diff --git a/src/AIModel/submodel.cxx b/src/AIModel/submodel.cxx
index 9d9c1e94c..2c3947c14 100644
--- a/src/AIModel/submodel.cxx
+++ b/src/AIModel/submodel.cxx
@@ -33,7 +33,6 @@ FGSubmodelMgr::FGSubmodelMgr()
     yaw_offset = 0.0;
 
     out[0] = out[1] = out[2] = 0;
-    in[3] = out[3] = 1;
     string contents_node;
     contrail_altitude = 30000;
     _count = 0;