Steven P. McNicoll wrote:
"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


I realize that GPS can be used as a substitute, and pointed that out in
my message.
His question was why the ground based procedure didn't have a chart note
"ADF or GPS required". What I was stating is that TERPS criteria does
not yet allow combining ground based and GPS on the chart, that's why
the procedure does not say "ADF or GPS required" (A temporary NOTAM can
address GPS but the chart can not). As I said, you can use GPS to
substitute in some situations based on regulations other than TERPS, but
TERPS criteria does not yet allow GPS notes to be charted on ground
based procedures (except on the old GPS overlay procedures).
TERPS criteria still requires ground based procedures to be built based
only on ground based equipment, so your not going to see a "GPS
required" note on a ground based procedure.

JPH