ERA15LA087

The private pilot conducted a preflight inspection of the experimental amateur-built airplane, and before the engine run-up, he locked the canopy by pushing the two canopy latches forward against the latch bolts. The pilot also verified the locked position of the canopy again before departing for a local flight, during which he planned to perform several touch-and-go landings. He reported that there were no in-flight abnormalities, but on short final approach for landing, the canopy unexpectedly opened. The airplane pitched nose down, and the pilot attempted to correct the abrupt maneuver by applying engine power and pulling back on the control stick; however, the airplane continued to descend and impacted the ground in a nose-down attitude. Postaccident examination of the airplane revealed that the cockpit canopy's locking system had been modified from the design provided by the airframe kit manufacturer. Functional testing revealed that the canopy latching mechanism was difficult to operate and to close fully and lacked a positive indication for determining if it was securely closed and locked. It is likely that, during the accident flight, while on final approach to land, the inadequate modification to the canopy latching mechanism allowed the canopy to open in flight, which rendered the airplane uncontrollable.

On December 30, 2014, about 1320 eastern standard time, an experimental amateur-built Zenith Zodiac CH 650, N419PE, was substantially damaged when it impacted terrain while on approach to landing to St. Lucie County International Airport (FPR), Fort Pierce, Florida. The private pilot was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91 and originated at 1200. After conducting a preflight inspection the pilot stated that he closed the canopy and pushed both locking handles forward until they stopped. After conducting a runup check of the engine, he verified that both of the latches remained closed, then departed on the accident flight. On return to the departure airport he entered the traffic pattern with the intention of performing several touch-and-go landings. After setting the flaps to 10° and trimming the airplane, the pilot turned onto final approach to runway 28, at an airspeed of 75 knots. At a height of about 50 ft, the cockpit canopy opened, and the airplane suddenly pitched nose down. The pilot responded by "pulling on the stick" and increasing engine power, but found the elevator control to be ineffective. He also noted that the canopy had opened about 3 inches. The airplane subsequently impacted the ground in a nose down attitude. Federal Aviation Administration (FAA) inspectors examined the airplane following the accident and found that the forward portion of the fuselage had been substantially damaged during the impact. According to FAA records, the pilot held a private pilot certificate with ratings for airplane single-engine land. His most recent FAA third class medical certificate was issued on July 2, 2013. The pilot reported 767 total hours of flight experience, of which 2 hours were in the same make and model as the accident airplane. His most recent flight review was dated November 7, 2013. The single-engine, two-seat, kit-built, low-wing, airplane was issued a special airworthiness certificate on August 15, 2014. It was powered by a Lycoming YIO-233-B2A, 115-horsepower engine, equipped with a Sensenich 2 blade propeller assembly. The most recent condition inspection was completed on August 29, 2014. At the time of the accident, the airframe total time was 14 hours. Examination of plans and photographs of an exemplar airframe provided by the airframe kit manufacturer revealed that the airplane's canopy latch system (figure 1) consisted of a middle canopy lock tube located behind the two cockpit seats that extended to the fuselage on both sides. A locking handle (black lever located at shoulder level) extended between the seats, which would lock the canopy when rotated to the locked position. The middle canopy lock tube was attached by linkage to a canopy latch assembly located on the outboard aft cockpit where the canopy met the airframe near the back of the cockpit. Thelatch assembly would rotate forward over a bolt positioned on the canopy frame to lock it into place. The canopy could be latched and locked from the outside by means of a handle located on the left side of the fuselage just below and aft of the canopy. Postaccident examination of the accident airplane revealed that in addition to the above described mechanism, the latch assemblies on both the left and right side of the cockpit had been fitted with red handles (figure 1 inset). Examination of the kit manufacturer's plans revealed that this handle was not a part of the original latching mechanism design. Figure 1 – Exemplar canopy latch system (foreground, courtesy of airframe kit manufacturer) and one of two red handles fitted to accident airplane's canopy latches (top left inset).Postaccident functional testing of the accident airplane's canopy revealed that the when closing the canopy, the edge repeatedly caught on the frame of the cabin in several locations, preventing it from seating correctly in the closed position. To ensure the canopy was fully closed and not catching on the frame, it had to be pulled outward towards the wing and manipulated into the closed position. From inside the cockpit, it was difficult to close the canopy fully without assistance from the outside, since it would catch on the frame. The canopy could not be latched using the locking lever (black handle) from inside the cockpit. When operating the latch by the red handle, no audible or tactile feedback (e.g., a "click") was provided when the latch was engaged. When both latches were pushed to their respective forward-most positions, it appeared that their respective bolts had not fully seated into their recesses.