(Ben Jackson) wrote in
news:PeIab.524381$uu5.87404@sccrnsc04:

What ACUs will allow you to select GPS display when a LOC
frequency is tuned in on the NAV? I know UPSAT's won't
actually select the GPS until you tune a normal VOR on the
associated NAV.


With the installations we have, the HSI has no idea what's
selected, or what frequency. There's a push/push button, which
cycles between VOR & GPS, and the HSI just gets voltage from
whichever is selected. There is no logic at all to prevent
using either one. The nav radios and the GPS are completely
independent, and have no relation to each other in any way.

--
Regards,

Stan