Boeing Co 717-200, VH-VQB

Investigation number

200402287

Occurrence date

21/06/2004

Location

Sydney, Aero.

Report release date

27/04/2005

Report status

Final

Investigation type

Occurrence Investigation

Investigation status

Completed

Aviation occurrence type

Taxiing collision/near collision

Occurrence category

Incident

Highest injury level

Minor

Safety Action Summary

As a result of this occurrence, the aircraft operator advised
the ATSB that it had initiated a number of immediate safety
initiatives to prevent a recurrence, including:

Issuing a notice to all contracted ground handling staff
requiring that the correct controller/PPU combination be cross
checked by two staff members prior to push back operation
commencing. It was intended that process would no longer be
required once the long term actions have been implemented.
A reassessment of all PPU operators was carried out by a
manufacturer approved trainer. This training and assessment was
documented in accordance with the contracted company
procedures.
Permission from the flight crew must be obtained prior to
connecting PPUs to aircraft (in addition to asking for the park
brake to be set). This is designed to reinforce the connection
between connecting the PPU to the aircraft and the need for the
park brake to be set.
The engine of the PPUs is to be stopped after connection to the
aircraft and started prior to push back using the remote control.
This ensures that the first remote control command is not a
commanding movement.
Lockable boxes are to be installed on the PPUs to house the
remote control units. The controllers remain with the PPU at all
times.
PPUs and controllers have been colour coded and large numbers
placed on the PPUs to allow quick visual identification.
The PPU manufacturer is to be asked to consider an engineering
solution that prohibits the use of the incorrect remote control
being used to inadvertently move an aircraft.
The function of the remote control communication indicator
lights is to be included in training syllabi and procedure
documentation.
The newly fitted test button on the remote control is utilized
as a safeguard by requiring the operator to test the remote
communication prior to beginning each push back operation.
Consideration be given to requesting the manufacturer to change
the control logic to require the test button to be used in the
period shortly before the push or pull button action.

The Australian Transport Safety Bureau did not conduct an
on-scene investigation of this occurrence. The report presented
below was prepared principally from information supplied to the
Bureau.

REPORTED INFORMATION

At 1855 on 21 June 2004, a Boeing 717-200 aircraft, registered
VH-VQB, was being prepared for departure at gate 49 at Sydney
Airport. At the same time, another company Boeing 717-200 aircraft,
registered VH-VQE, was being prepared for departure at the adjacent
gate 53.

Both aircraft had been prepared for pushback and had remote
control Power Push Units (PPU) positioned on the respective
aircraft main landing gear. VQB was in the final stages of
preparation for departure with all ground service equipment clear
of the aircraft, all passengers on-board and seated with door 1
Left (L1) open and the aerobridge connected to the aircraft. The
cabin service manager was completing documentation in the aircraft
near door L1, and two customer service officers were located on the
aerobridge.

VQE was ready for departure ahead of schedule and the flight
crew received a pushback clearance. They then advised the ground
crew that the aircraft was 'clear to push'. A push back was
commenced by a ground crewmember, using a hand-held remote control
unit, however the PPU did not respond to the ground crew's command
to commence reversing. The ground crewmember, initially believing
the remote control unit battery was discharged, replaced the
battery and attempted a second pushback without success.

At the time the command to pushback was sent to the PPU attached
to VQE at gate 53, VQB began to move rearwards at gate 49. The
flight crew of VQB, sensing the unexpected movement, immediately
applied the aircraft brakes; however the aircraft had moved
rearward more than a metre. As the aircraft moved, the two customer
service officers in the aerobridge became unsteady on their feet
and a flight attendant in the aircraft galley received a minor
scratch on one arm. Once the aircraft was stopped and secured, all
passengers were disembarked through door 1 Right using portable
stairs.

A subsequent examination of the aircraft revealed that VQB had
been damaged as a result of contact between the aircraft and the
aerobridge. The left angle of attack vane was bent, there was some
minor skin damage around the angle of attack vane mounting and the
L1 door trim was damaged. The damage was repaired and the aircraft
was returned to service the following day.

Aircraft Ground Handling

Ground handling services for the aircraft operator were provided
by a contracted ground handling agent. The agent owned and operated
the PPUs and trained staff in their operation. The PPUs were
attached to the aircraft main landing gear and provided motive
force for aircraft pushback without the need for a towbar. The PPUs
were activated via a hand-held remote control unit. The remote
control units had an operating range of approximately 100 metres
and were digitally encoded to ensure that the remote control unit
would only operate its assigned PPU. The two PPUs and controllers
used by the operator in Sydney were marked with matching serial
numbers and two amber lights would illuminate on the PPU when any
remote control button was pushed, signifying that the PPU was the
one being activated.

At the time of the occurrence, the ground handling crews for
gates 49 and 53 had inadvertently obtained the incorrect remote
control units for their respective PPUs prior to the commencement
of aircraft pushback.

Aircraft Details

Manufacturer

The Boeing Company

Model

717

Registration

VH-VQB

Serial number

55002

Operation type

Air Transport High Capacity

Departure point

Sydney, NSW

Destination

Coolangatta, QLD

Damage

Minor