Index: ps/trunk/binaries/data/mods/public/maps/random/danubius_triggers.js
===================================================================
--- ps/trunk/binaries/data/mods/public/maps/random/danubius_triggers.js
+++ ps/trunk/binaries/data/mods/public/maps/random/danubius_triggers.js
@@ -500,7 +500,7 @@
 	let ungarrisonLeft = false;
 	let ungarrisonRight = false;
 
-	let mapSize = Engine.QueryInterface(SYSTEM_ENTITY, IID_Terrain).GetTilesPerSide() * 4;
+	let mapSize = Engine.QueryInterface(SYSTEM_ENTITY, IID_Terrain).GetMapSize();
 
 	for (let ent of Engine.QueryInterface(SYSTEM_ENTITY, IID_RangeManager).GetNonGaiaEntities())
 	{
Index: ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/GuiInterface.js
@@ -135,7 +135,7 @@
 
 	let cmpTerrain = Engine.QueryInterface(SYSTEM_ENTITY, IID_Terrain);
 	if (cmpTerrain)
-		ret.mapSize = 4 * cmpTerrain.GetTilesPerSide();
+		ret.mapSize = cmpTerrain.GetMapSize();
 
 	// Add timeElapsed
 	let cmpTimer = Engine.QueryInterface(SYSTEM_ENTITY, IID_Timer);
Index: ps/trunk/binaries/data/mods/public/simulation/components/UnitMotionFlying.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/UnitMotionFlying.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/UnitMotionFlying.js
@@ -106,7 +106,7 @@
 				this.hasTarget = false;
 				this.landing = false;
 				// summon planes back from the edge of the map
-				var terrainSize = cmpTerrain.GetTilesPerSide() * 4;
+				var terrainSize = cmpTerrain.GetMapSize();
 				var cmpRangeManager = Engine.QueryInterface(SYSTEM_ENTITY, IID_RangeManager);
 				if (cmpRangeManager.GetLosCircular())
 				{
Index: ps/trunk/binaries/data/mods/public/simulation/components/tests/test_UnitMotionFlying.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/components/tests/test_UnitMotionFlying.js
+++ ps/trunk/binaries/data/mods/public/simulation/components/tests/test_UnitMotionFlying.js
@@ -71,7 +71,7 @@
 
 AddMock(entity, IID_Terrain, {
 	"GetGroundLevel": () => 4,
-	"GetTilesPerSide": () => 5
+	"GetMapSize": () => 20
 });
 
 AddMock(entity, IID_WaterManager, {
Index: ps/trunk/source/simulation2/components/CCmpTerrain.cpp
===================================================================
--- ps/trunk/source/simulation2/components/CCmpTerrain.cpp
+++ ps/trunk/source/simulation2/components/CCmpTerrain.cpp
@@ -102,6 +102,11 @@
 		return (u16)tiles;
 	}
 
+	virtual u32 GetMapSize() const
+	{
+		return GetTilesPerSide() * TERRAIN_TILE_SIZE;
+	}
+
 	virtual u16 GetVerticesPerSide() const
 	{
 		ssize_t vertices = m_Terrain->GetVerticesPerSide();
Index: ps/trunk/source/simulation2/components/ICmpTerrain.h
===================================================================
--- ps/trunk/source/simulation2/components/ICmpTerrain.h
+++ ps/trunk/source/simulation2/components/ICmpTerrain.h
@@ -52,6 +52,11 @@
 	 */
 	virtual u16 GetVerticesPerSide() const = 0;
 
+	/**
+	 * Returns the map size in metres (world space units).
+	 */
+	virtual u32 GetMapSize() const = 0;
+
 	virtual CTerrain* GetCTerrain() = 0;
 
 	/**
Index: ps/trunk/source/simulation2/components/ICmpTerrain.cpp
===================================================================
--- ps/trunk/source/simulation2/components/ICmpTerrain.cpp
+++ ps/trunk/source/simulation2/components/ICmpTerrain.cpp
@@ -25,4 +25,5 @@
 DEFINE_INTERFACE_METHOD_CONST_2("GetGroundLevel", entity_pos_t, ICmpTerrain, GetGroundLevel, entity_pos_t, entity_pos_t)
 DEFINE_INTERFACE_METHOD_CONST_2("CalcNormal", CFixedVector3D, ICmpTerrain, CalcNormal, entity_pos_t, entity_pos_t)
 DEFINE_INTERFACE_METHOD_CONST_0("GetTilesPerSide", u16, ICmpTerrain, GetTilesPerSide)
+DEFINE_INTERFACE_METHOD_CONST_0("GetMapSize", u32, ICmpTerrain, GetMapSize)
 END_INTERFACE_WRAPPER(Terrain)
Index: ps/trunk/source/simulation2/system/ComponentTest.h
===================================================================
--- ps/trunk/source/simulation2/system/ComponentTest.h
+++ ps/trunk/source/simulation2/system/ComponentTest.h
@@ -212,6 +212,11 @@
 		return 16;
 	}
 
+	virtual u32 GetMapSize() const
+	{
+		return GetTilesPerSide() * TERRAIN_TILE_SIZE;
+	}
+
 	virtual u16 GetVerticesPerSide() const
 	{
 		return 17;