Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 107.25; Flight Crew Total 2508.17; Flight Crew Type 1110.47
Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew Overcame Equipment Problem
Procedure; Human Factors
After takeoff we received a message from Dispatch to return to gate so the ramp could secure dangerous goods/Hazmat that was loaded . We advised that we were already airborne and discussed with dispatch a plan. The Dispatcher at the time did some research and advised that the ramp personnel that loaded the aircraft advised that the Hazmat/dangerous goods that was loaded correctly and secured. The DG sheet we received on preflight showed to misc Hazmat may with a weight of 257 LBS. Load planning and dispatch advised after we departed that the weight was actually 500 LBS; 250 LBS over what our initial sheet showed. The load planning and final weights seems to be correct; but the DG sheet we received from ACARS did not match that number. We continued the flight normally.
A320 Captain reported receiving Dispatch message stating Hazmat cargo weight was erroneously under reported by 250 lbs.