diff --git a/sw/simulator/Makefile b/sw/simulator/Makefile
index 774f2b0710..f023b22962 100644
--- a/sw/simulator/Makefile
+++ b/sw/simulator/Makefile
@@ -82,6 +82,14 @@ diffusion : stdlib.cmo diffusion.cmo
 clean :
 	rm -f *.cm* *~ *.out .depend *.o *.a *.so gaia simhitl booz_sim
 
+
+#
+#  NPS
+#
+JSBSIM_SRC = /home/gustavo...
+
+
+
 #
 # Dependencies
 #
diff --git a/sw/simulator/booz_flight_model.h b/sw/simulator/booz_flight_model.h
index 41935faefa..6fdbc3cd67 100644
--- a/sw/simulator/booz_flight_model.h
+++ b/sw/simulator/booz_flight_model.h
@@ -20,6 +20,7 @@ struct BoozFlightModel {
   VEC* state;
 
   /* user products */
+  VEC* pos_ecef;
   VEC* pos_ltp;
   VEC* speed_ltp;
   VEC* accel_ltp;
diff --git a/sw/simulator/nps_fdm.h b/sw/simulator/nps_fdm.h
new file mode 100644
index 0000000000..506643e1bf
--- /dev/null
+++ b/sw/simulator/nps_fdm.h
@@ -0,0 +1,80 @@
+#ifndef NPS_FDM
+#define NPS_FDM
+
+#include "std.h"
+#include <matrix.h>
+
+
+
+
+struct NpsFdmState {
+  
+  // generic vehicle state
+  bool_t on_ground;
+  
+  VEC* ecef_pos;
+  VEC* ecef_speed;
+  VEC* ecef_accel;
+
+  VEC* ltp_to_body_quat;
+  VEC* ltp_body_rate;
+  VEC* ltp_body_accel;
+
+  VEC* ecef_to_ltp_quat;
+  
+  // vehicle specific
+  union {
+    struct NpsDummy dummy;
+    struct NpsQuad  quad;
+    struct NpsSFW   fw;
+  };
+
+};
+
+
+
+struct NpsDummy {
+  /* force applied to the ball in Newton */
+  double f_input;
+};
+
+
+#define NPS_QUAD_MOTOR_FRONT 0
+#define NPS_QUAD_MOTOR_BACK  1
+#define NPS_QUAD_MOTOR_RIGHT 2
+#define NPS_QUAD_MOTOR_LEFT  3
+#define NPS_QUAD_MOTOR_NB    4
+
+struct NpsQuad {
+  /* battery voltage in V */
+  double battery;
+  /* motor commands [0:1]
+  VEC* motor_commands;
+  /* propeller rotation speed in rad/s */
+  VEC* prop_omega;
+};
+
+
+
+#define NPS_SFW_ACTUATOR_THROTTLE   0
+#define NPS_SFW_ACTUATOR_AILERON_R  1
+#define NPS_SFW_ACTUATOR_AILERON_L  2
+#define NPS_SFW_ACTUATOR_NB         3
+
+struct NpsSFW {
+
+  double prop_omega;
+  /*
+    deflection of control surfaces in radian
+    normalized throttle [0:1]
+  */
+  VEC* actuators;
+}
+
+
+
+
+
+
+
+#endif /* NPS_FDM */
diff --git a/sw/simulator/nps_test1.c b/sw/simulator/nps_test1.c
new file mode 100644
index 0000000000..ddcb266573
--- /dev/null
+++ b/sw/simulator/nps_test1.c
@@ -0,0 +1,41 @@
+#include "nps_fdm.h"
+
+
+static struct NpsFdmState fdm_state;
+
+
+
+static void feed_inputs(JSBSim::FGFDMExec* fdmex) {
+
+  double hover_force = 0.;
+
+  fdmex->SetPropertyValue("/fdm/jsbsim/fcs/force_front", fdm_state.dummy.f_input);
+  
+
+}
+
+static void fetch_state(JSBSim::FGFDMExec* fdmex) {
+
+  //  double foo = fdmex->GetPropagate()->GetInertialVelocityMagnitude();
+  //  double foo = fdmex->GetPropagate()->GetGeodLatitudeRad();
+  // cerr << "lat " << foo << endl ;
+  const JSBSim::FGColumnVector3 vel = fdmex->GetPropagate()->GetVel();
+  cerr << "vel " << vel << endl ;
+
+  //  eulers->ve[EULER_PHI] = vel
+
+  
+  //  fdm_state.ecef_pos = 
+
+}
+
+
+
+
+int main(int argc, char** argv) {
+
+  
+
+
+}
+