B737-900
Flight Crew Air Transport Pilot (ATP)
Distraction; Situational Awareness
Aircraft Equipment Problem Less Severe
General Maintenance Action
Equipment / Tooling; Human Factors
While removing my flight bag from the flight deck; it is likely that I hit a circuit breaker; breaking off the cap. After removing my flight bag; I turned to pick up my hat; which fell off while removing the bag; and I noticed the white barrel of the circuit breaker; with no cap. Further investigation found the cap in the cup holder below the broken circuit breaker. The exposed white barrel of the circuit breaker had the appearance that it was popped or open. But when the cap was slipped over the circuit breaker; it had the appearance of a normal circuit breaker; clearly proving that the circuit breaker was not popped. I advised Maintenance Control of the broken circuit breaker and that I was the likely cause. I also advised the oncoming crew and boarding agents. I then left for the hotel. As I was removing my flight bag; my hat caught something above my head and began to slide off. It is likely that this distraction diverted my attention from the heavy and cumbersome bag; and in a moment of inattention; allowed it to strike the circuit breaker and thus break off the cap. However; contributing factors would have to include; the heavy and cumbersome flight bag; the poorly designed ingress and egress of the flight bag storage area of the 737 and the awkward and unnatural feat of lifting the heavy bag far out from the body; while in a contorted position; twisted and bent over at the waist; all the while in the vicinity of the circuit breaker panel.
The Captain of a B737 damaged a circuit breaker while removing his flight bag from the cockpit storage area. He noticed the broken stem of the circuit breaker and reported the problem.