B737 Undifferentiated or Other Model
Flight Crew Last 90 Days 200; Flight Crew Total 20000; Flight Crew Type 3300
Situational Awareness; Training / Qualification
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Became Reoriented
Aircraft; Human Factors
Upon arrival our gate was occupied and we were instructed to hold. While stopping the aircraft it was noted that the brakes were very grabby as I brought the airplane to a complete stop. After being assigned a new gate we taxied to the new location and waited for the marshalling crew to arrive. Again the brakes grabbed several times as the airplane stopped. As we arrived at our final spot and the marshallers gave me the stop sign I was still a little concerned about the grabbiness of the brakes; so after initially setting the parking brake I released it and held them manually and started to let off a bit. I felt the aircraft move a bit and immediately reapplied the brake. At this time; however; the rampers were putting the chocks in and the aircraft rolled a bit. I talked to the ramp supervisor and the vulnerability of the ramper if the aircraft moves while they are near the wheels was discussed. I realize I should have waited until the chocks were signaled in to do any testing of the brakes and will be much more mindful of the safety issue involved in the future.
Flight was being marshaled into the gate. This arrival was a last minute gate change and there were only 3 [rampers] available for the arrival - 2 wingwalkers and 1 marshaller. Once the aircraft reached the stop mark; the Marshaller gave the stop sign (crossed wands) to the flight deck. The Marshaller then walked out of sight of the flight deck to chock the nose gear since the other two [rampers] were wingwalking and in position to chock the main gear. As the Marshaller was getting ready to place the chocks under the nose gear tires; the brakes were released and the aircraft started to roll backwards. The marshaller jumped clear and then the flight deck realized that they were rolling and reset the brake.
A B737 Captain and the ground person detailed to install the nose wheel chocks after gate arrival; describe an uncommanded brake release causing the aircraft to roll and the person placing the chocks to jump clear.