Transponder

[Phil Bird]

Posting this question to help a friend. He has been told that from February this year any new VH registered aircraft must be fitted with a transponder, even if the aircraft is not going to be flown into controlled airspace.

 

The only thing I could find was the requirement of an adsb transponder, if fitting one after February. Any one know??

 

Thanks

 

Phil

 

 

[Happyflyer]

As I understand it there is no requirement for a new GA aircraft to have a radio let alone a transponder. If fitting new transponder or new aircraft with transponder it must be mode S type.

 

 

[Kyle Communications]

I did read somewhere CASA had delayed the date by about a year or two for the implementation for it. I think it was 2017 but now 2019 0r 2020

 

 

[skippydiesel]

Why would anyone quibble about such an obvious safety aid.

 

I have one in my RAA registered aircraft - yes it cost more than I would like but what cost my life, even if it only helps avoid one unpleasant meeting in the air?

 

 

[jetjr]

Dont confuse ADSB with normal transponder

 

 

[Phil Bird]

Thank you for the reply's. There is no "Quibble" with safety, the reluctance to fit one is purely practical. The aircraft is a Cri Cri. This thing is tiny, the panel is no bigger then a shoe box.

 

 

[facthunter]

Transponder tells Radar who you are, when you are in range and helps RPT see you with TCAS info for them.. Doesn't help anyone else. Nev

 

 

[skippydiesel]

Thank you for the reply's. There is no "Quibble" with safety, the reluctance to fit one is purely practical. The aircraft is a Cri Cri. This thing is tiny, the panel is no bigger then a shoe box.

Hi Phil,

I elected to replace my old transponder (dud) with the same size (fits in the same tray) ADS -B. While I was researching the replacement, I found several panel space saver small units and several , I think they were called remote head units, that is the small control head on your panel is remote from the actual gizmo, which can be installed almost where ever you want. I imagine the latter may be applicable to a Cri Cri

 

 

[Groppo Australia]

CAO 20.18 is where you will find the answers

 

 

[skippydiesel]

Transponder tells Radar who you are, when you are in range and helps RPT see you with TCAS info for them.. Doesn't help anyone else. Nev

Hi Nev, Interesting comment - I have had ATC contact me directly twice regarding a possible conflict and at least another three contacts (about me) to other aircraft in the vicinity. My aircraft is an assembly of low radar registering materials (with the exception of the engine) so I assume ATC could "see" me because I had my transponder turned on. Perhaps I was wrong.

 

 

[Groppo Australia]

Hi Nev, Interesting comment - I have had ATC contact me directly twice regarding a possible conflict and at least another three contacts (about me) to other aircraft in the vicinity. My aircraft is an assembly of low radar registering materials (with the exception of the engine) so I assume ATC could "see" me because I had my transponder turned on. Perhaps I was wrong.

ATC has primary radar and secondary surveillance radar.. primary radar works as most people understand a radar to work.. SSR interrogates your transponder and they match your primary return with your transponder reply to get a position fix on your aircraft. Without a transponder you will just be a reflective object on the bearing you are from ATC's primary radar.

 

 

[skippydiesel]

....................Without a transponder you will just be a reflective object on the bearing you are from ATC's primary radar...........

Soooo - my transponder did help to locate my position in space, relative to that of other so equipped aircraft and cause ACT to warn me/the other aircraft of a potential conflict ?????

 

 

[Groppo Australia]

Soooo - my transponder did help to locate my position in space, relative to that of other so equipped aircraft and cause ACT to warn me/the other aircraft of a potential conflict ?????

The primary radar will have picked your aircraft up as a blip on the screen at a given bearing and distance from the station (if you are within its range). The SSR will have interrogated your transponder and it would have replied with a code (normally 1200 for VFR). Because the SSR array is directional, it knows what direction your transponder replies are coming from and measures the interrogation-reply round trip time to calculate a distance from the station. When this is compared with the primary radar returns, they can identify the blip as your aircraft. If you have mode C then your transponder will identify your aircraft and also give the altitude of your aircraft. If another aircraft is using a TCAS/TCAD then that aircraft will know your exact position in relation to their aircraft. With ADS-B, your transponder takes a feed from the GPS and transmits your GPS position.

So yes your transponder was most likely the only thing that allowed ATC to foresee possible conflict.

 

 

[facthunter]

If you don't have a transponder (or a particular ID) they may ask you to turn onto a specific heading and report your altitude and or sqwark another frequency. This enables a positive identification of you and verifies your altitude (by your words confirming it .Nothing else if no transponder) Nev

 

 

[skippydiesel]

I might be wrong but there still seems to be a little cloudy light between the Nev and Groppo position - Most of my flying is in the relatively high traffic area of the east coast & hinterland. I am confident that my transponder was a wise purchase. In some mysterious way (thanks for trying to enlighten me Gropp) it enhances my safety by having Big Brother (ATC) watching over me and giving larger, TCAS/TCAD equipped, aircraft the chance to ask me to hold, while they do a strait in (Moruya & Merimbula). Yes I know that the radio would have played its part in my traffic separation.

 

 

[Groppo Australia]

I might be wrong but there still seems to be a little cloudy light between the Nev and Groppo position - Most of my flying is in the relatively high traffic area of the east coast & hinterland. I am confident that my transponder was a wise purchase. In some mysterious way (thanks for trying to enlighten me Gropp) it enhances my safety by having Big Brother (ATC) watching over me and giving larger, TCAS/TCAD equipped, aircraft the chance to ask me to hold, while they do a strait in (Moruya & Merimbula). Yes I know that the radio would have played its part in my traffic separation.

Definitely a wise purchase.

 

 

[facthunter]

I think if you are in an area conflicting with IFR/ controlled airspace , you should have a transponder that's working properly . For the occasional crossing traffic situation If you are prepared to accept a delay (if needed) to give certainty of separation to other traffic, you should be able to operate without one. . If controllers don't have a clue who or what you are they are not helped when advising other traffic of a possible conflict. Vertical separation is verified if your transponder is in tolerance with your stated altitude. and you are maintaining the required separation for your band of altitude. Its 1,000' at the heights we fly. Nev

 

 

[skippydiesel]

I think if you are in an area conflicting with IFR/ controlled airspace , you should have a transponder that's working properly . For the occasional crossing traffic situation If you are prepared to accept a delay (if needed) to give certainty of separation to other traffic, you should be able to operate without one. . If controllers don't have a clue who or what you are they are not helped when advising other traffic of a possible conflict. Vertical separation is verified if your transponder is in tolerance with your stated altitude. and you are maintaining the required separation for your band of altitude. Its 1,000' at the heights we fly. Nev

All good stuff Nev - just a short story - Some years back, on a flight from South Grafton to The Oaks, via Ellerston, Scone & Katoomba - I was contacted by ATC, abeam Kempsie, (if my memory serves me right I was at 8,500 ft.) ATC advised a look out for an unidentified aircraft heading West - East, at my altitude, that was NOT responding to radio calls. The small aircraft passed uncomfortably close behind me, and from the on going calls, from ATC, on through the busy Tamworth airspace. Despite the empty sky feeling we all get - things do go wrong and the holes in the cheese can start to line up. I was glad Brisbane Centre knew exactly where, in space. I was that day.

 

 

[spacesailor]

or sqwark another frequency

 

How do you squwark without a transponder,

 

and due they come "handheld" (battery powered) as not all aircraft have 12v power, only a Handheld trx.

 

spacesailor