Check Airman
Yes I think you are correct for A320/330/340
via data page gps alt is available on the cdu.
although it’s been a while .
For 777 as far as I know, it’s not possible to read the gps alt on the cdu on any page , never saw it on the PFD on any a/c. Standing by for more technical heads to advise.
I only mention it because a previous post refers to gps alt as 6200ft , which corresponded broadly with the stby. altimeter apparently.
If gps alt was readily readable it could be a great help when faced with air data issues .
Last edited by Jack D; 24th Jan 2021 at 02:35.
Reason: Spelling