diff --git a/src/blackmisc/simulation/interpolationhints.cpp b/src/blackmisc/simulation/interpolationhints.cpp
new file mode 100644
index 000000000..ad11f3363
--- /dev/null
+++ b/src/blackmisc/simulation/interpolationhints.cpp
@@ -0,0 +1,91 @@
+/* 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 "blackmisc/aviation/aircraftsituation.h"
+
+using namespace BlackMisc::Geo;
+using namespace BlackMisc::PhysicalQuantities;
+
+namespace BlackMisc
+{
+    namespace Simulation
+    {
+        CInterpolationHints::CInterpolationHints() { }
+
+        CInterpolationHints::CInterpolationHints(bool isVtolAircraft) : m_isVtol(isVtolAircraft)
+        { }
+
+        void CInterpolationHints::resetElevation()
+        {
+            m_elevation = CElevationPlane();
+        }
+
+        bool CInterpolationHints::isWithinRange(const Geo::ICoordinateGeodetic &coordinate) const
+        {
+            if (m_elevation.isNull()) return false;
+            return m_elevation.isWithinRange(coordinate);
+        }
+
+        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 this->m_cgAboveGround.propertyByIndex(index.copyFrontRemoved());
+            case IndexElevationPlane:
+                return this->m_elevation.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:
+                this->m_cgAboveGround.setPropertyByIndex(index.copyFrontRemoved(), variant);
+                break;
+            case IndexElevationPlane:
+                this->m_elevation.setPropertyByIndex(index.copyFrontRemoved(), variant);
+                break;
+            case IndexIsVtolAircraft:
+                this->m_isVtol = variant.toBool();
+                break;
+            default:
+                CValueObject::setPropertyByIndex(index, variant);
+                break;
+            }
+        }
+
+        QString CInterpolationHints::convertToQString(bool i18n) const
+        {
+            static const QString s("%1 %2");
+            return s.arg(m_elevation.toQString(i18n), m_cgAboveGround.toQString(i18n));
+        }
+
+        QString CInterpolationHints::debugInfo(const Geo::CElevationPlane &deltaElevation) const
+        {
+            static const QString s("Lat: %1 Lng: %2 Elv: %3");
+            if (m_elevation.isNull() || deltaElevation.isNull()) return "null";
+            return s.arg(
+                       (deltaElevation.latitude() - m_elevation.latitude()).valueRoundedWithUnit(CAngleUnit::deg(), 10),
+                       (deltaElevation.longitude() - m_elevation.longitude()).valueRoundedWithUnit(CAngleUnit::deg(), 10),
+                       (deltaElevation.geodeticHeight() - m_elevation.geodeticHeight()).valueRoundedWithUnit(CLengthUnit::ft(), 2)
+                   );
+        }
+    } // namespace
+} // namespace
diff --git a/src/blackmisc/simulation/interpolationhints.h b/src/blackmisc/simulation/interpolationhints.h
new file mode 100644
index 000000000..3192436f7
--- /dev/null
+++ b/src/blackmisc/simulation/interpolationhints.h
@@ -0,0 +1,95 @@
+/* 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"
+
+namespace BlackMisc
+{
+    namespace Simulation
+    {
+        //! Hints for interpolator such as ground elevation
+        class BLACKMISC_EXPORT CInterpolationHints :
+            public BlackMisc::CValueObject<CInterpolationHints>
+        {
+        public:
+            //! Property indexes
+            enum ColumnIndex
+            {
+                IndexElevationPlane = CPropertyIndex::GlobalIndexCInterpolationHints,
+                IndexCenterOfGravity,
+                IndexIsVtolAircraft
+            };
+
+            //! Default constructor.
+            CInterpolationHints();
+
+            //! Constructor
+            CInterpolationHints(bool isVtolAircraft);
+
+            //! Get elevation
+            const BlackMisc::Geo::CElevationPlane &getElevation() const { return m_elevation;}
+
+            //! Set elevation
+            void setElevation(const BlackMisc::Geo::CElevationPlane &elevation) { m_elevation = elevation; }
+
+            //! Elevation set to null
+            void resetElevation();
+
+            //! Check if elevation is within radius and can be used
+            bool isWithinRange(const BlackMisc::Geo::ICoordinateGeodetic &coordinate) const;
+
+            //! Get CG above ground
+            const BlackMisc::PhysicalQuantities::CLength &getCGAboveGround() const { return m_cgAboveGround;}
+
+            //! Set CG above ground
+            void setCGAboveGround(const BlackMisc::PhysicalQuantities::CLength &cgAboveGround) { m_cgAboveGround = cgAboveGround; }
+
+            //! VTOL aircraft?
+            bool isVtolAircraft() const { return m_isVtol; }
+
+            //! VTOL aircraft
+            void setVtolAircraft(bool vtol) { m_isVtol = vtol; }
+
+            //! \copydoc BlackMisc::Mixin::Index::propertyByIndex
+            CVariant propertyByIndex(const BlackMisc::CPropertyIndex &index) const;
+
+            //! \copydoc BlackMisc::Mixin::Index::setPropertyByIndex
+            void setPropertyByIndex(const BlackMisc::CPropertyIndex &index, const CVariant &variant);
+
+            //! \copydoc BlackMisc::Mixin::String::toQString
+            QString convertToQString(bool i18n = false) const;
+
+            //! For debugging
+            QString debugInfo(const BlackMisc::Geo::CElevationPlane &deltaElevation) const;
+
+        private:
+            bool m_isVtol = false; //!< VTOL aircraft?
+            BlackMisc::Geo::CElevationPlane m_elevation; //! aircraft's elevation if available
+            BlackMisc::PhysicalQuantities::CLength m_cgAboveGround { 0, nullptr }; //!< center of gravity above ground
+
+            BLACK_METACLASS(
+                CInterpolationHints,
+                BLACK_METAMEMBER(isVtol),
+                BLACK_METAMEMBER(elevation),
+                BLACK_METAMEMBER(cgAboveGround)
+            );
+        };
+    } // namespace
+} // namespace
+
+Q_DECLARE_METATYPE(BlackMisc::Simulation::CInterpolationHints)
+
+#endif // guard