B737-800
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 110; Flight Crew Type 3000
Confusion; Troubleshooting
Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew Overcame Equipment Problem
Aircraft; Human Factors; Procedure
During deplaning; after arrival; I became aware of a height difference between the aircraft and jetway floors of almost a foot drop off. At first thinking it was a jetway issue; we alerted the Ops Agent. As we were standing near the aircraft door the aircraft kept rising; and I realized the nose gear was extending due to load shift. I ran down to the ramp and advised the Ramp Agents to stop unloading the forward cargo bin. At that point; perhaps half the passengers had deplaned; leaving the forward half of the aircraft empty. The nose gear strut was extended well past normal; but the tires did not leave the ground. While off-loading of the aft cargo bin continued; the APU was restarted; ground power disconnected to allow the interlocked jetway to be repositioned; and deplaning was resumed.
B737-800 Captain reported the aircraft nose strut extended during deplaning as the load was moved out of the forward cargo area.