diff --git a/dcs/task.py b/dcs/task.py
index 8ba14a8e..6d79b9a3 100644
--- a/dcs/task.py
+++ b/dcs/task.py
@@ -1209,7 +1209,7 @@ def __init__(self, channel=10, modechannel="X", callsign="TKR", bearing=True, un
                     "unitId": unit_id,
                     "modeChannel": modechannel,
                     "bearing": bearing,
-                    "system": 4 if aa else 3,
+                    "system": 5 if modechannel == "Y" else 4 if aa else 3,
                 }
             }
         }