CASA DP1102AS: ADS-B watered down!

[baswell]

Civil Aviation Safety Authority - DP 1102AS (http://www.casa.gov.au/scripts/nc.dll?WCMS:STANDARD::pc=PC_100613)

Main changes for VFR aircraft:

- no ADS-B requirement in G at all, no exception any more for uncontrolled RPT locations
- ADS-B capable transponder in G > 10,000'. (not required to have GPS source attached or be transmitting ADS-B)
- From 2020, ADS-B out required in A, B, C, D and E.

The first ones are clear wins for us bug smashers, the latter has some issues.

What if you have your aircraft at Port Lincoln and want to fly it to Parafield once a year for the annual or to get a BFR? You'll no longer be welcome!

It makes a mockery of class D being a "non radar" environment; not only is your good old mode-C not good enough anymore, you'd need to spend a small fortune on ADS-B for ATC not to officially be looking at you on radar?

Those flying IFR are still looking for a huge upgrade.

For new installations, you'll still need an ADS-B capable transponder from 2014, but only IF you to fly into CTA. That basically gives you the option of no transponder and staying OCTA, or installing Mode-S. I guess I can live with that.

This also seems over doing it a bit: aircraft operation at Melbourne, Sydney, Brisbane, Perth Airports will need a Mode-S (no ADS-B) transponder from January 1, 2016. And how about only flying through their airspace, does that constitute "operating at"?

In all, a lot better than the previous DP. Still leaves the issue of retrofitting existing aircraft by 2020; equipment prices will come down, but we still need to solve the CAR35 vs. STC issue.

[Frank Arouet]

May I be so bold as to ask if Mode C requirement remains the same WRT TCAS or CTA?

[baswell]

Not sure exactly what you mean. TCAS works fine with any mode-s (non-ADS-B) transponders, right?

There is no removed transponder carriage requirements as far as I can see.

I reckon QF, et al, will throw up a stink about the removal of the introduction of "ADS-B (or even TXPNDR) mandatory zones" around class G RPT fields.

[Frank Arouet]

That's what I'm asking. I think TCAS only works with mode C.

My guess there will still need to be mode C plus mode S.

[baswell]

From anything The Google returns me, it sounds like TCASII 7.0/7.1 is specifically designed for use with Mode-S. (An aircraft isn't certified TCASII unless it has a mode-S transponder itself? Makes sense as for resolution between two aircraft, you'd need the ID to identify each other?)

Not sure of course how older TCAS systems work with Mode-S - I imagine just fine because mode-S has been around for a long time and, as I understand it, was designed to be compatible with and simply an extension on mode-C.

I don't think having both a mode-s and mode-c transponder squawking at the same time in the same aircraft would actually work.

But I am by no means an expert on the subject...

[Jabawocky]

keep researching young grasshopper ;)

[baswell]

Mine was as much a question as a possible answer. I am trying to find this out also!

Seems you know the answer, so why not enlighten us!

[LeadSled]

Baswell et al,

There is already a mass of information on older pprune threads ---- go look. There is enough there to make you googleeyed, not to mention boggling your mind.

The (almost) only significance of TCAS II software amendment 7.1 is that it resolves a resolution anomaly, which is considered to be a major contribution to the Überlingen mid-air collision in 2002.

<http://www.honeywellairlinesolutions.com/downloads/TCAS.pdf>

The problem with latest CASA proposal for ADS-B is that, for all practical purposes, most GA aircraft will incur 90% of the expense for 10% of the capability ---- we really do risk analysis so wonderfully well in Australia!!