Aerocruze 100 ‘GS FLG’

[erkmann]

My Aerocruze 100 is driven by a G430W. Twice, on vectored RNAV approaches, I’ve been on altitude, on course, passing the FAF with the ARM indication on the AP. What can cause the indication to go to GS FLG?

 

[Jesse Saint]

You have to have a glideslope needle and have to be below the glideslope.