A330
Flight Crew Air Transport Pilot (ATP)
Confusion; Communication Breakdown; Distraction; Situational Awareness; Training / Qualification; Workload
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown; Ground Event / Encounter Other / Unknown
Flight Crew Became Reoriented; Flight Crew Took Evasive Action
Procedure; Human Factors; Company Policy
After the pushback the parking brake was set to 'Parked' and the Guideman on the interphone was cleared to disconnect. He acknowledged; and it sounded like the interphone was immediately unplugged. After an inordinately long period; during which time we in the cockpit were preoccupied with engine starting and distracted by multiple weight and balance uplinks; two ground crew members were observed walking away from aircraft left. They did not turn around for a salute; but; since so long had passed since the disconnect; it appeared that they had gotten tired of waiting for acknowledgment and simply walked away.At no time during this extended wait did the Guideman re-connect the interphone and tell us that they were experiencing difficulties. We called for taxi; and I momentarily released the parking brake; but then did our standard clearing procedure and observed the tug still visible below the left side cockpit window. I reset the parking brake to 'Parked'; and simultaneously heard the intercom re-connect and the Guideman inform us that they were still below. The parking brake had only been released for a moment and the normal; manual brakes were engaged the entire time. The aircraft did not move. I do believe that the nose wheel steering memo had disappeared prior to parking brake release.In summary; the pushback involved an inordinately long delay in disconnecting the tug; the failure to communicate an abnormal situation; and cockpit distractions. Our system of multiple; layered barriers worked; however; and trapped the errors before an incident occurred.This pushback illustrates a potential threat and loss of a barrier during pushback that was introduced with the recent procedure change. Under legacy pushback procedures; the tug operator remained in interphone contact with the Captain until the tug was disconnected and ready to drive away: 'Towbar removed; disconnecting headset; standby for hand signals.' Under the recent procedure changes; the Captain's call is 'Parking brake parked; cleared to disconnect interphone'. While the intent is ambiguous; many Guideman are immediately unplugging the interphone; and remain out of communication during the towbar removal process. During this time; there are men and equipment under the aircraft; frequently not visible from the cockpit; and disconnected from voice communications. This represents the loss of an important communications barrier.I would suggest that the pushback procedure and callouts be clarified to specify that the Guideman remain in interphone contact with the Captain until the tug is safely disconnected and ready to drive away. Any abnormal situations or difficulties should immediately be communicated to the cockpit.
During pushback at a foreign airport; an A330 Captain employed a new Pushback Crew disconnect command at which time he expected the Guideman to disconnect. After a long start process; the Captain released the parking brake and found the Guideman still connected.