According the mentioned article, the minimum unstick speed test, or VMU (velocity of minimum unstick) is planned for mid-month. This highly intense maneuver is used to determine what the lowest speed is at which the aircraft can still take off.
The tail skid is already installed under the structurally reinforced & prepared rear fuselage S.19. This specific tail bumper is added to protect the tail from any damage during the VMU test.
Perfect weather conditions are needed, with no turbulence and wind less than 5 kts, to insure the precision of the measurements.
Based on the article “Testing Times” published in Aviation Week.