TRANSPONDERS, MODE C or S needed?

[EDMO 1078]

I never fly where I need a Transponder, so I am writing this to get some information for a new pilot who says he is surrounded by controlled airspace and needs a Transponder.   I know at one time there was talk about needing the new mode S for certain airspace where the mode C would not be legal.

Also, at one time there was a small Transponder that fit into a round hole in the IP, and I cant remember the name of it.  Would this be a recommended model for someone with a light experimental plane?  Is it mode C or S?

I have flown several planes with Transponders, but never had one in a plane I owned.  Does the Transponder have to be registered to your N-number?   Seems like there were stories in the past of the DEA changing some Transponders of suspected Drug Smugglers so that even if they turned it off, it would still be on when the engine was running so they could track the planes.

Do you need an encoding altimeter for a transponder?

Hoping some good info for a friend, who will NOT be a drug smuggler, will come out of this post.  EDMO

Edited 6 Nov 2015 by EDMO

[birddog486 21]

Ed,

For now it looks like the requirement for ADSB-out is for mode S or a mode C transponder with extended squitter and will be required inside class B or C airspace, above 10,000 ft and above 18,000 which is class A airspace after the 2020 deadline. Pretty much following the Transponder requirements we have now except, the information your sending with the transponder tells them who you are.

 

For now there's still no requirement on having a transponder below 10K feet in class E airspace which covers most of the Eastern half of the country from 1200 feet AGL and 700 AGL over non towered airports unless there under larger class C or B airport airspace.

 

Checkout aircraft spruce on the transponder, they sell one that fits in a round hole in the panel and also some remote mounted transponders that can be hidden.

 

Travis

 

[marksires 484]

ADSB-Out will be required in 2020.  That will require either a transponder with an extended squitter (1090mhz) or a UAT (978mhz) transceiver.  The kicker is that either method requires a WAAS GPS source, and that is where the real expense is.  If I were you, I'd install a decent transponder antenna now (both mode c and mode s with es require the same antenna), and not buy the transponder until a month before I was ready to fly, and I'd buy a mode C then (with an altitude encoder also don't forget)  A lot will change between now and then.

Unless you are going to fly above 18,000 feet, or in Europe a UAT transceiver is ok. In fact the FAA would prefer you use UAT since the 1090mhz frequency will be crowded with all the airlines using them.

When it was close to the 2020 requirement, then I'd look for a UAT with a built in GPS option.  More of those are coming out, and the prices go down with every one that comes out.  With anything electronic, never buy it until you absolutely need it.  They get cheaper, smaller, and more reliable the longer you wait.

 

Mark

 

[marksires 484]

Mode 'S' transponders are coded to your aircraft (check the faa registry, you'll see a mode S code in the registration info).

Mode 'C' transponders are not coded to your aircraft.

You don't need an 'encoding altimeter', they are expensive.  You need a blind encoder, which is a few hundred bucks.

You can install a transponder and encoder in an experimental yourself, but it is subject to the same 2 year transponder check/certification that production aircraft are.  You also have to get it checked/certified before you turn it on in flight.  That check includes a check of you static system, so make sure it is good before you go to get that done.

Mark

 

[gregpro50 64]

I think this post is about me.  I just bought a plane from a member here that is very well equipped but doesn't have a transponder.  I live under class D airspace and would fly through other areas of class D airspace quite often.  Now technically class D doesn't require transponders to enter their airspace and they will let you in but drive you nuts every 5 minutes asking for a position report.  I also would like to use this plane for some cross-country trips and sometimes it's nice to have an extra set of eyes from flight following to help you out.

 

So that being said I'm looking for a mode C transponder to install with an encoder.  At this point I'm not too concerned about the ADS-B requirement.  So I'm trying to figure out what is a good transponder to look for.  A used KT-76A seems to be readily available for under $500 and an encoder can be had for $150 or so.  I know from past use that this particular transponder likes a warm up time before use though. Maybe I should bite the bullet and go for a Garmin GTX 327?  Or should I really be concerned about ADS-B and get one that has ADS-B out?

 

I don't exactly have more money than I know what to do with but for me I do look at a transponder as a safety item and wouldn't mind spending a little to get a good one.  I'm just not sure of what to look for.

[marksires 484]

I wouldn't throw money after a used KT76A personally.  My Avid has a GTX327, but I found it used for a good price.

I'd look at a KT74 (which has ADSB-out capabilities, but needs a GPS source), or the new L3-Lynx.  Appaero (Foreflight) has one that is ADS-B compliant in the works, supposed to be priced well.

[EDMO 1078]

Thanks to all of you for the info - most of it is way over my head - I guess I will just try to keep the ground close while staying away from congested areas and trying to miss the forest of towers they are putting up, and now the swarms of drones that are threatening.  If things get any more technical or expensive, I guess I will just have to imagine I am flying as I sit in my rockingchair or wheelchair!

EdMO

[marksires 484]

I wonder if a paintball gun will take down a drone....

[gregpro50 64]

I wouldn't throw money after a used KT76A personally.  My Avid has a GTX327, but I found it used for a good price.

I'd look at a KT74 (which has ADSB-out capabilities, but needs a GPS source), or the new L3-Lynx.  Appaero (Foreflight) has one that is ADS-B compliant in the works, supposed to be priced well.

I was looking at those but they're pretty pricey.  Impressive though.

Have you looked at the TRIG TT-21 compact transponders?  They are supposed to be ADS-B out capable.

 

 

[EDMO 1078]

I wonder if a paintball gun will take down a drone....

Good thought - maybe make it go blind - my stone-age thoughts were slingshot, pellet gun, bow and arrow (hard to shoot that from cockpit) - maybe crossbow, and they don't make any noise to get you canned.....

EDMO

Edited 6 Nov 2015 by EDMO

[EDMO 1078]

Somewhere in my junk pile from Alaska, I have an old transponder and also an encoding altimeter, but no wiring for either - probably not worth sending to anyone even if I can find them.

EdMO

[gregpro50 64]

It depends what it is really.  An old KT-76A would still do what it needs to do as long as it still works.  If it doesn't there are better options than dumping money into repairing one.  Wiring harnesses are still readily available.

 

Dig it out and throw it in that box and I'll have it tested for you.

Edited 6 Nov 2015 by gregpro50

[KFfan 151]

It depends what it is really.  An old KT-76A would still do what it needs to do as long as it still works.  If it doesn't there are better options than dumping money into repairing one.  Wiring harnesses are still readily available.

 

Dig it out and throw it in that box and I'll have it tested for you.

[EDMO 1078]

It depends what it is really.  An old KT-76A would still do what it needs to do as long as it still works.  If it doesn't there are better options than dumping money into repairing one.  Wiring harnesses are still readily available.

 

Dig it out and throw it in that box and I'll have it tested for you.

If I remember right, this is not a KT something - I forget the brand - Still looking for it - I don't need it tested for my use -

I will probably find it as soon as you buy one! 

EdMO

Edited 6 Nov 2015 by EDMO

[nlappos 413]

I solved this problem with my Avid flyer with an Ebay buying spree. I bought an Edo Aire RT 777 transponder for less than 200, and a simple encoder for 50. I found  great shop in NJ who checked it out for 125 and I have a full mode C system for 400!

Edited 6 Nov 2015 by nlappos

[gregpro50 64]

That looks like a great deal.  $400 for an installed mode C setup can't be beat.

How hard was the install?  I assume the transponder is just power and ground, and then wiring the encoder to the transponder, and splicing into the static port.

I also really like your Samsung tablet there.

Edited 6 Nov 2015 by gregpro50

[cowlove 33]

I got the Trig TT-21 and am super happy with it.  It's under a pound, fits a 2 1/4" hole, and is ADS-B out/1090ES capable once you hook it to any GPS position source.   It was a little on the pricey end, but I was/am very weight and space conscious.  

Jim

 

[gregpro50 64]

So I've been researching the upcoming ABS-B out mandate and I really don't think its going to apply to any of us since I don't think anyone here is going to be flying in class B or C airspace (and certainly not A).  My concern was the class D airspace that I fly in and ADS-B is not required in that.  I don't ever see a situation where I am going to be anywhere near B or C airspace.

I see a lot of people worried about the ABS-B mandate when it won't ever apply to them.

So it looks like any old mode C transponder will work for me.

Edited 7 Nov 2015 by gregpro50

[nlappos 413]

gregpro50,

Yes, I made the harness myself with parts bought online, used pinouts I found on the web. I bought connectors on Ebay (dsub breakout connector) (http://i.ebayimg.com/images/g/z9UAAOSwiCRUiyno/s-l1600.jpg) and just gave it a try. The antenna was a simple dipole that cost $22 on ebay, and its coax was $12. I had the tray with the xpdr, and just epoxied it to the supports behind the panel above the throttle, and tie-wrapped the unit to it behind the panel.

Here is a current ebay listing for a transponder and encoder: http://www.ebay.com/itm/Bendix-transponder-with-a-Narco-AR-850-encoder-/331698223323?hash=item4d3ac138db:g:SBsAAOSwI-BWN7Vz&vxp=mtr

The samsung works great, a little dim in bright sunlight, but still readable.

[allonsye 85]

gregpro50,

Here is a current ebay listing for a transponder and encoder: http://www.ebay.com/itm/Bendix-transponder-with-a-Narco-AR-850-encoder-/331698223323?hash=item4d3ac138db:g:SBsAAOSwI-BWN7Vz&vxp=mtr

This would be a major score.  Likely to go cheap.

[Doublecluch 15]

I solved this problem with my Avid flyer with an Ebay buying spree. I bought an Edo Aire RT 777 transponder for less than 200, and a simple encoder for 50. I found  great shop in NJ who checked it out for 125 and I have a full mode C system for 400!

NLAPPOS

  Is that the Galaxy Tab 4? What app are you running?  I have one and I'm considering velcroing it to my instrument panel instead of buying an iPad. 

Jeff

[nlappos 413]

Jeff

That is an old Galaxy, but instead today I use an Ipad Mini II, using Garmin Pilot. It does all the moving map, and weather (when I have a sim card in it).  I love it and it works very well.

The Ipad and Galaxy both worked well, and both basically suck in daylight readability, the Ipad might be a little better, just a little.

Edited 19 Feb 2019 by nlappos

[Doublecluch 15]

Jeff

That is an old Galaxy, but instead today I use an Ipad Mini II, using Garmin Pilot. It does all the moving map, and weather (when I have a sim card in it).  I love it and it works very well.

 I've been looking at iPad Minis, when I saw your Galaxy I thought hey I have one of those. 

[1avidflyer 1983]

I have a Samsung Tab A tablet that I run Avare GPS free app on.  Works good for me.  Bent up some thin aluminum glued with double sided tape plus a small piece of sticky backed Velcro near the top to keep it in place.  JImChuk