On Sun, 02 Jan 2005 15:23:47 GMT, "John R. Copeland"
wrote:

WAAS/GPS altitude is used for VNAV approaches.
It works very well, really.
Baro-VNAV is beyond the scope of the CNX80/GNS480.

I wonder why that is, since my encoding altimeter interfaces with my CNX80.
So, if I enter the altimeter setting, I will get a fairly accurate altitude
readout (within 10-20' of my panel altimeter).


As I've posted earlier, the glide-slope needle in my Flight Director
is not driven from the CNX80/GNS480 unless VNAV minima are published.

Well, I just picked up my a/c with the upgraded CNX80. Due to time
constraints, I did not do anything other than fly home and execute the GPS
Rwy 15 approach at KEPM. In any event, this is an LNAV approach with only
LNAV minimums. However, it does have vertical guidance as evidenced by a
screened descent line; a vertical rate of descent/GS table; and also a TCH
at the rwy end MAP.

Although there are no VNAV minima published, I DID receive vertical
guidance on both the NAV page of the CNX80 as well as on the VDI of my
external NSD360 HSI. So, clearly, there was nothing in my CNX80 inhibiting
external VDI on this approach.

I don't understand why your FD doesn't receive vertical guidance on
approaches where it is provided.


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