diff --git a/src/blackmisc/aviation/aircrafticaocode.cpp b/src/blackmisc/aviation/aircrafticaocode.cpp
index 66e992a69..1bcba68a7 100644
--- a/src/blackmisc/aviation/aircrafticaocode.cpp
+++ b/src/blackmisc/aviation/aircrafticaocode.cpp
@@ -777,16 +777,6 @@ namespace BlackMisc::Aviation
         return true;
     }
 
-    bool CAircraftIcaoCode::isValidWtc(const QString &candidate)
-    {
-        if (candidate.isEmpty()) { return true; } // we accept unspecified
-        if (candidate.length() == 1)
-        {
-            return candidate == "L" || candidate == "M" || candidate == "H" || candidate == "J";
-        }
-        return false;
-    }
-
     const QString &CAircraftIcaoCode::getUnassignedDesignator()
     {
         static const QString z("ZZZZ");
diff --git a/src/blackmisc/aviation/aircrafticaocode.h b/src/blackmisc/aviation/aircrafticaocode.h
index 6cab8abae..75abc27f4 100644
--- a/src/blackmisc/aviation/aircrafticaocode.h
+++ b/src/blackmisc/aviation/aircrafticaocode.h
@@ -327,9 +327,6 @@ namespace BlackMisc::Aviation
         //! Valid combined type
         static bool isValidCombinedType(const QString &combinedType);
 
-        //! Valid WTC code?
-        static bool isValidWtc(const QString &candidate);
-
         //! The unassigned designator ("ZZZZ")
         static const QString &getUnassignedDesignator();