In a recent post on his blog (click here), Melbourne researcher Paul Dean, reported on 13 pilot and air traffic control observations he obtained from Air Services Australia, (ASA) using the Freedom of Information Act. As I commented in my own blog post on this release (click here), many of these were of illuminated garbage-bags, chinese lanterns, and other such mundane objects. However, there were three which were more interesting, particularly an incident documented to have happened over Adelaide, South Australia in January 2014. Paul challenged us all to provide a "plain english" version of these events, rather than the technical language used in the ASA release. Here then is such a description of the Adelaide event.
1. At about 9.45am central standard time, on the morning of the 27 January 2014, Tiger Airline flight number 484, from Melbourne to Adelaide, an Airbus 320, was inbound on the last leg of its journey. It was to land at the 05 Adelaide runway, following the Alexi 5 Victor Standard Arrival Route. Alexi is the name of a fixed reference ("waypoint") at latitude 35deg 39mins south and longitude 139deg 04mins south.
2. At some uncited point in its final approach, flight 484 reported traffic at its 12 o'clock position, 5 nautical miles (NM) distance, i.e. in front of the aircraft.
3. Adelaide approach reported there was no observed traffic in that vicinity.
4. Flight 484 then requested a turn onto heading 210 degrees. 484 then reported the traffic was now in their right 3 o'clock position, 2.5 NM away. It was apparently seen visually. 484 then advised that it was turning back for its visual standard approach to the runway.
5. 484 then asked Adelaide approach had they any traffic on radar at their 3 o'clock position at 4NM?
6. Adelaide approach replied that they had an Airbus 320 past the 3 o'clock position at 6.8NM. Adelaide approach asked 484 if this was the traffic 484 was referring to? 484 replied that they were not sure. They had their traffic showing at 2.5NM, same level.
7. Shortly after this a Jetstar aircraft flight 774, another Airbus 320, flying Melbourne to Adelaide reported that their traffic collision avoidance system showed "something" at the waypoint named BATIP, (latitude 35deg 00.4mins south, longitude 138deg 26.9 east) "hovering" at 2000 feet, then it disappeared.
At 9am that morning the Bureau of Meteorology observations for Adelaide airport were:
Temperature 27.4 deg C. Relative humidity 23%. Cloud cover zero. Wind direction north. Wind speed 9 km/hr. MSLP 1014.8.
1. A diagram showing standard arrival route Alexi 6 victor STAR into Adelaide airport runway 05, may be viewed at, click here. Note the waypoints marked Alexi and ANVAC.
2. A diagram overlaid on a map of Adelaide (click here) shows the route aircraft take to runway 05 using the Alexi route (the Air Services Australia website does not have an Alexi 5 victor STAR route on it). Note this route goes through the waypoint ANVAC (see diagram above). This second diagram also shows the location of waypoint BATIP where "something" was said to have "hovered." This waypoint is actually out over the ocean, off the coast of Adelaide.
I hope this "plain english" material will assist readers understand what happened that morning.
Note added 5 February 2015.
Melbourne researcher Paul Dean submitted another FOI to Air Services Australia, who released further information on the incident:
The incident was reviewed on 5 February 2014 by ASA employee, Paul Hart who wrote:
"Requested radar replay to ascertain location of traffic. PH 5/2 review of replay suggests this was not a spurious return as following aircraft experienced similar, there was no breakdown of separation. Not ATS attributable." Then there are some radio buttons which indicate close occurrence (No Inv or LL). This stands for no investigation and no lessons learned.