diff --git a/src/blackmisc/simulation/interpolator.cpp b/src/blackmisc/simulation/interpolator.cpp
index 7102ba058..8d109a0ef 100644
--- a/src/blackmisc/simulation/interpolator.cpp
+++ b/src/blackmisc/simulation/interpolator.cpp
@@ -36,19 +36,7 @@ namespace BlackMisc
         }
 
         template <typename Derived>
-        BlackMisc::Aviation::CAircraftSituation CInterpolator<Derived>::getInterpolatedSituation(
-            qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup,
-            const CInterpolationHints &hints, CInterpolationStatus &status) const
-        {
-            status.reset();
-
-            auto currentSituation = derived()->getInterpolatedSituation(callsign, this->m_aircraftSituations, currentTimeSinceEpoc, setup, hints, status);
-            currentSituation.setCallsign(callsign); // make sure callsign is correct
-            return currentSituation;
-        }
-
-        template <typename Derived>
-        CAircraftParts CInterpolator<Derived>::getInterpolatedParts(const CCallsign &callsign, const CAircraftPartsList &parts, qint64 currentTimeMsSinceEpoch,
+        CAircraftParts CInterpolator<Derived>::getInterpolatedParts(const CCallsign &callsign, qint64 currentTimeMsSinceEpoch,
             const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log) const
         {
             Q_UNUSED(setup);
@@ -56,9 +44,8 @@ namespace BlackMisc
             if (currentTimeMsSinceEpoch < 0) { currentTimeMsSinceEpoch = QDateTime::currentMSecsSinceEpoch(); }
 
             // find the first parts not in the correct order, keep only the parts before that one
-            if (parts.isEmpty()) { return {}; }
-            const auto end = std::is_sorted_until(parts.begin(), parts.end(), [](auto && a, auto && b) { return b.getAdjustedMSecsSinceEpoch() < a.getAdjustedMSecsSinceEpoch(); });
-            const auto validParts = makeRange(parts.begin(), end);
+            const auto end = std::is_sorted_until(m_aircraftParts.begin(), m_aircraftParts.end(), [](auto && a, auto && b) { return b.getAdjustedMSecsSinceEpoch() < a.getAdjustedMSecsSinceEpoch(); });
+            const auto validParts = makeRange(m_aircraftParts.begin(), end);
 
             // stop if we don't have any parts
             if (validParts.isEmpty()) { return {}; }
@@ -112,14 +99,6 @@ namespace BlackMisc
             return currentParts;
         }
 
-        template <typename Derived>
-        CAircraftParts CInterpolator<Derived>::getInterpolatedParts(const CCallsign &callsign, qint64 currentTimeMsSinceEpoch,
-            const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log) const
-        {
-            partsStatus.reset();
-            return this->getInterpolatedParts(callsign, this->m_aircraftParts, currentTimeMsSinceEpoch, setup, partsStatus, log);
-        }
-
         template <typename Derived>
         void CInterpolator<Derived>::addAircraftSituation(const CAircraftSituation &situation)
         {
diff --git a/src/blackmisc/simulation/interpolator.h b/src/blackmisc/simulation/interpolator.h
index 36781fda9..3a6829262 100644
--- a/src/blackmisc/simulation/interpolator.h
+++ b/src/blackmisc/simulation/interpolator.h
@@ -44,12 +44,6 @@ namespace BlackMisc
             //! Current interpolated situation
             BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
                 const BlackMisc::Aviation::CCallsign &callsign, qint64 currentTimeSinceEpoc,
-                const CInterpolationAndRenderingSetup &setup, const CInterpolationHints &hints, CInterpolationStatus &status) const;
-
-            //! Current interpolated situation, to be implemented by subclass
-            BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
-                const BlackMisc::Aviation::CCallsign &callsign,
-                const BlackMisc::Aviation::CAircraftSituationList &situations, qint64 currentTimeSinceEpoc,
                 const CInterpolationAndRenderingSetup &setup, const CInterpolationHints &hints, CInterpolationStatus &status) const
             {
                 qFatal("Not implemented");
@@ -58,13 +52,7 @@ namespace BlackMisc
 
             //! Parts before given offset time (aka pending parts)
             BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
-                const Aviation::CCallsign &callsign,
-                const BlackMisc::Aviation::CAircraftPartsList &parts, qint64 cutoffTime,
-                const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log = false) const;
-
-            //! Parts before given offset time (aka pending parts)
-            BlackMisc::Aviation::CAircraftParts getInterpolatedParts(
-                const BlackMisc::Aviation::CCallsign &callsign, qint64 cutoffTime,
+                const Aviation::CCallsign &callsign, qint64 cutoffTime,
                 const CInterpolationAndRenderingSetup &setup, CPartsStatus &partsStatus, bool log = false) const;
 
             //! Add a new aircraft situation
diff --git a/src/blackmisc/simulation/interpolatorlinear.cpp b/src/blackmisc/simulation/interpolatorlinear.cpp
index 04a0c5de7..4491c8ba4 100644
--- a/src/blackmisc/simulation/interpolatorlinear.cpp
+++ b/src/blackmisc/simulation/interpolatorlinear.cpp
@@ -40,7 +40,7 @@ namespace BlackMisc
 {
     namespace Simulation
     {
-        CAircraftSituation CInterpolatorLinear::getInterpolatedSituation(const CCallsign &callsign, const CAircraftSituationList &situations, qint64 currentTimeMsSinceEpoc,
+        CAircraftSituation CInterpolatorLinear::getInterpolatedSituation(const CCallsign &callsign, qint64 currentTimeMsSinceEpoc,
             const CInterpolationAndRenderingSetup &setup, const CInterpolationHints &hints, CInterpolationStatus &status) const
         {
             status.reset();
@@ -53,8 +53,8 @@ namespace BlackMisc
 
             // find the first situation not in the correct order, keep only the situations before that one
             // any updates in wrong chronological order are discounted
-            const auto end = std::is_sorted_until(situations.begin(), situations.end(), [](auto && a, auto && b) { return b.getAdjustedMSecsSinceEpoch() < a.getAdjustedMSecsSinceEpoch(); });
-            const auto validSituations = makeRange(situations.begin(), end);
+            const auto end = std::is_sorted_until(m_aircraftSituations.begin(), m_aircraftSituations.end(), [](auto && a, auto && b) { return b.getAdjustedMSecsSinceEpoch() < a.getAdjustedMSecsSinceEpoch(); });
+            const auto validSituations = makeRange(m_aircraftSituations.begin(), end);
 
             // find the first situation earlier than the current time
             const auto pivot = std::partition_point(validSituations.begin(), validSituations.end(), [ = ](auto && s) { return s.getAdjustedMSecsSinceEpoch() > currentTimeMsSinceEpoc; });
diff --git a/src/blackmisc/simulation/interpolatorlinear.h b/src/blackmisc/simulation/interpolatorlinear.h
index c6623c6b3..fc7bbfcf0 100644
--- a/src/blackmisc/simulation/interpolatorlinear.h
+++ b/src/blackmisc/simulation/interpolatorlinear.h
@@ -36,13 +36,9 @@ namespace BlackMisc
                 CInterpolator("CInterpolatorLinear", parent)
             {}
 
-            // public base class signature
-            using CInterpolator::getInterpolatedSituation;
-
             //! \copydoc IInterpolator::getInterpolatedSituation
             BlackMisc::Aviation::CAircraftSituation getInterpolatedSituation(
-                const BlackMisc::Aviation::CCallsign &callsign,
-                const BlackMisc::Aviation::CAircraftSituationList &situations, qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup,
+                const BlackMisc::Aviation::CCallsign &callsign, qint64 currentTimeSinceEpoc, const CInterpolationAndRenderingSetup &setup,
                 const BlackMisc::Simulation::CInterpolationHints &hints, CInterpolationStatus &status) const;
 
             //! Log category