The pilot was also the owner/builder of the experimental airplane. He reported that the accident flight was the second flight since he completed assembly of the airplane. During takeoff, about 20 ft above ground level, the cockpit canopy “flew” forward to the full up position. The airplane immediately entered a nose-down attitude and touched back down on the runway with the propeller striking the runway. The airplane then bounced, touched down again, and skidded off the left side of the runway. The nose landing gear collapsed and the airplane came to rest upright in a grass area off the left side of the runway. The forward portion of the airplane’s fuselage was substantially damaged. The pilot further stated that the canopy latch for the airplane make and model was known to unlatch in flight, so he installed a secondary latch system when he assembled the airplane. The secondary latch system consisted of a latch and catch mechanism that could only be secured from inside the cockpit. He added that the latches had to align perfectly to work. The pilot further noted that the airframe kit manufacturer offered a modification to the canopy latching system, but the pilot had not installed it.