SonexBuilders.net

Hi All,

I have a question for the Australian builders out there about the upcoming mode S transponder requirement.

As I understand, 2017 is the year when we all have to have switched to a mode S ADS-B capable transponder.
I've also now heard that even though we can still fly with existing mode C transponders till 2017, as of the 6th of February 2014 you can't install mode C transponders anymore, any new aircraft to the register at that point will need a mode S transponder, also if you need to get your existing mode C transponder replaced after that point you will need to replace it with a mode S.
This document seems to confirm this (see first paragraph page 13):
http://www.airservicesaustralia.com/wp- ... RVICES.pdf

I'm currently aiming to get my Sonex flying mid to end 2014.
Since Mode S transponders are still ridiculously expensive (not to mention the price of the certified GPS modules), I was intending to purchase a working second hand mode C transponder for now and switch to a mode S when we get closer to 2017. The expectation is they should be dropping in price over the coming years as more manufacturers start producing them for the 2020 rollout in the US.

However, this requirement for mode S transponders on any new installations or replacements after 06/02/2014 would suggest that I will have to get me a mode S straight away (unless I get my plane in the air before 06/02/2014 which is very unlikely).

Is this your understanding as well? Any comments?

Ok, I found out a bit more about this and yes, as feared if you're building an aircraft now and you're not planning to have it registered before February 2014, you will have to get a Mode S transponder with ADS-B out support. If you had already bought your mode C transponder but not planning to be flying by then, sell it now!

Also, BE AWARE!
Not all Mode S transponders are acceptable, the Garmin GTX330 for example is not as it does not have the 1090Mhz "Extended Quitter" for ADS-B out support, you need to get the GTX330ES (or have it upgraded to the ES version for about $1500 if you already have a GTX330).

Luckily, for now you only need the transponder but you don’t actually need to have ADS-B out active yet which means you can hold off on installing the certified GNSS (GPS) unit that complies with TSO 145/146 until 2017 (these units also cost $3000 or more at this stage).

The information above applies to all VFR aircraft registered in Aus for operation in class A, B, C, E airspace and G airspace above 10000ft,
Whether you’re certified or experimental amateur built, GA or RAA, does not matter.