ERA19FA265

The pilot's loss of pitch control due to the in-flight opening of the canopy for reasons that could not be determined.

The pilot departed with the intent of remaining in the airport traffic pattern. Automatic Dependent Surveillance-Broadcast (ADS-B) data indicated that the airplane departed and climbed to an altitude of about 1,000 ft above ground level. Near the end of the downwind leg, the airplane entered a brief 50-ft climb, followed by a rapid descent to impact with the ground. Examination of the engine and airframe revealed no evidence of any preimpact mechanical malfunctions that would have precluded normal operation. Examination of the canopy roll bar and the tip-up canopy bow, which are connected in flight when the canopy is latched, indicated that they deformed in a dissimilar manner at impact. The roll bar and canopy bow were located about 12 ft apart at the accident site, and there was little damage to the handle and latch block, indicating that the canopy was likely not latched at the time of impact. Examination of the canopy and latch handle revealed that the handle and washers did not match any of the manufacturer’s drawings. The kit manufacturer issued a service letter about 3 years before the accident advising that, in the event of an inflight opening of a forward opening, tip-up canopy, the airplane would “most likely pitch down abruptly.” The pilot had recently modified the latch on the airplane’s tip-up canopy. The pilot had purchased a latch replacement kit from the airplane manufacturer; however, only the handle from the new latch kit was installed at the time of the accident, and additional washers that were not part of the kit had been added, likely to compensate for the longer dimensions of the new handle assembly. Whether full engagement of the latching mechanism could be achieved in this configuration could not be determined. Additionally, it could not be determined whether the pilot departed with the canopy unlatched or it became unlatched in flight, but it is likely that when the pilot reduced engine power to begin a descent for landing, the canopy opened enough to affect the airplane’s pitch control, resulting in a subsequent abrupt descent and impact with terrain.

The pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land and instrument airplane. The pilot was operating under the provisions of BasicMed and his most recent physical examination was completed on June 1, 2017. On a 2018 aviation insurance application, the pilot reported 10,075 total hours of flight experience, with 90 hours in the accident airplane make and model. Review of his logbook revealed that he had accrued 12.2 hours in the accident airplane since his most recent flight review on November 8, 2017. The airplane was built from a kit manufactured by Van's Aircraft Inc. and was issued an experimental light sport airworthiness certificate on August 10, 2010. FAA records indicated that the pilot purchased the airplane in 2013. The most recent condition inspection was completed on July 1, 2019, at which time the airplane had accrued 123.8 total hours. The airplane was equipped with a forward-hinged, tip-up canopy with a locking mechanism. The mechanism was a handle attached near the center and at the rear of the canopy frame. Once closed, the handle was turned 90° so that a tang on the end of the handle extended under the adjacent fuselage roll bar frame, where the tang was retained under a latch block. This mechanism was the original latch design. When the canopy was opened, it moved up and forward (toward the front of the airplane) about 90° vertical. Witnesses stated that the canopy handle latch had become bent, and the pilot had recently purchased and installed a new latch. Van's Aircraft records show that the pilot purchased the new latch on August 1, 2019. The kit manufacturer supplied an excerpt from the Pilot’s Operating Handbook from the closest available revision to the one sent with the kit to the builder. The handbook's before takeoff checklist, in part, stated, "Canopy – CHECK Latched." A canopy-open warning system was developed by the kit manufacturer; however, the warning system was not compatible with the electronic flight instrument system in the accident airplane and was not installed on the accident airplane. The airplane impacted a grass field in a near-vertical, nose down attitude about 1.8 nautical miles and 134° from the departure end of runway 27. All major components of the airplane were present at the accident site. The airplane was significantly fragmented and partially consumed by a postcrash fire. Two linear ground scars, consistent with the length of each wing, radiated from the center of the wreckage. The debris field extended about 120 ft from the main wreckage on a heading of about 80° and was surrounded by an area of burned grass about 200 ft long by 150 ft wide. The engine and cockpit area were found in an impact crater about 2 ft deep. Both wings were crushed aft from the leading edge against the main spar, and from the trailing edge forward to the main spar. The right flaperon was impact and fire damaged, and the inboard half was separated from the wing. The left flaperon was impact and fire damaged and completely separated from the wing. The fuselage forward of the stabilator was severely fragmented and partially fire damaged. The stabilator, vertical stabilizer, and rudder were separated from the aft fuselage. The stabilator was largely intact, with most of the fire and impact damage near its center. The stabilator spar was fractured at midspan. The pitch trim tab remained attached to the stabilator; however, the input control rod and attachment bracket were fractured and separated from the trim tab. The rudder remained attached to the vertical stabilizer; it was damaged and the lower 4 inches of the trailing edge was bent toward the right. Flight control continuity was established from the stabilator and the rudder from the control surface to the cockpit controls. Flaperon control continuity could not be established due to impact and fire damage. Control push-pull rod ends remained attached at the main cockpit control tube, and on the flaperon input control tubes. The fuel selector valve was not located. The electric fuel boost pump was sooted and thermally damaged. The nose landing gear was separated from the airplane and found near the wing ground scars. The roll bar and canopy bow were located about 12 ft apart. The propeller hub separated from the engine, and both blades separated from the hub. The engine would not rotate by hand. A borescope inspection of all four cylinders revealed normal coloration and condition of the piston tops, cylinder walls, and valves. All rocker arms and valve spring assemblies remained intact and were undamaged. The gascolator was breached, empty of fuel, and contained a small amount of debris in the filter screen. The inside of the gascolator bowl was sooted. Both carburetors were thermally damaged and separated from the engine and found hanging by their control cables. Each throttle control cable remained attached to its respective control arm on the carburetor. Both carburetor bowls were thermally destroyed, and the floats were not present. Both slides remained in place but were unable to move. The sparkplug electrodes and insulators appeared normal and were clean, except for the No. 2 top spark plug, which had white deposits on the bottom of the electrode. The Nos. 1 and 3 bottom sparkplugs were slightly wet with oil. None of the intake or exhaust manifold tubing remained attached to the intake and exhaust ports of the engine. The muffler remained partially attached and the springs were in place, with the case, inlet and exit tubes partially damaged. The engine driven fuel pump remained attached to the engine case; however, the fittings were separated, and the ports were partially fractured. The pump was removed and could be rotated by hand with some binding. A small amount of debris was found inside the pump, primarily on the side exposed by the fractured fitting port. Examination of the elevator trim actuator control assembly at the NTSB Materials Laboratory, Washington, D.C., revealed that fracture surfaces on the control rod were on slant angles consistent with ductile overstress fracture, and the rod was deformed adjacent to the fracture consistent with bending deformation. The bending deformation at the fracture and the mid-point were in opposite directions, consistent with a buckling failure under compression loading. Follow-up examination of the metal canopy roll bar frames and latching mechanism revealed that the fixed portion of the canopy bow was separated at the midspan attachment point. The left side of the roll bar was impact twisted 180° while the right side of the roll bar displayed little deformation in shape. The latch block remained affixed to the left side of the roll bar. The canopy bow that connected to the fixed portion of the canopy at the latching mechanism was fractured at the handle but displayed no twisting. The latch handle was intact and slightly bent in the portion of the handle opposite where it latched over the latch block. Examination of the canopy and latch handle revealed that, although the pilot had purchased the latch replacement kit, only the handle from the new latch kit was installed, and additional washers were added that were not a part of the replacement kit. On the new latch, the tube that protruded through the canopy was ¼ inch longer than the original handle tube. (see Figure 1.) The pre-impact functionality of the modified latching mechanism could not be established. Figure 1. Original Latch Handle Design On September 6, 2019, at 1312 eastern daylight time, a Vans Aircraft Inc. RV-12 airplane, N767FS, was destroyed when it impacted terrain in Lady Lake, Florida. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to two pilots and one pilot/mechanic who were scheduled to practice a formation flight with the accident pilot, the accident pilot stated