Two very large commercial airliners, one flying at 700kmh and the other travelling at 870kmh only took out around 3000 people on 11th Sept 2001, despite being loaded with 36,800 litres and 34,500 litres of Jet A-1 respectively - so I fail to understand how you could take out 5000 people with a single RA-Aus aircraft loaded with perhaps 100 litres of petrol at the very most, and unable to probably even reach 300 kmh, without the wings tearing off. It would be virtually impossible to take down any building with an RA-Aus aircraft.
I fully understand the need for an ASIC card for commercial airline operational areas, but the ASIC card is over-reach for probably 80% of the aviation areas of the country.
It's interesting to stop and think about the fact that all the terrorism attacks in aircraft around the world were carried out by people who had pilot training, piloting skills, and qualifications - not exactly your classic "raghead" terrorist.