ADS-B Transponder -- Do I need an ES?

[bret]

SO.....by 2020 we all need a position source" (gps) which meets FAR 91.227 like a 430?

[az_gila]

Originally Posted by RONSIM

to the "all-in-one" box, such as Freeflight or Navworx - (and, again, hopefully others).

1. No ES TXP needed
2. No other "position source" (for experimentals and LSAs) such as an expensive 430/650.
3. The traffic and weather can be displayed on my iFly or my iPad, or other inexpensive screens.

These advantages look like real money savers for folks who don't want/need avionics that represent a dollar value that is a large percentage of the value of the aircraft.

I think the stuff you mention will be the solution for a lot of certified aircraft - most of which will have a value that is a low multiplier of the certified Garmin 430/650 boxes...

Installation costs will be minimal.

[BobTurner]

Lot of confusion here.
1. The comparison between mode SES and UAT is for transmitters, e.g., ADSB-out. Now, many but not all UAT boxes also have a ADSB-in receiver. And, some but not all UAT boxes have a built-in gps. And some of those gps units have been certified by the manufacturer to be compliant with the FAR 91.227 requirements. Some have not.
2. Whatever transmitter you use, it has to be fed with a position source (currently only gps boxes) which meet the requirements spelled out in 91.227. It does not have to be an ifr navigator with a database, and there are boxes available not cheap but a lot less than a 430W.
3. There are no exemptions for EAB aircraft, although one company has chosen, for its own reasons, to make a certain box available only to EAB. The FAA is continuing its decade old policy of requiring an STC for anything installed in normally certified aircraft. But otherwise EAB and certified aircraft are bound by the same rules.
4. Another complication is that despite all the rules the FAA failed to require any communication protocols. So you must make sure the position source you buy can be 'read' and understood by the transmitter. For example, a 430W does not output the correct data unless it has updated software so that 'ADSB+' is a serial output option. Currently a Trig 31 will read this but only software 3.12 or higher! And a TT 22 won't read it at all (Trig says "soon"). UATs with built in compliant gps units of course should not have this problem.

[shuttle]

Just an FYI but in the UK the CAA has agreed to a trial of uncertified gps as a position source to a Mode S ES transponder for ADS-B Out. (All 1090 - we are not going 978 in Europe).

This allows the connection of a portable aviation gps to the transponder. The Trig and Funke transponders both set the ADS-B SIL (Source Integrity Level) to zero if fed with an NMEA 0183 datafeed.

It is this setup that the trial is seeking to evaluate. The theory being it is better to have people broadcasting their position via ADS-B Out fed by an uncertified gps than not broadcasting their position at all because they will never install a certified gps.

Incidentally you may also find some of the other related activities going on in the UK of interest. See here: http://www.fasvig.org. I am the Programme Coordinator for the Future Airspace Strategy VFR Implementation Group.

Steve