My most memorable day with helicopters was October 6th 1983. At that time I was a flight test engineer and that day I flew for the first time on a brand new prototype. The total time accumulated by the helicopter in the previous 3 flights was 1hr and 20 min. The flight with me on board was the 4th. It last 30 min and was mainly dedicated to track the MR (with the strobo light and the Chadwick vibrometer) and to expand the flight envelope up to 120 kts. All the minutes of that flight are stamped in my mind for ever.