The Airbus Military A400M has completed a challenging series of tests to determine the lowest speed at which it can take-off – known as minimum unstick speed or Vmu. During the tests, performed at Istres in France, the aircraft’s nose was raised until a special ‘bumper’ fitted to the rear fuselage struck the ground at the maximum pitch-up angle of 13 degrees. In the close-up photo sparks can be seen flying from the bumper as it drags on the runway.