What happened
At approximately 12:05 EDT, a privately owned BD5-J aircraft, registration C-GBDV, departed Ottawa/Carp Airport in Ontario. The pilot was performing a practice routine for an upcoming air show, which involved low-speed fly-ast maneuvers at roughly 500 feet above the ground. The routine included several cycles of extending and retracting the landing gear.
During one of these cycles, while the landing gear was extended, the aircraft suddenly rolled sharply to the right. The nose of the aircraft dropped, leading to a rapid descent and impact with the ground. The aircraft sustained substantial damage, and the pilot sustained fatal injuries. Video footage of the event showed that the engine was producing power and the ailerons were being deflected to counter the roll, but the pilot was unable to regain control before the impact.
The investigation
The investigation examined the aircraft's construction and maintenance history. The aircraft was an amateur-built kit plane that the pilot had converted from a piston-engine model to a turbojet version. While the pilot had maintained the aircraft according to regulations and had completed recent inspections without noted defects, investigators focused on the wing assembly process.
Because the wings are designed for quick disassembly for transport, they are attached using a specific mechanism involving tubular spars and taper bolts. Investigators scrutinized the installation of these bolts and the flap mechanism. They also reviewed the manufacturer's warnings regarding the potential for incorrect flap installation during the wing assembly process, which could lead to aerodynamic asymmetry under flight loads.
Findings
- The right flap had been incorrectly installed during the wing assembly, meaning the torque tube pin was not properly seated in the flap arm bushing.
- This improper installation allowed the right flap to retract partially or fully under in-flight aerodynamic loads, creating a flap asymmetry.
- This asymmetry caused an uncommanded and uncontrollable right roll that the pilot could not counteract with aileron input.
- The aircraft's low altitude at the time of the roll left the pilot with insufficient time or altitude to retract the flaps and recover the flight path.
- The wing's right-side taper bolt was not properly secured, as it did not penetrate deep enough into the spars to engage the locking feature of the nut.
- The locking feature on the left-side taper bolt was also found to be unserviceable.