Index: src/aircraft_cmd.cpp
===================================================================
--- src/aircraft_cmd.cpp	(revision 27325)
+++ src/aircraft_cmd.cpp	(working copy)
@@ -809,7 +809,7 @@
 		/* We are northwest or southeast of the airport */
 		dir = delta_y < 0 ? DIAGDIR_NW : DIAGDIR_SE;
 	}
-	dir = ChangeDiagDir(dir, (DiagDirDiff)ReverseDiagDir(DirToDiagDir(rotation)));
+	dir = ChangeDiagDir(dir, DiagDirDifference(DIAGDIR_NE, DirToDiagDir(rotation)));
 	return apc->entry_points[dir];
 }