diff --git a/sw/simulator/flightModel.ml b/sw/simulator/flightModel.ml
index 50f5264a12..14a326b028 100644
--- a/sw/simulator/flightModel.ml
+++ b/sw/simulator/flightModel.ml
@@ -156,8 +156,10 @@ module Make(A:Data.MISSION) = struct
    http://controls.ae.gatech.edu/papers/johnson_dasc_01.pdf
    http://controls.ae.gatech.edu/papers/johnson_mst_01.pdf
  *)
-  let state_update = fun state (wx, wy) dt ->
+  let state_update = fun state nominal_airspeed (wx, wy) dt ->
     let now = state.t +. dt in
+    if state.air_speed = 0. && state.thrust > 0. then
+      state.nominal_air_speed <- nominal_airspeed;
     state.air_speed <- state.nominal_air_speed*.(1.-.sin state.theta);
     if state.air_speed > 0. then begin
       let phi_dot_dot = roll_response_factor *. state.delta_a -. state.phi_dot in
diff --git a/sw/simulator/flightModel.mli b/sw/simulator/flightModel.mli
index 3da310ac5e..aee0a751e2 100644
--- a/sw/simulator/flightModel.mli
+++ b/sw/simulator/flightModel.mli
@@ -45,7 +45,7 @@ module Make :
       val nominal_airspeed : float (* m/s *)
       val roll_neutral_default : float (* rad *)
       val pitch_neutral_default : float (* rad *)
-      val state_update : state -> float * float -> float -> unit
-      (** [state_update state (wind_x, wind_y) dt] With m/s for wind and s for
+      val state_update : state -> float -> float * float -> float -> unit
+      (** [state_update nom_airspeed state (wind_x, wind_y) dt] With m/s for wind and s for
 	 dt *)
     end
diff --git a/sw/simulator/sim.ml b/sw/simulator/sim.ml
index db38e85ad9..c7aaa0bee0 100644
--- a/sw/simulator/sim.ml
+++ b/sw/simulator/sim.ml
@@ -154,7 +154,7 @@ module Make(AircraftItl : AIRCRAFT_ITL) = struct
 
     let fm_task = fun () ->
       FM.do_commands !state commands;
-      FM.state_update !state (!wind_x, !wind_y) fm_period
+      FM.state_update !state FM.nominal_airspeed (!wind_x, !wind_y) fm_period
        
     and ir_task = fun () ->
       let phi, theta, _ = FlightModel.get_attitude !state in