Transponders (again)

[Mogas]

I am thinking of getting a transponder.
What areas/airports are covered by SSR?

[RV4ker (RIP)]

I am thinking of getting a transponder.

Why?

[Mogas]

I now hangar at The Rest within FAKN CTR, right under the approach for 05.
Take off is no problem, just duck left into FANS special rules.
When I return from a flight to the east I am often told to decend and hold at the gorge while incoming traffic for 05 completes the approach.
This can be a real pain in the ........ if it is a nice hot and windy day.
It also generally gets very busy within the CTR.

[t-bird]

I don’t see how a transponder will solve your problem.

[Mogas]

FAKN sometimes enquire if we are transponder equipped. If they don't know exactly where you are they steer you very low and well away from FAKN. If they can monitor your position (modeC TX equipped) they seem willing to filter you through the traffic in and out of FAKN.

[Bennie Vorster]

What will the cost be of sutch a little toy? For me it seems to be a good idea.

[Mogas]

My limited research so far shows the Garmin GTX320A to be the cheapest at about R12500.
Still waiting for a quote from Composite Technologies.
If anybody has other prices please post.

[Arnulf]

My limited research so far shows the Garmin GTX320A to be the cheapest at about R12500.

Does that include an encoding altimeter?

Regards.
Arnulf

[Mogas]

Oops! Just phoned Centuary.
GTX320A incl encoder, antenna and VAT is about R15000 depending on exchange rate.

[Arnulf]

Probably cheaper to hold over the gorge now and then.

[RV4ker (RIP)]

Mogas
I have a mode C fitted to all the aeries I fly, even the Cubby and the RV as it a requirement to land at FABB. Even with the Mode C ATNS are not as accomodatingas they could be IMHO. Something about min IF separations and ltd radar coverage. I have found the transponder to be of only very limited use in VFR flying in controlled airspace. I have never for eg been able to route to FATP inside the TMA even with Mode C and I fly there plenty. They have very few schedule flights, but the ICAO min IF clearances dictate min separations which preclude direct routing to FATP even if mode C equipped.

I would suggest you have a look on ebaymotors.com (aviation spares). I have got heaps of aviation toys from there for very low landed cost (Full TSO IF panel which CAA won't let me use in an NTCA for some reason?). It is risky (there are some shisters there and it takes time to find and get hings here cheaply. UPS/Fedex/DHL cost more than the transpoder for shipping. If you are patient you will find one. The older and lesser known ones are chepest (Narco, Cessna Cesscom, Collins etc are cheaper than the Garmin, King and digital models).

I got a KT76A and Ameriking 350 Alt encoder (I think?) which work well. I got antenna from peter How at composite tech mounted on a base plate with BNC connector and then had them wired to work off a 12v cigarette lighter so could transfer Squawk from plane to plane, but all mine now have transponders so it basically a backup. The whole kit (KT76A & encoder) landed here was less than R3,000 (incl SRS manifest fee and VAT) and worked out the box - Just add power and connectors. (about $400 on ebay and $80 EMS via US Postal Services - equivalent of USA Speed services, but supported here by SAPO) It had no tray or connectors which made is less than half price of other similar units, but am sure a resourseful oukie like yourself could resolve something like that...

if you don't come right I may be willing to let mine go, but prefer to keep for spares. Have not used it for 12 months so don't know if still works. A new selector button cost me almost R1200 last year....

[RV4ker (RIP)]

http://motors.search.ebay.com/transpond ... sofocusZbs

[cobra]

FAKN sometimes enquire if we are transponder equipped. If they don't know exactly where you are they steer you very low and
well away from FAKN. If they can monitor your position (modeC TX quipped) they seem willing to filter you through the traffic in and out of FAKN.

Hi Mogas;

The problem is separation between VFR and IFR Traffic, especially in busy airspaces such as the JS CTR & TMA.

The question is, how is VFR traffic with no transponder and IFR traffic separated?

1) Aerodrome control is responsible for circuit traffic being - VFR traffic in VMC conditions. Should an aircraft
approach the airfield on an IFR flight plan, needless to say if it is IMC or VMC (Wx conditions), the IFR traffic
will have to cancel its IFR flight plan and change to VFR flight rules and subsequently handed over to Aerodrome
Control, at which time the Aerodrome Controller will be responsibility to maintain separation between aicraft.
In this case there will be no problem. However, ATCs may not enforce or even suggest such change to IFR traffic –
this is normally requested by the pilot to change his/her flight rules. Aerodrome controllers may not control
aircraft on an IFR flight plan approaching the airfield or maintain separation between “their” VFR and IFR traffic,
IFR traffic is a function of approach control/controllers.

2) Approach control maintains separation between aircraft by means of SSR with Mode C (Alt read-out).
In IMC conditions, the CTR will be controlled by Approach Control, no VFR traffic obviously!! Although the
aircraft will be handed to Aerodrome Control for landing clearance – rule -> runway and airspace APPROACH CONTROL
and taxiways AERODROME/GROUND CONTROL depending on the airfield SOPs

The problem is when there is VFR traffic and IFR traffic in the same controlled airspace. The approach controller
is responsible to maintain the necessary separation for IFR traffic. During this scenario although the Aerodrome
may have both aircraft insight the responsible approach controller will not have this visual conformation as the
approach control is not seated in the Aerodrome Tower.

I can only talk from experience at Waterkloof, in such a case there will coordination between the Aerodrome
controller at Waterkloof and the Approach controller at JS who is responsible for the IFR traffic separation into
Waterkloof – this is done by means of a telephone or radar as a tool to confirm aircraft identification –
the provision is that the Aerodrome controller has both aircraft insight and keep the VFR traffic clear of the
IFR traffic or have the aircraft identified on radar.

Primary radar is not used for positive radar identification for many year, SSR with Mode C is used. It is for
this reason that in busy airspaces with majority IFR traffic such as Tambo and Lanseria the ATC is reluctant
to allow aircraft to enter the airspace without a Transponder.

You may find asking for a clearance, and it is approved that there is most of the time no IFR traffic or that
there is no risk that there will be a reduction in separation.

Helicopters are often routed through the CTR of Tambo only if equipped with a transponder, as ATC need to maintain
the necessary separation between VFR and IF traffic and both are then positively identified.

THE PROBLEM e.g. - The corridor via Pinedine station has been there for years and traffic is cleared through low
level with no problem. WK NDB (no withdrawn) was collocated with Pinedene station and served as the outer maker
for the ILS runway 01. IFR traffic passes the beacon at 6500ft on final approach. An aircraft routed via WK will
have to be 5500 ft to maintain a 1000ft separation which is the minimum in case. WL is the inner marker for the ILS,
1 mile from touchdown.

As an example (I think this was about 12 year ago) - I cleared an aircraft VFR via WK (Pinedene Station) from the
east to Lanseria at 5500ft, aircraft following this route are only visible from the tower once it passes WK. The
pilot set freq 315 which was the freq for WL – the obvious happened – a IFR flight (C130) was on the ILS and passing
the inner maker at 5200-5500ft for landing and the VFR flight (Baron) came out from no were passing WL at 5500ft !!

At that time no SSR radar slave was installed at Waterloof nor had the VFR traffic a Transponder – if he did, and
we had SSR, this situation could have been avoided by monitoring the aircraft on radar, may it be from the tower
or from approach at JS on their SSR.

Since then a SSR salve has been installed (i think so) at Waterkloof and it is for this reason that ATC request
if aircraft are transponder equip for monitoring flight paths.

If ATC sees any risk in a reduction in separation between IFR traffic and VFR with no transponder, and they cannot
positively identify the aircraft visually, they will ask you to stay clear.

SPENDING THAT AMOUNT ON A TRANSPONDER ?? I SUGGEST YOU PHONE YOUR LOCAL ATC AND ASK IF THEY COULD GUARANTEE YOU
ROUTING WITH A TRANSPONDER ?? WILL YOU BE ABLE TO FLY IN THE CTR OR TMA OF JS VFR WITH A TRANSPONDER, THE ANSWER WILL
PROBABLY BE NO DUE TO THE NUMBER OF IFR TRAFFIC.

[cobra]

I may added that ATC will make exemption if they are satisfied that the VFR traffic (pilot) operating in the area uses it on a regular basis and is up to date
with procedures or have no other option, as with Demon, landing at Rietfontein.

Demon maybe you could give us some insight on your experiences

[Arnulf]

Hi Cobra,

thanks for this excellent post.

Cobra wrote:

However, ATCs may not enforce or even suggest such change to IFR traffic –
this is normally requested by the pilot to change his/her flight rules. Aerodrome controllers may not control
aircraft on an IFR flight plan approaching the airfield or maintain separation between “their” VFR and IFR traffic,
IFR traffic is a function of approach control/controllers.

As a matter of interest, we never cancel our IF flight plan, simply for the reason you mentioned. On an IF plan
it is the ATC's task to chase all VFR traffic away. On a nice sunny day we might consider an visual approach, but still on an IF plan.

Regards,
Arnulf