diff --git a/conf/Makefile.nps b/conf/Makefile.nps
new file mode 100644
index 0000000000..179066f73e
--- /dev/null
+++ b/conf/Makefile.nps
@@ -0,0 +1,104 @@
+# Hey Emacs, this is a -*- makefile -*-
+#
+# Copyright (C) 2012 The Paparazzi Team
+#
+# This file is part of paparazzi.
+#
+# paparazzi is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2, or (at your option)
+# any later version.
+#
+# paparazzi is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with paparazzi; see the file COPYING.  If not, write to
+# the Free Software Foundation, 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+#
+
+#
+# This is the common Makefile for the nps target.
+#
+
+SRC_ARCH = arch/sim
+
+CC = g++
+
+SIMDIR = $(PAPARAZZI_SRC)/sw/simulator
+
+# Launch with "make Q=''" to get full command display
+Q=@
+
+CFLAGS  = -W -Wall
+CFLAGS += $(INCLUDES)
+CFLAGS += $($(TARGET).CFLAGS)
+CFLAGS += $(LOCAL_CFLAGS)
+CFLAGS += -O2
+CFLAGS += -g
+
+LDFLAGS	+= $($(TARGET).LDFLAGS)
+
+#
+# General rules
+#
+
+$(TARGET).srcsnd = $(notdir $($(TARGET).srcs))
+$(TARGET).objso	= $($(TARGET).srcs:%.c=$(OBJDIR)/%.o)
+$(TARGET).objs	= $($(TARGET).objso:%.S=$(OBJDIR)/%.o)
+
+all compile: check_jsbsim $(OBJDIR)/simsitl
+
+
+check_jsbsim:
+	@echo Paparazzi jsbsim package found: $(JSBSIM_PKG)
+
+
+$(OBJDIR)/simsitl : $($(TARGET).objs)
+	@echo LD $@
+	$(Q)$(CC) $(CFLAGS) -o $@ $($(TARGET).objs) $(LDFLAGS)
+
+
+%.s: %.c
+	$(CC) $(CFLAGS) -S -o $@ $<
+
+%.s: %.cpp
+	$(CC) $(CFLAGS) -S -o $@ $<
+
+$(OBJDIR)/%.s: %.c
+	@echo CC $@
+	$(Q)test -d $(dir $@) || mkdir -p $(dir $@)
+	$(CC) $(CFLAGS) -S -o $@ $<
+
+$(OBJDIR)/%.s: %.cpp
+	@echo CC $@
+	$(Q)test -d $(dir $@) || mkdir -p $(dir $@)
+	$(CC) $(CFLAGS) -S -o $@ $<
+
+$(OBJDIR)/%.o: %.c $(OBJDIR)/../Makefile.ac
+	@echo CC $@
+	$(Q)test -d $(dir $@) || mkdir -p $(dir $@)
+	$(Q)$(CC) $(CFLAGS) -c -o $@ $<
+
+$(OBJDIR)/%.o: %.cpp $(OBJDIR)/../Makefile.ac
+	@echo CC $@
+	$(Q)test -d $(dir $@) || mkdir -p $(dir $@)
+	$(Q)$(CC) $(CFLAGS) -c -o $@ $<
+
+
+#
+# Dependencies
+#
+$(OBJDIR)/.depend:
+	@test -d $(OBJDIR) || mkdir -p $(OBJDIR)
+	@echo DEPEND $@
+	$(Q)$(CC) -MM -MG $(CFLAGS) $($(TARGET).srcs) | sed 's|\([^\.]*\.o\)|$(OBJDIR)/\1|' > $@
+
+ifneq ($(MAKECMDGOALS),clean)
+ifneq ($(MAKECMDGOALS),erase)
+-include $(OBJDIR)/.depend
+endif
+endif
diff --git a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
index cf819b2853..e935ddeec0 100644
--- a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
@@ -4,8 +4,6 @@
 # SITL Simulator
 #
 
-SIM_TYPE = JSBSIM
-
 JSBSIM_ROOT = /opt/jsbsim
 JSBSIM_INC = $(JSBSIM_ROOT)/include/JSBSim
 JSBSIM_LIB = $(JSBSIM_ROOT)/lib
@@ -19,6 +17,9 @@ NPSDIR = $(SIMDIR)/nps
 
 nps.ARCHDIR = sim
 
+# include Makefile.nps instead of Makefile.sim
+nps.MAKEFILE = nps
+
 nps.CFLAGS  += -DSITL -DUSE_NPS
 nps.CFLAGS  += `pkg-config glib-2.0 --cflags`
 nps.LDFLAGS += `pkg-config glib-2.0 --libs` -lm -lglibivy -lgsl -lgslcblas
diff --git a/sw/airborne/Makefile b/sw/airborne/Makefile
index 128493f2f8..6103d785be 100644
--- a/sw/airborne/Makefile
+++ b/sw/airborne/Makefile
@@ -38,7 +38,11 @@ ifneq ($(MAKECMDGOALS),clean)
   ifeq ($($(TARGET).ARCHDIR), )
     $(error Architecture not set, maybe you forgot to add the target? e.g. <target name="tunnel" board="twog_1.0"/>)
   else
-    include ../../conf/Makefile.$($(TARGET).ARCHDIR)
+    ifdef $(TARGET).MAKEFILE
+      include ../../conf/Makefile.$($(TARGET).MAKEFILE)
+    else
+      include ../../conf/Makefile.$($(TARGET).ARCHDIR)
+    endif
   endif
 endif