diff --git a/aman/config/AirportSequencing.py b/aman/config/AirportSequencing.py
index ff905dd..3443c19 100644
--- a/aman/config/AirportSequencing.py
+++ b/aman/config/AirportSequencing.py
@@ -7,6 +7,7 @@ class AirportSequencing:
         self.Airport = icao
         self.ActiveArrivalRunways = []
         self.RunwayDependencies = []
+        self.UseMustShallMay = True
 
     def clearData(self):
         self.ActiveArrivalRunways.clear()