mode A TX

[rutan around]

I sometimes fly an aircraft with a mode A only transponder. Can I expect ATC to give me a normal airways clearance to transit or land in class C airspace or is only done on special occasions? I can't readily find any information as to whether mode C is mandatory in C airspace or just nice to have, if fitted. I hope someone with knowledge in this area can advise me.
Thanks, RA

[ozblackbox]

Have a look at AIP Gen 1.5-10 para 6.

You need Mode A and Mode C to operate in class A, B and C. Also above 10,000ft AMSL. GAAP control zones are exempt.

There are exemptions. Relevant one being, for aircraft with an operating transponder, but without operating automatic pressure altitude reporting equipment having Mode C capability, the request may be made at any time.

The exemptions may be available subject to agreement with the relevant ATC unit.

[VH-XXX]

Without mode c fitted you may as well have it turned off for the trouble that it seems to cause for be controllers and TCAS etc. Is there any good reason why the aircraft doesn't have it fitted, I mean it's like a $400 unit?

I heard a guy once asking for a city orbit withode a only, they asked if he had mode c but he said it wasn't working, subsequently ATC said they would be advising casa that the aircraft attempted to enter cta knowingly without a working one.

Heard a 182 or similar skydiving at yltv on Saturday with mode c not working, every time he went up atc were asking him to recycle it. Was not worth the effort.

[topdrop]

ATC can give you an exemption where the flight is to somewhere where you will have your transponder repaired - since this is not the case, you need an exemption from CASA.

[The Green Goblin]

I've been transiting CTA after departure from a primary zone and have had ATC question my Altitude. The mode C was indicating +500 feet.

They asked me to proceed in mode A only.......

[Jabawocky]

GG

Turn ya mobile phone off :E:ok: or get better shieled wiring installed! ;)

J:ok:

[rutan around]

Ozblackbox
Thanks for your clear and concise reply.It gave me the information I was looking for. To others who posted the aircraft is 25 years old and any transponder was state of the art when it was built. Mode C is high on the list of must do's. $400 is not the problem. It's the 500nm round trip to an Avionics shop and 2 days of my time that's the hold up.The aircraft always operates OCTA . The question was posed just in case I had a need to enter class C before mode C is fitted.
Cheers RA

[Frank Arouet]

I'm obviously showing my ignorance, but will TCAS interrogate mode A TXP sans altitude for alerting? (Thinking alerted in the right direction for see and avoid).

Reason for asking is an affordable (?) price for those not going into CTR or class E airspace could allay fears of MAC by those RPT who don't like to look out the window in class G. They, the mode A blokes, could perhaps add on as they progressed into different airspace?

On a similar bend, can TCAS interrogate mode S now, or only mode C, and can will this work with a progression to ADSB OUT or will RPT have to have TCAS and ADSB IN?

For mid air collision avoidance I mean.

[rutan around]

Frank
Airliners with TCAS can "see" mode a transponders . I recently checked this out with a local airline pilot. I would assume they can see position and altitude on mode S .I don't whether they recieve information such as rego,pilots name and address ,grandmother's christian name etc. You would never bother fitting a TX without mode C. The question only comes up with older aircraft that had their TX fitted years ago when mode C was not required.
Cheers RA

[Jabawocky]

ahhhhh...... but what is the very important piece of information that Mode C provides.....thats what matters!

And yes when you can fit to your Auster or Ultralight or Glider one of these for very little money!

Microair Avionics (http://www.microair.com.au/index.aspx?page=186&productID=26)

Probably $3K for the bits, easy to fit, and get signed off with a check of the static and transponder output. :ok:

[Arnold E]

There is transponders and there are transponders, the one that you have reccomended, Jabba, is not one that I would bother with in my aircraft and I know plenty of others that would agree.
My 2 cents worth.

[VH-XXX]

Microair Avionics (http://www.microair.com.au/index.aspx?page=186&productID=26)


+ 1 for supporting local Australian manufacturers.

[Frank Arouet]

Cheapness and expense are relative terms. To all youse who have 100K jobs or work for the poor bloody public service, $2,500 t0 $3,000 isn't much. But thems that youse all reckon should have a transponder (ie RAA, gliders, sport rotorcraft, ornithopters, baloons, and ground effect vehicles probably can't afford it or reject it because they are just dinousaurs. (don't say if you can't afford it you shouldn't be flying because I will possibly and probably, drink more to forget your simplistic stupidity towards the 10,000 people who fly these contraptions). BUT... and cogniznt of the FACT that there is no such thing as a non TSO'd transponder, because it interfaces with Airservices gear, is there any inexpensive, (don't even mention ADSB), on board tool, that an RPT TCAS can interrogate to make themselves warm and fuzzy and know where other traffic is in the circuit without immediately looking out the window? Something like a cheap but "certified" mode A transponder that will ALERT that mob to "something" at any altitude that is in front of them and prompt them to look out the front and add to the very good concept of "alerted see and avoid" in the circuit area or GAFA?

I think I know the answer to my own question, but can't remember the name of the gadget, but will the airlines buy it? From what I understand the RAA mob only need this basic (but "certified" transponder). How much can one be made to retail for, and will anybody who feel it so necessary, subsidise it. (I think I know the answer to that question also).

Also, will RPT be happy with this arrangement to supplement the now pretty well mandatory carriage of radio for "alerted see and avoid" in the circuit.

This doesn't concern Airservices, because they don't want to talk to us, out of the system, peasants anyway.

[alisoncc]

Rutan around wrote:
To others who posted the aircraft is 25 years old and any transponder was state of the art when it was built.

Was a Field Eng with RCA out of Sunbury on Thames 1968-1970, we were shipping AVQ65's - GA transpondors, out the door as fast as we could get them. These were mode A, B, and C. Was installing King kit early-mid '70's that did the same. I can't think of any boxes being shipped as late as mid '80's - 25 yrs ago, that didn't have all modes.

PS. Sounds more like the feed from the altimeter isn't connected. So transpondor cannot provide altitude reporting on mode C.

[Jabawocky]

Arnold, as you know I have one of these

https://static.garmincdn.com/en/products/010-00188-00/g/cf-lg.jpg

But those who don't could go the other option.

Frank
You of all people along with your other freinds should not be making such hypocritical statements, it was not that long back you guys said so much that it makes me quite mad to read what you have just posted. :=

So which point of view is tongue in cheek?

J

PS on a seperate note, driving a car is a privilege not a right. Perhaps flying is also? :cool:

[Frank Arouet]

Jabawocky;

You of all people also know that I am an ardent supporter of any beneficial and financially viable evolutionary ATC tool to replace existing radar where it is needed. You also klnow that I support the concept of "alerted see and avoid" so why should it surprise you that I would ask for comment on the feasability of someone using an existing mode A transponder as a warning device in the GAFA if TCAS can interrogate it?

BTW was it the Zaon device which I didn't understand before but had it explained to me that I was thinking of. Will this talk to a mode A transponder?

Edit to ask, how much is that transponder in your pic? What is the other one Arnold is talking about?

[rutan around]

Alisoncc,
Thanks for the altimeter feed information. I'll have that checked out. Might save a few bucks. BTW by state of the art I meant the fact that a homebuilt actually had a TX. I know that as late as 1988 or even later you didn't need a TX to get into most places.
Cheers RA

[Jabawocky]

Frank

OK here is some light reading that covers most of the Mode A & C differences. Sorry its taken a while to respond but with disasters in DRW and functions with Prof Bob Carter this week my pprune budget had to be cut back.:p

Transponder Basics (http://www.public-action.com/911/transpon/)

Now in response to some questions you asked.
1. The Zaon device like all TCAS/PCAS and really primary radar is not that useful unless it has 3 dimensions being distance, azimuth and height or in this case a height difference. After reading the link above you will see that unless you have Mode C the altitude is missing and the rest of it is nice to know, but useless.

2. the GTX327 at present with a good exchange rate is about $100 more than the microair, so around $2350 plus other bits.

3.BUT... and cogniznt of the FACT that there is no such thing as a non TSO'd transponder, because it interfaces with Airservices gear, is there any inexpensive, (don't even mention ADSB), on board tool, that an RPT TCAS can interrogate to make themselves warm and fuzzy and know where other traffic is in the circuit without immediately looking out the window? Something like a cheap but "certified" mode A transponder that will ALERT that mob to "something" at any altitude that is in front of them and prompt them to look out the front and add to the very good concept of "alerted see and avoid" in the circuit area or GAFA?
This is the bit that tipped me over the edge, a few months back you and your friends bashed the living daylights out of the "if it aint TSO'd it aint no good nor going to happen" arguement, knowing all the time that the equipment coming would in fact be compliant by that time. And here you are now asking would a low cost non TSO device exist that would keep ASA and RPT happy for the purpose of enhancing situational awareness in the CTAF R aerodromes.

Maybe its me with an axe to grind but does anyone else see the hypocritical nature of the idea?

My idea would have been to have had folk support the concept of subsidised ADSB so that everyone had exactly what you are wanting for that same low cost to the individual like you, or in fact even less. Do not start on "there was never a subsidy", because there was not, it was a proposal to have one and some folk let it get away.

J

[Frank Arouet]

Jabawocky;

non TSO device exist that would keep ASA and RPT happy

I mentioned RPT in the GAFA being kept happy.

I'm interested in this thread because I am in the market for a transponder for my new A/C. I'll read the links.

it was a proposal to have one and some folk let it get away.



If it wasn't there, how could it get away?:uhoh:

[j3pipercub]

I don't think a mode A would help for the RPT guys. They'd just be asking you for your height constantly, instead of position and height...

[OZBUSDRIVER]

GAWD, Francis, you've been locked out of your own aerodrome because you do not have a device for communicating with an RPT TCAS...oh, the irony:}

Shoulda paid more attention in class, what!

[Frank Arouet]

Somebody's keyboard has an ID ten T problem.

I have two perfectly serviceable VHF radio's, one is a brand new Microair and the other a handheld backup. Where does it say a mode C transponder is mandatory in any class G airspace such as where I live or operate.

I also have strobes, nav and beacon lights, but my aircraft is not NVFR.

And why would all this concern you as a private pilot who hires other people's aeroplanes.;)

[OZBUSDRIVER]

Hey Francis, nup. Just savoring the moment. Irony is delicious, isn't it?:}