a5cfec8 100644
--- a/conf/airframes/ENAC/fixed-wing/minimag1.xml
+++ b/conf/airframes/ENAC/fixed-wing/minimag1.xml
@@ -131,7 +131,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/drops.xml b/conf/airframes/ENAC/fixed-wing/obsolete/drops.xml
index 8063458015..4d8785142a 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/drops.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/drops.xml
@@ -132,7 +132,7 @@ on<!DOCTYPE airframe SYSTEM "airframe.dtd">
 
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/funjet1.xml b/conf/airframes/ENAC/fixed-wing/obsolete/funjet1.xml
index bb92329b6f..2aa0faac18 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/funjet1.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/funjet1.xml
@@ -115,7 +115,7 @@
 
     <!-- define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/ -->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.104000002146"/>
+    <define name="ALTITUDE_PGAIN" value="0.104000002146"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/malolo_sim.xml b/conf/airframes/ENAC/fixed-wing/obsolete/malolo_sim.xml
index b2e23ff21b..9c00c23920 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/malolo_sim.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/malolo_sim.xml
@@ -113,7 +113,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/slayer2.xml b/conf/airframes/ENAC/fixed-wing/obsolete/slayer2.xml
index 2a0102d11f..2713996fa7 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/slayer2.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/slayer2.xml
@@ -116,7 +116,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.065"/>
+    <define name="ALTITUDE_PGAIN" value="0.065"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/solarstorm.xml b/conf/airframes/ENAC/fixed-wing/obsolete/solarstorm.xml
index 32e1144284..3297ee6a28 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/solarstorm.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/solarstorm.xml
@@ -118,7 +118,7 @@
 
     <!-- define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/ -->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/obsolete/spocII.xml b/conf/airframes/ENAC/fixed-wing/obsolete/spocII.xml
index 4d633cae3f..62dca8343e 100644
--- a/conf/airframes/ENAC/fixed-wing/obsolete/spocII.xml
+++ b/conf/airframes/ENAC/fixed-wing/obsolete/spocII.xml
@@ -120,7 +120,7 @@
 
     <!-- define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/ -->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/overview.xml b/conf/airframes/ENAC/fixed-wing/overview.xml
index d1e1abcec8..1546c72ee2 100644
--- a/conf/airframes/ENAC/fixed-wing/overview.xml
+++ b/conf/airframes/ENAC/fixed-wing/overview.xml
@@ -119,7 +119,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/soarzi.xml b/conf/airframes/ENAC/fixed-wing/soarzi.xml
index 9129f78984..f01c709ad3 100644
--- a/conf/airframes/ENAC/fixed-wing/soarzi.xml
+++ b/conf/airframes/ENAC/fixed-wing/soarzi.xml
@@ -110,7 +110,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="7.4" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/spocIII-1.xml b/conf/airframes/ENAC/fixed-wing/spocIII-1.xml
index 2cffe6c4b4..f23adbdb23 100644
--- a/conf/airframes/ENAC/fixed-wing/spocIII-1.xml
+++ b/conf/airframes/ENAC/fixed-wing/spocIII-1.xml
@@ -121,7 +121,7 @@
 
     <!-- define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/ -->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/spocIII-2.xml b/conf/airframes/ENAC/fixed-wing/spocIII-2.xml
index 698147c950..fb0daee142 100644
--- a/conf/airframes/ENAC/fixed-wing/spocIII-2.xml
+++ b/conf/airframes/ENAC/fixed-wing/spocIII-2.xml
@@ -124,7 +124,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
 
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/spocIII-3.xml b/conf/airframes/ENAC/fixed-wing/spocIII-3.xml
index 4d299c976e..33222d96ad 100644
--- a/conf/airframes/ENAC/fixed-wing/spocIII-3.xml
+++ b/conf/airframes/ENAC/fixed-wing/spocIII-3.xml
@@ -127,7 +127,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
 
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/twinjet2.xml b/conf/airframes/ENAC/fixed-wing/twinjet2.xml
index f6afa20cea..f1de7a00cd 100644
--- a/conf/airframes/ENAC/fixed-wing/twinjet2.xml
+++ b/conf/airframes/ENAC/fixed-wing/twinjet2.xml
@@ -131,7 +131,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.0450000017881"/>
+    <define name="ALTITUDE_PGAIN" value="0.0450000017881"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/ENAC/fixed-wing/weasel.xml b/conf/airframes/ENAC/fixed-wing/weasel.xml
index 4e8b48cc9b..d79e3d5160 100644
--- a/conf/airframes/ENAC/fixed-wing/weasel.xml
+++ b/conf/airframes/ENAC/fixed-wing/weasel.xml
@@ -144,7 +144,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.159999996424"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.159999996424"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="5."/>
 
diff --git a/conf/airframes/LAAS/mmlaas_N1.xml b/conf/airframes/LAAS/mmlaas_N1.xml
index 24b58f81ea..a2d7dd75e8 100644
--- a/conf/airframes/LAAS/mmlaas_N1.xml
+++ b/conf/airframes/LAAS/mmlaas_N1.xml
@@ -140,7 +140,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.15"/>
+    <define name="ALTITUDE_PGAIN" value="0.15"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/LAAS/mmlaas_N2.xml b/conf/airframes/LAAS/mmlaas_N2.xml
index 316967dfbe..6f5ac44349 100644
--- a/conf/airframes/LAAS/mmlaas_N2.xml
+++ b/conf/airframes/LAAS/mmlaas_N2.xml
@@ -136,7 +136,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.15"/>
+    <define name="ALTITUDE_PGAIN" value="0.15"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/LAAS/mmlaas_N3.xml b/conf/airframes/LAAS/mmlaas_N3.xml
index 098d28889e..67442bfe51 100644
--- a/conf/airframes/LAAS/mmlaas_N3.xml
+++ b/conf/airframes/LAAS/mmlaas_N3.xml
@@ -136,7 +136,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.15"/>
+    <define name="ALTITUDE_PGAIN" value="0.15"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml b/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
index cccc0d879e..24daaa0c01 100644
--- a/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
+++ b/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
@@ -130,7 +130,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/Poine/easy_glider1.xml b/conf/airframes/Poine/easy_glider1.xml
index c5361a4c41..6bec91ce31 100644
--- a/conf/airframes/Poine/easy_glider1.xml
+++ b/conf/airframes/Poine/easy_glider1.xml
@@ -97,7 +97,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/Poine/funjet42.xml b/conf/airframes/Poine/funjet42.xml
index f1dca5057c..158f0d26d4 100644
--- a/conf/airframes/Poine/funjet42.xml
+++ b/conf/airframes/Poine/funjet42.xml
@@ -118,7 +118,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/Poine/swift_1.xml b/conf/airframes/Poine/swift_1.xml
index 2f9a957b96..7aaaf1f204 100644
--- a/conf/airframes/Poine/swift_1.xml
+++ b/conf/airframes/Poine/swift_1.xml
@@ -112,7 +112,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/TU_Delft/EasyStartPanTiltCHIMU_SPI.xml b/conf/airframes/TU_Delft/EasyStartPanTiltCHIMU_SPI.xml
index ac96cb4c25..5cdac47292 100644
--- a/conf/airframes/TU_Delft/EasyStartPanTiltCHIMU_SPI.xml
+++ b/conf/airframes/TU_Delft/EasyStartPanTiltCHIMU_SPI.xml
@@ -94,7 +94,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/TU_Delft/MicrojetBR.xml b/conf/airframes/TU_Delft/MicrojetBR.xml
index 8acc51bd39..6285d9f8f8 100644
--- a/conf/airframes/TU_Delft/MicrojetBR.xml
+++ b/conf/airframes/TU_Delft/MicrojetBR.xml
@@ -112,7 +112,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.101000003517"/>
+    <define name="ALTITUDE_PGAIN" value="0.101000003517"/>
     <!-- outer loop saturation max m/s the alt tap can be-->
     <define name="ALTITUDE_MAX_CLIMB" value="4"/>
 
diff --git a/conf/airframes/TU_Delft/MicrojetBRimu.xml b/conf/airframes/TU_Delft/MicrojetBRimu.xml
index 15970180ae..d576a2d42d 100644
--- a/conf/airframes/TU_Delft/MicrojetBRimu.xml
+++ b/conf/airframes/TU_Delft/MicrojetBRimu.xml
@@ -147,7 +147,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.101000003517"/>
+    <define name="ALTITUDE_PGAIN" value="0.101000003517"/>
     <!-- outer loop saturation max m/s the alt tap can be-->
     <define name="ALTITUDE_MAX_CLIMB" value="4"/>
 
diff --git a/conf/airframes/TU_Delft/MicrojetCDW.xml b/conf/airframes/TU_Delft/MicrojetCDW.xml
index d6c6c8e9da..31e1587520 100644
--- a/conf/airframes/TU_Delft/MicrojetCDW.xml
+++ b/conf/airframes/TU_Delft/MicrojetCDW.xml
@@ -131,7 +131,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.01"/>
+    <define name="ALTITUDE_PGAIN" value="0.01"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="4."/>
 
diff --git a/conf/airframes/TU_Delft/Trip50A.xml b/conf/airframes/TU_Delft/Trip50A.xml
index 47af648455..8fe7c2f4ba 100644
--- a/conf/airframes/TU_Delft/Trip50A.xml
+++ b/conf/airframes/TU_Delft/Trip50A.xml
@@ -115,12 +115,12 @@
     <define name="POWER_CTL_BAT_NOMINAL" value="7.6" unit="volt"/>
 
 	<!-- Vertical Outerloop
-		v_ctl_climb_setpoint = ALTITUDE_PGAIN * altitude_error + altitude_pre_climb;
+		v_ctl_climb_setpoint = -ALTITUDE_PGAIN * altitude_error + altitude_pre_climb;
 		BoundAbs(v_ctl_climb_setpoint, V_CTL_ALTITUDE_MAX_CLIMB);
 	-->
 
     <!-- outer loop proportional gain: alt error 5 climb m/s -->
-    <define name="ALTITUDE_PGAIN" value="-0.0750000029802"/>
+    <define name="ALTITUDE_PGAIN" value="0.0750000029802"/>
     <!-- outer loop saturation: m/s-->
     <define name="ALTITUDE_MAX_CLIMB" value="5.0"/>
 
diff --git a/conf/airframes/TU_Delft/skywalker.xml b/conf/airframes/TU_Delft/skywalker.xml
index 13c5323ea3..d0934103de 100644
--- a/conf/airframes/TU_Delft/skywalker.xml
+++ b/conf/airframes/TU_Delft/skywalker.xml
@@ -128,7 +128,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.108000002801"/>
+    <define name="ALTITUDE_PGAIN" value="0.108000002801"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/TU_Delft/skywalkerfiber.xml b/conf/airframes/TU_Delft/skywalkerfiber.xml
index 705c23047f..56d8cd215e 100644
--- a/conf/airframes/TU_Delft/skywalkerfiber.xml
+++ b/conf/airframes/TU_Delft/skywalkerfiber.xml
@@ -254,7 +254,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.108000002801"/>
+    <define name="ALTITUDE_PGAIN" value="0.108000002801"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/delta_wing_minimal_example.xml b/conf/airframes/delta_wing_minimal_example.xml
index d3ef1a0e60..03390ecc18 100644
--- a/conf/airframes/delta_wing_minimal_example.xml
+++ b/conf/airframes/delta_wing_minimal_example.xml
@@ -101,7 +101,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/demo_module.xml b/conf/airframes/demo_module.xml
index 4960475090..87796d5b11 100644
--- a/conf/airframes/demo_module.xml
+++ b/conf/airframes/demo_module.xml
@@ -93,7 +93,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
     <!-- auto throttle inner loop -->
diff --git a/conf/airframes/easy_glider_example.xml b/conf/airframes/easy_glider_example.xml
index 64f0360482..592f0ec4a5 100644
--- a/conf/airframes/easy_glider_example.xml
+++ b/conf/airframes/easy_glider_example.xml
@@ -90,7 +90,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/easystar_ets_example.xml b/conf/airframes/easystar_ets_example.xml
index ca6edfda4f..c8f6cd9762 100644
--- a/conf/airframes/easystar_ets_example.xml
+++ b/conf/airframes/easystar_ets_example.xml
@@ -115,7 +115,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.0" unit="volt"/>
     <!-- outer loop -->
-    <define name="ALTITUDE_PGAIN" value="-0.075" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.075" unit="(m/s)/m"/>
     <define name="ALTITUDE_MAX_CLIMB" value="4." unit="m/s"/>
     <!-- auto throttle inner loop -->
     <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.5" unit="%"/>
diff --git a/conf/airframes/easystar_example.xml b/conf/airframes/easystar_example.xml
index 55359f87af..ac084df143 100644
--- a/conf/airframes/easystar_example.xml
+++ b/conf/airframes/easystar_example.xml
@@ -109,7 +109,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.0" unit="volt"/>
     <!-- outer loop -->
-    <define name="ALTITUDE_PGAIN" value="-0.075" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.075" unit="(m/s)/m"/>
     <define name="ALTITUDE_MAX_CLIMB" value="4." unit="m/s"/>
     <!-- auto throttle inner loop -->
     <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.5" unit="%"/>
diff --git a/conf/airframes/example_twog_analogimu.xml b/conf/airframes/example_twog_analogimu.xml
index 1438d76fd1..c3c7b088bc 100644
--- a/conf/airframes/example_twog_analogimu.xml
+++ b/conf/airframes/example_twog_analogimu.xml
@@ -117,7 +117,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/flixr_discovery.xml b/conf/airframes/flixr_discovery.xml
index 5e1086b8df..1d5c2dba24 100644
--- a/conf/airframes/flixr_discovery.xml
+++ b/conf/airframes/flixr_discovery.xml
@@ -242,7 +242,7 @@ http://paparazzi.enac.fr/w/index.php?title=Theory_of_Operation
     <define name="POWER_CTL_BAT_NOMINAL" value="11.2" unit="volt"/>
 
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.04" unit="(m/s)/m"/>
 
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2." unit="m/s"/>
diff --git a/conf/airframes/funjet_cam_example.xml b/conf/airframes/funjet_cam_example.xml
index c656caa2e5..eec31b0c7b 100644
--- a/conf/airframes/funjet_cam_example.xml
+++ b/conf/airframes/funjet_cam_example.xml
@@ -130,7 +130,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/funjet_example.xml b/conf/airframes/funjet_example.xml
index 11395c3d09..b438800498 100644
--- a/conf/airframes/funjet_example.xml
+++ b/conf/airframes/funjet_example.xml
@@ -121,7 +121,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/jsbsim.xml b/conf/airframes/jsbsim.xml
index b54d3a608c..884282fc63 100644
--- a/conf/airframes/jsbsim.xml
+++ b/conf/airframes/jsbsim.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mentor_tum.xml b/conf/airframes/mentor_tum.xml
index 75506ead78..8738c37351 100644
--- a/conf/airframes/mentor_tum.xml
+++ b/conf/airframes/mentor_tum.xml
@@ -143,7 +143,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="14.8" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.04" unit="(m/s)/m"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2.5" unit="m/s"/>
 
diff --git a/conf/airframes/microjet_example.xml b/conf/airframes/microjet_example.xml
index d8e1c2741b..f10836eb47 100644
--- a/conf/airframes/microjet_example.xml
+++ b/conf/airframes/microjet_example.xml
@@ -104,7 +104,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/extra/press_t.xml b/conf/airframes/mm/extra/press_t.xml
index 4dc6cac213..9414e57a77 100644
--- a/conf/airframes/mm/extra/press_t.xml
+++ b/conf/airframes/mm/extra/press_t.xml
@@ -109,7 +109,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/extra/probe_t.xml b/conf/airframes/mm/extra/probe_t.xml
index 122ce88b1b..5fa620602f 100644
--- a/conf/airframes/mm/extra/probe_t.xml
+++ b/conf/airframes/mm/extra/probe_t.xml
@@ -129,7 +129,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/extra/turbine_trigger.xml b/conf/airframes/mm/extra/turbine_trigger.xml
index 832bcc8003..c7231e6f9f 100644
--- a/conf/airframes/mm/extra/turbine_trigger.xml
+++ b/conf/airframes/mm/extra/turbine_trigger.xml
@@ -114,7 +114,7 @@
 
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
     <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.45"/>
     <define name="AUTO_THROTTLE_MIN_CRUISE_THROTTLE" value="0.25"/>
diff --git a/conf/airframes/mm/fixed-wing/drops.xml b/conf/airframes/mm/fixed-wing/drops.xml
index adbb39135d..c632d53023 100644
--- a/conf/airframes/mm/fixed-wing/drops.xml
+++ b/conf/airframes/mm/fixed-wing/drops.xml
@@ -148,7 +148,7 @@
 
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjet43.xml b/conf/airframes/mm/fixed-wing/funjet43.xml
index 10dd68e24f..eabe9f2e5c 100644
--- a/conf/airframes/mm/fixed-wing/funjet43.xml
+++ b/conf/airframes/mm/fixed-wing/funjet43.xml
@@ -132,7 +132,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetdca.xml b/conf/airframes/mm/fixed-wing/funjetdca.xml
index 4c2f963df9..ff1d3c25d2 100644
--- a/conf/airframes/mm/fixed-wing/funjetdca.xml
+++ b/conf/airframes/mm/fixed-wing/funjetdca.xml
@@ -142,7 +142,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetdcb.xml b/conf/airframes/mm/fixed-wing/funjetdcb.xml
index 80446620d3..663bc9db78 100644
--- a/conf/airframes/mm/fixed-wing/funjetdcb.xml
+++ b/conf/airframes/mm/fixed-wing/funjetdcb.xml
@@ -142,7 +142,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetdcc.xml b/conf/airframes/mm/fixed-wing/funjetdcc.xml
index 7a4f87e9bc..ef825e6177 100644
--- a/conf/airframes/mm/fixed-wing/funjetdcc.xml
+++ b/conf/airframes/mm/fixed-wing/funjetdcc.xml
@@ -142,7 +142,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjeteth1.xml b/conf/airframes/mm/fixed-wing/funjeteth1.xml
index e679eeacf3..a2dd77a337 100644
--- a/conf/airframes/mm/fixed-wing/funjeteth1.xml
+++ b/conf/airframes/mm/fixed-wing/funjeteth1.xml
@@ -105,7 +105,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="10" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjeteth2.xml b/conf/airframes/mm/fixed-wing/funjeteth2.xml
index 5a666fe84c..a726380c8a 100644
--- a/conf/airframes/mm/fixed-wing/funjeteth2.xml
+++ b/conf/airframes/mm/fixed-wing/funjeteth2.xml
@@ -106,7 +106,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="10" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetfmi1.xml b/conf/airframes/mm/fixed-wing/funjetfmi1.xml
index 429b9eec0c..df29431aab 100644
--- a/conf/airframes/mm/fixed-wing/funjetfmi1.xml
+++ b/conf/airframes/mm/fixed-wing/funjetfmi1.xml
@@ -104,7 +104,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetfmi2.xml b/conf/airframes/mm/fixed-wing/funjetfmi2.xml
index 3f9b9f56b4..12a3a94068 100644
--- a/conf/airframes/mm/fixed-wing/funjetfmi2.xml
+++ b/conf/airframes/mm/fixed-wing/funjetfmi2.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetfmi3.xml b/conf/airframes/mm/fixed-wing/funjetfmi3.xml
index 72372a383c..d15f38ad64 100644
--- a/conf/airframes/mm/fixed-wing/funjetfmi3.xml
+++ b/conf/airframes/mm/fixed-wing/funjetfmi3.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi1.xml b/conf/airframes/mm/fixed-wing/funjetgfi1.xml
index 90379b7bab..88e6476785 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi1.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi1.xml
@@ -102,7 +102,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi3.xml b/conf/airframes/mm/fixed-wing/funjetgfi3.xml
index 5dfce50d10..cc0dabc6d2 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi3.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi3.xml
@@ -101,7 +101,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="10.0" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.024"/>
+    <define name="ALTITUDE_PGAIN" value="0.024"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi4.xml b/conf/airframes/mm/fixed-wing/funjetgfi4.xml
index 8e63dbcc0f..c7201bff39 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi4.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi4.xml
@@ -101,7 +101,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="10" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.024"/>
+    <define name="ALTITUDE_PGAIN" value="0.024"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi5.xml b/conf/airframes/mm/fixed-wing/funjetgfi5.xml
index 73f5659005..3db64f77ce 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi5.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi5.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi6.xml b/conf/airframes/mm/fixed-wing/funjetgfi6.xml
index 34ce308509..9a5c61ae3b 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi6.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi6.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi7.xml b/conf/airframes/mm/fixed-wing/funjetgfi7.xml
index 52f693da86..86f94cd668 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi7.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi7.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi8.xml b/conf/airframes/mm/fixed-wing/funjetgfi8.xml
index ac8b1d932e..c22f36eb26 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi8.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi8.xml
@@ -138,7 +138,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetgfi9.xml b/conf/airframes/mm/fixed-wing/funjetgfi9.xml
index 63dbbe4fa9..e04398612c 100644
--- a/conf/airframes/mm/fixed-wing/funjetgfi9.xml
+++ b/conf/airframes/mm/fixed-wing/funjetgfi9.xml
@@ -103,7 +103,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetlisa.xml b/conf/airframes/mm/fixed-wing/funjetlisa.xml
index 2749bcda4a..2f60992b26 100644
--- a/conf/airframes/mm/fixed-wing/funjetlisa.xml
+++ b/conf/airframes/mm/fixed-wing/funjetlisa.xml
@@ -119,7 +119,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetlisam.xml b/conf/airframes/mm/fixed-wing/funjetlisam.xml
index 227bd13066..59fb28d262 100644
--- a/conf/airframes/mm/fixed-wing/funjetlisam.xml
+++ b/conf/airframes/mm/fixed-wing/funjetlisam.xml
@@ -119,7 +119,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetmm.xml b/conf/airframes/mm/fixed-wing/funjetmm.xml
index 8d755fe12a..96e420621c 100644
--- a/conf/airframes/mm/fixed-wing/funjetmm.xml
+++ b/conf/airframes/mm/fixed-wing/funjetmm.xml
@@ -174,7 +174,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/funjetmm2.xml b/conf/airframes/mm/fixed-wing/funjetmm2.xml
index f2bafaf219..aff387909b 100644
--- a/conf/airframes/mm/fixed-wing/funjetmm2.xml
+++ b/conf/airframes/mm/fixed-wing/funjetmm2.xml
@@ -109,7 +109,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/fw_ins_arduimu.xml b/conf/airframes/mm/fixed-wing/fw_ins_arduimu.xml
index 95e9e6626f..f84c35738f 100644
--- a/conf/airframes/mm/fixed-wing/fw_ins_arduimu.xml
+++ b/conf/airframes/mm/fixed-wing/fw_ins_arduimu.xml
@@ -134,7 +134,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/merlin.xml b/conf/airframes/mm/fixed-wing/merlin.xml
index 99252a54fc..1410519bbe 100644
--- a/conf/airframes/mm/fixed-wing/merlin.xml
+++ b/conf/airframes/mm/fixed-wing/merlin.xml
@@ -98,7 +98,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/miniwing.xml b/conf/airframes/mm/fixed-wing/miniwing.xml
index e5652f773c..315f24b678 100644
--- a/conf/airframes/mm/fixed-wing/miniwing.xml
+++ b/conf/airframes/mm/fixed-wing/miniwing.xml
@@ -101,7 +101,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="7.4" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/slowfast.xml b/conf/airframes/mm/fixed-wing/slowfast.xml
index f75cfe7ec0..441258bff1 100644
--- a/conf/airframes/mm/fixed-wing/slowfast.xml
+++ b/conf/airframes/mm/fixed-wing/slowfast.xml
@@ -132,7 +132,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/slowfast2.xml b/conf/airframes/mm/fixed-wing/slowfast2.xml
index 00ccacc125..fa51a248e3 100644
--- a/conf/airframes/mm/fixed-wing/slowfast2.xml
+++ b/conf/airframes/mm/fixed-wing/slowfast2.xml
@@ -138,7 +138,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/fixed-wing/twinstarmm.xml b/conf/airframes/mm/fixed-wing/twinstarmm.xml
index 3cd0098b02..fe41567d28 100644
--- a/conf/airframes/mm/fixed-wing/twinstarmm.xml
+++ b/conf/airframes/mm/fixed-wing/twinstarmm.xml
@@ -125,7 +125,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/hangar/black_one.xml b/conf/airframes/mm/hangar/black_one.xml
index 495b6b29a5..04ac08009a 100644
--- a/conf/airframes/mm/hangar/black_one.xml
+++ b/conf/airframes/mm/hangar/black_one.xml
@@ -123,7 +123,7 @@
 
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.025"/>
+    <define name="ALTITUDE_PGAIN" value="0.025"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/hangar/glass_one1.xml b/conf/airframes/mm/hangar/glass_one1.xml
index 2602279579..d61e4f640e 100644
--- a/conf/airframes/mm/hangar/glass_one1.xml
+++ b/conf/airframes/mm/hangar/glass_one1.xml
@@ -112,7 +112,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="8.4" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="4."/>
 
diff --git a/conf/airframes/mm/hangar/glass_one2.xml b/conf/airframes/mm/hangar/glass_one2.xml
index 7f24ebbc53..c3e8343e00 100644
--- a/conf/airframes/mm/hangar/glass_one2.xml
+++ b/conf/airframes/mm/hangar/glass_one2.xml
@@ -96,7 +96,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="8.4" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="4."/>
 
diff --git a/conf/airframes/mm/hangar/glass_one3.xml b/conf/airframes/mm/hangar/glass_one3.xml
index 32622b4ced..665f098017 100644
--- a/conf/airframes/mm/hangar/glass_one3.xml
+++ b/conf/airframes/mm/hangar/glass_one3.xml
@@ -113,7 +113,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="8.4" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="4."/>
 
diff --git a/conf/airframes/mm/hangar/lila.xml b/conf/airframes/mm/hangar/lila.xml
index 13c5c9b312..e4a45d4cef 100644
--- a/conf/airframes/mm/hangar/lila.xml
+++ b/conf/airframes/mm/hangar/lila.xml
@@ -115,7 +115,7 @@
 
     <!--define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/hangar/mac06a.xml b/conf/airframes/mm/hangar/mac06a.xml
index 9c305700e8..74720aab50 100644
--- a/conf/airframes/mm/hangar/mac06a.xml
+++ b/conf/airframes/mm/hangar/mac06a.xml
@@ -108,7 +108,7 @@
 
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/mm/hangar/red_one.xml b/conf/airframes/mm/hangar/red_one.xml
index 958f00df41..0853322166 100644
--- a/conf/airframes/mm/hangar/red_one.xml
+++ b/conf/airframes/mm/hangar/red_one.xml
@@ -122,7 +122,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!--define name="POWER_CTL_BAT_NOMINAL" value="8.4" unit="volt"/-->
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="4."/>
 
diff --git a/conf/airframes/obsolete/easystar2.xml b/conf/airframes/obsolete/easystar2.xml
index 865b98335d..2353bd6e31 100644
--- a/conf/airframes/obsolete/easystar2.xml
+++ b/conf/airframes/obsolete/easystar2.xml
@@ -103,7 +103,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.0" unit="volt"/>
     <!-- outer loop -->
-    <define name="ALTITUDE_PGAIN" value="-0.075" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.075" unit="(m/s)/m"/>
     <define name="ALTITUDE_MAX_CLIMB" value="4." unit="m/s"/>
     <!-- auto throttle inner loop -->
     <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.5" unit="%"/>
diff --git a/conf/airframes/obsolete/hitl_usb.xml b/conf/airframes/obsolete/hitl_usb.xml
index 271def9b9e..2aa099933b 100644
--- a/conf/airframes/obsolete/hitl_usb.xml
+++ b/conf/airframes/obsolete/hitl_usb.xml
@@ -49,7 +49,7 @@
 
 	<define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
 	<!-- outer loop proportional gain -->
-	<define name="ALTITUDE_PGAIN" value="-0.03"/>
+	<define name="ALTITUDE_PGAIN" value="0.03"/>
 	<!-- outer loop saturation -->
 	<define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/kalscott_easystar.xml b/conf/airframes/obsolete/kalscott_easystar.xml
index 97168e48a9..bbce1ae25d 100644
--- a/conf/airframes/obsolete/kalscott_easystar.xml
+++ b/conf/airframes/obsolete/kalscott_easystar.xml
@@ -90,7 +90,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.0" unit="volt"/>
     <!-- outer loop -->
-    <define name="ALTITUDE_PGAIN" value="-0.075" unit="(m/s)/m"/>
+    <define name="ALTITUDE_PGAIN" value="0.075" unit="(m/s)/m"/>
     <define name="ALTITUDE_MAX_CLIMB" value="4." unit="m/s"/>
     <!-- auto throttle inner loop -->
     <define name="AUTO_THROTTLE_NOMINAL_CRUISE_THROTTLE" value="0.5" unit="%"/>
diff --git a/conf/airframes/obsolete/malolo_sim.xml b/conf/airframes/obsolete/malolo_sim.xml
index eeab12d335..c174862755 100644
--- a/conf/airframes/obsolete/malolo_sim.xml
+++ b/conf/airframes/obsolete/malolo_sim.xml
@@ -112,7 +112,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjet5.xml b/conf/airframes/obsolete/microjet5.xml
index 946fb86383..f31b8978be 100644
--- a/conf/airframes/obsolete/microjet5.xml
+++ b/conf/airframes/obsolete/microjet5.xml
@@ -109,7 +109,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
 
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjet5_tp_auto.xml b/conf/airframes/obsolete/microjet5_tp_auto.xml
index be614631f5..afe322f10d 100644
--- a/conf/airframes/obsolete/microjet5_tp_auto.xml
+++ b/conf/airframes/obsolete/microjet5_tp_auto.xml
@@ -114,7 +114,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjet6.xml b/conf/airframes/obsolete/microjet6.xml
index 4f7b693e30..278ccb8b04 100644
--- a/conf/airframes/obsolete/microjet6.xml
+++ b/conf/airframes/obsolete/microjet6.xml
@@ -108,7 +108,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjetI.xml b/conf/airframes/obsolete/microjetI.xml
index 051250a86e..fac28cf5f3 100644
--- a/conf/airframes/obsolete/microjetI.xml
+++ b/conf/airframes/obsolete/microjetI.xml
@@ -118,7 +118,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjetII.xml b/conf/airframes/obsolete/microjetII.xml
index a40f85753e..56527374a3 100644
--- a/conf/airframes/obsolete/microjetII.xml
+++ b/conf/airframes/obsolete/microjetII.xml
@@ -120,7 +120,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjetIII.xml b/conf/airframes/obsolete/microjetIII.xml
index 564619d6ce..370e12d9bb 100644
--- a/conf/airframes/obsolete/microjetIII.xml
+++ b/conf/airframes/obsolete/microjetIII.xml
@@ -106,7 +106,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/microjet_raw_makefile.xml b/conf/airframes/obsolete/microjet_raw_makefile.xml
index d7b9ca439f..9a90c057c0 100644
--- a/conf/airframes/obsolete/microjet_raw_makefile.xml
+++ b/conf/airframes/obsolete/microjet_raw_makefile.xml
@@ -114,7 +114,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
 
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.04"/>
+    <define name="ALTITUDE_PGAIN" value="0.04"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/minimag1.xml b/conf/airframes/obsolete/minimag1.xml
index 622cd4ff30..84ebbe4b4d 100644
--- a/conf/airframes/obsolete/minimag1.xml
+++ b/conf/airframes/obsolete/minimag1.xml
@@ -102,7 +102,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/minimag_fs.xml b/conf/airframes/obsolete/minimag_fs.xml
index d073e6a4bd..20d2c008c8 100644
--- a/conf/airframes/obsolete/minimag_fs.xml
+++ b/conf/airframes/obsolete/minimag_fs.xml
@@ -116,7 +116,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/mmlaas_N1_carto_cam.xml b/conf/airframes/obsolete/mmlaas_N1_carto_cam.xml
index 91d9cf60c7..aba86e33cf 100644
--- a/conf/airframes/obsolete/mmlaas_N1_carto_cam.xml
+++ b/conf/airframes/obsolete/mmlaas_N1_carto_cam.xml
@@ -101,7 +101,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.15"/>
+    <define name="ALTITUDE_PGAIN" value="0.15"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/osam_xsens_twog.xml b/conf/airframes/obsolete/osam_xsens_twog.xml
index 5a312189e1..aa0f4b0a7c 100644
--- a/conf/airframes/obsolete/osam_xsens_twog.xml
+++ b/conf/airframes/obsolete/osam_xsens_twog.xml
@@ -145,7 +145,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/slayer1.xml b/conf/airframes/obsolete/slayer1.xml
index 480ffdcb32..461dcb6a12 100644
--- a/conf/airframes/obsolete/slayer1.xml
+++ b/conf/airframes/obsolete/slayer1.xml
@@ -105,7 +105,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.045"/>
+    <define name="ALTITUDE_PGAIN" value="0.045"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/slayer3.xml b/conf/airframes/obsolete/slayer3.xml
index 548bbb12b4..2a95d06c66 100644
--- a/conf/airframes/obsolete/slayer3.xml
+++ b/conf/airframes/obsolete/slayer3.xml
@@ -105,7 +105,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.065"/>
+    <define name="ALTITUDE_PGAIN" value="0.065"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/slayerJH.xml b/conf/airframes/obsolete/slayerJH.xml
index 19fd72defe..6a278105e3 100644
--- a/conf/airframes/obsolete/slayerJH.xml
+++ b/conf/airframes/obsolete/slayerJH.xml
@@ -102,7 +102,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.045"/>
+    <define name="ALTITUDE_PGAIN" value="0.045"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/slicer1.xml b/conf/airframes/obsolete/slicer1.xml
index 262a0b86b4..fd7d6ca55d 100644
--- a/conf/airframes/obsolete/slicer1.xml
+++ b/conf/airframes/obsolete/slicer1.xml
@@ -116,7 +116,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/slicer2.xml b/conf/airframes/obsolete/slicer2.xml
index 177b45ff1d..200f0bcaf2 100644
--- a/conf/airframes/obsolete/slicer2.xml
+++ b/conf/airframes/obsolete/slicer2.xml
@@ -110,7 +110,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/spirit.xml b/conf/airframes/obsolete/spirit.xml
index 3548022de3..f5ce1864e2 100644
--- a/conf/airframes/obsolete/spirit.xml
+++ b/conf/airframes/obsolete/spirit.xml
@@ -115,7 +115,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="14.8" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/spirit_proto.xml b/conf/airframes/obsolete/spirit_proto.xml
index 068173094c..de7a378b82 100644
--- a/conf/airframes/obsolete/spirit_proto.xml
+++ b/conf/airframes/obsolete/spirit_proto.xml
@@ -104,7 +104,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="14.8" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/storm1.xml b/conf/airframes/obsolete/storm1.xml
index a583d7fcdf..85220e68cf 100644
--- a/conf/airframes/obsolete/storm1.xml
+++ b/conf/airframes/obsolete/storm1.xml
@@ -132,7 +132,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/tiny2.xml b/conf/airframes/obsolete/tiny2.xml
index 8be88a08f5..03356e82e3 100644
--- a/conf/airframes/obsolete/tiny2.xml
+++ b/conf/airframes/obsolete/tiny2.xml
@@ -101,7 +101,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.07"/>
+    <define name="ALTITUDE_PGAIN" value="0.07"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/tiny_hitl.xml b/conf/airframes/obsolete/tiny_hitl.xml
index 775b886dc1..c0d95cbfaf 100644
--- a/conf/airframes/obsolete/tiny_hitl.xml
+++ b/conf/airframes/obsolete/tiny_hitl.xml
@@ -100,7 +100,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.03"/>
+    <define name="ALTITUDE_PGAIN" value="0.03"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/obsolete/twinjet1.xml b/conf/airframes/obsolete/twinjet1.xml
index 93aa9131de..c83cffebcf 100644
--- a/conf/airframes/obsolete/twinjet1.xml
+++ b/conf/airframes/obsolete/twinjet1.xml
@@ -98,7 +98,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.05"/>
+    <define name="ALTITUDE_PGAIN" value="0.05"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/twinstar1.xml b/conf/airframes/obsolete/twinstar1.xml
index 8983be2f67..79623757b2 100644
--- a/conf/airframes/obsolete/twinstar1.xml
+++ b/conf/airframes/obsolete/twinstar1.xml
@@ -110,7 +110,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.025"/>
+    <define name="ALTITUDE_PGAIN" value="0.025"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/twinstar6.xml b/conf/airframes/obsolete/twinstar6.xml
index 6a8e226640..79dd203fa5 100644
--- a/conf/airframes/obsolete/twinstar6.xml
+++ b/conf/airframes/obsolete/twinstar6.xml
@@ -119,7 +119,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.05"/>
+    <define name="ALTITUDE_PGAIN" value="0.05"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/obsolete/tyto1.xml b/conf/airframes/obsolete/tyto1.xml
index 1301eab688..365f87caff 100644
--- a/conf/airframes/obsolete/tyto1.xml
+++ b/conf/airframes/obsolete/tyto1.xml
@@ -119,7 +119,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.37"/>
+    <define name="ALTITUDE_PGAIN" value="0.37"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="5."/>
 
diff --git a/conf/airframes/obsolete/xxx1.xml b/conf/airframes/obsolete/xxx1.xml
index 3e8735ccbb..84c07f1cb8 100644
--- a/conf/airframes/obsolete/xxx1.xml
+++ b/conf/airframes/obsolete/xxx1.xml
@@ -115,7 +115,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.05"/>
+    <define name="ALTITUDE_PGAIN" value="0.05"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/test_hb.xml b/conf/airframes/test_hb.xml
index a1be4eb324..d622aa2e7e 100644
--- a/conf/airframes/test_hb.xml
+++ b/conf/airframes/test_hb.xml
@@ -140,7 +140,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/> <!-- -0.024 -->
+    <define name="ALTITUDE_PGAIN" value="0.06"/> <!-- -0.024 -->
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/twinjet_example.xml b/conf/airframes/twinjet_example.xml
index 85ebfb13ca..5242e3a8ea 100644
--- a/conf/airframes/twinjet_example.xml
+++ b/conf/airframes/twinjet_example.xml
@@ -126,7 +126,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.05"/>
+    <define name="ALTITUDE_PGAIN" value="0.05"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/twinjet_overo.xml b/conf/airframes/twinjet_overo.xml
index 6322bcdeef..6690a46bc5 100644
--- a/conf/airframes/twinjet_overo.xml
+++ b/conf/airframes/twinjet_overo.xml
@@ -128,7 +128,7 @@
 
  <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.05"/>
+    <define name="ALTITUDE_PGAIN" value="0.05"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="3."/>
 
diff --git a/conf/airframes/twinstar_example.xml b/conf/airframes/twinstar_example.xml
index 9d8e075d66..15bcc6803a 100644
--- a/conf/airframes/twinstar_example.xml
+++ b/conf/airframes/twinstar_example.xml
@@ -138,7 +138,7 @@
   <section name="VERTICAL CONTROL" prefix="V_CTL_">
     <define name="POWER_CTL_BAT_NOMINAL" value="11.1" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.06"/>
+    <define name="ALTITUDE_PGAIN" value="0.06"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/airframes/usb_test.xml b/conf/airframes/usb_test.xml
index 22474e839b..270e209269 100644
--- a/conf/airframes/usb_test.xml
+++ b/conf/airframes/usb_test.xml
@@ -119,7 +119,7 @@
 
     <define name="POWER_CTL_BAT_NOMINAL" value="10" unit="volt"/>
     <!-- outer loop proportional gain -->
-    <define name="ALTITUDE_PGAIN" value="-0.024"/>
+    <define name="ALTITUDE_PGAIN" value="0.024"/>
     <!-- outer loop saturation -->
     <define name="ALTITUDE_MAX_CLIMB" value="2."/>
 
diff --git a/conf/settings/tuning.xml b/conf/settings/tuning.xml
index 401cad6489..7ac490b6c8 100644
--- a/conf/settings/tuning.xml
+++ b/conf/settings/tuning.xml
@@ -44,7 +44,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuningJH.xml b/conf/settings/tuningJH.xml
index a74e6456d1..4ec3404d4e 100644
--- a/conf/settings/tuningJH.xml
+++ b/conf/settings/tuningJH.xml
@@ -50,7 +50,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_ctl_adaptive.xml b/conf/settings/tuning_ctl_adaptive.xml
index 461f9ee81d..1bd8cd4b2f 100644
--- a/conf/settings/tuning_ctl_adaptive.xml
+++ b/conf/settings/tuning_ctl_adaptive.xml
@@ -28,7 +28,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="climb">
diff --git a/conf/settings/tuning_ctl_new.xml b/conf/settings/tuning_ctl_new.xml
index 3685cbd25a..fc0daf033d 100644
--- a/conf/settings/tuning_ctl_new.xml
+++ b/conf/settings/tuning_ctl_new.xml
@@ -28,7 +28,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="climb">
diff --git a/conf/settings/tuning_infrared.xml b/conf/settings/tuning_infrared.xml
index 968e398992..ff71e03697 100644
--- a/conf/settings/tuning_infrared.xml
+++ b/conf/settings/tuning_infrared.xml
@@ -61,7 +61,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_ins.xml b/conf/settings/tuning_ins.xml
index d83f39de8f..28fe187e0d 100644
--- a/conf/settings/tuning_ins.xml
+++ b/conf/settings/tuning_ins.xml
@@ -52,7 +52,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_ins_dcm.xml b/conf/settings/tuning_ins_dcm.xml
index acd6b921f6..e366904c04 100644
--- a/conf/settings/tuning_ins_dcm.xml
+++ b/conf/settings/tuning_ins_dcm.xml
@@ -55,7 +55,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_loiter.xml b/conf/settings/tuning_loiter.xml
index 69a23ab867..5c96f2394b 100644
--- a/conf/settings/tuning_loiter.xml
+++ b/conf/settings/tuning_loiter.xml
@@ -60,7 +60,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_pers.xml b/conf/settings/tuning_pers.xml
index 057be42057..b31a024066 100644
--- a/conf/settings/tuning_pers.xml
+++ b/conf/settings/tuning_pers.xml
@@ -61,7 +61,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain" param="V_CTL_ALTITUDE_PGAIN"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/conf/settings/tuning_tp_auto.xml b/conf/settings/tuning_tp_auto.xml
index 95d8caee94..5c2c5fe704 100644
--- a/conf/settings/tuning_tp_auto.xml
+++ b/conf/settings/tuning_tp_auto.xml
@@ -43,7 +43,7 @@
       </dl_settings>
 
       <dl_settings name="alt">
-        <dl_setting MAX="0" MIN="-0.2" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain"/>
+        <dl_setting MAX="0.2" MIN="0" STEP="0.01" VAR="v_ctl_altitude_pgain" shortname="alt_pgain"/>
       </dl_settings>
 
       <dl_settings name="auto_throttle">
diff --git a/sw/airborne/firmwares/fixedwing/guidance/guidance_v.c b/sw/airborne/firmwares/fixedwing/guidance/guidance_v.c
index 6d27c606a0..043c7335d3 100644
--- a/sw/airborne/firmwares/fixedwing/guidance/guidance_v.c
+++ b/sw/airborne/firmwares/fixedwing/guidance/guidance_v.c
@@ -112,7 +112,7 @@ void v_ctl_init( void ) {
   /* outer loop */
   v_ctl_altitude_setpoint = 0.;
   v_ctl_altitude_pre_climb = 0.;
-  v_ctl_altitude_pgain = V_CTL_ALTITUDE_PGAIN;
+  v_ctl_altitude_pgain = ABS(V_CTL_ALTITUDE_PGAIN);
   v_ctl_altitude_error = 0.;
 
   /* inner loops */
@@ -194,7 +194,7 @@ void v_ctl_altitude_loop( void ) {
 #endif
 
   v_ctl_altitude_error = estimator_z - v_ctl_altitude_setpoint;
-  v_ctl_climb_setpoint = altitude_pgain_boost * v_ctl_altitude_pgain * v_ctl_altitude_error
+  v_ctl_climb_setpoint = altitude_pgain_boost * -v_ctl_altitude_pgain * v_ctl_altitude_error
     + v_ctl_altitude_pre_climb;
   BoundAbs(v_ctl_climb_setpoint, V_CTL_ALTITUDE_MAX_CLIMB);
 
diff --git a/sw/airborne/firmwares/fixedwing/guidance/guidance_v_n.c b/sw/airborne/firmwares/fixedwing/guidance/guidance_v_n.c
index 1cb63583c6..35e97fd49b 100644
--- a/sw/airborne/firmwares/fixedwing/guidance/guidance_v_n.c
+++ b/sw/airborne/firmwares/fixedwing/guidance/guidance_v_n.c
@@ -117,7 +117,7 @@ void v_ctl_init( void ) {
   /* outer loop */
   v_ctl_altitude_setpoint = 0.;
   v_ctl_altitude_pre_climb = 0.;
-  v_ctl_altitude_pgain = V_CTL_ALTITUDE_PGAIN;
+  v_ctl_altitude_pgain = ABS(V_CTL_ALTITUDE_PGAIN);
   v_ctl_altitude_error = 0.;
 
   /* inner loops */
@@ -180,7 +180,7 @@ void v_ctl_altitude_loop( void ) {
 
   // Altitude error
   v_ctl_altitude_error = estimator_z - v_ctl_altitude_setpoint;
-  v_ctl_climb_setpoint = v_ctl_altitude_pgain * v_ctl_altitude_error + v_ctl_altitude_pre_climb;
+  v_ctl_climb_setpoint = -v_ctl_altitude_pgain * v_ctl_altitude_error + v_ctl_altitude_pre_climb;
 
   // Lead controller
   //v_ctl_climb_setpoint = ((LEAD_CTRL_TAU*LEAD_CTRL_A + LEAD_CTRL_Te)*climb_sp + LEAD_CTRL_TAU*(v_ctl_climb_setpoint - LEAD_CTRL_A*last_lead_input)) / (LEAD_CTRL_TAU + LEAD_CTRL_Te);