def METHOD_NAME(self):
    root = self.get_aircraft_xml_tree('f16_test').getroot()
    ixz_element = root.find('mass_balance/ixz')
    fdm = self.create_fdm()
    self.load_script('f16_test')
    fdm.run_ic()
    # Check that Jinv is indeed the inverse of J.
    mass_balance = fdm.get_mass_balance()
    J = mass_balance.get_J()
    Jinv = mass_balance.get_Jinv()
    identity = J*Jinv
    self.assertAlmostEqual(identity[0,0], 1.0)
    self.assertAlmostEqual(identity[0,1], 0.0)
    self.assertAlmostEqual(identity[0,2], 0.0)
    self.assertAlmostEqual(identity[1,0], 0.0)
    self.assertAlmostEqual(identity[1,1], 1.0)
    self.assertAlmostEqual(identity[1,2], 0.0)
    self.assertAlmostEqual(identity[2,0], 0.0)
    self.assertAlmostEqual(identity[2,1], 0.0)
    self.assertAlmostEqual(identity[2,2], 1.0)
    fdm['inertia/pointmass-weight-lbs'] = 0.0
    fdm['propulsion/tank[0]/contents-lbs'] = 0.0
    fdm['propulsion/tank[1]/contents-lbs'] = 0.0
    fdm.run()
    self.assertAlmostEqual(fdm['inertia/weight-lbs'],
                           fdm['inertia/empty-weight-lbs'])
    self.assertAlmostEqual(fdm['inertia/ixz-slugs_ft2'],
                           float(ixz_element.text))