There is some confusion floating around here regarding the Chelton EFIS and FreeFlight GPS.  Keith Tomasen asked me to post the following:

 

According to the AIM (Chapter 5 on Air Traffic Procedures - the section on IFR Flight Plans) says to use /G for aircraft equipped with GPS which have enroute and terminal capability (that's Class A2).  You don't need Class A1, which includes approaches.  Chelton (with the FreeFlight receiver and Chelton software w/ GPS integrity monitoring) is legal for enroute and terminal operations, and for primary navigation as well.  So you can use /G.   Since /G is for filing IFR plans, obviously the point is moot if your unit isn't IFR legal at all.

 

Alan stated that with the FreeFlight (1101 or 1201) you get GPS precision approaches.  As Bryan pointed out, the Chelton is not legal for APV approaches (approaches with precision vertical -- namely, LNAV/VNAV and LPV).  You can use your baro-VNAV to fly a vertical course down to the MDA, but it's still an LNAV approach, not an APV.   You cannot proceed to the lower DA minimums with a Chelton.

 

Bryan is correct on APV approaches, but the statement that Chelton is not currently an approved receiver by the FAA is incorrect.  The Chelton FlightLogic EFIS with the FreeFlight 1201 GPS WAAS receiver is certified for stand-alone IFR navigation under WAAS.  The (experimental) Chelton EFIS SV-Sport and SV-Pro, when equipped with the Freeflight 1101 or 1201, meet the same operational requirements as the FlightLogic.