A321
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
At cruise; I adjusted my lap belt and the left hand portion of the belt came loose from the seat pan. I was able to locate the nut and washer that had completely detached from the bolt; and I reattached the belt assembly by hand. I entered this discrepancy in the aircraft logbook; advising that the assembly was only hand tightened.  I felt this was a safety issue; as I could have been injured if we had performed a rejected takeoff; or if we had encountered severe turbulence. FAA regulations state I need to wear my lap belt at all times while in my seat. I reattached the lap belt by hand so that I would have some degree of safety and protection. I don't know how this nut backed off the bolt holding my lap belt to the seat. Other A321 aircraft in our fleet should probably be inspected. Other A321 aircraft in our fleet should be inspected for lap belt security. It looked like a lock nut type fastener that obviously failed during service. I will be giving my lap belts a firm pull to check security from now on.
Pilot reported that the seat lap belt attaching hardware came off during flight.