diff --git a/src/AutoPilotPlugins/Common/RadioComponent.qml b/src/AutoPilotPlugins/Common/RadioComponent.qml
index c62a9e909530fe9d772829446d9ddb8f83e7a4a6..fe5a030afd3ec7ad27f71eba0d5517e055be275f 100644
--- a/src/AutoPilotPlugins/Common/RadioComponent.qml
+++ b/src/AutoPilotPlugins/Common/RadioComponent.qml
@@ -108,7 +108,8 @@ QGCView {
             id: zeroTrimsDialogComponent
 
             QGCViewMessage {
-                message: "Before calibrating you should zero all your trims and subtrims. Click Ok to start Calibration."
+                message: "Before calibrating you should zero all your trims and subtrims. Click Ok to start Calibration.\n\n" +
+                         (QGroundControl.multiVehicleManager.activeVehicle.px4Firmware ? "" : "Please ensure all motor power is disconnected AND all props are removed from the vehicle.")
 
                 function accept() {
                     hideDialog()
diff --git a/src/AutoPilotPlugins/Common/RadioComponentController.cc b/src/AutoPilotPlugins/Common/RadioComponentController.cc
index b4e8cb3fb68cfc66507cd41cf7be0771b009aa84..abf2e726b5e03fb8f4319e32f560ee24f5181acb 100644
--- a/src/AutoPilotPlugins/Common/RadioComponentController.cc
+++ b/src/AutoPilotPlugins/Common/RadioComponentController.cc
@@ -854,7 +854,15 @@ void RadioComponentController::_writeCalibration(void)
         getParameterFact(FactSystem::defaultComponentId, trimTpl.arg(oneBasedChannel))->setRawValue((float)info->rcTrim);
         getParameterFact(FactSystem::defaultComponentId, minTpl.arg(oneBasedChannel))->setRawValue((float)info->rcMin);
         getParameterFact(FactSystem::defaultComponentId, maxTpl.arg(oneBasedChannel))->setRawValue((float)info->rcMax);
-        getParameterFact(FactSystem::defaultComponentId, revTpl.arg(oneBasedChannel))->setRawValue(info->reversed ? -1.0f : 1.0f);
+
+        // APM has a backwards interpretation of "reversed" on the Pitch control. So be careful.
+        float reversedParamValue;
+        if (_px4Vehicle() || info->function != rcCalFunctionPitch) {
+            reversedParamValue = info->reversed ? -1.0f : 1.0f;
+        } else {
+            reversedParamValue = info->reversed ? 1.0f : -1.0f;
+        }
+        getParameterFact(FactSystem::defaultComponentId, revTpl.arg(oneBasedChannel))->setRawValue(reversedParamValue);
     }
     
     // Write function mapping parameters
diff --git a/src/Vehicle/Vehicle.cc b/src/Vehicle/Vehicle.cc
index 6edc82999be031bf3eb986cbbace4e97b19c2ea2..a973cc9d1dad730aa62481ee26e95655802babae 100644
--- a/src/Vehicle/Vehicle.cc
+++ b/src/Vehicle/Vehicle.cc
@@ -375,7 +375,7 @@ void Vehicle::_handleRCChannelsRaw(mavlink_message_t& message)
         if (channelValue == UINT16_MAX) {
             pwmValues[i] = -1;
         } else {
-            channelCount = i;
+            channelCount = i + 1;
             pwmValues[i] = channelValue;
         }
     }
diff --git a/src/qgcunittest/RadioConfigTest.cc b/src/qgcunittest/RadioConfigTest.cc
index 5e876d7d64beedba94fd2ec34bcb7aca04b771b2..99923b04eec47780832a92d4aa434177ed48c879 100644
--- a/src/qgcunittest/RadioConfigTest.cc
+++ b/src/qgcunittest/RadioConfigTest.cc
@@ -176,7 +176,7 @@ const struct RadioConfigTest::ChannelSettings RadioConfigTest::_rgChannelSetting
 
     // Channels 1-4: Mapped to attitude control function
     { RadioComponentController::rcCalFunctionRoll,			_testMinValue, _testMaxValue, _testCenterValue, true },
-    { RadioComponentController::rcCalFunctionPitch,			_testMinValue, _testMaxValue, _testCenterValue, false },
+    { RadioComponentController::rcCalFunctionPitch,			_testMinValue, _testMaxValue, _testCenterValue, true },
     { RadioComponentController::rcCalFunctionYaw,			_testMinValue, _testMaxValue, _testCenterValue, true },
     { RadioComponentController::rcCalFunctionThrottle,		_testMinValue, _testMaxValue, _testMinValue,    false },