diff --git a/src/blackcore/context/contextownaircraft.h b/src/blackcore/context/contextownaircraft.h
index 8b7ff2469..2c992455a 100644
--- a/src/blackcore/context/contextownaircraft.h
+++ b/src/blackcore/context/contextownaircraft.h
@@ -108,7 +108,7 @@ namespace BlackCore
 
             //! Update position
             //! \note this is in \sa IContextOwnAircraft as we want to set test positions from the GUI / elsewhere
-            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude) = 0;
+            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const BlackMisc::Aviation::CAltitude &pressureAltitude) = 0;
 
             //! Update own cockpit
             virtual bool updateCockpit(const BlackMisc::Aviation::CComSystem &com1, const BlackMisc::Aviation::CComSystem &com2, const BlackMisc::Aviation::CTransponder &transponder, const BlackMisc::CIdentifier &originator) = 0;
diff --git a/src/blackcore/context/contextownaircraftempty.h b/src/blackcore/context/contextownaircraftempty.h
index a3791e6af..77c7a3895 100644
--- a/src/blackcore/context/contextownaircraftempty.h
+++ b/src/blackcore/context/contextownaircraftempty.h
@@ -38,10 +38,11 @@ namespace BlackCore
             }
 
             //! \copydoc IContextOwnAircraft::updateOwnPosition
-            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude) override
+            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const BlackMisc::Aviation::CAltitude &pressureAltitude) override
             {
                 Q_UNUSED(position);
                 Q_UNUSED(altitude);
+                Q_UNUSED(pressureAltitude)
                 logEmptyContextWarning(Q_FUNC_INFO);
                 return false;
             }
diff --git a/src/blackcore/context/contextownaircraftimpl.cpp b/src/blackcore/context/contextownaircraftimpl.cpp
index 9fecf8fc7..0f6299555 100644
--- a/src/blackcore/context/contextownaircraftimpl.cpp
+++ b/src/blackcore/context/contextownaircraftimpl.cpp
@@ -212,7 +212,7 @@ namespace BlackCore
             return true;
         }
 
-        bool CContextOwnAircraft::updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude)
+        bool CContextOwnAircraft::updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const CAltitude &pressureAltitude)
         {
             if (m_debugEnabled) { CLogMessage(this, CLogCategory::contextSlot()).debug() << Q_FUNC_INFO << position << altitude; }
             QWriteLocker l(&m_lockAircraft);
@@ -224,6 +224,12 @@ namespace BlackCore
                 changed = true;
                 m_ownAircraft.setAltitude(altitude);
             }
+
+            if (m_ownAircraft.getPressureAltitude() != pressureAltitude)
+            {
+                changed = true;
+                m_ownAircraft.setPressureAltitude(pressureAltitude);
+            }
             return changed;
         }
 
diff --git a/src/blackcore/context/contextownaircraftimpl.h b/src/blackcore/context/contextownaircraftimpl.h
index 5a8c860e8..b60cf38c9 100644
--- a/src/blackcore/context/contextownaircraftimpl.h
+++ b/src/blackcore/context/contextownaircraftimpl.h
@@ -120,7 +120,7 @@ namespace BlackCore
             virtual bool updateOwnIcaoCodes(const BlackMisc::Aviation::CAircraftIcaoCode &aircraftIcaoCode, const BlackMisc::Aviation::CAirlineIcaoCode &airlineIcaoCode) override;
 
             //! \copydoc IContextOwnAircraft::updateOwnPosition
-            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude) override;
+            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const BlackMisc::Aviation::CAltitude &pressureAltitude) override;
 
             //! \copydoc IContextOwnAircraft::updateCockpit
             virtual bool updateCockpit(const BlackMisc::Aviation::CComSystem &com1, const BlackMisc::Aviation::CComSystem &com2, const BlackMisc::Aviation::CTransponder &transponder, const BlackMisc::CIdentifier &originator) override;
diff --git a/src/blackcore/context/contextownaircraftproxy.cpp b/src/blackcore/context/contextownaircraftproxy.cpp
index e7ee0313d..cfd033677 100644
--- a/src/blackcore/context/contextownaircraftproxy.cpp
+++ b/src/blackcore/context/contextownaircraftproxy.cpp
@@ -75,9 +75,9 @@ namespace BlackCore
             return this->m_dBusInterface->callDBusRet<bool>(QLatin1String("updateSelcal"), selcal, originator);
         }
 
-        bool CContextOwnAircraftProxy::updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude)
+        bool CContextOwnAircraftProxy::updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const CAltitude &pressureAltitude)
         {
-            return this->m_dBusInterface->callDBusRet<bool>(QLatin1String("updateOwnPosition"), position, altitude);
+            return this->m_dBusInterface->callDBusRet<bool>(QLatin1String("updateOwnPosition"), position, altitude, pressureAltitude);
         }
 
         bool CContextOwnAircraftProxy::updateOwnCallsign(const CCallsign &callsign)
diff --git a/src/blackcore/context/contextownaircraftproxy.h b/src/blackcore/context/contextownaircraftproxy.h
index 75a31ba3a..e110964b5 100644
--- a/src/blackcore/context/contextownaircraftproxy.h
+++ b/src/blackcore/context/contextownaircraftproxy.h
@@ -64,7 +64,7 @@ namespace BlackCore
             //! \publicsection
             //! @{
             virtual BlackMisc::Simulation::CSimulatedAircraft getOwnAircraft() const override;
-            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude) override;
+            virtual bool updateOwnPosition(const BlackMisc::Geo::CCoordinateGeodetic &position, const BlackMisc::Aviation::CAltitude &altitude, const BlackMisc::Aviation::CAltitude &pressureAltitude) override;
             virtual bool updateCockpit(const BlackMisc::Aviation::CComSystem &com1, const BlackMisc::Aviation::CComSystem &com2, const BlackMisc::Aviation::CTransponder &transponder, const BlackMisc::CIdentifier &originator) override;
             virtual bool updateActiveComFrequency(const BlackMisc::PhysicalQuantities::CFrequency &frequency, BlackMisc::Aviation::CComSystem::ComUnit comUnit, const BlackMisc::CIdentifier &originator) override;
             virtual bool updateOwnAircraftPilot(const BlackMisc::Network::CUser &pilot) override;
diff --git a/src/blackcore/vatsim/networkvatlib.cpp b/src/blackcore/vatsim/networkvatlib.cpp
index 02cf6ed81..11b03e984 100644
--- a/src/blackcore/vatsim/networkvatlib.cpp
+++ b/src/blackcore/vatsim/networkvatlib.cpp
@@ -204,8 +204,7 @@ namespace BlackCore
                 {
                     // Normal / Stealth mode
                     VatPilotPosition pos;
-                    //! \fixme we need to distinguish true and pressure altitude
-                    pos.altitudePressure = myAircraft.getAltitude().value(CLengthUnit::ft());
+                    pos.altitudePressure = myAircraft.getPressureAltitude().value(CLengthUnit::ft());
                     pos.altitudeTrue = myAircraft.getAltitude().value(CLengthUnit::ft());
                     pos.heading      = myAircraft.getHeading().value(CAngleUnit::deg());
                     pos.pitch        = myAircraft.getPitch().value(CAngleUnit::deg());
diff --git a/src/blackgui/editors/situationform.cpp b/src/blackgui/editors/situationform.cpp
index 805b75506..03dd42415 100644
--- a/src/blackgui/editors/situationform.cpp
+++ b/src/blackgui/editors/situationform.cpp
@@ -9,8 +9,10 @@
 
 #include "situationform.h"
 #include "ui_situationform.h"
+#include "blackmisc/pq/pressure.h"
 #include "blackmisc/pq/angle.h"
 #include "blackmisc/stringutils.h"
+#include "blackmisc/logmessage.h"
 #include <QDoubleValidator>
 
 using namespace BlackMisc;
@@ -29,14 +31,19 @@ namespace BlackGui
 
             ui->le_Bank->setValidator(new QDoubleValidator(-180.0 + CAngleUnit::deg().getEpsilon(), 180.0, 3, ui->le_Bank));
             ui->le_Pitch->setValidator(new QDoubleValidator(-180.0 + CAngleUnit::deg().getEpsilon(), 180.0, 3, ui->le_Pitch));
+            ui->le_Pressure->setValidator(new QDoubleValidator(980.0, 1046.0, 2, ui->le_Pressure));
 
             connect(ui->hs_Bank, &QSlider::valueChanged, this, &CSituationForm::bankSliderChanged);
             connect(ui->hs_Pitch, &QSlider::valueChanged, this, &CSituationForm::pitchSliderChanged);
+            connect(ui->hs_Pressure, &QSlider::valueChanged, this, &CSituationForm::pressureSliderChanged);
             connect(ui->le_Bank, &QLineEdit::editingFinished, this, &CSituationForm::bankEntered);
             connect(ui->le_Pitch, &QLineEdit::editingFinished, this, &CSituationForm::pitchEntered);
+            connect(ui->le_Pressure, &QLineEdit::editingFinished, this, &CSituationForm::pressureEntered);
             connect(ui->tb_ResetBank, &QToolButton::clicked, this, &CSituationForm::resetBank);
             connect(ui->tb_ResetPitch, &QToolButton::clicked, this, &CSituationForm::resetPitch);
+            connect(ui->tb_ResetPressure, &QToolButton::clicked, this, &CSituationForm::resetPressure);
             connect(ui->pb_Set, &QPushButton::clicked, this, &CSituationForm::changeAircraftSituation);
+            connect(ui->pb_SetEnvironment, &QPushButton::clicked, this, &CSituationForm::changeAircraftSituation);
             connect(ui->comp_Coordinate, &CCoordinateForm::changeCoordinate, this, &CSituationForm::changeAircraftSituation);
         }
 
@@ -50,9 +57,13 @@ namespace BlackGui
 
         CAircraftSituation CSituationForm::getSituation() const
         {
-            CAircraftSituation s(ui->comp_Coordinate->getCoordinate());
+            const BlackMisc::Geo::CCoordinateGeodetic position = ui->comp_Coordinate->getCoordinate();
+            CAircraftSituation s(position);
             s.setBank(this->getBankAngle());
             s.setPitch(this->getPitchAngle());
+
+            CAltitude pressureAltitude(position.geodeticHeight().toPressureAltitude(this->getBarometricPressureMsl()));
+            s.setPressureAltitude(pressureAltitude);
             return s;
         }
 
@@ -84,6 +95,20 @@ namespace BlackGui
             return CAngle::normalizeDegrees180(vd, RoundDigits);
         }
 
+        double CSituationForm::getBarometricPressureMslMillibar() const
+        {
+            const QString v(ui->le_Pressure->text().replace(',', '.'));
+            bool ok;
+            double vd = v.toDouble(&ok);
+            if (!ok) { vd = 1013.25; }
+            return vd;
+        }
+
+        CPressure CSituationForm::getBarometricPressureMsl() const
+        {
+            return CPressure (getBarometricPressureMslMillibar(), CPressureUnit::mbar());
+        }
+
         void CSituationForm::setReadOnly(bool readonly)
         {
             ui->comp_Coordinate->setReadOnly(readonly);
@@ -128,6 +153,13 @@ namespace BlackGui
             ui->le_Pitch->setText(QString::number(value));
         }
 
+        void CSituationForm::pressureSliderChanged(int value)
+        {
+            const int pressure = qRound(this->getBarometricPressureMslMillibar());
+            if (value == pressure) { return; } // avoid roundtrips
+            ui->le_Pressure->setText(QString::number(value));
+        }
+
         void CSituationForm::bankEntered()
         {
             const double ad = this->getBankAngleDegrees();
@@ -161,5 +193,22 @@ namespace BlackGui
             ui->le_Pitch->setText("0");
             ui->hs_Pitch->setValue(0);
         }
+
+        void CSituationForm::pressureEntered()
+        {
+            const double pd = this->getBarometricPressureMslMillibar();
+            QString n = QString::number(pd, 'g', 4 + RoundDigits);
+            if (ui->le_Pressure->validator()) { dotToLocaleDecimalPoint(n); }
+            ui->le_Pressure->setText(n);
+            const int pi = qRound(pd);
+            if (pi == ui->hs_Pressure->value()) { return; } // avoid roundtrips
+            ui->hs_Pressure->setValue(pi);
+        }
+
+        void CSituationForm::resetPressure()
+        {
+            ui->le_Pressure->setText("1013.00");
+            ui->hs_Pressure->setValue(1013);
+        }
     } // ns
 } // ns
diff --git a/src/blackgui/editors/situationform.h b/src/blackgui/editors/situationform.h
index e53d9882b..56030ac81 100644
--- a/src/blackgui/editors/situationform.h
+++ b/src/blackgui/editors/situationform.h
@@ -74,12 +74,21 @@ namespace BlackGui
             //! Get pitch angle
             double getPitchAngleDegrees() const;
 
+            //! Get barometric pressure at mean sea level
+            BlackMisc::PhysicalQuantities::CPressure getBarometricPressureMsl() const;
+
+            //! Get pressure at mean sea level
+            double getBarometricPressureMslMillibar() const;
+
             void bankSliderChanged(int value);
             void pitchSliderChanged(int value);
+            void pressureSliderChanged(int value);
             void bankEntered();
             void resetBank();
             void pitchEntered();
             void resetPitch();
+            void pressureEntered();
+            void resetPressure();
 
             QScopedPointer<Ui::CSituationForm> ui;
         };
diff --git a/src/blackgui/editors/situationform.ui b/src/blackgui/editors/situationform.ui
index f1813bb45..474db4fd1 100644
--- a/src/blackgui/editors/situationform.ui
+++ b/src/blackgui/editors/situationform.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>386</width>
-    <height>324</height>
+    <width>512</width>
+    <height>439</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -37,7 +37,7 @@
         <property name="frameShadow">
          <enum>QFrame::Raised</enum>
         </property>
-        <layout class="QGridLayout" name="gl_Situation" columnstretch="1,1,1,3">
+        <layout class="QGridLayout" name="gl_Situation" columnstretch="1,0,0,0">
          <item row="0" column="0">
           <widget class="QLabel" name="lbl_Bank">
            <property name="text">
@@ -110,7 +110,7 @@
            </property>
           </widget>
          </item>
-         <item row="2" column="0">
+         <item row="3" column="0">
           <spacer name="vs_Situation">
            <property name="orientation">
             <enum>Qt::Vertical</enum>
@@ -145,7 +145,7 @@
            </property>
           </widget>
          </item>
-         <item row="2" column="3" alignment="Qt::AlignRight">
+         <item row="3" column="3" alignment="Qt::AlignRight">
           <widget class="QPushButton" name="pb_Set">
            <property name="text">
             <string>set</string>
@@ -183,6 +183,112 @@
      </layout>
     </widget>
    </item>
+   <item>
+    <widget class="QGroupBox" name="gb_Environment">
+     <property name="title">
+      <string>Environment</string>
+     </property>
+     <layout class="QVBoxLayout" name="verticalLayout">
+      <item>
+       <widget class="QFrame" name="comp_Environment">
+        <property name="frameShape">
+         <enum>QFrame::NoFrame</enum>
+        </property>
+        <property name="frameShadow">
+         <enum>QFrame::Raised</enum>
+        </property>
+        <layout class="QGridLayout" name="gl_Environment" columnstretch="1,0,0,0">
+         <item row="0" column="0">
+          <widget class="QLabel" name="lbl_Pressure">
+           <property name="text">
+            <string>Pressure MSL (980 - 1046 mbar)</string>
+           </property>
+           <property name="wordWrap">
+            <bool>false</bool>
+           </property>
+          </widget>
+         </item>
+         <item row="0" column="1">
+          <widget class="QLineEdit" name="le_Pressure">
+           <property name="text">
+            <string>1013.00</string>
+           </property>
+          </widget>
+         </item>
+         <item row="0" column="2">
+          <widget class="QToolButton" name="tb_ResetPressure">
+           <property name="text">
+            <string>...</string>
+           </property>
+           <property name="icon">
+            <iconset resource="../../blackmisc/blackmisc.qrc">
+             <normaloff>:/diagona/icons/diagona/icons/cross-white.png</normaloff>:/diagona/icons/diagona/icons/cross-white.png</iconset>
+           </property>
+          </widget>
+         </item>
+         <item row="0" column="3">
+          <widget class="QSlider" name="hs_Pressure">
+           <property name="sizePolicy">
+            <sizepolicy hsizetype="Expanding" vsizetype="Fixed">
+             <horstretch>0</horstretch>
+             <verstretch>0</verstretch>
+            </sizepolicy>
+           </property>
+           <property name="minimum">
+            <number>980</number>
+           </property>
+           <property name="maximum">
+            <number>1046</number>
+           </property>
+           <property name="singleStep">
+            <number>1</number>
+           </property>
+           <property name="value">
+            <number>1013</number>
+           </property>
+           <property name="orientation">
+            <enum>Qt::Horizontal</enum>
+           </property>
+           <property name="invertedAppearance">
+            <bool>false</bool>
+           </property>
+           <property name="invertedControls">
+            <bool>false</bool>
+           </property>
+           <property name="tickPosition">
+            <enum>QSlider::TicksAbove</enum>
+           </property>
+           <property name="tickInterval">
+            <number>1</number>
+           </property>
+          </widget>
+         </item>
+         <item row="1" column="3" alignment="Qt::AlignRight">
+          <widget class="QPushButton" name="pb_SetEnvironment">
+           <property name="text">
+            <string>set</string>
+           </property>
+          </widget>
+         </item>
+         <item row="1" column="0">
+          <spacer name="verticalSpacer">
+           <property name="orientation">
+            <enum>Qt::Vertical</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>20</width>
+             <height>40</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </widget>
+      </item>
+     </layout>
+    </widget>
+   </item>
   </layout>
  </widget>
  <customwidgets>
diff --git a/src/blackmisc/aviation/aircraftsituation.cpp b/src/blackmisc/aviation/aircraftsituation.cpp
index 647b7b055..d5338a033 100644
--- a/src/blackmisc/aviation/aircraftsituation.cpp
+++ b/src/blackmisc/aviation/aircraftsituation.cpp
@@ -30,7 +30,10 @@ namespace BlackMisc
 
         CAircraftSituation::CAircraftSituation(const CCoordinateGeodetic &position, const CHeading &heading, const CAngle &pitch, const CAngle &bank, const CSpeed &gs, const CAltitude &groundElevation)
             : m_position(position), m_heading(heading), m_pitch(pitch),
-              m_bank(bank), m_groundSpeed(gs), m_groundElevation(groundElevation) {}
+              m_bank(bank), m_groundSpeed(gs), m_groundElevation(groundElevation)
+        {
+            m_pressureAltitude = position.geodeticHeight().toPressureAltitude(CPressure(1013.25, CPressureUnit::mbar()));
+        }
 
         CAircraftSituation::CAircraftSituation(const CCallsign &correspondingCallsign, const CCoordinateGeodetic &position, const CHeading &heading, const CAngle &pitch, const CAngle &bank, const CSpeed &gs, const CAltitude &groundElevation)
             : m_correspondingCallsign(correspondingCallsign),
@@ -38,6 +41,7 @@ namespace BlackMisc
               m_bank(bank), m_groundSpeed(gs), m_groundElevation(groundElevation)
         {
             m_correspondingCallsign.setTypeHint(CCallsign::Aircraft);
+            m_pressureAltitude = position.geodeticHeight().toPressureAltitude(CPressure(1013.25, CPressureUnit::mbar()));
         }
 
         QString CAircraftSituation::convertToQString(bool i18n) const
@@ -219,6 +223,12 @@ namespace BlackMisc
             return this->getGroundElevation();
         }
 
+        void CAircraftSituation::setPressureAltitude(const CAltitude &altitude)
+        {
+            Q_ASSERT(altitude.getAltitudeType() == CAltitude::PressureAltitude);
+            m_pressureAltitude = altitude;
+        }
+
         void CAircraftSituation::setCallsign(const CCallsign &callsign)
         {
             m_correspondingCallsign = callsign;
diff --git a/src/blackmisc/aviation/aircraftsituation.h b/src/blackmisc/aviation/aircraftsituation.h
index 1af33d3eb..a8a22b4fc 100644
--- a/src/blackmisc/aviation/aircraftsituation.h
+++ b/src/blackmisc/aviation/aircraftsituation.h
@@ -187,6 +187,12 @@ namespace BlackMisc
             //! Set altitude
             void setAltitude(const CAltitude &altitude) { m_position.setGeodeticHeight(altitude); }
 
+            //! Get pressure altitude
+            const CAltitude &getPressureAltitude() const { return m_pressureAltitude; }
+
+            //! Set pressure altitude
+            void setPressureAltitude(const CAltitude &altitude);
+
             //! Get pitch
             const PhysicalQuantities::CAngle &getPitch() const { return m_pitch; }
 
@@ -238,6 +244,7 @@ namespace BlackMisc
         private:
             CCallsign m_correspondingCallsign;
             Geo::CCoordinateGeodetic m_position;
+            Aviation::CAltitude m_pressureAltitude { 0, nullptr };
             CHeading m_heading;
             PhysicalQuantities::CAngle m_pitch;
             PhysicalQuantities::CAngle m_bank;
@@ -252,6 +259,7 @@ namespace BlackMisc
                 CAircraftSituation,
                 BLACK_METAMEMBER(correspondingCallsign),
                 BLACK_METAMEMBER(position),
+                BLACK_METAMEMBER(pressureAltitude),
                 BLACK_METAMEMBER(heading),
                 BLACK_METAMEMBER(pitch),
                 BLACK_METAMEMBER(bank),
diff --git a/src/blackmisc/aviation/altitude.cpp b/src/blackmisc/aviation/altitude.cpp
index 982d1848e..8fcaf4e91 100644
--- a/src/blackmisc/aviation/altitude.cpp
+++ b/src/blackmisc/aviation/altitude.cpp
@@ -64,11 +64,11 @@ namespace BlackMisc
         void CAltitude::convertToPressureAltitude(const CPressure &seaLevelPressure)
         {
             if (m_altitudeType == PressureAltitude) { return; }
-            static const CPressure standardPressure(1013.25, CPressureUnit::mbar());
-            const CPressure delta = (standardPressure - seaLevelPressure);
-            double deltaV = delta.value(CPressureUnit::mbar());
-            deltaV *= 30.0;
-            addValueSameUnit(deltaV);
+            const CPressure deltaPressure = standardISASeaLevelPressure() - seaLevelPressure;
+            const double deltaPressureV = deltaPressure.value(CPressureUnit::mbar());
+            const double deltaAltitudeV = deltaPressureV * 30.0; // 30.0 ft per mbar
+            CLength deltaAltitude(deltaAltitudeV, CLengthUnit::ft());
+            *this += deltaAltitude;
             m_altitudeType = PressureAltitude;
         }
 
diff --git a/src/blackmisc/simulation/simulatedaircraft.h b/src/blackmisc/simulation/simulatedaircraft.h
index 1454b0dbd..61e588e45 100644
--- a/src/blackmisc/simulation/simulatedaircraft.h
+++ b/src/blackmisc/simulation/simulatedaircraft.h
@@ -185,6 +185,12 @@ namespace BlackMisc
             //! Set altitude
             void setAltitude(const BlackMisc::Aviation::CAltitude &altitude) { m_situation.setAltitude(altitude); }
 
+            //! Get pressure altitude
+            const BlackMisc::Aviation::CAltitude &getPressureAltitude() const { return m_situation.getPressureAltitude(); }
+
+            //! Set pressure altitude
+            void setPressureAltitude(const BlackMisc::Aviation::CAltitude &altitude) { m_situation.setPressureAltitude(altitude); }
+
             //! Get groundspeed
             const BlackMisc::PhysicalQuantities::CSpeed &getGroundSpeed() const { return m_situation.getGroundSpeed(); }
 
diff --git a/src/plugins/simulator/fs9/simulatorfs9.cpp b/src/plugins/simulator/fs9/simulatorfs9.cpp
index 55db61646..074d16b70 100644
--- a/src/plugins/simulator/fs9/simulatorfs9.cpp
+++ b/src/plugins/simulator/fs9/simulatorfs9.cpp
@@ -397,6 +397,7 @@ namespace BlackSimPlugin
                 simDataOwnAircraft.getCom2System(),
                 simDataOwnAircraft.getTransponder(),
                 this->identifier());
+            this->updateOwnSituation(simDataOwnAircraft.getSituation());
             reverseLookupAndUpdateOwnAircraftModel(simDataOwnAircraft.getModelString());
         }
 
diff --git a/src/plugins/simulator/fscommon/fsuipcimpl.cpp b/src/plugins/simulator/fscommon/fsuipcimpl.cpp
index f5057dfde..5bfea072c 100644
--- a/src/plugins/simulator/fscommon/fsuipcimpl.cpp
+++ b/src/plugins/simulator/fscommon/fsuipcimpl.cpp
@@ -267,6 +267,7 @@ namespace BlackSimPlugin
             qint8 xpdrModeSb3Raw = 0, xpdrIdentSb3Raw = 0;
             qint32 groundspeedRaw = 0, pitchRaw = 0, bankRaw = 0, headingRaw = 0;
             qint64 altitudeRaw = 0;
+            double pressureAltitudeRaw = 0; // 34B0
             qint32 groundAltitudeRaw = 0;
             qint64 latitudeRaw = 0, longitudeRaw = 0;
             qint16 lightsRaw = 0;
@@ -311,6 +312,7 @@ namespace BlackSimPlugin
                     (situationN || FSUIPC_Read(0x0560, 8, &latitudeRaw, &dwResult)) &&
                     (situationN || FSUIPC_Read(0x0568, 8, &longitudeRaw, &dwResult)) &&
                     (situationN || FSUIPC_Read(0x0020, 4, &groundAltitudeRaw, &dwResult)) &&
+                    (situationN || FSUIPC_Read(0x34B0, 8, &pressureAltitudeRaw, &dwResult)) &&
 
                     // model name
                     FSUIPC_Read(0x3d00, 256, &modelNameRaw, &dwResult) &&
@@ -402,11 +404,13 @@ namespace BlackSimPlugin
                     CHeading heading = CHeading(headingRaw * angleCorrectionFactor, CHeading::True, CAngleUnit::deg());
                     CSpeed groundspeed(groundspeedRaw / 65536.0, CSpeedUnit::m_s());
                     CAltitude altitude(altitudeRaw / (65536.0 * 65536.0), CAltitude::MeanSeaLevel, CLengthUnit::m());
+                    CAltitude pressureAltitude(pressureAltitudeRaw, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m());
                     situation.setBank(bank);
                     situation.setHeading(heading);
                     situation.setPitch(pitch);
                     situation.setGroundSpeed(groundspeed);
                     situation.setAltitude(altitude);
+                    situation.setPressureAltitude(pressureAltitude);
                     aircraft.setSituation(situation);
 
                 } // situation
diff --git a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
index 322cb4b14..0b751ceac 100644
--- a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
+++ b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
@@ -38,6 +38,7 @@ namespace BlackSimPlugin
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PLANE LONGITUDE", "Degrees");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PLANE ALTITUDE", "Feet");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PLANE ALT ABOVE GROUND", "Feet");
+            hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PRESSURE ALTITUDE", "Meters");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "STATIC CG TO GROUND", "Feet");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PLANE HEADING DEGREES TRUE", "Degrees");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "PLANE PITCH DEGREES", "Degrees");
@@ -65,6 +66,7 @@ namespace BlackSimPlugin
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "GENERAL ENG COMBUSTION:2", "Bool");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "GENERAL ENG COMBUSTION:3", "Bool");
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraft, "GENERAL ENG COMBUSTION:4", "Bool");
+
             hr +=  SimConnect_AddToDataDefinition(hSimConnect, CSimConnectDefinitions::DataOwnAircraftTitle, "TITLE", NULL, SIMCONNECT_DATATYPE_STRING256);
             if (hr != S_OK)
             {
diff --git a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
index dbdc4521a..141e63b61 100644
--- a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
+++ b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
@@ -28,17 +28,18 @@ namespace BlackSimPlugin
         //! \sa SimConnect events http://msdn.microsoft.com/en-us/library/cc526980.aspx
         struct DataDefinitionOwnAircraft
         {
-            double latitude;        //!< Latitude (deg)
-            double longitude;       //!< Longitude (deg)
-            double altitude;        //!< Altitude (ft)
-            double altitudeAGL;     //!< Altitude above ground (ft)
-            double cgToGround;      //!< Static CG to ground (ft)
-            double trueHeading;     //!< True heading (deg)
-            double pitch;           //!< Pitch (deg)
-            double bank;            //!< Bank (deg)
-            double velocity;        //!< Ground velocity
-            double elevation;       //!< Elevation (ft)
-            double simOnGround;     //!< Is aircraft on ground?
+            double latitude;            //!< Latitude (deg)
+            double longitude;           //!< Longitude (deg)
+            double altitude;            //!< Altitude (ft)
+            double altitudeAGL;         //!< Altitude above ground (ft)
+            double pressureAltitude;    //!< Pressure altitude (m)
+            double cgToGround;          //!< Static CG to ground (ft)
+            double trueHeading;         //!< True heading (deg)
+            double pitch;               //!< Pitch (deg)
+            double bank;                //!< Bank (deg)
+            double velocity;            //!< Ground velocity
+            double elevation;           //!< Elevation (ft)
+            double simOnGround;         //!< Is aircraft on ground?
 
             double lightStrobe;     //!< Is strobe light on?
             double lightLanding;    //!< Is landing light on?
diff --git a/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp b/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
index 9034da05e..1e76059f2 100644
--- a/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
+++ b/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
@@ -371,6 +371,7 @@ namespace BlackSimPlugin
             aircraftSituation.setGroundSpeed(CSpeed(simulatorOwnAircraft.velocity, CSpeedUnit::kts()));
             aircraftSituation.setGroundElevation(CAltitude(simulatorOwnAircraft.elevation, CAltitude::MeanSeaLevel, CLengthUnit::ft()));
             aircraftSituation.setAltitude(CAltitude(simulatorOwnAircraft.altitude, CAltitude::MeanSeaLevel, CLengthUnit::ft()));
+            aircraftSituation.setPressureAltitude(CAltitude(simulatorOwnAircraft.pressureAltitude, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m()));
 
             const CAircraftLights lights(simulatorOwnAircraft.lightStrobe,
                                          simulatorOwnAircraft.lightLanding,
diff --git a/src/plugins/simulator/fsxcommon/simulatorfsxsimconnectproc.cpp b/src/plugins/simulator/fsxcommon/simulatorfsxsimconnectproc.cpp
index d885cff2f..64318a040 100644
--- a/src/plugins/simulator/fsxcommon/simulatorfsxsimconnectproc.cpp
+++ b/src/plugins/simulator/fsxcommon/simulatorfsxsimconnectproc.cpp
@@ -179,7 +179,7 @@ namespace BlackSimPlugin
                     {
                     case CSimConnectDefinitions::RequestOwnAircraft:
                         {
-                            static_assert(sizeof(DataDefinitionOwnAircraft) == 30 * sizeof(double), "DataDefinitionOwnAircraft has an incorrect size.");
+                            static_assert(sizeof(DataDefinitionOwnAircraft) == 31 * sizeof(double), "DataDefinitionOwnAircraft has an incorrect size.");
                             const DataDefinitionOwnAircraft *ownAircaft = (DataDefinitionOwnAircraft *)&pObjData->dwData;
                             simulatorFsxP3D->updateOwnAircraftFromSimulator(*ownAircaft);
                             break;
diff --git a/src/plugins/simulator/xplane/simulatorxplane.cpp b/src/plugins/simulator/xplane/simulatorxplane.cpp
index 10f3868e5..e108ca2cc 100644
--- a/src/plugins/simulator/xplane/simulatorxplane.cpp
+++ b/src/plugins/simulator/xplane/simulatorxplane.cpp
@@ -153,10 +153,15 @@ namespace BlackSimPlugin
                 m_service->getTransponderModeAsync(&m_xplaneData.xpdrMode);
                 m_service->getTransponderIdentAsync(&m_xplaneData.xpdrIdent);
                 m_service->getAllWheelsOnGroundAsync(&m_xplaneData.onGroundAll);
+                m_service->getQNHAsync(&m_xplaneData.seaLeveLPressure);
 
                 CAircraftSituation situation;
                 situation.setPosition({ m_xplaneData.latitude, m_xplaneData.longitude, 0 });
+                CAltitude altitude { m_xplaneData.altitude, CAltitude::MeanSeaLevel, CLengthUnit::m() };
                 situation.setAltitude({ m_xplaneData.altitude, CAltitude::MeanSeaLevel, CLengthUnit::m() });
+                CPressure seaLevelPressure({ m_xplaneData.seaLeveLPressure, CPressureUnit::inHg() });
+                CAltitude pressureAltitude(altitude.toPressureAltitude(seaLevelPressure));
+                situation.setPressureAltitude(pressureAltitude);
                 situation.setHeading({ m_xplaneData.trueHeading, CHeading::True, CAngleUnit::deg() });
                 situation.setPitch({ m_xplaneData.pitch, CAngleUnit::deg() });
                 situation.setBank({ m_xplaneData.roll, CAngleUnit::deg() });
diff --git a/src/plugins/simulator/xplane/simulatorxplane.h b/src/plugins/simulator/xplane/simulatorxplane.h
index 5597500b6..3d60c8808 100644
--- a/src/plugins/simulator/xplane/simulatorxplane.h
+++ b/src/plugins/simulator/xplane/simulatorxplane.h
@@ -182,12 +182,13 @@ namespace BlackSimPlugin
                 double gearReployRatio;
                 QList<double> enginesN1Percentage;
                 double speedBrakeRatio;
+                double seaLeveLPressure;
             } m_xplaneData;
 
             void resetData()
             {
                 m_xplaneData = { "", "", 0, 0, 0, 0, 0, 0, 0, false, 122800, 122800, 122800, 122800, 2000, 0, false, false, false, false,
-                                 false, false, 0, 0, {}, false
+                                 false, false, 0, 0, {}, 0.0, 0.0
                                };
 
             }
diff --git a/src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp b/src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp
index 5c635d600..6c2982880 100644
--- a/src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp
+++ b/src/plugins/simulator/xplane/xswiftbusserviceproxy.cpp
@@ -376,6 +376,17 @@ namespace BlackSimPlugin
         }
 
 
+        double CXSwiftBusServiceProxy::getQNH() const
+        {
+            return m_dbusInterface->callDBusRet<double>(QLatin1String("getQNH"));
+        }
+
+        void CXSwiftBusServiceProxy::getQNHAsync(double *o_qnh)
+        {
+            m_dbusInterface->callDBusAsync(QLatin1String("getQNH"), setterCallback(o_qnh));
+        }
+
+
         void CXSwiftBusServiceProxy::setCom1Active(int freq)
         {
             m_dbusInterface->callDBus(QLatin1String("setCom1Active"), freq);
diff --git a/src/plugins/simulator/xplane/xswiftbusserviceproxy.h b/src/plugins/simulator/xplane/xswiftbusserviceproxy.h
index 6b78d72d5..f954e1643 100644
--- a/src/plugins/simulator/xplane/xswiftbusserviceproxy.h
+++ b/src/plugins/simulator/xplane/xswiftbusserviceproxy.h
@@ -319,12 +319,17 @@ namespace BlackSimPlugin
             //! @}
 
             //! \copydoc XSwiftBus::CService::getTaxiLightsOn
-
             //! @{
             bool getTaxiLightsOn() const;
             void getTaxiLightsOnAsync(bool *o_taxiLightsOn);
             //! @}
 
+            //! \copydoc XSwiftBus::CService::getQNH
+            //! @{
+            double getQNH() const;
+            void getQNHAsync(double *o_qnh);
+            //! @}
+
             //! \copydoc XSwiftBus::CService::setCom1Active
             void setCom1Active(int freq);
 
diff --git a/src/swiftguistandard/swiftguistd.h b/src/swiftguistandard/swiftguistd.h
index 00c04590e..25bfa980a 100644
--- a/src/swiftguistandard/swiftguistd.h
+++ b/src/swiftguistandard/swiftguistd.h
@@ -148,7 +148,7 @@ private:
     //! \param wgsLatitude  WGS latitude
     //! \param wgsLongitude WGS longitude
     //! \param altitude
-    void setTestPosition(const QString &wgsLatitude, const QString &wgsLongitude, const BlackMisc::Aviation::CAltitude &altitude);
+    void setTestPosition(const QString &wgsLatitude, const QString &wgsLongitude, const BlackMisc::Aviation::CAltitude &altitude, const BlackMisc::Aviation::CAltitude &pressureAltitude);
 
     //! Is given main page selected?
     //! \param mainPage index to be checked
diff --git a/src/swiftguistandard/swiftguistdaircraft.cpp b/src/swiftguistandard/swiftguistdaircraft.cpp
index 22722117b..44d03bc6a 100644
--- a/src/swiftguistandard/swiftguistdaircraft.cpp
+++ b/src/swiftguistandard/swiftguistdaircraft.cpp
@@ -47,7 +47,7 @@ bool SwiftGuiStd::reloadOwnAircraft()
     return changed;
 }
 
-void SwiftGuiStd::setTestPosition(const QString &wgsLatitude, const QString &wgsLongitude, const CAltitude &altitude)
+void SwiftGuiStd::setTestPosition(const QString &wgsLatitude, const QString &wgsLongitude, const CAltitude &altitude, const CAltitude &pressureAltitude)
 {
     CCoordinateGeodetic coordinate(
         CLatitude::fromWgs84(wgsLatitude),
@@ -56,5 +56,5 @@ void SwiftGuiStd::setTestPosition(const QString &wgsLatitude, const QString &wgs
 
     m_ownAircraft.setPosition(coordinate);
     m_ownAircraft.setAltitude(altitude);
-    sGui->getIContextOwnAircraft()->updateOwnPosition(coordinate, altitude);
+    sGui->getIContextOwnAircraft()->updateOwnPosition(coordinate, altitude, pressureAltitude);
 }
diff --git a/src/swiftguistandard/swiftguistdmenus.cpp b/src/swiftguistandard/swiftguistdmenus.cpp
index e94ca5808..a39e14d7b 100644
--- a/src/swiftguistandard/swiftguistdmenus.cpp
+++ b/src/swiftguistandard/swiftguistdmenus.cpp
@@ -37,23 +37,33 @@ void SwiftGuiStd::onMenuClicked()
     QObject *sender = QObject::sender();
     if (sender == ui->menu_TestLocationsEDRY)
     {
-        this->setTestPosition("N 049° 18' 17", "E 008° 27' 05", CAltitude(312, CAltitude::MeanSeaLevel, CLengthUnit::ft()));
+        this->setTestPosition("N 049° 18' 17", "E 008° 27' 05",
+                              CAltitude(312, CAltitude::MeanSeaLevel, CLengthUnit::ft()),
+                              CAltitude(312, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::ft()));
     }
     else if (sender == ui->menu_TestLocationsEDNX)
     {
-        this->setTestPosition("N 048° 14′ 22", "E 011° 33′ 41", CAltitude(486, CAltitude::MeanSeaLevel, CLengthUnit::m()));
+        this->setTestPosition("N 048° 14′ 22", "E 011° 33′ 41",
+                              CAltitude(486, CAltitude::MeanSeaLevel, CLengthUnit::m()),
+                              CAltitude(486, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m()));
     }
     else if (sender == ui->menu_TestLocationsEDDM)
     {
-        this->setTestPosition("N 048° 21′ 14", "E 011° 47′ 10", CAltitude(448, CAltitude::MeanSeaLevel, CLengthUnit::m()));
+        this->setTestPosition("N 048° 21′ 14", "E 011° 47′ 10",
+                              CAltitude(448, CAltitude::MeanSeaLevel, CLengthUnit::m()),
+                              CAltitude(448, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m()));
     }
     else if (sender == ui->menu_TestLocationsEDDF)
     {
-        this->setTestPosition("N 50° 2′ 0", "E 8° 34′ 14", CAltitude(100, CAltitude::MeanSeaLevel, CLengthUnit::m()));
+        this->setTestPosition("N 50° 2′ 0", "E 8° 34′ 14",
+                              CAltitude(100, CAltitude::MeanSeaLevel, CLengthUnit::m()),
+                              CAltitude(100, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m()));
     }
     else if (sender == ui->menu_TestLocationsLOWW)
     {
-        this->setTestPosition("N 48° 7′ 6.3588", "E 16° 33′ 39.924", CAltitude(100, CAltitude::MeanSeaLevel, CLengthUnit::m()));
+        this->setTestPosition("N 48° 7′ 6.3588", "E 16° 33′ 39.924",
+                              CAltitude(100, CAltitude::MeanSeaLevel, CLengthUnit::m()),
+                              CAltitude(100, CAltitude::MeanSeaLevel, CAltitude::PressureAltitude, CLengthUnit::m()));
     }
     else if (sender == ui->menu_WindowFont)
     {
diff --git a/src/xswiftbus/service.h b/src/xswiftbus/service.h
index 8482ea984..98c9615c6 100644
--- a/src/xswiftbus/service.h
+++ b/src/xswiftbus/service.h
@@ -194,6 +194,9 @@ namespace XSwiftBus
         //! Get whether taxi lights are on
         bool getTaxiLightsOn() const { return m_taxiLightsOn.get(); }
 
+        //! Get barometric pressure at sea level in inches of mercury.
+        double getQNH() const { return m_qnhInhg.get(); }
+
         //! Set the current COM1 active frequency in kHz
         void setCom1Active(int freq) { m_com1Active.set(freq / 10); }
 
@@ -275,6 +278,7 @@ namespace XSwiftBus
         DataRef<xplane::data::sim::aircraft::engine::acf_num_engines> m_numberOfEngines;
         ArrayDataRef<xplane::data::sim::flightmodel::engine::ENGN_N1_> m_enginesN1Percentage;
         DataRef<xplane::data::sim::flightmodel2::controls::speedbrake_ratio> m_speedBrakeRatio;
+        DataRef<xplane::data::sim::weather::barometer_sealevel_inhg> m_qnhInhg;
     };
 
 }
diff --git a/tests/blackmisc/testaviation.cpp b/tests/blackmisc/testaviation.cpp
index c061ad6d5..ba88495cc 100644
--- a/tests/blackmisc/testaviation.cpp
+++ b/tests/blackmisc/testaviation.cpp
@@ -203,6 +203,19 @@ namespace BlackMiscTest
         QVERIFY2(atc1 != atc3, "ATC stations shall not be equal");
     }
 
+    void CTestAviation::altitude()
+    {
+        CAltitude altitude1(448, CAltitude::MeanSeaLevel, CLengthUnit::ft());
+        CPressure seaLevelPressure1(1025, CPressureUnit::mbar());
+        CAltitude pressureAltitude1 = altitude1.toPressureAltitude(seaLevelPressure1);
+        QCOMPARE(pressureAltitude1.value(CLengthUnit::ft()), 95.5);
+
+        CAltitude altitude2(500, CAltitude::MeanSeaLevel, CLengthUnit::m());
+        CPressure seaLevelPressure2(29.56, CPressureUnit::inHg());
+        CAltitude pressureAltitude2 = altitude2.toPressureAltitude(seaLevelPressure2);
+        QCOMPARE(qRound(pressureAltitude2.value(CLengthUnit::m())), 612);
+    }
+
 } // namespace
 
 //! \endcond
diff --git a/tests/blackmisc/testaviation.h b/tests/blackmisc/testaviation.h
index 467b3d925..2e9351517 100644
--- a/tests/blackmisc/testaviation.h
+++ b/tests/blackmisc/testaviation.h
@@ -47,6 +47,9 @@ namespace BlackMiscTest
 
         //! Testing copying and equality of objects
         void copyAndEqual();
+
+        //! CAltitude tests
+        void altitude();
     };
 } // namespace