diff --git a/src/blackcore/airspacemonitor.cpp b/src/blackcore/airspacemonitor.cpp
index d7edcabbf..155da0947 100644
--- a/src/blackcore/airspacemonitor.cpp
+++ b/src/blackcore/airspacemonitor.cpp
@@ -407,6 +407,13 @@ namespace BlackCore
         return m_aircraftInRange.containsCallsign(callsign);
     }
 
+    bool CAirspaceMonitor::isVtolAircraft(const CCallsign &callsign) const
+    {
+        if (callsign.isEmpty()) { return false; }
+        const CSimulatedAircraft aircraft = this->getAircraftInRangeForCallsign(callsign);
+        return aircraft.isVtol();
+    }
+
     CAtcStation CAirspaceMonitor::getAtcStationForComUnit(const CComSystem &comSystem)
     {
         CAtcStation station;
diff --git a/src/blackcore/airspacemonitor.h b/src/blackcore/airspacemonitor.h
index 94687f4ce..0ceec3f62 100644
--- a/src/blackcore/airspacemonitor.h
+++ b/src/blackcore/airspacemonitor.h
@@ -94,6 +94,7 @@ namespace BlackCore
         virtual BlackMisc::Simulation::CAircraftModel getAircraftInRangeModelForCallsign(const BlackMisc::Aviation::CCallsign &callsign) const override;
         virtual int getAircraftInRangeCount() const override;
         virtual bool isAircraftInRange(const BlackMisc::Aviation::CCallsign &callsign) const override;
+        virtual bool isVtolAircraft(const BlackMisc::Aviation::CCallsign &callsign) const override;
         virtual BlackMisc::Simulation::CAirspaceAircraftSnapshot getLatestAirspaceAircraftSnapshot() const override;
         virtual BlackMisc::Aviation::CAircraftSituationList remoteAircraftSituations(const BlackMisc::Aviation::CCallsign &callsign) const override;
         virtual int remoteAircraftSituationsCount(const BlackMisc::Aviation::CCallsign &callsign) const override;
diff --git a/src/blackcore/context/contextnetworkimpl.cpp b/src/blackcore/context/contextnetworkimpl.cpp
index ce827ea42..b51c99512 100644
--- a/src/blackcore/context/contextnetworkimpl.cpp
+++ b/src/blackcore/context/contextnetworkimpl.cpp
@@ -531,6 +531,12 @@ namespace BlackCore
             return m_airspace->isAircraftInRange(callsign);
         }
 
+        bool CContextNetwork::isVtolAircraft(const CCallsign &callsign) const
+        {
+            if (this->isDebugEnabled()) { CLogMessage(this, CLogCategory::contextSlot()).debug() << Q_FUNC_INFO; }
+            return m_airspace->isVtolAircraft(callsign);
+        }
+
         CSimulatedAircraft CContextNetwork::getAircraftInRangeForCallsign(const CCallsign &callsign) const
         {
             if (this->isDebugEnabled()) { CLogMessage(this, BlackMisc::CLogCategory::contextSlot()).debug() << Q_FUNC_INFO << callsign; }
diff --git a/src/blackcore/context/contextnetworkimpl.h b/src/blackcore/context/contextnetworkimpl.h
index 621a09d58..c53fa9755 100644
--- a/src/blackcore/context/contextnetworkimpl.h
+++ b/src/blackcore/context/contextnetworkimpl.h
@@ -118,6 +118,7 @@ namespace BlackCore
             virtual BlackMisc::Aviation::CCallsignSet getAircraftInRangeCallsigns() const override;
             virtual int getAircraftInRangeCount() const override;
             virtual bool isAircraftInRange(const BlackMisc::Aviation::CCallsign &callsign) const override;
+            virtual bool isVtolAircraft(const BlackMisc::Aviation::CCallsign &callsign) const override;
             virtual BlackMisc::Simulation::CSimulatedAircraft getAircraftInRangeForCallsign(const BlackMisc::Aviation::CCallsign &callsign) const override;
             virtual BlackMisc::Simulation::CAircraftModel getAircraftInRangeModelForCallsign(const BlackMisc::Aviation::CCallsign &callsign) const override;
             virtual BlackMisc::CStatusMessageList getReverseLookupMessages(const BlackMisc::Aviation::CCallsign &callsign) const override;
diff --git a/src/blackcore/simulatorcommon.cpp b/src/blackcore/simulatorcommon.cpp
index 3aac00237..f7f6d2669 100644
--- a/src/blackcore/simulatorcommon.cpp
+++ b/src/blackcore/simulatorcommon.cpp
@@ -16,7 +16,6 @@
 #include "blackmisc/simulation/aircraftmodellist.h"
 #include "blackmisc/simulation/airspaceaircraftsnapshot.h"
 #include "blackmisc/simulation/interpolator.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/simulatedaircraft.h"
 #include "blackmisc/pq/physicalquantity.h"
 #include "blackmisc/simplecommandparser.h"
@@ -571,7 +570,6 @@ namespace BlackCore
         CStatusMessageList msgs;
         if (!CBuildConfig::isLocalDeveloperDebugBuild()) { return msgs; }
         if (!m_addAgainAircraftWhenRemoved.isEmpty()) { msgs.push_back(CStatusMessage(this).error("m_addAgainAircraftWhenRemoved not empty: '%1'") << m_addAgainAircraftWhenRemoved.getCallsignStrings(true).join(", ")); }
-        if (!m_hints.isEmpty()) { msgs.push_back(CStatusMessage(this).error("m_hints not empty: '%1'") << CCallsignSet(m_hints.keys()).getCallsignStrings(true).join(", ")); }
         return msgs;
     }
 
@@ -679,7 +677,6 @@ namespace BlackCore
         // rendering related stuff
         m_addAgainAircraftWhenRemoved.clear();
         m_callsignsToBeRendered.clear();
-        m_hints.clear();
 
         this->resetHighlighting();
         this->resetAircraftStatistics();
@@ -762,11 +759,9 @@ namespace BlackCore
         static const QString sep("\n");
         if (s.tsCurrent > 0)
         {
-            dm = QStringLiteral("Hints: ") % s.usedHints.asString(false, true) %
-                 QStringLiteral("\n") %
-                 QStringLiteral("Setup: ") % s.usedSetup.toQString(true) %
+            dm = QStringLiteral("Setup: ") % s.usedSetup.toQString(true) %
                  QStringLiteral("\n\n") %
-                 QStringLiteral("Situation: ") % s.toQString(false, false, true, true, true, true, sep);
+                 QStringLiteral("Situation: ") % s.toQString(false, true, true, true, true, sep);
         }
         if (p.tsCurrent > 0) { dm += (dm.isEmpty() ? QStringLiteral("") : QStringLiteral("\n\n")) % QStringLiteral("Parts: ") % p.toQString(sep); }
         if (!dm.isEmpty())
diff --git a/src/blackcore/simulatorcommon.h b/src/blackcore/simulatorcommon.h
index 21245c87a..43b41e8f0 100644
--- a/src/blackcore/simulatorcommon.h
+++ b/src/blackcore/simulatorcommon.h
@@ -27,7 +27,6 @@
 #include "blackmisc/simulation/simulatorinternals.h"
 #include "blackmisc/simulation/settings/simulatorsettings.h"
 #include "blackmisc/simulation/interpolationrenderingsetup.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/interpolationlogger.h"
 #include "blackmisc/aviation/callsignset.h"
 #include "blackmisc/pq/length.h"
@@ -221,7 +220,6 @@ namespace BlackCore
 
         // some optional functionality which can be used by the simulators as needed
         BlackMisc::Simulation::CSimulatedAircraftList m_addAgainAircraftWhenRemoved; //!< add this model again when removed, normally used to change model
-        QHash<BlackMisc::Aviation::CCallsign, BlackMisc::Simulation::CInterpolationHints> m_hints; //!< hints for callsign, contains last ground elevation fetched
 
         // weather
         bool m_isWeatherActivated = false;                         //!< Is simulator weather activated?
diff --git a/src/blackmisc/propertyindex.h b/src/blackmisc/propertyindex.h
index 1a0aaa5af..7aaac04f6 100644
--- a/src/blackmisc/propertyindex.h
+++ b/src/blackmisc/propertyindex.h
@@ -159,7 +159,6 @@ namespace BlackMisc
             GlobalIndexCAtcStationsSettings             = 14800,
             GlobalIndexRawFsdMessageSettings            = 14900,
             GlobalIndexCInterpolatioRenderingSetup      = 16000,
-            GlobalIndexCInterpolationHints              = 16100,
             GlobalIndexSwiftPilotClient                 = 17000,
             GlobalIndexSwiftCore                        = 17100,
             GlobalIndexSwiftLauncher                    = 17200,
diff --git a/src/blackmisc/simulation/interpolationhints.cpp b/src/blackmisc/simulation/interpolationhints.cpp
deleted file mode 100644
index 854c90a8f..000000000
--- a/src/blackmisc/simulation/interpolationhints.cpp
+++ /dev/null
@@ -1,223 +0,0 @@
-/* Copyright (C) 2016
- * swift project Community / Contributors
- *
- * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
- * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
- * including this file, may be copied, modified, propagated, or distributed except according to the terms
- * contained in the LICENSE file.
- */
-
-#include "interpolationhints.h"
-#include "interpolationlogger.h"
-#include "blackmisc/aviation/aircraftsituation.h"
-
-using namespace BlackMisc::Aviation;
-using namespace BlackMisc::Geo;
-using namespace BlackMisc::PhysicalQuantities;
-
-#include <QStringBuilder>
-
-namespace BlackMisc
-{
-    namespace Simulation
-    {
-        CInterpolationHints::CInterpolationHints() { }
-
-        CInterpolationHints::CInterpolationHints(bool isVtolAircraft) : m_isVtol(isVtolAircraft)
-        { }
-
-        CInterpolationHints::CInterpolationHints(bool isVtolAircraft, bool hasParts, bool log) :
-            m_isVtol(isVtolAircraft), m_hasParts(hasParts), m_logInterpolation(log)
-        { }
-
-        const CElevationPlane &CInterpolationHints::getElevationPlane(ICoordinateGeodetic &reference, const CLength &radius, SituationLog *log) const
-        {
-            if (m_elevationPlane.isNull())
-            {
-                if (log)
-                {
-                    static const QString lm("By provider (no valid plane)");
-                    log->elevationInfo = lm;
-                }
-                return CElevationPlane::null();
-            }
-            const CLength d = reference.calculateGreatCircleDistance(m_elevationPlane);
-            if (d <= radius)
-            {
-                if (log)
-                {
-                    static const QString lm("Using elevation plane, distance: %1");
-                    log->elevationInfo = lm.arg(d.valueRoundedWithUnit(CLengthUnit::m(), 1));
-                }
-                return m_elevationPlane;
-            }
-            else
-            {
-                if (log)
-                {
-                    static const QString lm("Invalid elevation plane, distance: %1");
-                    log->elevationInfo = lm.arg(d.valueRoundedWithUnit(CLengthUnit::m(), 1));
-                }
-                return CElevationPlane::null();
-            }
-        }
-
-        CAltitude CInterpolationHints::getGroundElevation(const CAircraftSituation &situation, bool useProvider, bool forceProvider, SituationLog *log) const
-        {
-            return this->getGroundElevation(situation, CLength::null(), useProvider, forceProvider, log);
-        }
-
-        CAltitude CInterpolationHints::getGroundElevation(const CAircraftSituation &situation, const CLength &validRadius, bool useProvider, bool forceProvider, SituationLog *log) const
-        {
-            Q_ASSERT_X(!(forceProvider && !useProvider), Q_FUNC_INFO, "Invalid parameter combination");
-            if (forceProvider && useProvider && m_elevationProvider)
-            {
-                if (log)
-                {
-                    static const QString lm("By provider (forced)");
-                    log->elevationInfo = lm;
-                }
-                Q_ASSERT_X(false, Q_FUNC_INFO, "Elevation provider must no longer be used");
-                return m_elevationProvider(situation);
-            }
-
-            const CLength radius = CLength::maxValue(validRadius, m_elevationPlane.getRadius());
-            const bool validPlane = m_elevationPlane.isWithinRange(situation, radius);
-            if (!validPlane && useProvider && m_elevationProvider)
-            {
-                if (log)
-                {
-                    static const QString lm("By provider (no valid plane)");
-                    log->elevationInfo = lm;
-                }
-                return m_elevationProvider(situation);
-            }
-
-            if (validPlane)
-            {
-                if (log)
-                {
-                    static const QString lm("Using elevation plane, radius: %1");
-                    log->elevationInfo = lm.arg(radius.valueRoundedWithUnit(CLengthUnit::m(), 1));
-                }
-                return m_elevationPlane.getAltitude();
-            }
-
-            if (log)
-            {
-                static const QString lm("Not using provider, no valid plane");
-                log->elevationInfo = lm;
-            }
-
-            return CAltitude::null();
-        }
-
-        CAltitude CInterpolationHints::getGroundElevation(const CAircraftSituation &situation, const CLength &validRadius, SituationLog *log) const
-        {
-            return this->getGroundElevation(situation, validRadius, false, false, log);
-        }
-
-        CAltitude CInterpolationHints::getGroundElevation(const CAircraftSituation &situation, SituationLog *log) const
-        {
-            return this->getGroundElevation(situation, CLength::null(), log);
-        }
-
-        void CInterpolationHints::resetElevationPlane()
-        {
-            m_elevationPlane = CElevationPlane();
-        }
-
-        bool CInterpolationHints::isWithinRange(const Geo::ICoordinateGeodetic &coordinate) const
-        {
-            if (m_elevationPlane.isNull()) { return false; }
-            return m_elevationPlane.isWithinRange(coordinate);
-        }
-
-        const CLength &CInterpolationHints::getCGAboveGroundOrZero() const
-        {
-            static const CLength zero;
-            return this->hasCGAboveGround() ? this->getCGAboveGround() : zero;
-        }
-
-        void CInterpolationHints::setAircraftParts(const CAircraftParts &parts, bool hasParts)
-        {
-            m_hasParts = hasParts;
-            m_aircraftParts = parts;
-        }
-
-        bool CInterpolationHints::hasElevationProvider() const
-        {
-            return static_cast<bool>(m_elevationProvider);
-        }
-
-        CVariant CInterpolationHints::propertyByIndex(const CPropertyIndex &index) const
-        {
-            if (index.isMyself()) { return CVariant::from(*this); }
-            const ColumnIndex i = index.frontCasted<ColumnIndex>();
-            switch (i)
-            {
-            case IndexCenterOfGravity: return m_cgAboveGround.propertyByIndex(index.copyFrontRemoved());
-            case IndexElevationPlane: return m_elevationPlane.propertyByIndex(index.copyFrontRemoved());
-            case IndexIsVtolAircraft: return CVariant::fromValue(m_isVtol);
-            default: return CValueObject::propertyByIndex(index);
-            }
-        }
-
-        void CInterpolationHints::setPropertyByIndex(const CPropertyIndex &index, const CVariant &variant)
-        {
-            if (index.isMyself()) { (*this) = variant.to<CInterpolationHints>(); return; }
-            const ColumnIndex i = index.frontCasted<ColumnIndex>();
-            switch (i)
-            {
-            case IndexCenterOfGravity:
-                m_cgAboveGround.setPropertyByIndex(index.copyFrontRemoved(), variant);
-                break;
-            case IndexElevationPlane:
-                m_elevationPlane.setPropertyByIndex(index.copyFrontRemoved(), variant);
-                break;
-            case IndexIsVtolAircraft:
-                m_isVtol = variant.toBool();
-                break;
-            default:
-                CValueObject::setPropertyByIndex(index, variant);
-                break;
-            }
-        }
-
-        QString CInterpolationHints::convertToQString(bool i18n) const
-        {
-            Q_UNUSED(i18n);
-            return this->asString(true, true);
-        }
-
-        QString CInterpolationHints::asString(bool withParts, bool withElevationPlane) const
-        {
-            return
-                QStringLiteral("VTOL: ") % boolToYesNo(m_isVtol) %
-                QStringLiteral(" parts: ") % boolToYesNo(m_hasParts) %
-                (
-                    withParts && m_hasParts ?
-                    QStringLiteral(" parts: ") % m_aircraftParts.toQString(true) :
-                    QStringLiteral("")
-                ) %
-                QStringLiteral(" CG: ") % m_cgAboveGround.valueRoundedWithUnit(CLengthUnit::m(), 1) %
-                (
-                    withElevationPlane ?
-                    QStringLiteral(" elv.plane: ") % m_elevationPlane.toQString(true) :
-                    QStringLiteral(" elv.plane: ") % boolToNullNotNull(m_elevationPlane.isNull())
-                ) %
-                QStringLiteral(" elv.pr.: ") % boolToYesNo(m_elevationProvider ? true : false);
-        }
-
-        QString CInterpolationHints::debugInfo(const CElevationPlane &deltaElevation) const
-        {
-            static const QString s("Lat: %1 Lng: %2 Elv: %3");
-            if (m_elevationPlane.isNull() || deltaElevation.isNull()) return "null";
-            return s.arg(
-                       (deltaElevation.latitude() - m_elevationPlane.latitude()).valueRoundedWithUnit(CAngleUnit::deg(), 10),
-                       (deltaElevation.longitude() - m_elevationPlane.longitude()).valueRoundedWithUnit(CAngleUnit::deg(), 10),
-                       (deltaElevation.geodeticHeight() - m_elevationPlane.geodeticHeight()).valueRoundedWithUnit(CLengthUnit::ft(), 2)
-                   );
-        }
-    } // namespace
-} // namespace
diff --git a/src/blackmisc/simulation/interpolationhints.h b/src/blackmisc/simulation/interpolationhints.h
deleted file mode 100644
index 52131aeee..000000000
--- a/src/blackmisc/simulation/interpolationhints.h
+++ /dev/null
@@ -1,179 +0,0 @@
-/* Copyright (C) 2016
- * swift project Community / Contributors
- *
- * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
- * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
- * including this file, may be copied, modified, propagated, or distributed except according to the terms
- * contained in the LICENSE file.
- */
-
-//! \file
-
-#ifndef BLACKMISC_SIMULATION_INTERPOLATIONHINTS_H
-#define BLACKMISC_SIMULATION_INTERPOLATIONHINTS_H
-
-#include "blackmisc/blackmiscexport.h"
-#include "blackmisc/geo/elevationplane.h"
-#include "blackmisc/valueobject.h"
-#include "blackmisc/aviation/aircraftparts.h"
-
-namespace BlackMisc
-{
-    namespace Aviation { class CAircraftSituation; }
-    namespace Simulation
-    {
-        struct SituationLog;
-
-        //! Hints for interpolator such as ground elevation
-        class BLACKMISC_EXPORT CInterpolationHints : public CValueObject<CInterpolationHints>
-        {
-        public:
-            //! Property indexes
-            enum ColumnIndex
-            {
-                IndexElevationPlane = CPropertyIndex::GlobalIndexCInterpolationHints,
-                IndexCenterOfGravity,
-                IndexIsVtolAircraft
-            };
-
-            //! Default constructor.
-            CInterpolationHints();
-
-            //! Constructor
-            CInterpolationHints(bool isVtolAircraft);
-
-            //! Constructor
-            CInterpolationHints(bool isVtolAircraft, bool hasParts, bool log);
-
-            //! Get elevation plane
-            const Geo::CElevationPlane &getElevationPlane() const { return m_elevationPlane;}
-
-            //! Get elevation plane
-            const Geo::CElevationPlane &getElevationPlane(Geo::ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &radius, SituationLog *log = nullptr) const;
-
-            //! Set elevation
-            //! \remark used to store a ground elevation and use it as well for nearby situatons
-            void setElevationPlane(const Geo::CElevationPlane &elevation) { m_elevationPlane = elevation; }
-
-            //! Elevation plane set to null
-            void resetElevationPlane();
-
-        private:
-            //! \todo KB 2018-03 ground flag refactoring
-            //! Get elevation from CInterpolationHints::getElevationProvider or CInterpolationHints::getElevation
-            //! \remark avoid unnecessary calls on XPlane (calling elevation provider)
-            //! \param situation where to check
-            //! \param useProvider using the provider if available
-            //! \param forceProvider use the provider and ignore any elevation plane
-            //! \param log optional chance to write info about elevation
-            //! \see setElevationProvider
-            //! \see setElevationPlane
-            //! \deprecated
-            Aviation::CAltitude getGroundElevation(const Aviation::CAircraftSituation &situation, bool useProvider, bool forceProvider = false, SituationLog *log = nullptr) const;
-
-            //! Get elevation from CInterpolationHints::getElevationProvider or CInterpolationHints::getElevation
-            //! \remark if validRadius is >= Geo::CElevationPlane::radius use validRadius
-            //! \deprecated
-            Aviation::CAltitude getGroundElevation(const Aviation::CAircraftSituation &situation, const PhysicalQuantities::CLength &validRadius, bool useProvider, bool forceProvider = false, SituationLog *log = nullptr) const;
-
-            //! Get ground elevation by using the elevation plane
-            //! \deprecated
-            Aviation::CAltitude getGroundElevation(const Aviation::CAircraftSituation &situation, const PhysicalQuantities::CLength &validRadius, SituationLog *log = nullptr) const;
-
-            //! Get ground elevation by using the elevation plane
-            //! \deprecated
-            Aviation::CAltitude getGroundElevation(const Aviation::CAircraftSituation &situation, SituationLog *log = nullptr) const;
-
-        public:
-            //! Check if elevation is within radius and can be used
-            bool isWithinRange(const Geo::ICoordinateGeodetic &coordinate) const;
-
-            //! Get CG above ground
-            const PhysicalQuantities::CLength &getCGAboveGround() const { return m_cgAboveGround;}
-
-            //! Get CG above ground or 0 ("Zero")
-            const PhysicalQuantities::CLength &getCGAboveGroundOrZero() const;
-
-            //! Has CG above ground
-            bool hasCGAboveGround() const { return m_cgAboveGround.isNull(); }
-
-            //! Set CG above ground
-            void setCGAboveGround(const PhysicalQuantities::CLength &cgAboveGround) { m_cgAboveGround = cgAboveGround; }
-
-            //! VTOL aircraft?
-            bool isVtolAircraft() const { return m_isVtol; }
-
-            //! VTOL aircraft
-            void setVtolAircraft(bool vtol) { m_isVtol = vtol; }
-
-            //! Log interpolation?
-            bool isLoggingInterpolation() const { return m_logInterpolation; }
-
-            //! Log interpolation?
-            void setLoggingInterpolation(bool log) { m_logInterpolation = log; }
-
-            //! Has valid aircraft parts?
-            bool hasAircraftParts() const { return m_hasParts; }
-
-            //! Aircraft parts required for interpolation
-            Aviation::CAircraftParts getAircraftParts() const { return m_aircraftParts; }
-
-            //! Set aircraft parts required for interpolation if any
-            //! \remark when used to reset value (default object) use hasParts false. Needed as there is no null parts object
-            void setAircraftParts(const Aviation::CAircraftParts &parts, bool hasParts = true);
-
-            //! Function object that can obtain ground elevation
-            using ElevationProvider = std::function<Aviation::CAltitude(const Aviation::CAircraftSituation &)>;
-
-            //! Has elevation provider?
-            //! \deprecated
-            bool hasElevationProvider() const;
-
-            //! Set function object that can obtain ground elevation
-            //! \remark either a provider can be used or an elevation plan can be set
-            //! \see setElevationPlane
-            //! \see getGroundElevation
-            //! \deprecated
-            void setElevationProvider(const ElevationProvider &ep) { m_elevationProvider = ep; }
-
-            //! \copydoc BlackMisc::Mixin::Index::propertyByIndex
-            CVariant propertyByIndex(const CPropertyIndex &index) const;
-
-            //! \copydoc BlackMisc::Mixin::Index::setPropertyByIndex
-            void setPropertyByIndex(const CPropertyIndex &index, const CVariant &variant);
-
-            //! \copydoc BlackMisc::Mixin::String::toQString
-            QString convertToQString(bool i18n = false) const;
-
-            //! Formatted as string
-            QString asString(bool withParts, bool withElevationPlane) const;
-
-            //! For debugging
-            QString debugInfo(const Geo::CElevationPlane &deltaElevation) const;
-
-        private:
-            bool m_isVtol = false;           //!< VTOL aircraft?
-            bool m_hasParts = false;         //!< Has valid aircraft parts?
-            bool m_logInterpolation = false; //!< Log.interpolation
-            Aviation::CAircraftParts    m_aircraftParts;     //!< Aircraft parts
-            Geo::CElevationPlane        m_elevationPlane;    //!< Aircraft's elevation if available
-            ElevationProvider           m_elevationProvider; //!< Provider of ground elevation (lazy computation)
-            PhysicalQuantities::CLength m_cgAboveGround { 0, nullptr }; //!< center of gravity above ground
-
-            BLACK_METACLASS(
-                CInterpolationHints,
-                BLACK_METAMEMBER(isVtol),
-                BLACK_METAMEMBER(elevationPlane),
-                BLACK_METAMEMBER(cgAboveGround),
-                BLACK_METAMEMBER(hasParts),
-                BLACK_METAMEMBER(aircraftParts),
-                BLACK_METAMEMBER(logInterpolation)
-                // elevationProvider not included
-            );
-        };
-    } // namespace
-} // namespace
-
-Q_DECLARE_METATYPE(BlackMisc::Simulation::CInterpolationHints)
-
-#endif // guard
diff --git a/src/blackmisc/simulation/interpolationlogger.cpp b/src/blackmisc/simulation/interpolationlogger.cpp
index 9c3eb1834..69b1589b1 100644
--- a/src/blackmisc/simulation/interpolationlogger.cpp
+++ b/src/blackmisc/simulation/interpolationlogger.cpp
@@ -407,7 +407,7 @@ namespace BlackMisc
         }
 
         QString SituationLog::toQString(
-            bool withHints, bool withSetup,
+            bool withSetup,
             bool withCurrentSituation,
             bool withElevation, bool withOtherPositions, bool withDeltaTimes, const QString &separator) const
         {
@@ -419,11 +419,6 @@ namespace BlackMisc
                    QStringLiteral(" | type: ") % this->interpolationType() %
                    QStringLiteral(" | gnd.fa.: ") % QString::number(groundFactor) %
                    QStringLiteral(" | #nw.sit.: ") % QString::number(noNetworkSituations) %
-                   (
-                       withHints ?
-                       separator % QStringLiteral("hints: ") % usedHints.asString(false, true) :
-                       QStringLiteral("")
-                   ) %
                    (
                        withSetup ?
                        separator % QStringLiteral("setup: ") % usedSetup.toQString(true) :
diff --git a/src/blackmisc/simulation/interpolationlogger.h b/src/blackmisc/simulation/interpolationlogger.h
index 3e73c13fc..1f00da713 100644
--- a/src/blackmisc/simulation/interpolationlogger.h
+++ b/src/blackmisc/simulation/interpolationlogger.h
@@ -13,7 +13,6 @@
 #define BLACKMISC_SIMULATION_INTERPOLATIONLOGGER_H
 
 #include "interpolationrenderingsetup.h"
-#include "interpolationhints.h"
 #include "blackmisc/simulation/remoteaircraftprovider.h"
 #include "blackmisc/aviation/aircraftpartslist.h"
 #include "blackmisc/aviation/aircraftsituationlist.h"
@@ -48,7 +47,6 @@ namespace BlackMisc
             Aviation::CAircraftSituation situationCurrent; //!< interpolated situation
             PhysicalQuantities::CLength  cgAboveGround;    //!< center of gravity
             CInterpolationAndRenderingSetupPerCallsign usedSetup; //!< used setup
-            CInterpolationHints usedHints; //!< hints
 
             //! Delta time between interpolation and current time
             double deltaCurrentToInterpolatedTime() const
@@ -72,10 +70,9 @@ namespace BlackMisc
             }
 
             //! To string
-            QString toQString(
-                bool withHints, bool withSetup,
-                bool withCurrentSituation, bool withElevation,
-                bool withOtherPositions, bool withDeltaTimes, const QString &separator = {" "}) const;
+            QString toQString(bool withSetup,
+                              bool withCurrentSituation, bool withElevation,
+                              bool withOtherPositions, bool withDeltaTimes, const QString &separator = {" "}) const;
         };
 
         //! Log entry for parts interpolation
diff --git a/src/blackmisc/simulation/interpolator.cpp b/src/blackmisc/simulation/interpolator.cpp
index 6c7a850dc..fa2663d2d 100644
--- a/src/blackmisc/simulation/interpolator.cpp
+++ b/src/blackmisc/simulation/interpolator.cpp
@@ -9,7 +9,6 @@
 
 #include "interpolator.h"
 #include "blackconfig/buildconfig.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/interpolationlogger.h"
 #include "blackmisc/simulation/interpolatorlinear.h"
 #include "blackmisc/simulation/interpolatorspline.h"
@@ -54,14 +53,14 @@ namespace BlackMisc
         template <typename Derived>
         CAircraftSituation CInterpolator<Derived>::getInterpolatedSituation(
             qint64 currentTimeMsSinceEpoc,
-            const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints,
+            const CInterpolationAndRenderingSetupPerCallsign &setup,
             CInterpolationStatus &status)
         {
             Q_ASSERT_X(!m_callsign.isEmpty(), Q_FUNC_INFO, "Missing callsign");
 
             // this code is used by linear and spline interpolator
             status.reset();
-            const bool doLogging = this->hasAttachedLogger() && hints.isLoggingInterpolation();
+            const bool doLogging = this->hasAttachedLogger() && setup.logInterpolation();
             SituationLog log;
             SituationLog *logP = doLogging ? &log : nullptr;
 
@@ -81,15 +80,15 @@ namespace BlackMisc
             // * As XP uses lazy init we will call getGroundElevation only when needed
             // * default here via getElevationPlane
             // CAltitude currentGroundElevation(hints.getGroundElevation(currentSituation, currentSituation.getDistancePerTime(1000), true, false, logP));
-            const CElevationPlane currentGroundElevation = hints.getElevationPlane(currentSituation, currentSituation.getDistancePerTime(1000), logP);
-            currentSituation.setGroundElevation(currentGroundElevation); // set as default
+            const CElevationPlane currentGroundElevation = this->findClosestElevationWithinRange(currentSituation, currentSituation.getDistancePerTime(1000));
+            currentSituation.setGroundElevationChecked(currentGroundElevation); // set as default
 
             // data, split situations by time
             if (currentTimeMsSinceEpoc < 0) { currentTimeMsSinceEpoc = QDateTime::currentMSecsSinceEpoch(); }
 
             // interpolant function from derived class
             // CInterpolatorLinear::Interpolant or CInterpolatorSpline::Interpolant
-            const auto interpolant = derived()->getInterpolant(currentTimeMsSinceEpoc, setup, hints, status, log);
+            const auto interpolant = derived()->getInterpolant(currentTimeMsSinceEpoc, setup, status, log);
 
             // succeeded so far?
             if (!status.isInterpolated())
@@ -99,12 +98,12 @@ namespace BlackMisc
             }
 
             // use derived interpolant function
-            currentSituation.setPosition(interpolant.interpolatePosition(setup, hints));
-            currentSituation.setAltitude(interpolant.interpolateAltitude(setup, hints));
+            currentSituation.setPosition(interpolant.interpolatePosition(setup));
+            currentSituation.setAltitude(interpolant.interpolateAltitude(setup));
             currentSituation.setMSecsSinceEpoch(interpolant.getInterpolatedTime());
 
             // PBH before ground so we can use PBH in guessing ground
-            if (setup.isForcingFullInterpolation() || hints.isVtolAircraft() || status.isInterpolated())
+            if (setup.isForcingFullInterpolation() || status.isInterpolated())
             {
                 const auto pbh = interpolant.pbh();
                 currentSituation.setHeading(pbh.getHeading());
@@ -118,9 +117,9 @@ namespace BlackMisc
             constexpr double NoGroundFactor = -1;
             double groundFactor = NoGroundFactor;
 
-            if (hints.hasAircraftParts())
+            if (setup.isAircraftPartsEnabled())
             {
-                groundFactor = hints.getAircraftParts().isOnGroundInterpolated();
+                // groundFactor = hints.getAircraftParts().isOnGroundInterpolated();
                 if (groundFactor > 0.0)
                 {
                     // if not having an ground elevation yet, we fetch from provider (if there is a provider)
@@ -131,8 +130,9 @@ namespace BlackMisc
 
                     if (!currentGroundElevation.isNull())
                     {
-                        Q_ASSERT_X(currentGroundElevation.getReferenceDatum() == CAltitude::MeanSeaLevel, Q_FUNC_INFO, "Need MSL value");
-                        const CAltitude groundElevationCG = currentGroundElevation.withOffset(hints.getCGAboveGround());
+                        Q_ASSERT_X(currentGroundElevation.getAltitude().getReferenceDatum() == CAltitude::MeanSeaLevel, Q_FUNC_INFO, "Need MSL value");
+                        const CLength cg = this->getCG(m_callsign);
+                        const CAltitude groundElevationCG = currentGroundElevation.getAltitude().withOffset(cg);
                         currentSituation.setGroundElevationChecked(currentGroundElevation);
                         // alt = ground + aboveGround * groundFactor
                         //     = ground + (altitude - ground) * groundFactor
@@ -146,7 +146,7 @@ namespace BlackMisc
 
             // depending on ground factor set ground flag and reliability
             // it will use the hints ground flag or elevation/CG or guessing
-            CInterpolator::setGroundFlagFromInterpolator(hints, groundFactor, currentSituation);
+            // CInterpolator::setGroundFlagFromInterpolator(hints, groundFactor, currentSituation);
 
             // we transfer ground elevation for future usage
             if (currentSituation.hasGroundElevation())
@@ -165,7 +165,6 @@ namespace BlackMisc
                 log.callsign = m_callsign;
                 log.groundFactor = groundFactor;
                 log.situationCurrent = currentSituation;
-                log.usedHints = hints;
                 log.usedSetup = setup;
                 m_logger->logInterpolation(log);
             }
@@ -412,7 +411,7 @@ namespace BlackMisc
         }
 
         template <typename Derived>
-        void CInterpolator<Derived>::setGroundFlagFromInterpolator(const CInterpolationHints &hints, double groundFactor, CAircraftSituation &situation)
+        void CInterpolator<Derived>::setGroundFlagFromInterpolator(double groundFactor, CAircraftSituation &situation) const
         {
             // by interpolation
             if (groundFactor >= 1.0)
@@ -428,15 +427,17 @@ namespace BlackMisc
 
             // on elevation and CG
             // remark: to some extend redundant as situation.getCorrectedAltitude() already corrects altitude
+            Q_ASSERT_X(!m_callsign.isEmpty(), Q_FUNC_INFO, "Need callsign");
             if (situation.hasGroundElevation())
             {
                 static const CLength onGroundThresholdLimit(1.0, CLengthUnit::m());
                 static const CLength notOnGroundThresholdLimit(10.0, CLengthUnit::m()); // upper boundary
                 CLength offset = onGroundThresholdLimit; // very small offset from allowed
-                CAircraftSituation::OnGroundReliability reliability = CAircraftSituation::OnGroundByElevation;
-                if (hints.hasCGAboveGround())
+                CAircraftSituation::OnGroundDetails reliability = CAircraftSituation::OnGroundByElevation;
+                CLength cg = this->getCG(m_callsign);
+                if (!cg.isNull())
                 {
-                    offset += hints.getCGAboveGround();
+                    offset += cg;
                     reliability = CAircraftSituation::OnGroundByElevationAndCG;
                 }
                 else
@@ -465,7 +466,7 @@ namespace BlackMisc
             }
 
             // for VTOL aircraft we give up
-            if (hints.isVtolAircraft())
+            if (this->isVtolAircraft(m_callsign))
             {
                 situation.setOnGround(CAircraftSituation::OnGroundSituationUnknown, CAircraftSituation::OnGroundReliabilityNoSet);
                 return;
diff --git a/src/blackmisc/simulation/interpolator.h b/src/blackmisc/simulation/interpolator.h
index d8c2deb23..55a81111f 100644
--- a/src/blackmisc/simulation/interpolator.h
+++ b/src/blackmisc/simulation/interpolator.h
@@ -14,6 +14,8 @@
 
 #include "interpolationrenderingsetup.h"
 #include "blackmisc/simulation/remoteaircraftprovider.h"
+#include "blackmisc/simulation/interpolationsetupprovider.h"
+#include "blackmisc/simulation/simulationenvironmentprovider.h"
 #include "blackmisc/aviation/aircraftpartslist.h"
 #include "blackmisc/aviation/aircraftsituation.h"
 #include "blackmisc/aviation/aircraftpartslist.h"
@@ -29,7 +31,6 @@ namespace BlackMisc
     namespace Aviation { class CCallsign; }
     namespace Simulation
     {
-        class CInterpolationHints;
         class CInterpolationLogger;
         class CInterpolatorLinear;
         class CInterpolatorSpline;
@@ -38,14 +39,18 @@ namespace BlackMisc
 
         //! Interpolator, calculation inbetween positions
         template <typename Derived>
-        class CInterpolator : public QObject
+        class CInterpolator :
+            public CSimulationEnvironmentAware,
+            public CInterpolationSetupAware,
+            public CRemoteAircraftAware,
+            public QObject
         {
         public:
             //! Log categories
             const CLogCategoryList &getLogCategories();
 
             //! Current interpolated situation
-            Aviation::CAircraftSituation getInterpolatedSituation(qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints, CInterpolationStatus &status);
+            Aviation::CAircraftSituation getInterpolatedSituation(qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetupPerCallsign &setup, CInterpolationStatus &status);
 
             //! Parts before given offset time (aka pending parts)
             Aviation::CAircraftParts getInterpolatedParts(
@@ -78,7 +83,6 @@ namespace BlackMisc
             }
 
             //! Attach an observer to read the interpolator's state for debugging
-            //! \remark situation logging requires CInterpolationHints::isLoggingInterpolation to be \c true
             //! \remark parts logging has a \c bool \c log flag
             void attachLogger(CInterpolationLogger *logger) { m_logger = logger; }
 
@@ -112,7 +116,7 @@ namespace BlackMisc
             CInterpolator(const QString &objectName, const Aviation::CCallsign &callsign, QObject *parent);
 
             //! Set on ground flag
-            static void setGroundFlagFromInterpolator(const CInterpolationHints &hints, double groundFactor, Aviation::CAircraftSituation &situation);
+            void setGroundFlagFromInterpolator(double groundFactor, Aviation::CAircraftSituation &situation) const;
 
         private:
             CInterpolationLogger *m_logger = nullptr;
diff --git a/src/blackmisc/simulation/interpolatordummy.h b/src/blackmisc/simulation/interpolatordummy.h
index 8e873cbdf..bbf0fd776 100644
--- a/src/blackmisc/simulation/interpolatordummy.h
+++ b/src/blackmisc/simulation/interpolatordummy.h
@@ -15,7 +15,6 @@
 #include "blackmisc/aviation/aircraftparts.h"
 #include "blackmisc/aviation/aircraftsituation.h"
 #include "blackmisc/aviation/callsign.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/interpolationlogger.h"
 #include "blackmisc/simulation/interpolationrenderingsetup.h"
 #include "blackmisc/simulation/interpolator.h"
@@ -38,11 +37,11 @@ namespace BlackMisc
 
             //! \copydoc CInterpolator::getInterpolatedSituation
             BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
-                qint64, const CInterpolationAndRenderingSetupGlobal &, const CInterpolationHints &, CInterpolationStatus &) { return {}; }
+                qint64, const CInterpolationAndRenderingSetupPerCallsign &, CInterpolationStatus &) { return {}; }
 
             //! \copydoc CInterpolator::getInterpolatedParts
             BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
-                qint64, const CInterpolationAndRenderingSetupGlobal &, CPartsStatus &, bool = false) const { return {}; }
+                qint64, const CInterpolationAndRenderingSetupPerCallsign &, CPartsStatus &, bool = false) const { return {}; }
 
             //! \copydoc CInterpolator::addAircraftSituation
             void addAircraftSituation(const BlackMisc::Aviation::CAircraftSituation &) {}
diff --git a/src/blackmisc/simulation/interpolatorlinear.cpp b/src/blackmisc/simulation/interpolatorlinear.cpp
index d2adbc82d..43285613b 100644
--- a/src/blackmisc/simulation/interpolatorlinear.cpp
+++ b/src/blackmisc/simulation/interpolatorlinear.cpp
@@ -14,7 +14,6 @@
 #include "blackmisc/geo/coordinategeodetic.h"
 #include "blackmisc/pq/length.h"
 #include "blackmisc/pq/physicalquantity.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/logmessage.h"
 #include "blackmisc/compare.h"
 #include "blackmisc/verify.h"
@@ -49,11 +48,12 @@ namespace BlackMisc
             m_pbh(m_simulationTimeFraction, situation1, situation2)
         {}
 
-        CInterpolatorLinear::Interpolant CInterpolatorLinear::getInterpolant(qint64 currentTimeMsSinceEpoc,
-                const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints, CInterpolationStatus &status, SituationLog &log) const
+        CInterpolatorLinear::Interpolant CInterpolatorLinear::getInterpolant(
+            qint64 currentTimeMsSinceEpoc,
+            const CInterpolationAndRenderingSetupPerCallsign &setup,
+            CInterpolationStatus &status, SituationLog &log) const
         {
             Q_UNUSED(setup);
-            Q_UNUSED(hints);
             status.reset();
 
             // with the latest updates of T243 the order and the offsets are supposed to be correct
@@ -118,11 +118,10 @@ namespace BlackMisc
 
             // take hint into account to calculate elevation and above ground level
             // do not call for XP (lazy init)
-            if (!hints.hasElevationProvider())
-            {
-                oldSituation.setGroundElevationChecked(hints.getElevationPlane());
-                newSituation.setGroundElevationChecked(hints.getElevationPlane());
-            }
+            const CElevationPlane planeOld = this->findClosestElevationWithinRange(oldSituation, CElevationPlane::singlePointRadius());
+            const CElevationPlane planeNew = this->findClosestElevationWithinRange(newSituation, CElevationPlane::singlePointRadius());
+            oldSituation.setGroundElevationChecked(planeOld);
+            newSituation.setGroundElevationChecked(planeNew);
 
             CAircraftSituation currentSituation(oldSituation); // also sets ground elevation if available
 
@@ -144,7 +143,7 @@ namespace BlackMisc
             currentSituation.setMSecsSinceEpoch(interpolatedTime);
             status.setInterpolatedAndCheckSituation(true, currentSituation);
 
-            if (this->hasAttachedLogger() && hints.isLoggingInterpolation())
+            if (this->hasAttachedLogger() && setup.logInterpolation())
             {
                 log.tsCurrent = currentTimeMsSinceEpoc;
                 log.deltaSampleTimesMs = sampleDeltaTimeMs;
@@ -159,10 +158,9 @@ namespace BlackMisc
             return { oldSituation, newSituation, simulationTimeFraction, interpolatedTime };
         }
 
-        CCoordinateGeodetic CInterpolatorLinear::Interpolant::interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const
+        CCoordinateGeodetic CInterpolatorLinear::Interpolant::interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup) const
         {
             Q_UNUSED(setup);
-            Q_UNUSED(hints);
 
             const std::array<double, 3> oldVec(m_oldSituation.getPosition().normalVectorDouble());
             const std::array<double, 3> newVec(m_newSituation.getPosition().normalVectorDouble());
@@ -175,10 +173,9 @@ namespace BlackMisc
             return currentPosition;
         }
 
-        CAltitude CInterpolatorLinear::Interpolant::interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const
+        CAltitude CInterpolatorLinear::Interpolant::interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup) const
         {
             Q_UNUSED(setup);
-            Q_UNUSED(hints);
 
             // Interpolate altitude: Alt = (AltB - AltA) * t + AltA
             // avoid underflow below ground elevation by using getCorrectedAltitude
diff --git a/src/blackmisc/simulation/interpolatorlinear.h b/src/blackmisc/simulation/interpolatorlinear.h
index 9f007c94d..efd9efed1 100644
--- a/src/blackmisc/simulation/interpolatorlinear.h
+++ b/src/blackmisc/simulation/interpolatorlinear.h
@@ -49,8 +49,8 @@ namespace BlackMisc
 
                 //! Perform the interpolation
                 //! @{
-                Geo::CCoordinateGeodetic interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const;
-                Aviation::CAltitude interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const;
+                Geo::CCoordinateGeodetic interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup) const;
+                Aviation::CAltitude interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup) const;
                 //! @}
 
                 //! Interpolator for pitch, bank, heading, groundspeed
@@ -75,8 +75,7 @@ namespace BlackMisc
             };
 
             //! Get the interpolant for the given time point
-            Interpolant getInterpolant(qint64 currentTimeMsSinceEpoc, const CInterpolationAndRenderingSetupPerCallsign &setup,
-                                       const CInterpolationHints &hints, CInterpolationStatus &status, SituationLog &log) const;
+            Interpolant getInterpolant(qint64 currentTimeMsSinceEpoc, const CInterpolationAndRenderingSetupPerCallsign &setup, CInterpolationStatus &status, SituationLog &log) const;
         };
     } // ns
 } // ns
diff --git a/src/blackmisc/simulation/interpolatormulti.cpp b/src/blackmisc/simulation/interpolatormulti.cpp
index 30510613b..d2d84f442 100644
--- a/src/blackmisc/simulation/interpolatormulti.cpp
+++ b/src/blackmisc/simulation/interpolatormulti.cpp
@@ -24,13 +24,13 @@ namespace BlackMisc
         {}
 
         CAircraftSituation CInterpolatorMulti::getInterpolatedSituation(qint64 currentTimeSinceEpoc,
-            const CInterpolationAndRenderingSetupPerCallsign &setup,
-            const CInterpolationHints &hints, CInterpolationStatus &status)
+                const CInterpolationAndRenderingSetupPerCallsign &setup,
+                CInterpolationStatus &status)
         {
             switch (m_mode)
             {
-            case ModeLinear: return m_linear.getInterpolatedSituation(currentTimeSinceEpoc, setup, hints, status);
-            case ModeSpline: return m_spline.getInterpolatedSituation(currentTimeSinceEpoc, setup, hints, status);
+            case ModeLinear: return m_linear.getInterpolatedSituation(currentTimeSinceEpoc, setup, status);
+            case ModeSpline: return m_spline.getInterpolatedSituation(currentTimeSinceEpoc, setup, status);
             default: break;
             }
             return {};
diff --git a/src/blackmisc/simulation/interpolatormulti.h b/src/blackmisc/simulation/interpolatormulti.h
index d4d53f96a..1b014cd9f 100644
--- a/src/blackmisc/simulation/interpolatormulti.h
+++ b/src/blackmisc/simulation/interpolatormulti.h
@@ -34,10 +34,11 @@ namespace BlackMisc
             Aviation::CAircraftSituation getInterpolatedSituation(
                 qint64 currentTimeSinceEpoc,
                 const CInterpolationAndRenderingSetupPerCallsign &setup,
-                const CInterpolationHints &hints, CInterpolationStatus &status);
+                CInterpolationStatus &status);
 
             //! \copydoc CInterpolator::getInterpolatedParts
-            Aviation::CAircraftParts getInterpolatedParts(qint64 currentTimeSinceEpoc,
+            Aviation::CAircraftParts getInterpolatedParts(
+                qint64 currentTimeSinceEpoc,
                 const CInterpolationAndRenderingSetupPerCallsign &setup,
                 CPartsStatus &partsStatus, bool log = false) const;
 
diff --git a/src/blackmisc/simulation/interpolatorspline.cpp b/src/blackmisc/simulation/interpolatorspline.cpp
index 27de1a920..40098e21f 100644
--- a/src/blackmisc/simulation/interpolatorspline.cpp
+++ b/src/blackmisc/simulation/interpolatorspline.cpp
@@ -8,7 +8,6 @@
  */
 
 #include "blackmisc/simulation/interpolatorspline.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/logmessage.h"
 #include "blackmisc/verify.h"
 
@@ -95,11 +94,12 @@ namespace BlackMisc
             }
         }
 
-        CInterpolatorSpline::Interpolant CInterpolatorSpline::getInterpolant(qint64 currentTimeMsSinceEpoc,
-                const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints, CInterpolationStatus &status,
-                SituationLog &log)
+        CInterpolatorSpline::Interpolant CInterpolatorSpline::getInterpolant(
+            qint64 currentTimeMsSinceEpoc,
+            const CInterpolationAndRenderingSetupPerCallsign &setup,
+            CInterpolationStatus &status,
+            SituationLog &log)
         {
-            Q_UNUSED(hints);
             Q_UNUSED(setup);
 
             // recalculate derivatives only if they changed
@@ -135,17 +135,19 @@ namespace BlackMisc
                 // - on an airport the plane does not move very fast, or not at all
                 // - and the elevation remains (almost) constant for a wider area
                 // - flying the ground elevation not really matters
-                if (!hints.getElevationPlane().isNull())
-                {
-                    // do not override existing values
-                    m_s[0].setGroundElevationChecked(hints.getElevationPlane());
-                    m_s[1].setGroundElevationChecked(hints.getElevationPlane());
-                    m_s[2].setGroundElevationChecked(hints.getElevationPlane());
-                }
+                const CElevationPlane plane0 = this->findClosestElevationWithinRange(m_s[0], CElevationPlane::singlePointRadius());
+                const CElevationPlane plane1 = this->findClosestElevationWithinRange(m_s[1], CElevationPlane::singlePointRadius());
+                const CElevationPlane plane2 = this->findClosestElevationWithinRange(m_s[2], CElevationPlane::singlePointRadius());
 
-                const double a0 = m_s[0].getCorrectedAltitude(hints.getCGAboveGround()).value();
-                const double a1 = m_s[1].getCorrectedAltitude(hints.getCGAboveGround()).value();
-                const double a2 = m_s[2].getCorrectedAltitude(hints.getCGAboveGround()).value();
+                // do not override existing values
+                m_s[0].setGroundElevationChecked(plane0);
+                m_s[1].setGroundElevationChecked(plane1);
+                m_s[2].setGroundElevationChecked(plane2);
+
+                const CLength cg = this->getCG(m_callsign);
+                const double a0 = m_s[0].getCorrectedAltitude(cg).value();
+                const double a1 = m_s[1].getCorrectedAltitude(cg).value();
+                const double a2 = m_s[2].getCorrectedAltitude(cg).value();
 
                 const std::array<std::array<double, 3>, 3> normals {{ m_s[0].getPosition().normalVectorDouble(), m_s[1].getPosition().normalVectorDouble(), m_s[2].getPosition().normalVectorDouble() }};
                 PosArray pa;
@@ -190,7 +192,7 @@ namespace BlackMisc
             status.setInterpolated(true);
             m_interpolant.setTimes(currentTimeMsSinceEpoc, timeFraction, interpolatedTime);
 
-            if (this->hasAttachedLogger() && hints.isLoggingInterpolation())
+            if (this->hasAttachedLogger() && setup.logInterpolation())
             {
                 log.interpolationSituations.push_back(m_s[0]);
                 log.interpolationSituations.push_back(m_s[1]);
@@ -205,10 +207,9 @@ namespace BlackMisc
             return m_interpolant;
         }
 
-        CCoordinateGeodetic CInterpolatorSpline::Interpolant::interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const
+        CCoordinateGeodetic CInterpolatorSpline::Interpolant::interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup) const
         {
             Q_UNUSED(setup);
-            Q_UNUSED(hints);
 
             const double newX = evalSplineInterval(m_currentTimeMsSinceEpoc, m_pa.t[1], m_pa.t[2], m_pa.x[1], m_pa.x[2], m_pa.dx[1], m_pa.dx[2]);
             const double newY = evalSplineInterval(m_currentTimeMsSinceEpoc, m_pa.t[1], m_pa.t[2], m_pa.y[1], m_pa.y[2], m_pa.dy[1], m_pa.dy[2]);
@@ -219,10 +220,9 @@ namespace BlackMisc
             return currentPosition;
         }
 
-        CAltitude CInterpolatorSpline::Interpolant::interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const
+        CAltitude CInterpolatorSpline::Interpolant::interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup) const
         {
             Q_UNUSED(setup);
-            Q_UNUSED(hints);
 
             const double newA = evalSplineInterval(m_currentTimeMsSinceEpoc, m_pa.t[1], m_pa.t[2], m_pa.a[1], m_pa.a[2], m_pa.da[1], m_pa.da[2]);
             return CAltitude(newA, m_altitudeUnit);
diff --git a/src/blackmisc/simulation/interpolatorspline.h b/src/blackmisc/simulation/interpolatorspline.h
index d3f904324..053b3cb96 100644
--- a/src/blackmisc/simulation/interpolatorspline.h
+++ b/src/blackmisc/simulation/interpolatorspline.h
@@ -63,8 +63,8 @@ namespace BlackMisc
 
                 //! Perform the interpolation
                 //! @{
-                Geo::CCoordinateGeodetic interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const;
-                Aviation::CAltitude interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup, const CInterpolationHints &hints) const;
+                Geo::CCoordinateGeodetic interpolatePosition(const CInterpolationAndRenderingSetupPerCallsign &setup) const;
+                Aviation::CAltitude interpolateAltitude(const CInterpolationAndRenderingSetupPerCallsign &setup) const;
                 //! @}
 
                 //! Interpolator for pitch, bank, heading, groundspeed
@@ -92,8 +92,7 @@ namespace BlackMisc
 
             //! Strategy used by CInterpolator::getInterpolatedSituation
             Interpolant getInterpolant(qint64 currentTimeMsSinceEpoc,
-                                       const CInterpolationAndRenderingSetupPerCallsign &setup,
-                                       const CInterpolationHints &hints, CInterpolationStatus &status, SituationLog &log);
+                                       const CInterpolationAndRenderingSetupPerCallsign &setup, CInterpolationStatus &status, SituationLog &log);
 
         private:
             qint64 m_prevSampleAdjustedTime = 0; //!< previous sample time + offset
diff --git a/src/blackmisc/simulation/registermetadatasimulation.cpp b/src/blackmisc/simulation/registermetadatasimulation.cpp
index 7675d2df4..c778cfba5 100644
--- a/src/blackmisc/simulation/registermetadatasimulation.cpp
+++ b/src/blackmisc/simulation/registermetadatasimulation.cpp
@@ -32,7 +32,6 @@ namespace BlackMisc
             CInterpolationAndRenderingSetupPerCallsign::registerMetadata();
             CInterpolationAndRenderingSetupGlobal::registerMetadata();
             CInterpolationSetupList::registerMetadata();
-            CInterpolationHints::registerMetadata();
             CMatchingStatisticsEntry::registerMetadata();
             CMatchingStatistics::registerMetadata();
             CModelSettings::registerMetadata();
diff --git a/src/blackmisc/simulation/remoteaircraftprovider.cpp b/src/blackmisc/simulation/remoteaircraftprovider.cpp
index 4ae5221a1..ac5a8d19f 100644
--- a/src/blackmisc/simulation/remoteaircraftprovider.cpp
+++ b/src/blackmisc/simulation/remoteaircraftprovider.cpp
@@ -28,6 +28,12 @@ namespace BlackMisc
             return this->provider()->isAircraftInRange(callsign);
         }
 
+        bool CRemoteAircraftAware::isVtolAircraft(const CCallsign &callsign) const
+        {
+            Q_ASSERT_X(this->provider(), Q_FUNC_INFO, "No object available");
+            return this->provider()->isVtolAircraft(callsign);
+        }
+
         int CRemoteAircraftAware::getAircraftInRangeCount() const
         {
             Q_ASSERT_X(this->provider(), Q_FUNC_INFO, "No object available");
diff --git a/src/blackmisc/simulation/remoteaircraftprovider.h b/src/blackmisc/simulation/remoteaircraftprovider.h
index bf9ffbee9..b7f728f29 100644
--- a/src/blackmisc/simulation/remoteaircraftprovider.h
+++ b/src/blackmisc/simulation/remoteaircraftprovider.h
@@ -75,6 +75,10 @@ namespace BlackMisc
             //! \threadsafe
             virtual bool isAircraftInRange(const BlackMisc::Aviation::CCallsign &callsign) const = 0;
 
+            //! Is VTOL aircraft?
+            //! \threadsafe
+            virtual bool isVtolAircraft(const BlackMisc::Aviation::CCallsign &callsign) const = 0;
+
             //! Current snapshot
             //! \threadsafe
             virtual BlackMisc::Simulation::CAirspaceAircraftSnapshot getLatestAirspaceAircraftSnapshot() const = 0;
@@ -195,6 +199,9 @@ namespace BlackMisc
             //! \copydoc IRemoteAircraftProvider::isAircraftInRange
             bool isAircraftInRange(const BlackMisc::Aviation::CCallsign &callsign) const;
 
+            //! \copydoc IRemoteAircraftProvider::isVtolAircraft
+            bool isVtolAircraft(const BlackMisc::Aviation::CCallsign &callsign) const;
+
             //! \copydoc IRemoteAircraftProvider::getAircraftInRangeCount
             int getAircraftInRangeCount() const;
 
diff --git a/src/blackmisc/simulation/simulation.h b/src/blackmisc/simulation/simulation.h
index 34e012cd9..70f0166f6 100644
--- a/src/blackmisc/simulation/simulation.h
+++ b/src/blackmisc/simulation/simulation.h
@@ -19,7 +19,6 @@
 #include "blackmisc/simulation/airspaceaircraftsnapshot.h"
 #include "blackmisc/simulation/distributorlist.h"
 #include "blackmisc/simulation/distributorlistpreferences.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/interpolationrenderingsetup.h"
 #include "blackmisc/simulation/interpolationsetuplist.h"
 #include "blackmisc/simulation/matchingstatistics.h"
diff --git a/src/blackmisc/simulation/simulationenvironmentprovider.cpp b/src/blackmisc/simulation/simulationenvironmentprovider.cpp
index 1bea8ba45..ef641334c 100644
--- a/src/blackmisc/simulation/simulationenvironmentprovider.cpp
+++ b/src/blackmisc/simulation/simulationenvironmentprovider.cpp
@@ -36,7 +36,7 @@ namespace BlackMisc
             return this->rememberGroundElevation(elevationPlane, elevationPlane.getRadius());
         }
 
-        bool ISimulationEnvironmentProvider::insertCG(const CLength &cg, const Aviation::CCallsign &cs)
+        bool ISimulationEnvironmentProvider::insertCG(const CLength &cg, const CCallsign &cs)
         {
             if (cs.isEmpty()) { return false; }
             const bool remove = cg.isNull();
@@ -77,7 +77,7 @@ namespace BlackMisc
             return delta;
         }
 
-        CElevationPlane ISimulationEnvironmentProvider::findClosestElevationWithinRange(const ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range)
+        CElevationPlane ISimulationEnvironmentProvider::findClosestElevationWithinRange(const ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range) const
         {
             return this->getElevationCoordinates().findClosestWithinRange(reference, range);
         }
@@ -153,7 +153,7 @@ namespace BlackMisc
             this->clearCGs();
         }
 
-        CElevationPlane CSimulationEnvironmentAware::findClosestElevationWithinRange(const ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range)
+        CElevationPlane CSimulationEnvironmentAware::findClosestElevationWithinRange(const ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range) const
         {
             if (!this->hasProvider()) { return CElevationPlane::null(); }
             return this->provider()->findClosestElevationWithinRange(reference, range);
@@ -177,6 +177,12 @@ namespace BlackMisc
             return this->provider()->getDefaultModel();
         }
 
+        CLength CSimulationEnvironmentAware::getCG(const CCallsign &callsign) const
+        {
+            if (!this->hasProvider()) { return CLength::null(); }
+            return this->provider()->getCG(callsign);
+        }
+
         bool CSimulationEnvironmentAware::hasCG(const CCallsign &callsign) const
         {
             if (!this->hasProvider()) { return false; }
diff --git a/src/blackmisc/simulation/simulationenvironmentprovider.h b/src/blackmisc/simulation/simulationenvironmentprovider.h
index 6f9bd918b..5ebc38aa7 100644
--- a/src/blackmisc/simulation/simulationenvironmentprovider.h
+++ b/src/blackmisc/simulation/simulationenvironmentprovider.h
@@ -37,7 +37,7 @@ namespace BlackMisc
 
             //! Find closest elevation
             //! \threadsafe
-            Geo::CElevationPlane findClosestElevationWithinRange(const Geo::ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range);
+            Geo::CElevationPlane findClosestElevationWithinRange(const Geo::ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range) const;
 
             //! Get the represented plugin
             //! \threadsafe
@@ -122,7 +122,7 @@ namespace BlackMisc
             void setSimulationEnvironmentProvider(ISimulationEnvironmentProvider *provider) { this->setProvider(provider); }
 
             //! \copydoc ISimulationEnvironmentProvider::findClosestElevationWithinRange
-            Geo::CElevationPlane findClosestElevationWithinRange(const Geo::ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range);
+            Geo::CElevationPlane findClosestElevationWithinRange(const Geo::ICoordinateGeodetic &reference, const PhysicalQuantities::CLength &range) const;
 
             //! \copydoc ISimulationEnvironmentProvider::getSimulatorPluginInfo
             CSimulatorPluginInfo getSimulatorPluginInfo() const;
diff --git a/src/plugins/simulator/emulated/simulatoremulated.cpp b/src/plugins/simulator/emulated/simulatoremulated.cpp
index 202d65c11..680887614 100644
--- a/src/plugins/simulator/emulated/simulatoremulated.cpp
+++ b/src/plugins/simulator/emulated/simulatoremulated.cpp
@@ -439,11 +439,8 @@ namespace BlackSimPlugin
                 CInterpolatorMulti *im = m_interpolators[cs];
                 CInterpolationStatus statusInterpolation;
                 CPartsStatus statusParts;
-                CInterpolationHints hints;
                 Q_ASSERT_X(im, Q_FUNC_INFO, "interpolator missing");
-                if (m_hints.contains(cs)) { hints = m_hints[cs]; }
-                hints.setLoggingInterpolation(log);
-                const CAircraftSituation s = im->getInterpolatedSituation(now, setup, hints, statusInterpolation);
+                const CAircraftSituation s = im->getInterpolatedSituation(now, setup, statusInterpolation);
                 const CAircraftParts p = im->getInterpolatedParts(now, setup, statusParts, log);
                 m_countInterpolatedParts++;
                 m_countInterpolatedSituations++;
diff --git a/src/plugins/simulator/fs9/fs9client.cpp b/src/plugins/simulator/fs9/fs9client.cpp
index 9c8dd0c15..97db0a8a8 100644
--- a/src/plugins/simulator/fs9/fs9client.cpp
+++ b/src/plugins/simulator/fs9/fs9client.cpp
@@ -15,7 +15,6 @@
 #include "directplayerror.h"
 #include "directplayutils.h"
 #include "blackcore/simulator.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/aviation/aircraftsituation.h"
 #include "blackmisc/geo/coordinategeodetic.h"
 #include "blackmisc/logmessage.h"
@@ -174,10 +173,8 @@ namespace BlackSimPlugin
 
             if (m_clientStatus == Disconnected) { return; }
             CInterpolationStatus status;
-            CInterpolationHints hints; // \fixme 201701 #865 KB if there is an elevation provider for FS9 add it here or set elevation
             CInterpolationAndRenderingSetupPerCallsign setup = this->simulator()->getInterpolationSetupPerCallsignOrDefault(m_callsign);
-            hints.setLoggingInterpolation(setup.logInterpolation());
-            const CAircraftSituation situation = m_interpolator.getInterpolatedSituation(-1, setup, hints, status);
+            const CAircraftSituation situation = m_interpolator.getInterpolatedSituation(-1, setup, status);
 
             // Test only for successful position. FS9 requires constant positions
             if (!status.hasValidSituation()) { return; }
diff --git a/src/plugins/simulator/fsxcommon/simconnectobject.cpp b/src/plugins/simulator/fsxcommon/simconnectobject.cpp
index 9dd2f0307..5f5a6d46e 100644
--- a/src/plugins/simulator/fsxcommon/simconnectobject.cpp
+++ b/src/plugins/simulator/fsxcommon/simconnectobject.cpp
@@ -163,10 +163,10 @@ namespace BlackSimPlugin
         CAircraftSituation CSimConnectObject::getInterpolatedSituation(
             qint64 currentTimeSinceEpoc,
             const CInterpolationAndRenderingSetupPerCallsign &setup,
-            const CInterpolationHints &hints, CInterpolationStatus &status) const
+            CInterpolationStatus &status) const
         {
             Q_ASSERT(m_interpolator);
-            return m_interpolator->getInterpolatedSituation(currentTimeSinceEpoc, setup, hints, status);
+            return m_interpolator->getInterpolatedSituation(currentTimeSinceEpoc, setup, status);
         }
 
         CAircraftParts CSimConnectObject::getInterpolatedParts(
diff --git a/src/plugins/simulator/fsxcommon/simconnectobject.h b/src/plugins/simulator/fsxcommon/simconnectobject.h
index 2ecb57a80..a8215dcbf 100644
--- a/src/plugins/simulator/fsxcommon/simconnectobject.h
+++ b/src/plugins/simulator/fsxcommon/simconnectobject.h
@@ -164,7 +164,7 @@ namespace BlackSimPlugin
             BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
                 qint64 currentTimeSinceEpoc,
                 const BlackMisc::Simulation::CInterpolationAndRenderingSetupPerCallsign &setup,
-                const BlackMisc::Simulation::CInterpolationHints &hints, BlackMisc::Simulation::CInterpolationStatus &status) const;
+                BlackMisc::Simulation::CInterpolationStatus &status) const;
 
             //! \copydoc BlackMisc::Simulation::CInterpolator::getInterpolatedParts
             BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
diff --git a/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp b/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
index 2dde66ee8..e95ad243f 100644
--- a/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
+++ b/src/plugins/simulator/fsxcommon/simulatorfsxcommon.cpp
@@ -15,7 +15,6 @@
 #include "blackmisc/simulation/fscommon/fscommonutil.h"
 #include "blackmisc/simulation/aircraftmodel.h"
 #include "blackmisc/simulation/interpolatormulti.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/simulatorplugininfo.h"
 #include "blackmisc/aviation/airportlist.h"
 #include "blackmisc/geo/elevationplane.h"
@@ -489,11 +488,6 @@ namespace BlackSimPlugin
             CElevationPlane elevation(remoteAircraftData.latitude, remoteAircraftData.longitude, remoteAircraftData.elevation);
             elevation.setSinglePointRadius();
 
-            // const QString debug(hints.debugInfo(elevation));
-            CInterpolationHints &hints = m_hints[simObject.getCallsign()];
-            hints.setElevationPlane(elevation); // update elevation
-            hints.setCGAboveGround({ remoteAircraftData.cgToGround, CLengthUnit::ft() }); // normally never changing, but if user changes ModelMatching update possible
-
             // set it in the remote aircraft provider
             this->updateAircraftGroundElevation(simObject.getCallsign(), elevation);
 
@@ -915,7 +909,6 @@ namespace BlackSimPlugin
 
             // clean up anyway
             this->removeFromAddPendingAndAddAgainAircraft(callsign);
-            m_hints.remove(callsign);
 
             // really remove from simulator
             if (!m_simConnectObjects.contains(callsign)) { return false; } // already fully removed or not yet added
@@ -1126,10 +1119,7 @@ namespace BlackSimPlugin
 
                 // get interpolated situation
                 CInterpolationStatus interpolatorStatus;
-                CInterpolationHints hints(m_hints[callsign]);
-                hints.setAircraftParts(useAircraftParts ? parts : CAircraftParts(), useAircraftParts);
-                hints.setLoggingInterpolation(logInterpolationAndParts);
-                const CAircraftSituation interpolatedSituation = simObject.getInterpolatedSituation(currentTimestamp, setup, hints, interpolatorStatus);
+                const CAircraftSituation interpolatedSituation = simObject.getInterpolatedSituation(currentTimestamp, setup, interpolatorStatus);
 
                 if (interpolatorStatus.hasValidSituation())
                 {
diff --git a/src/plugins/simulator/xplane/simulatorxplane.cpp b/src/plugins/simulator/xplane/simulatorxplane.cpp
index 2a6b87069..a7c8faca4 100644
--- a/src/plugins/simulator/xplane/simulatorxplane.cpp
+++ b/src/plugins/simulator/xplane/simulatorxplane.cpp
@@ -632,9 +632,6 @@ namespace BlackSimPlugin
                 Q_ASSERT_X(CThreadUtils::isCurrentThreadObjectThread(this), Q_FUNC_INFO, "wrong thread");
                 if (callsign.isEmpty()) { return false; } // can happen if an object is not an aircraft
 
-                // clean up anyway
-                m_hints.remove(callsign);
-
                 // really remove from simulator
                 if (!m_xplaneAircraftObjects.contains(callsign)) { return false; } // already fully removed or not yet added
 
@@ -837,10 +834,7 @@ namespace BlackSimPlugin
 
                 // get interpolated situation
                 CInterpolationStatus interpolatorStatus;
-                CInterpolationHints hints(m_hints[callsign]);
-                hints.setAircraftParts(useAircraftParts ? parts : CAircraftParts(), useAircraftParts);
-                hints.setLoggingInterpolation(logInterpolationAndParts);
-                const CAircraftSituation interpolatedSituation = xplaneAircraft.getInterpolatedSituation(currentTimestamp, setup, hints, interpolatorStatus);
+                const CAircraftSituation interpolatedSituation = xplaneAircraft.getInterpolatedSituation(currentTimestamp, setup, interpolatorStatus);
 
                 if (interpolatorStatus.hasValidSituation())
                 {
@@ -999,13 +993,8 @@ namespace BlackSimPlugin
 
             CElevationPlane elevation(CLatitude(latitudeDeg, CAngleUnit::deg()), CLongitude(longitudeDeg, CAngleUnit::deg()), CAltitude(elevationMeters, CLengthUnit::m()));
             elevation.setSinglePointRadius();
-
-            // The entire vertical offset (CG offset) is still very experimental in X-Plane. Libxplanemp simply calculates the lowest Y
-            // value from all the OpenGL model vertices. I assume its in meters.
-            // The unit of modelVerticalOffset is still very unknown. This needs to be confirmed.
-            CInterpolationHints &hints = m_hints[cs];
-            hints.setElevationPlane(elevation); // update elevation
-            hints.setCGAboveGround({ modelVerticalOffsetMeters, CLengthUnit::m() });
+            this->rememberGroundElevation(elevation);
+            this->insertCG(CLength(modelVerticalOffsetMeters, CLengthUnit::m()), callsign);
 
             // set it in the remote aircraft provider
             this->updateAircraftGroundElevation(cs, elevation);
diff --git a/src/plugins/simulator/xplane/xplanempaircraft.cpp b/src/plugins/simulator/xplane/xplanempaircraft.cpp
index 3e5b5d6e0..d27d1a7b3 100644
--- a/src/plugins/simulator/xplane/xplanempaircraft.cpp
+++ b/src/plugins/simulator/xplane/xplanempaircraft.cpp
@@ -92,10 +92,10 @@ namespace BlackSimPlugin
         CAircraftSituation CXPlaneMPAircraft::getInterpolatedSituation(
             qint64 currentTimeSinceEpoc,
             const CInterpolationAndRenderingSetupPerCallsign &setup,
-            const CInterpolationHints &hints, CInterpolationStatus &status) const
+            CInterpolationStatus &status) const
         {
             Q_ASSERT(m_interpolator);
-            return m_interpolator->getInterpolatedSituation(currentTimeSinceEpoc, setup, hints, status);
+            return m_interpolator->getInterpolatedSituation(currentTimeSinceEpoc, setup, status);
         }
 
         CAircraftParts CXPlaneMPAircraft::getInterpolatedParts(
diff --git a/src/plugins/simulator/xplane/xplanempaircraft.h b/src/plugins/simulator/xplane/xplanempaircraft.h
index 57b122bf5..105fefd26 100644
--- a/src/plugins/simulator/xplane/xplanempaircraft.h
+++ b/src/plugins/simulator/xplane/xplanempaircraft.h
@@ -90,7 +90,7 @@ namespace BlackSimPlugin
             BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
                 qint64 currentTimeSinceEpoc,
                 const BlackMisc::Simulation::CInterpolationAndRenderingSetupPerCallsign &setup,
-                const BlackMisc::Simulation::CInterpolationHints &hints, BlackMisc::Simulation::CInterpolationStatus &status) const;
+                BlackMisc::Simulation::CInterpolationStatus &status) const;
 
             //! \copydoc BlackMisc::Simulation::CInterpolator::getInterpolatedParts
             BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
diff --git a/src/xswiftbus/traffic.cpp b/src/xswiftbus/traffic.cpp
index dfec22afc..b8595a3f5 100644
--- a/src/xswiftbus/traffic.cpp
+++ b/src/xswiftbus/traffic.cpp
@@ -15,7 +15,6 @@
 #include "traffic.h"
 #include "utils.h"
 #include "blackmisc/simulation/interpolator.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/aviation/aircraftsituation.h"
 #include "blackmisc/aviation/callsign.h"
 #include "blackmisc/verify.h"
@@ -47,34 +46,6 @@ namespace XSwiftBus
         surfaces.lights.timeOffset = static_cast<quint16>(qrand() % 0xffff);
     }
 
-    BlackMisc::Simulation::CInterpolationHints CTraffic::Plane::hints()
-    {
-        //! \todo MS 865 CInterpolationAndRenderingSetup allows to setup interpolation in the GUI
-        //        Also to disable aircraft parts / or logging parts (log file). I wonder if you want to consider it here
-        //        e.g. interpolator->getInterpolatorSetup().getLogCallsigns().contains(callsign)
-        //        if the setup is needed more than once, store it here to avoid multiple locks
-        using namespace BlackMisc::PhysicalQuantities;
-        using namespace BlackMisc::Aviation;
-        using namespace BlackMisc::Simulation;
-
-        CInterpolationAndRenderingSetupPerCallsign setup;
-        CInterpolationHints hints;
-        CPartsStatus status;
-        constexpr double fudgeFactor = 3.0; //! \fixme Value should be different for each plane, derived from the CSL model geometry
-        hints.setAircraftParts(interpolator.getInterpolatedParts(-1, setup, status));
-        hints.setCGAboveGround({ fudgeFactor, CLengthUnit::m() }); // fudge factor
-        hints.setElevationProvider([this](const auto & situation)
-        {
-            const auto meters = terrainProbe.getElevation(
-                                    situation.latitude().value(CAngleUnit::deg()),
-                                    situation.longitude().value(CAngleUnit::deg()),
-                                    situation.getAltitude().value(CLengthUnit::m()));
-            if (std::isnan(meters)) { return CAltitude::null(); }
-            return CAltitude(CLength(meters, CLengthUnit::m()), CAltitude::MeanSeaLevel);
-        });
-        return hints;
-    }
-
     CTraffic::CTraffic(QObject *parent) :
         QObject(parent)
     {
@@ -432,7 +403,7 @@ namespace XSwiftBus
                 {
                     BlackMisc::Simulation::CInterpolationAndRenderingSetupPerCallsign setup;
                     BlackMisc::Simulation::CInterpolationStatus status;
-                    BlackMisc::Aviation::CAircraftSituation situation = plane->interpolator.getInterpolatedSituation(-1, setup, plane->hints(), status);
+                    BlackMisc::Aviation::CAircraftSituation situation = plane->interpolator.getInterpolatedSituation(-1, setup, status);
                     if (! status.hasValidSituation()) { return xpmpData_Unavailable; }
 
                     //! \fixme KB 2018-01 commented out with T229. Change detection needs to go somewhere else
diff --git a/src/xswiftbus/traffic.h b/src/xswiftbus/traffic.h
index 72b2f6859..c8c313bef 100644
--- a/src/xswiftbus/traffic.h
+++ b/src/xswiftbus/traffic.h
@@ -31,7 +31,6 @@
 #define XSWIFTBUS_TRAFFIC_OBJECTPATH "/xswiftbus/traffic"
 //! \endcond
 
-namespace BlackMisc { namespace Simulation { class CInterpolationHints; } }
 namespace XSwiftBus
 {
     /*!
@@ -154,7 +153,6 @@ namespace XSwiftBus
             char label[32] {};
             BlackMisc::Simulation::CInterpolatorMulti interpolator;
             CTerrainProbe terrainProbe;
-            BlackMisc::Simulation::CInterpolationHints hints();
             XPMPPlaneSurfaces_t surfaces;
             QVector<std::pair<qint64, std::function<void(Plane *)>>> pendingSurfaces;
             float targetGearPosition = 0;
diff --git a/tests/blackmisc/testinterpolatorlinear.cpp b/tests/blackmisc/testinterpolatorlinear.cpp
index d68c869f1..d8d86a8fc 100644
--- a/tests/blackmisc/testinterpolatorlinear.cpp
+++ b/tests/blackmisc/testinterpolatorlinear.cpp
@@ -34,7 +34,6 @@
 #include "blackmisc/pq/physicalquantity.h"
 #include "blackmisc/pq/speed.h"
 #include "blackmisc/pq/units.h"
-#include "blackmisc/simulation/interpolationhints.h"
 #include "blackmisc/simulation/remoteaircraftprovider.h"
 
 #include <QCoreApplication>
@@ -84,7 +83,6 @@ namespace BlackMiscTest
 
         // interpolation functional check
         CInterpolationStatus status;
-        const CInterpolationHints hints;
         const CInterpolationAndRenderingSetupPerCallsign setup;
         double latOld = 360.0;
         double lngOld = 360.0;
@@ -93,9 +91,9 @@ namespace BlackMiscTest
             // This will use time range
             // from:  ts - 2 * deltaT + offset
             // to:    ts              + offset
-            CAircraftSituation currentSituation(interpolator.getInterpolatedSituation
-                                                (currentTime, setup, hints, status)
-                                               );
+            CAircraftSituation currentSituation(
+                interpolator.getInterpolatedSituation(currentTime, setup, status)
+            );
             QVERIFY2(status.isInterpolated(), "Value was not interpolated");
             const double latDeg = currentSituation.getPosition().latitude().valueRounded(CAngleUnit::deg(), 5);
             const double lngDeg = currentSituation.getPosition().longitude().valueRounded(CAngleUnit::deg(), 5);
@@ -123,9 +121,9 @@ namespace BlackMiscTest
                 // This will use range
                 // from:  ts - 2* deltaT + offset
                 // to:    ts             + offset
-                CAircraftSituation currentSituation(interpolator.getInterpolatedSituation
-                                                    (currentTime, setup, hints, status)
-                                                   );
+                CAircraftSituation currentSituation(
+                    interpolator.getInterpolatedSituation(currentTime, setup, status)
+                );
                 QVERIFY2(status.isInterpolated(), "Not interpolated");
                 QVERIFY2(!currentSituation.getCallsign().isEmpty(), "Empty callsign");
                 QVERIFY2(currentSituation.getCallsign() == cs, "Wrong callsign");