On August 18, 2016, about 1530 central daylight time, an experimental amateur-built Collins RV6A airplane, N576RV, impacted terrain during takeoff from runway 27 at the Pekin Municipal Airport (C15), near Pekin, Illinois. The private pilot sustained serious injuries. The airplane was substantially damaged during the impact. The airplane was registered to and operated by the pilot as a 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions prevailed in the area about the time of the accident, and the flight was not operated on a flight plan. The flight was originating from C15 at the time of the accident and was destined for the Whiteside County Airport-Jos H Bittorf Field, near Sterling/Rockfalls, Illinois.According to an initial first-responder, the pilot indicated that he had forgotten to latch the canopy. The canopy opened during the takeoff and the airplane subsequently impacted terrain. After the accident, the pilot made an emergency radio call over C15's common traffic advisory frequency, which went unanswered. The pilot made a cell phone call and was able to reach a representative from the fixed base operator (FBO) who subsequently went to the accident site and notified emergency responders. The pilot was taken to a hospital for the serious injuries he sustained. The pilot indicated in his accident report that a jet delayed his takeoff. He reported the outside air temperature was over 90 degrees and he unlatched the canopy to get air into the cockpit. The jet departed after 10 minutes. The pilot subsequently departed and about 30 feet above ground he noticed the canopy was unlatched. He attempted to close the latch, got distracted, and did not maintain airplane control. At 1454, the recorded weather at the General Downing - Peoria International Airport, near Peoria, Illinois, was: Wind 210 degrees at 12 knots; visibility 10 statute miles; sky condition clear; temperature 31 degrees C; dew point 22 degrees C; altimeter 30.01 inches of mercury. The FBO employee indicated that a crucial thing to be taken away from this accident is that the local radio frequency at small town airports should be able to be heard in every room of the FBO or airport office.