What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During takeoff, the lower left main landing gear (lmlg) piston strut separated from the aircraft, along with the wheel and brake assembly. An investigation revealed a missing bolt in the lower torque link, which normally retains the lower strut portion. No other related damage to the torque links was observed. The missing bolt was the direct cause of the separation; however, the reason for the bolt's detachment could not be determined.
No technical factor was selected in block 21A, because the physical reason the bolt detached could not be determined (e.g., lack of torque, improper safety wire, cotter pin failure, or structural shear), selecting a technical failure code would be an inaccurate assumption.
As the FAA filed it
DURING TAKEOFF, THE LOWER LEFT MAIN LANDING GEAR (LMLG) PISTON STRUT SEPARATED FROM THE AIRCRAFT, ALONG WITH THE WHEEL AND BRAKE ASSEMBLY. AN INVESTIGATION REVEALED A MISSING BOLT IN THE LOWER TORQUE LINK, WHICH NORMALLY RETAINS THE LOWER STRUT PORTION. NO OTHER RELATED DAMAGE TO THE TORQUE LINKS WAS OBSERVED. THE MISSING BOLT WAS THE DIRECT CAUSE OF THE SEPARATION; HOWEVER, THE REASON FOR THE BOLT'S DETACHMENT COULD NOT BE DETERMINED.
NO TECHNICAL FACTOR WAS SELECTED IN BLOCK 21A, BECAUSE THE PHYSICAL REASON THE BOLT DETACHED COULD NOT BE DETERMINED (E.G., LACK OF TORQUE, IMPROPER SAFETY WIRE, COTTER PIN FAILURE, OR STRUCTURAL SHEAR), SELECTING A TECHNICAL FAILURE CODE WOULD BE AN INACCURATE ASSUMPTION.