GPS Navigator Usage and Confusion

[Hang 4]

If you use APR instead of NAV you will get lateral guidance but will also be armed for the GS. So the aircraft if on AP will descend possibly without a clearance.

Fair point. I've always been vectored into the approach at an altitude well below and far from the glide slope intercept, so it hasn't been a factor. Having said that, NAV sounds like a better practice than APR. I always learn something new with these discussions.

 

[midlifeflyer]

Fair point. I've always been vectored into the approach at an altitude well below and far from the glide slope intercept.

Most of the time, it's not a big AP problem, but I don't think it's about "it's not a problem until it is." "Join" is primarily a traffic management instruction and it usually is far from the FAF, although I recall one incident from my years in Denver when a pilot was dinged for descending from the IF without being cleared. I've received "join" instructions a more than 15 nm from the FAF and not cleared until the GP was about a mile from centering (and then I had to prompt ATC). Client got a "join" with an altitude during a lesson a few weeks ago not far from the IAF.

The issue I do see is pilots not understanding the difference between being "cleared for the approach" and being cleared to follow it laterally but not vertically and how NAV vs APR (and now vs VNAV) fits in. I give "join" instructions during recurrent training often to see what the pilot does (with or without an AP), so I get to see it.

 

[Steamflyer]

The issue I do see is pilots not understanding the difference between being "cleared for the approach" and being cleared to follow it laterally but not vertically and how NAV vs APR (and now vs VNAV) fits in. I give "join" instructions during recurrent training often to see what the pilot does (with or without an AP), so I get to see it.

This is an important point - many times have been asked to joint the FAC, but that is not a clearance to descended whether on a GS or via step-downs if non-precision approach. Cleared for the approach is permission to descend. Pretty straightforward, but seems to confuse some students at times.