Blastoid, yes, you have it 100% correct. It is “inherent to the Australian aviation culture” that IFR and some VFR will use radio arranged separation rather than alerted see and avoid when in VMC. The radio arranged separation system can only work in Australia where traffic densities are so low. As I explained previously, once two aircraft start arranging separation, the frequency is blocked for any other traffic announcements.
In the USA and other countries in which I have flown, a system called “alerted see and avoid” is used. It is the one that BASI/ATSB claims is necessary for airline aircraft. With an alerted see and avoid system, an aircraft receives an announcement from another aircraft and then looks in that direction to avoid the other plane.
Yes, you are correct. In the US system (and in systems right around the world) unalerted see and avoid is the norm in low traffic density airspace. It actually results in the same level, or a slightly higher level, of safety than what we get with our “radio arranged separation”. I believe the reason is easy to understand. If you look at the BASI/ATSB MTAF and MBZ reports (1993 and 2003), you will see that there are many unalerted see and avoid incidents happening. This is because the frequency is blocked with people using radio arranged separation, or often the radio is on the wrong frequency or the volume is turned down.
We have a system at the present time in Class G airspace that relies very much on unalerted see and avoid. It is a fact of life that pilots have to be vigilant at all times.
Launceston incident
In relation to the Launceston incident, the ATSB report was totally biased and showed that the investigators had no understanding of how the ICAO Class E airspace should work. The Tobago pilot was monitoring both the tower and the ATC area frequency and had full traffic information on the Virgin aircraft. He sighted the aircraft well out and claims to this day that there was never any chance of a collision. He agrees that the Virgin plane came closer than he thought it would, however he maintains that if necessary he simply would have altered heading or descended. He told the ATSB investigators that there was simply no chance of a collision – that is why he did not alter heading, climb or descend.
In that particular situation it was the big sky theory that saved the potential collision. If it had been necessary for the Tobago pilot to alter heading or climb and descend, it would have been alerted see and avoid. If the collision had been prevented by TCAS it would have been the TCAS that saved the potential collision. Remember that in the USA there is no transponder requirement in similar non-radar airspace – nor do they even recommend that VFR aircraft monitor the tower or any frequency. They do not have this recommendation as they have found it to be totally unnecessary. Obviously 100 years of experience counts.
If the Launceston situation occurred without a mandatory transponder requirement and if the Tobago was not fitted with a transponder, there never would have been an incident reported. This is because the Virgin aircraft never sighted the Tobago, and the Tobago pilot believed there was no incident. This shows what an incredible beat up the situation was. It was clearly the system working correctly and the ATSB beat it up out of all proportion and called it a serious incident. You may like to look at my website (see
http://www.dicksmithflyer.com.au/Con...?ContentID=288) because the Tobago pilot does not agree with the ATSB report but has never been able to gain access to the actual wording of what was said during the communication in which he was involved. I understand that people at Virgin were able to read the transcript, but not the private pilot. Readers can make their own judgement on that.
In relation to it being an acceptable level of safety, all I can say is that it is certainly better than what we have overhead busier airports such Ayers Rock and Broome. The airspace above those airports is Class G - there is no requirement for a transponder at all and the airline aircraft is not being separated from other IFR. I would prefer to go to Class E with mandatory transponder, than Class G without transponder any day.
Icarus2001, you ask how I know that some benefits are already happening. It is quite simple – I ask advice. For example, the ATSB figures show that resolution advisories are reducing, and I have spoken to many pilots who are now gaining the benefit of being able to track directly over Class D towers – where in the past they were often diverted or held. The Tobago pilot of the Launceston incident is an example. He has claimed that with the system before 27 November 2003 up to 50% of the time when overflying Launceston, he was given extra tracking distance – even if it was only an IFR Navajo in the airspace and the conditions CAVOK.
I Fly, the reason I would not support the Russian system here is that it is the most restrictive and costly in the world. It is basically a type of Class A airspace everywhere with VFR being forced to fly as if they were IFR. It is constant position reporting all the time for VFR, similar to our pre-1991 Aussie system.
Scramjet77, the difference between the Aussie MBZ calling in the blind system and the US CTAF system is that they obtain a far higher level of compliance with their recommended procedures than we do with our mandatory procedures. All the data I have seen shows that they do not have the major problems that we have in relation to unalerted see and avoid at non-tower airports. The most obvious reason for this is that their system relies on alerted see and avoid with more announcements, rather than radio arranged separation with two aircraft blocking the frequency.
More importantly, virtually every non-tower airport you operate at in the United States that has airline traffic also features a UNICOM. The UNICOM gives a third party confirmation that the radio is working. Our very high number of unalerted see and avoid in MBZs does not come from non-radio aircraft, it comes primarily from simple pilot error. I believe by moving to the US system we would have similar compliance rates and our quite serious problems in MBZs would be reduced.
In relation to your question number 1, I do not have exact figures for the cost of so far introducing NAS 2b and the attempted 2c, however it could be some millions of dollars. This will pale into insignificance when compared to the continuing savings by the industry as they do not have to hold or be sent extra distances in the old Class C airspace.
I can’t show exactly how the claimed $70 million savings will be achieved other than point you to the Willoughby Report, where an independent expert stated that this was his estimate. I’ve always believed that the savings would be far higher.
CaptainMidnight, my comments in relation to the design safety case remain. Mick Toller of CASA particularly told Airservices that they would not be required to do a design safety case in relation to certain NAS features. Even though this was stated by Mick, it appears that Airservices’ internal procedures stated that they must do a full design safety case. As I have stated numerous times before, that's Airservices’ responsibility, not Mick Toller’s or mine.
By the way, there is nothing to say that a design safety case cannot primarily rely on statistics from a proven system. It is obvious that if someone did a correct design safety case on the full US system (the FAA has never bothered) it would show that the system was acceptably safe.
AirNoAirservicesAustralia, you are basically claiming that the US system (i.e. a system where VFR aircraft do not monitor ATC frequencies when enroute as in the USA) cannot work in Australia. If you really believe that in the system before 27 November 2003, VFR pilots were monitoring the correct ATC frequency when enroute, you are wrong. Many pilots ended up on the wrong frequency or with the volume turned down because of the constant communication on the frequency that was irrelevant to them. I would suggest that if there is an IFR aircraft climbing or descending in enroute Class G or E airspace that the pilot remains vigilant to see and avoid other traffic. This is what I did as a pilot before 27 November 2003 and I continue to do so now.
Four Seven Eleven, as pointed out by
Voices of Reason, an aircraft flying from New York to Fairbanks is actually in Canadian airspace, and in the northern airspace their Class A airspace drops to FL245.
Four Seven Eleven, whether you like it or not, you work for a commercial organisation. As an air traffic controller your income comes from the commercial sale of your services to a customer. You will benefit if your organisation produces higher profits as your union will be astute enough to make sure you get a share – that is good. Don’t kid yourself, you are not some type of charitable safety regulator – you are just as commercial as when I stood behind the counter selling products. You sit behind a radar screen selling air traffic services. Don’t be holier than thou, everyone knows that your interests are commercial and that is in total conflict with having Government regulatory powers for airspace – which your organisation has.