track fpa v nav fpa selection

[newbiea320]

Hi there,

I'm in the midst of type conversion on to the A320 and trying to get my head around the various modes and how they are selected for non precision approach.

My understanding is that you can fly a NPA in either Final App, Nav/FPA and Track/FPA

I'm trying to understand how you would fly a NAV/FPA approach and how you would select it i.e. which button presses are required:

Assuming I am given a heading and cleared approach will the aircraft lock on to an inbound radial for the approach automatically or do I have to set up a direct to radial inbound or is it only possible to be in nav mode if cleared direct to a point on the final approach path?
In order to use the FPA function do the flight directors have to be off and the bird switched on and if I do that by pushing Track/FPA button will the aircraft not drop into Track/FPA?

Just trying to make sense of it and grateful for any help!

Thanks

A320newbie

[upontop325]

The flight directors do not have to be selected off. When you toggle the track/FPA, the AP will adjust the a/c’s heading to fly the selected track. As long as you are on a track that will intercept the course in the FMS, you simply press the NAV button (the dot will show up beside the selected track on the FCU,) and it will capture in NAV mode. Make sure to verify that NAV displays on the FMA (the track digits disappear from the FCU, just the dot remains. ) For the the vertical part of the approach, you can preset the required FPA and pull the FPA knob when you reach the required descent point.

To fly fly a track/FPA, just use the track selector to dial the required inbound track as you’re joining the centreline...the FPA part is exactly the same as the first example.