GTX 327 or 330

[N787R]

I am trying to decide what transponder to order.

1) I am not sure how mode S is supposed to work. With mode S, does it mean that I do not need to punch in any code from ATC?

2) Also how does the traffic alert of 330 work? If I install a 430, do I get traffic alerts?

3) Do you have any suggestions for alternative to Garmin ?

Thanks

Ben

[Geico266]

3. Stick with Garmin.
2. Traffic only works if you are in a radar contolled area, and I think only on the 530 & 430.
1. It gives ATC a serial number. You still have to squawk the codes.

[kevinh]

I have a 330 - and love it, especially in the crowded bay area.

However, TIS is being desupported (I forgot when - but not too far away). At that point one of the main reasons for buying a 330 over the 327 goes away.

[MSFT-1]

I really like the GTX 330. It is significantly more expensive but has several nice features.

You still will need to punch in a squawk code when ATC gives you one though they can see your tail number, type, airspeed etc from the mode S.

The 330 will automatically go silent when you are on the ground. It actually says "Ground" on the display when you land. Nice.

If you are in good TIS coverage the traffic is very impressive. I often don't see airplanes near me when it annunciates the traffic. It shows direction, relative altitude, whether the bogie is climbing, level or decending and its direction of travel. You can mute the voice output.

The display on an EFIS or on the 430 is very readable and useful.

The key to the value of the traffic is where you fly. I live near a very active major airport and several military bases (southern Virginia) and so I always have TIS coverage but I know when I fly to southwestern Virginia the TIS coverage is much more sparse.

[MSFT-1]

TIS is going away but it will be several more years (like 2014 I think). Also, the software in the GTX-330 is designed to be upgradable to support ADS-B (or so I've been told).

[DavidBurton]

Originally Posted by N787R

I am trying to decide what transponder to order.

1) I am not sure how mode S is supposed to work. With mode S, does it mean that I do not need to punch in any code from ATC?

2) Also how does the traffic alert of 330 work? If I install a 430, do I get traffic alerts?

3) Do you have any suggestions for alternative to Garmin ?

Thanks
Ben

Hi Ben,

The GTX 330 is capable of receiving digital data in the cockpit, broadcast up to you from ASR-9 radars. These are the approach radars typically used around major class B airports . The data will give you traffic information that shows the location, height relative to you, direction and distance. The unit will annunciate a conflict. I won't fly without it. You can display the traffic on a number of displays. GNS 430s and GPS 396s for example are popular. The newer ASR-11 radars that are replacing some of the ASR-9s are capable of sending up traffic information but the FAA is not enabling this at this time. I hope it changes. I think traffic in the cockpit is so important that I'm willing to deal with Mode-S until ADS-B is rolled out.

DaveB

[GaryK]

The traffic will also be displayed on the Grand Rapids Technology EFIS maps if you purchase the ARINC 429 adaptor.


Gary
N715AB