diff --git a/src/blackmisc/aviation/aircraftlights.cpp b/src/blackmisc/aviation/aircraftlights.cpp
index 827bc3fdd..f82fa8fa6 100644
--- a/src/blackmisc/aviation/aircraftlights.cpp
+++ b/src/blackmisc/aviation/aircraftlights.cpp
@@ -8,11 +8,12 @@
  */
 
 #include "blackmisc/aviation/aircraftlights.h"
+#include "blackmisc/aviation/aircraftsituation.h"
 #include "blackmisc/stringutils.h"
 #include "blackmisc/variant.h"
 #include <QStringBuilder>
 
-using namespace BlackMisc;
+using namespace BlackMisc::PhysicalQuantities;
 
 namespace BlackMisc
 {
@@ -36,6 +37,52 @@ namespace BlackMisc
             return CAircraftLights {false, false, false, false, false, false, false, false};
         }
 
+        CAircraftLights CAircraftLights::guessedLights(const CAircraftSituation &situation)
+        {
+            const bool isOnGround = situation.getOnGround() == CAircraftSituation::OnGround;
+            const double gsKts = situation.getGroundSpeed().value(CSpeedUnit::kts());
+            CAircraftLights lights;
+            lights.setCabinOn(true);
+            lights.setRecognitionOn(true);
+
+            // when first detected moving, lights on
+            if (isOnGround)
+            {
+                lights.setTaxiOn(true);
+                lights.setBeaconOn(true);
+                lights.setNavOn(true);
+
+                if (gsKts > 5)
+                {
+                    // mode taxi
+                    lights.setTaxiOn(true);
+                    lights.setLandingOn(false);
+                }
+                else if (gsKts > 30)
+                {
+                    // mode accelaration for takeoff
+                    lights.setTaxiOn(false);
+                    lights.setLandingOn(true);
+                }
+                else
+                {
+                    // slow movements or parking
+                    lights.setTaxiOn(false);
+                    lights.setLandingOn(false);
+                }
+            }
+            else
+            {
+                // not on ground
+                lights.setTaxiOn(false);
+                lights.setBeaconOn(true);
+                lights.setNavOn(true);
+                // landing lights for < 10000ft (normally MSL, here ignored)
+                lights.setLandingOn(situation.getAltitude().value(CLengthUnit::ft()) < 10000);
+            }
+            return lights;
+        }
+
         QString CAircraftLights::convertToQString(bool i18n) const
         {
             Q_UNUSED(i18n);
@@ -58,24 +105,15 @@ namespace BlackMisc
             const ColumnIndex i = index.frontCasted<ColumnIndex>();
             switch (i)
             {
-            case IndexBeacon:
-                return CVariant::from(m_beaconOn);
-            case IndexLanding:
-                return CVariant::from(m_landingOn);
-            case IndexLogo:
-                return CVariant::from(m_logoOn);
-            case IndexNav:
-                return CVariant::from(m_navOn);
-            case IndexStrobe:
-                return CVariant::from(m_strobeOn);
-            case IndexTaxi:
-                return CVariant::from(m_taxiOn);
-            case IndexRecognition:
-                return CVariant::from(m_recognition);
-            case IndexCabin:
-                return CVariant::from(m_cabin);
-            default:
-                return CValueObject::propertyByIndex(index);
+            case IndexBeacon: return CVariant::from(m_beaconOn);
+            case IndexLanding: return CVariant::from(m_landingOn);
+            case IndexLogo: return CVariant::from(m_logoOn);
+            case IndexNav: return CVariant::from(m_navOn);
+            case IndexStrobe: return CVariant::from(m_strobeOn);
+            case IndexTaxi: return CVariant::from(m_taxiOn);
+            case IndexRecognition: return CVariant::from(m_recognition);
+            case IndexCabin: return CVariant::from(m_cabin);
+            default: return CValueObject::propertyByIndex(index);
             }
         }
 
@@ -87,33 +125,15 @@ namespace BlackMisc
             const ColumnIndex i = index.frontCasted<ColumnIndex>();
             switch (i)
             {
-            case IndexBeacon:
-                this->m_beaconOn = variant.toBool();
-                break;
-            case IndexLanding:
-                this->m_landingOn = variant.toBool();
-                break;
-            case IndexLogo:
-                this->m_logoOn = variant.toBool();
-                break;
-            case IndexNav:
-                this->m_navOn = variant.toBool();
-                break;
-            case IndexStrobe:
-                this->m_strobeOn = variant.toBool();
-                break;
-            case IndexTaxi:
-                this->m_taxiOn = variant.toBool();
-                break;
-            case IndexCabin:
-                this->m_cabin = variant.toBool();
-                break;
-            case IndexRecognition:
-                this->m_recognition = variant.toBool();
-                break;
-            default:
-                CValueObject::setPropertyByIndex(index, variant);
-                break;
+            case IndexBeacon: m_beaconOn = variant.toBool(); break;
+            case IndexLanding: m_landingOn = variant.toBool(); break;
+            case IndexLogo: m_logoOn = variant.toBool(); break;
+            case IndexNav: m_navOn = variant.toBool(); break;
+            case IndexStrobe: m_strobeOn = variant.toBool(); break;
+            case IndexTaxi: m_taxiOn = variant.toBool(); break;
+            case IndexCabin: m_cabin = variant.toBool(); break;
+            case IndexRecognition: m_recognition = variant.toBool(); break;
+            default: CValueObject::setPropertyByIndex(index, variant); break;
             }
         }
 
@@ -140,5 +160,10 @@ namespace BlackMisc
             m_recognition = false;
             m_cabin = false;
         }
+
+        void CAircraftLights::guessLights(const CAircraftSituation &situation)
+        {
+            *this = guessedLights(situation);
+        }
     } // namespace
 } // namespace
diff --git a/src/blackmisc/aviation/aircraftlights.h b/src/blackmisc/aviation/aircraftlights.h
index 5e8ca87e3..d9a042fc0 100644
--- a/src/blackmisc/aviation/aircraftlights.h
+++ b/src/blackmisc/aviation/aircraftlights.h
@@ -26,6 +26,8 @@ namespace BlackMisc
 {
     namespace Aviation
     {
+        class CAircraftSituation;
+
         //! Value object encapsulating information about aircraft's lights
         class BLACKMISC_EXPORT CAircraftLights :
             public CValueObject<CAircraftLights>,
@@ -111,6 +113,9 @@ namespace BlackMisc
             //! All off
             void setAllOff();
 
+            //! Guess the lights
+            void guessLights(const CAircraftSituation &situation);
+
             //! \copydoc BlackMisc::Mixin::Index::propertyByIndex
             CVariant propertyByIndex(const BlackMisc::CPropertyIndex &index) const;
 
@@ -126,6 +131,9 @@ namespace BlackMisc
             //! Returns object with all lights switched off
             static CAircraftLights allLightsOff();
 
+            //! Guessed lights
+            static CAircraftLights guessedLights(const CAircraftSituation &situation);
+
         private:
             bool m_strobeOn = false;
             bool m_landingOn = false;
diff --git a/src/blackmisc/aviation/aircraftparts.cpp b/src/blackmisc/aviation/aircraftparts.cpp
index a589b00a0..7b48f9013 100644
--- a/src/blackmisc/aviation/aircraftparts.cpp
+++ b/src/blackmisc/aviation/aircraftparts.cpp
@@ -7,14 +7,16 @@
  * contained in the LICENSE file.
  */
 
-#include "blackmisc/aviation/aircraftparts.h"
+#include "aircraftparts.h"
+#include "aircraftlights.h"
+#include "aircraftsituation.h"
 #include "blackmisc/comparefunctions.h"
 #include "blackmisc/stringutils.h"
 
 #include "QStringBuilder"
 #include <QtGlobal>
 
-using namespace BlackMisc;
+using namespace BlackMisc::PhysicalQuantities;
 
 namespace BlackMisc
 {
@@ -39,6 +41,45 @@ namespace BlackMisc
             return json;
         }
 
+        CAircraftParts CAircraftParts::guessedParts(const CAircraftSituation &situation, bool vtol, int engineNumber)
+        {
+            CAircraftParts parts;
+            CAircraftEngineList engines;
+            parts.setLights(CAircraftLights::guessedLights(situation));
+
+            const bool onGround = situation.isOnGround();
+            if (onGround)
+            {
+                parts.setGearDown(true);
+                engines.initEngines(engineNumber, situation.isMoving());
+            }
+            else
+            {
+                parts.setGearDown(false);
+                engines.initEngines(engineNumber, true);
+                if (vtol)
+                {
+
+                }
+                else if (situation.hasGroundElevation())
+                {
+                    const double aGroundFt = situation.getHeightAboveGround().value(CLengthUnit::ft());
+                    if (aGroundFt < 1000)
+                    {
+                        parts.setGearDown(true);
+                        parts.setFlapsPercent(25);
+                    }
+                    else if (aGroundFt < 2000)
+                    {
+                        parts.setGearDown(true);
+                        parts.setFlapsPercent(10);
+                    }
+                }
+            }
+            parts.setEngines(engines);
+            return parts;
+        }
+
         CVariant CAircraftParts::propertyByIndex(const BlackMisc::CPropertyIndex &index) const
         {
             if (index.isMyself()) { return CVariant::from(*this); }
@@ -92,6 +133,15 @@ namespace BlackMisc
             return 0;
         }
 
+        CAircraftLights CAircraftParts::getAdjustedLights() const
+        {
+            CAircraftLights lights = this->getLights();
+            const bool anyEngine = this->isAnyEngineOn();
+            lights.setRecognitionOn(anyEngine);
+            lights.setCabinOn(anyEngine);
+            return lights;
+        }
+
         void CAircraftParts::setAllLightsOn()
         {
             m_lights.setAllOn();
@@ -117,6 +167,11 @@ namespace BlackMisc
             return m_engines.isAnyEngineOn();
         }
 
+        void CAircraftParts::guessParts(const CAircraftSituation &situation)
+        {
+            *this = guessedParts(situation);
+        }
+
         double CAircraftParts::isOnGroundInterpolated() const
         {
             if (m_isOnGroundInterpolated < 0)
diff --git a/src/blackmisc/aviation/aircraftparts.h b/src/blackmisc/aviation/aircraftparts.h
index 4657db045..acd41598a 100644
--- a/src/blackmisc/aviation/aircraftparts.h
+++ b/src/blackmisc/aviation/aircraftparts.h
@@ -29,6 +29,8 @@ namespace BlackMisc
 {
     namespace Aviation
     {
+        class CAircraftSituation;
+
         //! Value object encapsulating information of aircraft's parts
         class BLACKMISC_EXPORT CAircraftParts :
             public CValueObject<CAircraftParts>,
@@ -68,7 +70,10 @@ namespace BlackMisc
             //! Get aircraft lights
             CAircraftLights getLights() const { return m_lights; }
 
-            //! Reference to lights, meant wor easy direct changes of the values
+            //! Lights adjusted depending on engines
+            CAircraftLights getAdjustedLights() const;
+
+            //! Reference to lights, meant for easy direct changes of the values
             CAircraftLights &lights() { return m_lights; }
 
             //! Set aircraft lights
@@ -125,12 +130,17 @@ namespace BlackMisc
             //! Set aircraft on ground
             void setOnGround(bool onGround) { m_isOnGround = onGround; }
 
+            //! Guess the parts
+            void guessParts(const CAircraftSituation &situation);
+
             //! Is aircraft on ground? (Smoothly interpolated between 0 and 1.)
             //! \remark 1..on ground 0..not on ground
+            //! \deprecated
             double isOnGroundInterpolated() const;
 
             //! Set aircraft on ground. (Smoothly interpolated between 0 and 1.)
             //! \remark 1..on ground 0..not on ground
+            //! \deprecated
             void setOnGroundInterpolated(double onGround) { m_isOnGroundInterpolated = onGround; }
 
             //! \copydoc BlackMisc::Mixin::String::toQString
@@ -139,6 +149,9 @@ namespace BlackMisc
             //! Incremental JSON object
             QJsonObject toIncrementalJson() const;
 
+            //! Guessed parts
+            static CAircraftParts guessedParts(const CAircraftSituation &situation, bool vtol = false, int engineNumber = 4);
+
         private:
             CAircraftLights m_lights;
             CAircraftEngineList m_engines;
diff --git a/src/blackmisc/aviation/aircraftsituation.cpp b/src/blackmisc/aviation/aircraftsituation.cpp
index 28d452fcb..d63801742 100644
--- a/src/blackmisc/aviation/aircraftsituation.cpp
+++ b/src/blackmisc/aviation/aircraftsituation.cpp
@@ -98,11 +98,16 @@ namespace BlackMisc
             case CAircraftSituation::InFromParts: return inFromParts;
             case CAircraftSituation::InNoGroundInfo: return InNoGroundInfo;
             case CAircraftSituation::NotSet:
-            default:
-                return unknown;
+            default: return unknown;
             }
         }
 
+        const CLength &CAircraftSituation::deltaNearGround()
+        {
+            static const CLength small(0.5, CLengthUnit::m());
+            return small;
+        }
+
         CVariant CAircraftSituation::propertyByIndex(const BlackMisc::CPropertyIndex &index) const
         {
             if (index.isMyself()) { return CVariant::from(*this); }
@@ -122,8 +127,8 @@ namespace BlackMisc
             case IndexGroundSpeed: return m_groundSpeed.propertyByIndex(index.copyFrontRemoved());
             case IndexGroundElevationPlane: return m_groundElevationPlane.propertyByIndex(index.copyFrontRemoved());
             case IndexCallsign: return m_correspondingCallsign.propertyByIndex(index.copyFrontRemoved());
-            case IndexIsOnGround: return CVariant::fromValue(m_isOnGround);
-            case IndexIsOnGroundString: return CVariant::fromValue(this->isOnGroundAsString());
+            case IndexIsOnGround: return CVariant::fromValue(m_onGround);
+            case IndexIsOnGroundString: return CVariant::fromValue(this->onGroundAsString());
             case IndexOnGroundReliability: return CVariant::fromValue(m_onGroundDetails);
             case IndexOnGroundReliabilityString: return CVariant::fromValue(this->getOnDetailsAsString());
             default: return CValueObject::propertyByIndex(index);
@@ -144,7 +149,7 @@ namespace BlackMisc
             case IndexGroundSpeed: m_groundSpeed.setPropertyByIndex(index.copyFrontRemoved(), variant); break;
             case IndexGroundElevationPlane: m_groundElevationPlane.setPropertyByIndex(index.copyFrontRemoved(), variant); break;
             case IndexCallsign: m_correspondingCallsign.setPropertyByIndex(index.copyFrontRemoved(), variant); break;
-            case IndexIsOnGround: m_isOnGround = variant.toInt(); break;
+            case IndexIsOnGround: m_onGround = variant.toInt(); break;
             case IndexOnGroundReliability: m_onGroundDetails = variant.toInt(); break;
             default: CValueObject::setPropertyByIndex(index, variant); break;
             }
@@ -166,7 +171,7 @@ namespace BlackMisc
             case IndexCallsign: return m_correspondingCallsign.comparePropertyByIndex(index.copyFrontRemoved(), compareValue.getCallsign());
             case IndexIsOnGround:
             case IndexIsOnGroundString:
-                return Compare::compare(m_isOnGround, compareValue.m_isOnGround);
+                return Compare::compare(m_onGround, compareValue.m_onGround);
             case IndexOnGroundReliability:
             case IndexOnGroundReliabilityString:
                 return Compare::compare(m_onGroundDetails, compareValue.m_onGroundDetails);
@@ -194,23 +199,73 @@ namespace BlackMisc
             m_onGroundDetails = CAircraftSituation::NotSet;
         }
 
-        const QString &CAircraftSituation::isOnGroundAsString() const
+        const QString &CAircraftSituation::onGroundAsString() const
         {
-            return CAircraftSituation::isOnGroundToString(this->isOnGround());
+            return CAircraftSituation::isOnGroundToString(this->getOnGround());
         }
 
         bool CAircraftSituation::isOnGroundInfoAvailable() const
         {
-            return this->isOnGround() != CAircraftSituation::OnGroundSituationUnknown &&
+            return this->getOnGround() != CAircraftSituation::OnGroundSituationUnknown &&
                    this->getOnGroundDetails() != CAircraftSituation::NotSet;
         }
 
+        void CAircraftSituation::setOnGround(bool onGround)
+        {
+            this->setOnGround(onGround ? OnGround : NotOnGround);
+        }
+
+        void CAircraftSituation::setOnGround(CAircraftSituation::IsOnGround onGround)
+        {
+            m_onGround = static_cast<int>(onGround);
+            m_onGroundFactor = (onGround == OnGround) ?  1.0 : 0.0;
+        }
+
         void CAircraftSituation::setOnGround(CAircraftSituation::IsOnGround onGround, CAircraftSituation::OnGroundDetails details)
         {
             this->setOnGround(onGround);
             this->setOnGroundDetails(details);
         }
 
+        void CAircraftSituation::setOnGroundFactor(double groundFactor)
+        {
+            if (groundFactor < 0.0) { m_onGroundFactor = -1.0; return; }
+            if (groundFactor > 1.0) { m_onGroundFactor =  1.0; return; }
+            m_onGroundFactor = groundFactor;
+        }
+
+        bool CAircraftSituation::guessOnGround(bool vtol, const PhysicalQuantities::CLength &cg)
+        {
+            if (this->getOnGroundDetails() == NotSet) { return false; }
+            IsOnGround og = this->isOnGroundByElevation(cg);
+            if (og != OnGroundSituationUnknown)
+            {
+                this->setOnGround(og, CAircraftSituation::OnGroundByGuessing);
+                return true;
+            }
+
+            // we guess on speed, pitch and bank by excluding situations
+            this->setOnGround(CAircraftSituation::NotOnGround, CAircraftSituation::OnGroundByGuessing);
+            if (qAbs(this->getPitch().value(CAngleUnit::deg())) > 10)  { return true; }
+            if (qAbs(this->getBank().value(CAngleUnit::deg())) > 10)   { return true; }
+            if (this->getGroundSpeed().value(CSpeedUnit::km_h()) > 50) { return true; }
+
+            // on VTOL we stop here
+            if (vtol) { return false; }
+
+            // not sure, but this is a guess
+            this->setOnGround(CAircraftSituation::OnGround, CAircraftSituation::OnGroundByGuessing);
+            return true;
+        }
+
+        CLength CAircraftSituation::getGroundDistance(const CLength &centerOfGravity) const
+        {
+            if (centerOfGravity.isNull() || !this->hasGroundElevation()) { return CLength::null(); }
+            const CAltitude groundPlusCG = this->getGroundElevation().withOffset(centerOfGravity);
+            const CLength groundDistance = (this->getAltitude() - groundPlusCG);
+            return groundDistance;
+        }
+
         const QString &CAircraftSituation::getOnDetailsAsString() const
         {
             return CAircraftSituation::onGroundDetailsToString(this->getOnGroundDetails());
@@ -218,7 +273,15 @@ namespace BlackMisc
 
         QString CAircraftSituation::getOnGroundInfo() const
         {
-            return this->isOnGroundAsString() % QLatin1Char(' ') % this->getOnDetailsAsString();
+            return this->onGroundAsString() % QLatin1Char(' ') % this->getOnDetailsAsString();
+        }
+
+        CAircraftSituation::IsOnGround CAircraftSituation::isOnGroundByElevation(const CLength &cg) const
+        {
+            const CLength groundDistance = this->getGroundDistance(cg);
+            if (groundDistance.isNull()) { return OnGroundSituationUnknown; }
+            if (groundDistance.isNegativeWithEpsilonConsidered() || groundDistance.abs() < deltaNearGround()) { return OnGround; }
+            return NotOnGround;
         }
 
         bool CAircraftSituation::hasGroundElevation() const
@@ -292,18 +355,17 @@ namespace BlackMisc
             }
             else
             {
-                static const CLength small(0.5, CLengthUnit::m());
                 const CAltitude groundPlusCG = this->getGroundElevation().withOffset(centerOfGravity);
-                const CLength groundDistance = (this->getAltitude() - groundPlusCG);
-                if (groundDistance.abs() < small) { return this->getAltitude(); }
-                const bool toGround = (this->getAltitude() < groundPlusCG) || (forceToGround && this->isOnGround() == OnGround);
-                if (toGround)
-                {
-                    // underflow or overflow forced to ground
-                    if (corrected) { *corrected = true; }
-                    return groundPlusCG;
-                }
-                return this->getAltitude();
+                if (groundPlusCG.isNull()) { return this->getAltitude(); }
+                const CLength groundDistance = this->getAltitude() - groundPlusCG;
+                const bool underOrNearGround = groundDistance.isNegativeWithEpsilonConsidered() || groundDistance.abs() < deltaNearGround();
+                const bool forceDragGnd = (dragToGround && this->getOnGround() == OnGround) && (this->hasInboundGroundInformation() || this->getOnGroundDetails() == OnGroundByGuessing);
+                const bool toGround = underOrNearGround || forceDragGnd;
+                if (!toGround) { return this->getAltitude(); }
+
+                // underflow or overflow forced to ground
+                if (corrected) { *corrected = true; }
+                return groundPlusCG;
             }
         }
 
@@ -313,6 +375,12 @@ namespace BlackMisc
             m_pressureAltitude = altitude;
         }
 
+        bool CAircraftSituation::isMoving() const
+        {
+            const double gsKmh = this->getGroundSpeed().value(CSpeedUnit::km_h());
+            return gsKmh >= 1.0;
+        }
+
         CLength CAircraftSituation::getDistancePerTime(const CTime &time) const
         {
             if (this->getGroundSpeed().isNull()) { return CLength(0, CLengthUnit::nullUnit()); }
diff --git a/src/blackmisc/aviation/aircraftsituation.h b/src/blackmisc/aviation/aircraftsituation.h
index 62d3c8520..ff29e221b 100644
--- a/src/blackmisc/aviation/aircraftsituation.h
+++ b/src/blackmisc/aviation/aircraftsituation.h
@@ -147,23 +147,38 @@ namespace BlackMisc
             virtual Geo::CLongitude longitude() const override { return m_position.longitude(); }
 
             //! On ground?
-            IsOnGround isOnGround() const { return static_cast<CAircraftSituation::IsOnGround>(m_isOnGround); }
+            IsOnGround getOnGround() const { return static_cast<CAircraftSituation::IsOnGround>(m_onGround); }
+
+            //! Is on ground?
+            bool isOnGround() const { return this->getOnGround() == OnGround; }
 
             //! On ground?
-            const QString &isOnGroundAsString() const;
+            const QString &onGroundAsString() const;
 
             //! On ground info available?
             bool isOnGroundInfoAvailable() const;
 
             //! Set on ground
-            void setOnGround(bool onGround) { this->setOnGround(onGround ? OnGround : NotOnGround); }
+            void setOnGround(bool onGround);
 
             //! Set on ground
-            void setOnGround(CAircraftSituation::IsOnGround onGround) { m_isOnGround = static_cast<int>(onGround); }
+            void setOnGround(CAircraftSituation::IsOnGround onGround);
 
             //! Set on ground
             void setOnGround(CAircraftSituation::IsOnGround onGround, CAircraftSituation::OnGroundDetails details);
 
+            //! On ground factor 0..1 (on ground), -1 not set
+            double getOnGroundFactor() const { return m_onGroundFactor; }
+
+            //! Set on ground factor 0..1 (on ground), -1 not set
+            void setOnGroundFactor(double groundFactor);
+
+            //! Guess on ground flag
+            bool guessOnGround(bool vtol = false, const PhysicalQuantities::CLength &cg = PhysicalQuantities::CLength::null());
+
+            //! Distance to ground, null if impossible to calculate
+            PhysicalQuantities::CLength getGroundDistance(const PhysicalQuantities::CLength &centerOfGravity) const;
+
             //! On ground reliability
             OnGroundDetails getOnGroundDetails() const { return static_cast<CAircraftSituation::OnGroundDetails>(m_onGroundDetails); }
 
@@ -191,6 +206,9 @@ namespace BlackMisc
             //! Elevation of the ground directly beneath
             const Geo::CElevationPlane &getGroundElevationPlane() const { return m_groundElevationPlane; }
 
+            //! Is on ground by elevation data, requires elevation and CG
+            IsOnGround isOnGroundByElevation(const PhysicalQuantities::CLength &cg) const;
+
             //! Is ground elevation value available
             bool hasGroundElevation() const;
 
@@ -222,8 +240,9 @@ namespace BlackMisc
             //! Get altitude
             const CAltitude &getAltitude() const { return m_position.geodeticHeight(); }
 
-            //! Get altitude under consideration of ground elevation
-            CAltitude getCorrectedAltitude(const PhysicalQuantities::CLength &centerOfGravity = {}, bool forceToGround = true, bool *corrected = nullptr) const;
+            //! Get altitude under consideration of ground elevation and ground flag
+            //! \remark with dragToGround it will also compensate overflows, otherwise ony underflow
+            CAltitude getCorrectedAltitude(const PhysicalQuantities::CLength &centerOfGravity = PhysicalQuantities::CLength::null(), bool dragToGround = true, bool *corrected = nullptr) const;
 
             //! Set altitude
             void setAltitude(const CAltitude &altitude) { m_position.setGeodeticHeight(altitude); }
@@ -252,6 +271,9 @@ namespace BlackMisc
             //! Set ground speed
             void setGroundSpeed(const PhysicalQuantities::CSpeed &groundspeed) { m_groundSpeed = groundspeed; }
 
+            //! Is moving? Means ground speed > epsilon
+            bool isMoving() const;
+
             //! Distance per time
             PhysicalQuantities::CLength getDistancePerTime(const PhysicalQuantities::CTime &time) const;
 
@@ -293,18 +315,22 @@ namespace BlackMisc
             //! Enum to string
             static const QString &onGroundDetailsToString(OnGroundDetails reliability);
 
+            //! Delta distance, near to ground
+            static const PhysicalQuantities::CLength &deltaNearGround();
+
         private:
             CCallsign m_correspondingCallsign;
-            Geo::CCoordinateGeodetic m_position; // NULL position
+            Geo::CCoordinateGeodetic m_position; //!< NULL position as default
             Aviation::CAltitude m_pressureAltitude { 0, nullptr };
-            CHeading m_heading;
-            PhysicalQuantities::CAngle m_pitch;
-            PhysicalQuantities::CAngle m_bank;
-            PhysicalQuantities::CSpeed m_groundSpeed;
-            Geo::CElevationPlane m_groundElevationPlane; //!< NULL elevation as default
-            int m_isOnGround = static_cast<int>(CAircraftSituation::OnGroundSituationUnknown);
-            int m_onGroundDetails = static_cast<int>(CAircraftSituation::NotSet);
+            CHeading m_heading { 0, nullptr };
+            PhysicalQuantities::CAngle m_pitch { 0, nullptr };
+            PhysicalQuantities::CAngle m_bank  { 0, nullptr };
+            PhysicalQuantities::CSpeed m_groundSpeed { 0, nullptr };
             bool m_isInterim = false;
+            Geo::CElevationPlane m_groundElevationPlane; //!< NULL elevation as default
+            int m_onGround = static_cast<int>(CAircraftSituation::OnGroundSituationUnknown);
+            int m_onGroundDetails = static_cast<int>(CAircraftSituation::NotSet);
+            double m_onGroundFactor = -1; //!< interpolated ground flag, 1..on ground, 0..not on ground, -1 no info
 
             BLACK_METACLASS(
                 CAircraftSituation,
@@ -316,8 +342,9 @@ namespace BlackMisc
                 BLACK_METAMEMBER(bank),
                 BLACK_METAMEMBER(groundSpeed),
                 BLACK_METAMEMBER(groundElevationPlane),
-                BLACK_METAMEMBER(isOnGround),
+                BLACK_METAMEMBER(onGround),
                 BLACK_METAMEMBER(onGroundDetails),
+                BLACK_METAMEMBER(onGroundFactor),
                 BLACK_METAMEMBER(timestampMSecsSinceEpoch),
                 BLACK_METAMEMBER(timeOffsetMs),
                 BLACK_METAMEMBER(isInterim)
diff --git a/src/blackmisc/aviation/aircraftsituationlist.cpp b/src/blackmisc/aviation/aircraftsituationlist.cpp
index aaaa41b78..4f2e04509 100644
--- a/src/blackmisc/aviation/aircraftsituationlist.cpp
+++ b/src/blackmisc/aviation/aircraftsituationlist.cpp
@@ -66,7 +66,7 @@ namespace BlackMisc
             {
                 if (situation.isNewerThanAdjusted(latest))
                 {
-                    situation.setOnGround(latest.isOnGround(), latest.getOnGroundDetails());
+                    situation.setOnGround(latest.getOnGround(), latest.getOnGroundDetails());
                     c++;
                 }
             }
diff --git a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
index 0b751ceac..e8ade8b5e 100644
--- a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
+++ b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.cpp
@@ -8,6 +8,8 @@
  */
 
 #include "simconnectdatadefinition.h"
+#include "blackmisc/aviation/aircraftparts.h"
+#include "blackmisc/aviation/aircraftenginelist.h"
 #include "blackmisc/logmessage.h"
 #include <tuple>
 
@@ -186,6 +188,16 @@ namespace BlackSimPlugin
             return hr;
         }
 
+        DataDefinitionRemoteAircraftPartsWithoutLights::DataDefinitionRemoteAircraftPartsWithoutLights()
+        {
+            this->resetToInvalid();
+        }
+
+        DataDefinitionRemoteAircraftPartsWithoutLights::DataDefinitionRemoteAircraftPartsWithoutLights(const CAircraftParts &parts)
+        {
+            this->initFromParts(parts);
+        }
+
         bool DataDefinitionRemoteAircraftPartsWithoutLights::operator==(const DataDefinitionRemoteAircraftPartsWithoutLights &rhs) const
         {
             return std::tie(flapsLeadingEdgeLeftPercent, flapsLeadingEdgeRightPercent, flapsTrailingEdgeLeftPercent, flapsTrailingEdgeRightPercent,
@@ -204,6 +216,19 @@ namespace BlackSimPlugin
             engine4Combustion = on ? 1 : 0;
         }
 
+        void DataDefinitionRemoteAircraftPartsWithoutLights::setEngine(int number1based, bool on)
+        {
+            double v = on ? 1.0 : 0.0;
+            switch (number1based)
+            {
+            case 1: engine1Combustion = v; break;
+            case 2: engine2Combustion = v; break;
+            case 3: engine3Combustion = v; break;
+            case 4: engine4Combustion = v; break;
+            default: break;
+            }
+        }
+
         void DataDefinitionRemoteAircraftPartsWithoutLights::resetAllFlaps()
         {
             flapsLeadingEdgeLeftPercent = 0;
@@ -231,6 +256,21 @@ namespace BlackSimPlugin
             engine4Combustion = -1;
         }
 
+        void DataDefinitionRemoteAircraftPartsWithoutLights::initFromParts(const CAircraftParts &parts)
+        {
+            gearHandlePosition = parts.isGearDown() ? 1.0 : 0.0;
+            flapsTrailingEdgeLeftPercent = flapsTrailingEdgeRightPercent = parts.getFlapsPercent() / 100.0;
+            flapsLeadingEdgeLeftPercent = flapsLeadingEdgeRightPercent = parts.getFlapsPercent() * 0.2 / 100.0;
+            spoilersHandlePosition = parts.isSpoilersOut() ? 1.0 : 0.0;
+            this->setAllEngines(false); // init
+
+            int e = 1;
+            for (const CAircraftEngine &engine : parts.getEngines())
+            {
+                this->setEngine(e++, engine.isOn());
+            }
+        }
+
         CAircraftLights DataDefinitionRemoteAircraftLights::toLights() const
         {
             return CAircraftLights(lightStrobe, lightLanding, lightTaxi, lightBeacon, lightNav, lightLogo, lightRecognition, lightCabin);
diff --git a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
index 141e63b61..a05812568 100644
--- a/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
+++ b/src/plugins/simulator/fsxcommon/simconnectdatadefinition.h
@@ -19,6 +19,7 @@
 #include <algorithm>
 #include <QString>
 
+namespace BlackMisc { namespace Aviation { class CAircraftParts; }}
 namespace BlackSimPlugin
 {
     namespace FsxCommon
@@ -85,12 +86,21 @@ namespace BlackSimPlugin
             double engine3Combustion;             //!< Engine 3 combustion flag
             double engine4Combustion;             //!< Engine 4 combustion flag
 
+            //! Ctor
+            DataDefinitionRemoteAircraftPartsWithoutLights();
+
+            //! Ctor
+            DataDefinitionRemoteAircraftPartsWithoutLights(const BlackMisc::Aviation::CAircraftParts &parts);
+
             //! Equal to other parts
             bool operator==(const DataDefinitionRemoteAircraftPartsWithoutLights &rhs) const;
 
             //! All engines on/off
             void setAllEngines(bool on);
 
+            //! Set given engine
+            void setEngine(int number1based, bool on);
+
             //! Reset all flaps
             void resetAllFlaps();
 
@@ -99,6 +109,9 @@ namespace BlackSimPlugin
 
             //! Reset to invalid values
             void resetToInvalid();
+
+            //! Init from parts
+            void initFromParts(const BlackMisc::Aviation::CAircraftParts &parts);
         };
 
         //! Data for aircraft lighs
diff --git a/tests/blackmisc/testinterpolatorparts.cpp b/tests/blackmisc/testinterpolatorparts.cpp
index 4ce4d77dc..64c8e8595 100644
--- a/tests/blackmisc/testinterpolatorparts.cpp
+++ b/tests/blackmisc/testinterpolatorparts.cpp
@@ -111,11 +111,11 @@ namespace BlackMiscTest
 
         CAircraftSituation s0 = situations[0];
         s0.adjustGroundFlag(partsOnGround);
-        QVERIFY2(s0.isOnGround(), "Supposed to be on ground");
+        QVERIFY2(s0.getOnGround(), "Supposed to be on ground");
 
         s0 = situations[0];
         s0.adjustGroundFlag(partsNotOnGround);
-        QVERIFY2(!s0.isOnGround(), "Supposed to be not on ground");
+        QVERIFY2(!s0.getOnGround(), "Supposed to be not on ground");
 
         qint64 distanceMs = -1;
         const qint64 Offset = 33;