After a five-minute delay in securing the aft cargo door, the
Boeing 737 was cleared for pushback. The ground engineer then
passed a message to the crew to 'call control', but gave no
indication of urgency. The crew decided to concentrate on the
departure and to call control when airborne.
After takeoff, the crew contacted Load Control and were advised
that the load controller had been attempting to make contact to
inform them that the loadsheet may have been inaccurate. The crew
were not warned via the ACARS data communication system before
takeoff. The crew had not been monitoring the Load Control
frequency as they had already received the final loadsheet.
Aircraft performance and handling were not affected.
Investigation revealed that the leading hand of the loading gang
had given a 'Ramp Clearance' to the load controller while the
loading of the cargo hold was still in progress. The 'Ramp
Clearance' indicated to the load controller that either all
compartments had been loaded as required, or that the entire load
had been accounted for and was either alongside the aircraft or in
transit to the aircraft. However, due to unserviceable webbing in
the doorway of compartment 4 of the aft cargo hold, the loading
gang relocated 10 bags to compartment 3 of the aft hold after the
leading hand had given the 'Ramp Clearance' and the load controller
had sent the final load sheet to the aircraft.
The leading hand advised the load controller of the change, and
the load controller amended the load calculations. The load
controller then attempted to contact the crew on the Load Control
frequency, without success, as the crew were not monitoring the
frequency. The load controller then contacted Movement Control in
Cairns to have the ground engineer attending the departure, ask the
crew to 'call control'. The engineer passed the message, but the
crew did not contact Load Control until after takeoff. Thus, the
aircraft departed with the loadsheet unamended.
Standard Operating Procedures for Load Control specified that
ACARS messages should not be sent to the aircraft after the final
loadsheet was issued. This was based on the need to avoid
distracting the crew performing vital actions during departure,
plus the likelihood that the crew could miss the message. The load
controller was required to inform the crew verbally of any late
changes to the loadsheet. In addition, when the company implemented
its new load control system, management decided that due to cockpit
workload, crews would be required to monitor only two frequencies
(Air Traffic Control and Movement Control) during the period within
15 minutes of pushback.
Prior to the occurrence, the company had initiated a review of
procedures relating to the issue of ramp clearances. Alternative
procedures were being trialled. However, the new procedures were
not a factor in the occurrence.
At the conclusion of the trials, new procedures were implemented
in Melbourne in December 2000, and training was scheduled for
February and March 2001 prior to implementation of the new
procedures at other ports.