When to use the backcourse option approach?

jetman35 wrote:

When do I use the Approach button?

This is an easy one: Once ATC has finished telling you the gory details of your approach -- I'm talking about the part that usually ends with "...descent and maintain (xxxxft) until established on the localizer." --it's best to really wait until you're at that altitude --- that's when you press the APP button.

If ATC hasn't made a mistake with your altitude or heading you should notice the aircraft reacting banking left or right trying to find it's way through the eye of the needle.
This is your confirmation that everything is going to be fine and you can start breathing again 😀

I have been selecting the Nav button on my final attitude and heading and that will get me to the selected runaway. Are you saying that if I use the Approach option, that will get me in no matter backcourse or primary course?

Jetman

jetman35 wrote:

I have been selecting the Nav button on my final attitude and heading and that will get me to the selected runaway. Are you saying that if I use the Approach option, that will get me in no matter backcourse or primary course?

Jetman

I'm not sure why you wanna mess with Backcourse in the first place when all you wanna do is get to your destination.

Regarding the radio stack, once ATC has assigned the RWY for you, look up the frequency for that RWY on your map and let's say it is 110.35 - you'll have to dial that into your NAV1 radio, the STBY one on the right. Now to activate what you just dialled in, you have to get it to the part on the left (Active).
You do that by clicking on the little left/right pointing arrow just below.

Try that and don't get it confused with the NAV Mode switch or the NAV Hold button on the panel.

The ILS and the backcourse are two separate elements.

You use the approach button if you'd like the AP to hold the approach for you, but only on an ILS approach, where the localiser and GS station are at the beginning of the RWY threshold. Here, you just need to dial in the frequency information, runway course, and within 10nm of the runway, press APP. This does not land the aircraft for you, it only holds the approach stable to 200ft.

You'd "mess" with the backcourse button, as Tailhook so eloquently puts it, because in some circumstances, wind doesn't always play the part we want it to.

For example, let us suppose that runway 09 at Funky Airport has a full ILS installation. However, the wind for today is 12/260 gusting to 19. That means, that to land on runway 09 at Funky Airport would be suicidal because you'd effectively be landing with a 19kt tailwind. So, we opt to land on runway 27. This end of the runway doesn't have an ILS system, but we are in IMC conditions so really need some sort of aid. Therefore, we can track the runway by reverse sensing (right is left and left is right) the localiser in RWY 9; the opposite end. Here, the backcourse button serves the purpose of the APP button, it'll hold the backcourse approach, i.e. the approach opposite the runway. Bear in mind, that only in very rare circumstances does a backcourse approach come complete with a GS.