diff --git a/src/blackmisc/simulation/interpolationlogger.cpp b/src/blackmisc/simulation/interpolationlogger.cpp
index ff72b1745..5945a2b4c 100644
--- a/src/blackmisc/simulation/interpolationlogger.cpp
+++ b/src/blackmisc/simulation/interpolationlogger.cpp
@@ -132,7 +132,7 @@ namespace BlackMisc
             if (logs.isEmpty()) { return {}; }
             const QString tableHeader =
                 QLatin1String("<thead><tr>") %
-                QLatin1String("<th>c.</th><th>CS</th><th>VTOL</th><th>timestamp</th><th>since</th>") %
+                QLatin1String("<th title=\"changed situation\">cs.</th><th>CS</th><th>VTOL</th><th>timestamp</th><th>since</th>") %
                 QLatin1String("<th>ts old</th><th>ts new</th><th>ts cur</th>") %
                 QLatin1String("<th>&Delta;t</th><th>&Delta;t fr.</th><th>fraction</th>") %
                 QLatin1String("<th>lat.old</th><th>lat.new</th><th>lat.cur</th>") %
@@ -141,7 +141,8 @@ namespace BlackMisc
                 QLatin1String("<th>elv.old</th><th>elv.new</th><th>elv.cur</th>") %
                 QLatin1String("<th>gnd.factor</th>") %
                 QLatin1String("<th>onGnd.old</th><th>onGnd.new</th><th>onGnd.cur</th>") %
-                QLatin1String("<th>parts</th><th>c.</th><th>parts details</th>") %
+                QLatin1String("<th>CG</th>") %
+                QLatin1String("<th>parts</th><th title=\"changed parts\">cp.</th><th>parts details</th>") %
                 QLatin1String("</tr></thead>\n");
 
             static const CLengthUnit ft = CLengthUnit::ft();
@@ -198,11 +199,13 @@ namespace BlackMisc
                     QLatin1String("<td class=\"cur\">") % log.currentSituation.getOnGroundInfo() % QLatin1String("</td>");
 
                 tableRows +=
+                    QLatin1String("<td>") % log.cgAboveGround.valueRoundedWithUnit(CLengthUnit::ft(), 0) % QLatin1String("</td>") %
                     QLatin1String("<td>") % boolToYesNo(log.useParts) % QLatin1String("</td>") %
-                    (changedParts ? QLatin1String("<td>*</td>") : QLatin1String("<td></td>")) %
+                    (changedParts ? QLatin1String("<td class=\"changed\">*</td>") : QLatin1String("<td></td>")) %
                     QLatin1String("<td>") % (log.useParts ? log.parts.toQString(true) : QLatin1String("")) % QLatin1String("</td>") %
                     QLatin1String("</tr>\n");
             }
+
             tableRows += QLatin1String("</tbody>\n");
             return QLatin1String("<table class=\"small\">\n") % tableHeader % tableRows % QLatin1String("</table>\n");
         }
diff --git a/src/blackmisc/simulation/interpolationlogger.h b/src/blackmisc/simulation/interpolationlogger.h
index 6d4c02491..6f9b65449 100644
--- a/src/blackmisc/simulation/interpolationlogger.h
+++ b/src/blackmisc/simulation/interpolationlogger.h
@@ -70,15 +70,16 @@ namespace BlackMisc
                 BlackMisc::Aviation::CAircraftSituation oldSituation;     //!< old situation
                 BlackMisc::Aviation::CAircraftSituation newSituation;     //!< new situation
                 BlackMisc::Aviation::CAircraftSituation currentSituation; //!< interpolated situation
+                BlackMisc::PhysicalQuantities::CLength cgAboveGround;     //!< center of gravity
             };
 
             //! Log entry for parts interpolation
             struct PartsLog
             {
                 qint64 timestamp = -1; //!< current timestamp
+                bool empty = false;    //!< empty parts?
                 BlackMisc::Aviation::CCallsign callsign;   //!< current callsign
                 BlackMisc::Aviation::CAircraftParts parts; //!< parts to be logged
-                bool empty = false;
             };
 
             //! Log current interpolation cycle, only stores in memory, for performance reasons
diff --git a/src/blackmisc/simulation/interpolator.cpp b/src/blackmisc/simulation/interpolator.cpp
index 9f57709ec..a5c147963 100644
--- a/src/blackmisc/simulation/interpolator.cpp
+++ b/src/blackmisc/simulation/interpolator.cpp
@@ -58,7 +58,7 @@ namespace BlackMisc
             if (currentTimeMsSinceEpoc < 0) { currentTimeMsSinceEpoc = QDateTime::currentMSecsSinceEpoch(); }
 
             // interpolant function from derived class
-            auto interpolant = derived()->getInterpolant(currentTimeMsSinceEpoc, setup, hints, status, log);
+            const auto interpolant = derived()->getInterpolant(currentTimeMsSinceEpoc, setup, hints, status, log);
 
             // succeeded so far?
             if (!status.didInterpolationSucceed()) { return currentSituation; }
@@ -84,8 +84,8 @@ namespace BlackMisc
                     if (!currentGroundElevation.isNull())
                     {
                         Q_ASSERT_X(currentGroundElevation.getReferenceDatum() == CAltitude::MeanSeaLevel, Q_FUNC_INFO, "Need MSL value");
-                        currentSituation.setAltitude(CAltitude(currentSituation.getAltitude() * (1.0 - groundFactor)
-                                                               + currentGroundElevation * groundFactor,
+                        currentSituation.setAltitude(CAltitude(currentSituation.getAltitude() * (1.0 - groundFactor) +
+                                                               currentGroundElevation * groundFactor,
                                                                currentSituation.getAltitude().getReferenceDatum()));
                     }
                 }
@@ -116,6 +116,7 @@ namespace BlackMisc
             {
                 log.timestamp = currentTimeMsSinceEpoc;
                 log.callsign = m_callsign;
+                log.cgAboveGround = hints.getCGAboveGround();
                 log.vtolAircraft = hints.isVtolAircraft();
                 log.currentSituation = currentSituation;
                 log.useParts = hints.hasAircraftParts();
@@ -187,7 +188,7 @@ namespace BlackMisc
             {
                 static const CAircraftParts emptyParts;
                 this->logParts(currentTimeMsSinceEpoch, emptyParts, true, log);
-                emptyParts;
+                return emptyParts;
             }
 
             // find the first parts not in the correct order, keep only the parts before that one
diff --git a/src/blackmisc/simulation/interpolator.h b/src/blackmisc/simulation/interpolator.h
index 72f8d8397..8504f75cc 100644
--- a/src/blackmisc/simulation/interpolator.h
+++ b/src/blackmisc/simulation/interpolator.h
@@ -123,6 +123,8 @@ namespace BlackMisc
             PhysicalQuantities::CAngle getPitch() const;
             PhysicalQuantities::CAngle getBank() const;
             PhysicalQuantities::CSpeed getGroundSpeed() const;
+            Aviation::CAircraftSituation getOldSituation() const { return oldSituation; }
+            Aviation::CAircraftSituation getNewSituation() const { return newSituation; }
             //! @}
 
             //! Change time fraction
diff --git a/src/blackmisc/simulation/interpolatorspline.cpp b/src/blackmisc/simulation/interpolatorspline.cpp
index 560ee92af..ab632326d 100644
--- a/src/blackmisc/simulation/interpolatorspline.cpp
+++ b/src/blackmisc/simulation/interpolatorspline.cpp
@@ -94,7 +94,6 @@ namespace BlackMisc
         {
             Q_UNUSED(hints);
             Q_UNUSED(setup);
-            Q_UNUSED(log);
 
             // recalculate derivatives only if they changed
             if (currentTimeMsSinceEpoc > m_nextSampleTime)
@@ -129,6 +128,8 @@ namespace BlackMisc
                 m_altitudeUnit = situationsOlder.begin()->getAltitude().getUnit();
                 pbh = { *situationsOlder.begin(), *(situationsNewer.end() - 1) };
             }
+            log.oldSituation = pbh.getOldSituation();
+            log.newSituation = pbh.getNewSituation();
 
             status.setInterpolationSucceeded(true);
             status.setChangedPosition(true);