On April 4, 2014, about 1620 eastern daylight time, an experimental amateur-built Helpling Tango 2, N599WT, was destroyed during collision with terrain and a subsequent post-crash fire after takeoff from Ocala International Airport (OCF), Ocala, Florida. The private pilot/owner/builder was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Several witnesses provided statements to the police, and their statements were consistent throughout. Some said that their attention was drawn to the sound of the airplane's engine during its pre-takeoff run-up due to a "popping" sound; but reported that the engine sound was smooth and continuous at "full" power throughout the takeoff. After takeoff, the airplane climbed about 20 feet above the runway when the left canopy opened "suddenly" and began "flapping up and down." The airplane began "porpoising" before it entered a steep left bank and subsequently impacted the ground in a left-wing-low attitude and a postcrash fire ensued. The pilot's fiancé did not witness the accident, but responded immediately to the accident site where the pilot was found some distance from the airplane. He reported to both police and an NTSB investigator that the pilot stated the canopy opened unexpectedly. Approximately three weeks after the accident, and while still recovering from her injuries, the pilot prepared a statement with the assistance of a friend. She reported that the canopy "popped open" at low altitude and she responded by reducing engine power. The airplane then impacted the grass on the left side of the runway and caught fire. The pilot egressed the airplane, crawled some distance away, and awaited assistance. She reported there were no mechanical deficiencies with the airplane that would have precluded normal operation. Examination of photographs taken by the Ocala Police Department (OPD) revealed that the airplane came to rest upright. The engine compartment, instrument panel, cockpit, cabin area, and both wings were consumed by fire. The empennage appeared largely intact. The pilot held a private pilot certificate with ratings for airplane single engine land. Her most recent Federal Aviation Administration (FAA) third class medical certificate was issued on September 27, 2012. The pilot reported 675 total hours of flight experience, of which 22 hours were in the accident airplane make and model. According to FAA records, the airplane's airworthiness certificate was issued February 15, 2013. The airplane had accrued 12.5 total aircraft hours at the time of the accident. According to the chief test pilot for the airplane kit manufacturer, incidents of the left canopy opening in flight had been reported to the company on three occasions, and all were on takeoff. None of the three events resulted in an accident. On one occasion, the canopy completely separated from the airplane. The pilot continued the takeoff, completed a traffic pattern, and subsequently landed without incident. The airplane was described as "easily controllable throughout the flight and landing." In the other two events, the takeoffs were aborted. According to the reports, in two of the events, the canopy was left unlatched prior to takeoff, and on the other occasion, the canopy was latched "improperly." In a telephone interview, the manufacturer's vice president was asked if the company published a checklist for the Tango 2 airplane. He explained that the company offered a template, or outline checklist, but that it was impossible to produce a checklist appropriate to all individual airplanes, due to the variations in equipment selected by each owner/builder. FAA Advisory Circular 90-89A, Amateur-Built Aircraft and Ultralight Flight Testing Handbook, Section 9: Paperwork; stated, "Checklists: In addition to the assembly/airworthiness checklist previously discussed in section 7, the builder should prepare the following checklists: preflight; take-off/cruise; before starting; descent/before landing; starting the engine; after landing; before takeoff; securing the aircraft; and emergency procedures. A checklist to cover the above procedures may seem a tedious task, but it will only be the size of a 5x8 card -- similar to a checklist for a Cessna 150 or a Piper PA-28-140. NOTE: The amateur-builder should anticipate several revisions to the checklists." In a telephone interview, the pilot/owner/builder explained that she did develop a checklist for the airplane, had it with her, and consulted it prior to the accident flight. She stated that one item on the checklist was to ensure the security of the canopy, but stated she "could never know" if she had neglected to secure the canopy, or if the latch had somehow malfunctioned. During the accident the left canopy separated from the airplane and was found outside the fire area. The handle was found in the open position. The canopy frame and latch point in the fuselage were fire damaged.