"JPH" wrote in message
news:TjYog.11140$f76.5031@dukeread06...

Good question. I'm sure that will be an option in the not too distant
future, but right now you can't mix and match ground-based systems with
GPS on published procedures due to TERPS requirements. That's another set
of guidelines that allows substitution with GPS in some circumstances, and
already you may have seen NOTAMS stating "Procedure NA except for IFR
certified GPS equipped aircraft" where the NOTAM specifically allows
substitution for DME or ADF ancillary equipment.


It's an option now. See AIM para 1-1-19.f.:

http://www.faa.gov/atpubs/AIM/Chap1/aim0101.html#1-1-19