German investigators confirmed the June 4, 2026 Lufthansa Boeing 787-9 nose-gear collapse at Frankfurt Airport resulted from a missing downlock pin, which was located untouched in its storage box inside the forward hold with its red warning flag still attached. During a routine ground test to diagnose a gear door solenoid malfunction, two technicians in the cockpit cycled the landing gear lever to UP without installing the required safety pin, allowing the NLG to retract under full hydraulic force and slam the nose onto the tarmac. The landing gear system operated exactly as designed, ruling out mechanical failure and pinpointing a checklist discipline lapse. The incident injured 23 personnel, including two with serious trauma, and will keep aircraft D-ABPQ AOG for many months pending extensive fuselage and gear-bay structural repairs.