Hi
NAS Crusaders,
At the risk of being annoying, and I'm sure I am, can the only one of you who has credibility
(Lead) give your take on the previous posts.
Leady, I do not agree with you, but at least you keep it civil.
To remind you:
The
intent of ICAO airspace classifications may well be to apply equal risk levels to all airspace, whether it be G, A, or anything in between. But we all know that there's theory and there's practice. Some things look great 'in theory' and are absolute dogs 'in practice.' I'm sure Leyland thought the P76 was a dead-set winner.
As for Class E and NAS, I'd put the following: If the intent of the ICAO airspace classification system is to apportion equal levels of risk across all airspace, based on traffic densities, I'd really appreciate a steer to the definitive,
quantitative study that was done when the decision was made to reclassify large swathes of Class C as Class E under that dog otherwise known as NAS.
Surely this must have been done if the underlying principle of airspace classification involves assessing traffic levels to ensure equal risk. Didn't think so. It was a 'suck it and see' judgement that resulted in potentially fatal NMACs. If it looks like a dog, cocks its leg like a dog and barks like a dog, it is a dog.
I also proffer the following from the CASA commissioned Launy study:
Given that Class E presents a higher risk profile than Class C, without a marked changed in efficiency, it is reasonable to maintain the status quo at Launceston. Moving from Class C to Class E classification removes a significant safeguard against a MAC. It also moves away from the premise of risk being maintained to ALARP principals.
The study goes on to say:
With the scenario of high capacity jet PT operations in mind, the reviewers could not endorse the use of Class E over Class D airspace as enhancing efficiency or safety.
As to the slavish adherence to ICAO principles, there's one further thing I'd like to add in reference to the Avalon PIR . If we are going to insist that we follow ICAO, then we don't cherry-pick. One of the more disturbing conclusions from the recent Avalon PIR was as follows:
The potential conflict risk area identified in the previous Avalon Aeronautical Study remained. This area was identified as an area to the North of Avalon where VFR aircraft travelling East and West had the potential to conflict with IFR PT aircraft arriving and departing Avalon (approximately 8 to 12 NM North of the aerodrome). Airspace changes proposed in the ACP will assist in mitigating this conflict risk. Barriers to this threat include surveillance and monitoring of the airspace by air traffic control, airspace design measures to provide IFR/VFR segregation; and ACAS protection.
It seems to me that ACAS/TCAS is being used as a partial justifier for downgrading Class C to Class E. If anyone disagrees, please speak up.
Given that the level of air traffic services is inextricably linked to airspace classification, ICAO states the following:
The carriage of airborne collision avoidance systems (ACAS) by aircraft in a given area shall not be a factor in determining the need for air traffic services in that area.
Leady, I look forward to your response, given that you, at least, have cred and debate the issues.