avoid crashes due to invalid WTC entries

aman/sys/aco/RunwayManager.py

@@ -29,7 +29,12 @@ class RunwayManager:
             if None == self.RunwayInbounds[runway].Inbound.WTC or None == node.Inbound.WTC:
                 spacingWTC = 3
             else:
-                spacingWTC = self.Spacings[self.RunwayInbounds[runway].Inbound.WTC][node.Inbound.WTC]
+                if self.RunwayInbounds[runway].Inbound.WTC not in self.Spacings.WtcSpacing:
+                    spacingWTC = 3
+                elif node.Inbound.WTC not in self.Spacings.WtcSpacing[self.RunwayInbounds[runway].Inbound.WTC]:
+                    spacingWTC = self.Spacings.WtcSpacing[self.RunwayInbounds[runway].Inbound.WTC]['L']
+                else:
+                    spacingWTC = self.Spacings.WtcSpacing[self.RunwayInbounds[runway].Inbound.WTC][node.Inbound.WTC]
 
             # get the runway time spacing
             spacingRunway = self.Configuration.RunwayConstraints.findRunway(runway).Spacing