diff --git a/src/blackmisc/aviation/aircraftsituation.cpp b/src/blackmisc/aviation/aircraftsituation.cpp
index 760ebfff1..47cb59eb8 100644
--- a/src/blackmisc/aviation/aircraftsituation.cpp
+++ b/src/blackmisc/aviation/aircraftsituation.cpp
@@ -310,6 +310,17 @@ namespace BlackMisc
             return CAircraftSituation::onGroundDetailsToString(this->getOnGroundDetails());
         }
 
+        bool CAircraftSituation::setOnGroundDetails(CAircraftSituation::OnGroundDetails details)
+        {
+            if (details != OnGroundByGuessing)
+            {
+                m_onGroundGuessingDetails.clear();
+            }
+            if (this->getOnGroundDetails() == details) { return false; }
+            m_onGroundDetails = static_cast<int>(details);
+            return true;
+        }
+
         bool CAircraftSituation::setOnGroundFromGroundFactorFromInterpolation(double threshold)
         {
             this->setOnGroundDetails(OnGroundByInterpolation);
@@ -512,12 +523,14 @@ namespace BlackMisc
             m_correspondingCallsign.setTypeHint(CCallsign::Aircraft);
         }
 
-        bool CAircraftSituation::adjustGroundFlag(const CAircraftParts &parts, double timeDeviationFactor, qint64 *differenceMs)
+        bool CAircraftSituation::adjustGroundFlag(const CAircraftParts &parts, bool alwaysSetDetails, double timeDeviationFactor, qint64 *differenceMs)
         {
             Q_ASSERT_X(timeDeviationFactor >= 0 && timeDeviationFactor <= 1.0, Q_FUNC_INFO, "Expect 0..1");
             static const qint64 Max = std::numeric_limits<qint64>::max();
             if (differenceMs) { *differenceMs = Max; }
+
             if (this->getOnGroundDetails() == CAircraftSituation::InFromNetwork) { return false; }
+            if (alwaysSetDetails) { this->setOnGroundDetails(InFromParts); }
             const qint64 d = this->getAdjustedTimeDifferenceMs(parts.getAdjustedMSecsSinceEpoch());
             const bool adjust = (d >= 0) || qAbs(d) < (timeDeviationFactor * parts.getTimeOffsetMs()); // future or past within deviation range
             if (!adjust) { return false; }
@@ -527,14 +540,16 @@ namespace BlackMisc
             return true;
         }
 
-        bool CAircraftSituation::adjustGroundFlag(const CAircraftPartsList &partsList, double timeDeviationFactor, qint64 *differenceMs)
+        bool CAircraftSituation::adjustGroundFlag(const CAircraftPartsList &partsList, bool alwaysSetDetails, double timeDeviationFactor, qint64 *differenceMs)
         {
             Q_ASSERT_X(timeDeviationFactor >= 0 && timeDeviationFactor <= 1.0, Q_FUNC_INFO, "Expect 0..1");
-            if (this->getOnGroundDetails() == CAircraftSituation::InFromNetwork) { return false; }
-            if (partsList.isEmpty()) { return false; }
-
             static const qint64 Max = std::numeric_limits<qint64>::max();
             if (differenceMs) { *differenceMs = Max; }
+
+            if (this->getOnGroundDetails() == CAircraftSituation::InFromNetwork) { return false; }
+            if (alwaysSetDetails) { this->setOnGroundDetails(InFromParts); }
+            if (partsList.isEmpty()) { return false; }
+
             CAircraftParts bestParts;
             bool adjust = false;
             qint64 bestDistance = Max;
diff --git a/src/blackmisc/aviation/aircraftsituation.h b/src/blackmisc/aviation/aircraftsituation.h
index f2f501a06..9e1717119 100644
--- a/src/blackmisc/aviation/aircraftsituation.h
+++ b/src/blackmisc/aviation/aircraftsituation.h
@@ -197,7 +197,7 @@ namespace BlackMisc
             const QString &getOnDetailsAsString() const;
 
             //! On ground details
-            void setOnGroundDetails(CAircraftSituation::OnGroundDetails details) { m_onGroundDetails = static_cast<int>(details); }
+            bool setOnGroundDetails(CAircraftSituation::OnGroundDetails details);
 
             //! Set on ground as interpolated from ground fatcor
             bool setOnGroundFromGroundFactorFromInterpolation(double threshold = 0.5);
@@ -320,14 +320,14 @@ namespace BlackMisc
             //! \param alwaysSetDetails mark as CAircraftSituation::InFromParts regardless of parts
             //! \param timeDeviationFactor 0..1 (of offset time) small deviations from time are accepted
             //! \param differenceMs returns time difference
-            bool adjustGroundFlag(const CAircraftParts &parts, double timeDeviationFactor = 0.1, qint64 *differenceMs = nullptr);
+            bool adjustGroundFlag(const CAircraftParts &parts, bool alwaysSetDetails, double timeDeviationFactor = 0.1, qint64 *differenceMs = nullptr);
 
             //! Transfer ground flag from parts list
             //! \param partsList containing the gnd flag
             //! \param alwaysSetDetails mark as CAircraftSituation::InFromParts regardless of parts
             //! \param timeDeviationFactor 0..1 (of offset time) small deviations from time are accepted
             //! \param differenceMs returns time difference
-            bool adjustGroundFlag(const CAircraftPartsList &partsList, double timeDeviationFactor = 0.1, qint64 *differenceMs = nullptr);
+            bool adjustGroundFlag(const CAircraftPartsList &partsList, bool alwaysSetDetails, double timeDeviationFactor = 0.1, qint64 *differenceMs = nullptr);
 
             //! Get flag indicating this is an interim position update
             bool isInterim() const { return m_isInterim; }
diff --git a/src/blackmisc/aviation/aircraftsituationlist.cpp b/src/blackmisc/aviation/aircraftsituationlist.cpp
index 22242fd99..2714f93ff 100644
--- a/src/blackmisc/aviation/aircraftsituationlist.cpp
+++ b/src/blackmisc/aviation/aircraftsituationlist.cpp
@@ -48,6 +48,7 @@ namespace BlackMisc
             int c = 0;
             for (CAircraftSituation &situation : *this)
             {
+                situation.setOnGroundDetails(CAircraftSituation::InFromParts);
                 if (situation.adjustGroundFlag(parts, timeDeviationFactor)) { c++; };
             }
             return c;
@@ -92,5 +93,29 @@ namespace BlackMisc
             }
             return false;
         }
+
+        bool CAircraftSituationList::containsOnGroundDetails(CAircraftSituation::OnGroundDetails details) const
+        {
+            return this->contains(&CAircraftSituation::getOnGroundDetails, details);
+        }
+
+        bool CAircraftSituationList::areAllOnGroundDetailsSame(CAircraftSituation::OnGroundDetails details) const
+        {
+            for (const CAircraftSituation &situation : *this)
+            {
+                if (situation.getOnGroundDetails() != details) { return false; }
+            }
+            return true;
+        }
+
+        int CAircraftSituationList::setOnGroundDetails(CAircraftSituation::OnGroundDetails details)
+        {
+            int c = 0;
+            for (CAircraftSituation &situation : *this)
+            {
+                if (situation.setOnGroundDetails(details)) { c++; }
+            }
+            return c;
+        }
     } // namespace
 } // namespace
diff --git a/src/blackmisc/aviation/aircraftsituationlist.h b/src/blackmisc/aviation/aircraftsituationlist.h
index b77fbe18b..2b38c7786 100644
--- a/src/blackmisc/aviation/aircraftsituationlist.h
+++ b/src/blackmisc/aviation/aircraftsituationlist.h
@@ -68,6 +68,15 @@ namespace BlackMisc
 
             //! Any situation outside range
             bool hasGroundElevationOutsideRange(const PhysicalQuantities::CLength &range) const;
+
+            //! Contains on ground details
+            bool containsOnGroundDetails(CAircraftSituation::OnGroundDetails details) const;
+
+            //! Are all on ground details the same
+            bool areAllOnGroundDetailsSame(CAircraftSituation::OnGroundDetails details) const;
+
+            //! Set on ground details for all situations
+            int setOnGroundDetails(CAircraftSituation::OnGroundDetails details);
         };
     } // namespace
 } // namespace