Bob Murphie,
A quick explanation of where the money is coming from, its basically the airlines through ASA.
ASA is a corporation it doesn't have shareholder(s), it has one The Australian Government. Any profits basically go 60% to government general revenue(not to aviation) and 40% retained.
Last year they made $106 million.
The thinking behind the subsidy is. The airlines will get cost savings from the reduced separation and increased surveillance due installation of more ADS-B stations, (they are way cheaper to instal and maintain than SSRs), ASA will get cost savings from the removal of the SSRs, which should then manifest in less cost to airlines.
ASA and the airlines need GA to get onboard real soon, hence the subsidy(bribe). GA is in a strong bargaining position but there are time constraints when you will lose your position.
Dick, alot of the SSRs are already seriously close to their use-by dates, they don't have 5 years to play about. ADS-B is up and working.
To a certain extent it works in parallel with procedural separation, but due to ADS-Bs proven surveillance capablities it supplants it, with radar like standards. Think 10 minute separation standards against 5 miles. e.g. 10 minutes after passing at a combined speed of 16 miles a minute equals aircraft 160 miles apart against 5 miles.
ASA will need to replace the radar heads soon. That money would come from the GA subsidy, if ASA have to go to the expense of replacing SSRs they will want to get their moneys worth and the subsidy would go. At the moment the cost benefit analysis leans towards subsidising GA and not replacing the SSRs. If things drag on the SSRs will HAVE to be replaced.
How many GA aircraft travel regularly OS? How many will be affected by what Sweden implement? Our system works, there is a window of opportunity to get a proven system free or cheap. That window is not being manipulated, it will close, the SSRs will need to be either replaced or removed. Unfortunately the deal is close-ended, decisions need to be made.