What happened

On 5 November 2011, a Construcciones Aeronáuticas S A C212-CC (C212) aircraft, registered VH-MQD, was conducting parachute operations, in controlled airspace, over the Western Grass Drop Zone at Royal Australian Air Force Base Richmond Aerodrome (Richmond), New South Wales (NSW). Air traffic control (ATC) had assigned the C212 flight crew clearance to conduct a parachute drop.

A Boeing Company 737-7BX (737) aircraft, registered VH-VBP, operating a scheduled passenger flight from Sydney, NSW to Cairns, Queensland, was cleared by ATC to track via Richmond, underneath the C212. A loss of separation occurred between the declared parachute operations area and the 737. At the time, the paratroopers had just exited the C212 and ATC issued the 737 flight crew, who were in the process of taking avoiding action, with a safety alert. The last paratrooper out of the aircraft reported that while in free fall and about 10 seconds after exiting the aircraft, they were at the same altitude as the 737, about 2,000 m away.

What the ATSB found

The ATSB identified that Airservices Australia (Airservices) had no standard, documented procedure to assure separation of aircraft departing Sydney via Richmond during parachute operations at Richmond, nor a documented means for controllers to display in the air traffic control computer system when a parachute drop clearance had been issued.

The ATSB also found that two of the controllers involved had not been provided with training in compromised separation recovery techniques. Furthermore, Airservices’ process for recognition of prior learning, and the subsequent training provided to one of the controllers, had not effectively addressed the variances between that controller’s skills and knowledge (after an absence working overseas) and the operational role requirements of a Sydney Terminal Control Unit air traffic controller.

What's been done as a result

Airservices advised that the Sydney Terminal Control Unit Local Instructions were amended to include a requirement for coordination between the Sydney Approach West controller and the adjacent Departures position when parachute operations were being conducted at Richmond.

Airservices also amended their procedures manual to include human-machine interface directives for the display of information for aircraft involved in parachute operations.

Safety message

This occurrence highlights three important safety lessons for air traffic controllers and flight crew:

  • Documented procedures and phraseology are crucial when managing risks associated with unfamiliar operations
  • Terminal area speed restrictions help maintain aircraft separation— air traffic controllers should always consider the potential safety implications before cancelling a speed restriction
  • Flight crews need to be aware that the cancellation of a speed restriction may not always be available when requested, due to operational ATC requirements.