On Sat, 23 Jul 2005 04:41:18 -0700, wrote:

Not so. VOR is still the primary means of navigation in the NAS. Even the
latest and greatest airline aircraft with dual GPS sensors, dual FMSes, triple
IRUs, etc, cannot be dispatched without operate VOR receivers (in their case
two).

The presumption is that the GPS system can fail at any time; at least in a given
area. WAAS doesn't mitigate that whatsoever.

Could you reconcile your statement with AIM 1-1-20 c.

"7. Unlike TSO-C129 avionics, which were certified as a supplement to other
means of navigation, WAAS avionics are evaluated without reliance on other
navigation systems. As such, installation of WAAS avionics does not require
the aircraft to have other equipment appropriate to the route to be flown."


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)