Another stupid GNS430 trick

Guest Discussion
1

Stop me if you’ve heard this one before…

For situational awareness and a rough idea of runway centerline extension, set your GPS direct to the airport (which it probably is already), set OBS mode, and twist the course pointer to runway heading. The needle will show more or less where the runway centerline is (actually a bearing to the ARP, but close enough for most purposes). Handy for getting set up for approach when arriving from an oblique angle and you’re having trouble picking out the airport.

Meanwhile, your GPS will be reading out the bearing and distance to the airport (set the heading bug) so you know where to keep looking.

This seems obvious, but I never thought of it until yesterday (arriving at an oblique angle and having difficulty picking out the airport.)

OBS mode is one of those things that made me ask “why?” but for which the answers are slowly emerging.

Somebody ought to write a “getting the most out of your GPS” book if it hasn’t already been done…

2

Dave,

Your technique is interesting – it wouldn’t have occured to me to do that because I keep thinking “VOR” when I hear “OBS”. I use a Garmin 295 – don’t have my Cirrus yet, but I think they are similar with the 295 functions being mostly a subset of the 430.

What I do to get guidance to the airport is say “Goto”, then I choose an approach that matches the direction from which I’m coming. Then select “vectors”. It draws a 30nm heavy magenta line from the FAF in a sort of extended final approach segment, which is often the same as the extended centerline. I bet the 430 can do that as well.

That way you can get course guidance from the map as well as the compass.

I normally use my '295 with the map page showing and four numbers, no HSI, showing on the right. That leaves more space for the map. I keep distance, track, bearing to station, and turn, which is the difference between track and bearing.

Rob

Stop me if you’ve heard this one before…

For situational awareness and a rough idea of runway centerline extension, set your GPS direct to the airport (which it probably is already), set OBS mode, and twist the course pointer to runway heading. The needle will show more or less where the runway centerline is (actually a bearing to the ARP, but close enough for most purposes). Handy for getting set up for approach when arriving from an oblique angle and you’re having trouble picking out the airport.

Meanwhile, your GPS will be reading out the bearing and distance to the airport (set the heading bug) so you know where to keep looking.

This seems obvious, but I never thought of it until yesterday (arriving at an oblique angle and having difficulty picking out the airport.)

OBS mode is one of those things that made me ask “why?” but for which the answers are slowly emerging.

Somebody ought to write a “getting the most out of your GPS” book if it hasn’t already been done…

3

Dave - it is even easier than that. Mind you I don’t have the fancy ‘B’ or ‘C’ model just the ‘A’ model; however, I am sure your can figure this out too.

When you put a direct-to destination generally a “data block” appears on the ARNAV screen in the lower left corner. That data block displays amoung other things the Bearing, Desired Track, and Grnd Track. The Bearing is the one I watch to do the same thing you describe. For example, if the bearing (to the airport) and the ground track are both 240 and I want to line up for runway 27 I would simply turn left 30 degrees for a 30 degree angle of intercept to the runway 27 center line. The trick is to watch the ‘bearing’ number in the data block. It will increase in value. When it becomes (or shortly before it becomes) 270 turn the plane to the right so that the ground track and bearing both show 270. It is really quite straightforward and doesn’t require twisting, tuning, etc.

4

Why not just use the heading bug?

Stop me if you’ve heard this one before…

For situational awareness and a rough idea of runway centerline extension, set your GPS direct to the airport (which it probably is already), set OBS mode, and twist the course pointer to runway heading. The needle will show more or less where the runway centerline is (actually a bearing to the ARP, but close enough for most purposes). Handy for getting set up for approach when arriving from an oblique angle and you’re having trouble picking out the airport.

Meanwhile, your GPS will be reading out the bearing and distance to the airport (set the heading bug) so you know where to keep looking.

This seems obvious, but I never thought of it until yesterday (arriving at an oblique angle and having difficulty picking out the airport.)

OBS mode is one of those things that made me ask “why?” but for which the answers are slowly emerging.

Somebody ought to write a “getting the most out of your GPS” book if it hasn’t already been done…

5

Clever way of getting on thecenterline!

Paraphrasing Paul Simon: “50 ways to use you GPS…”.

With NDBs abound in Europe (and not in SR20’s…), I’ve been figuring how to use the 430’s for NDB simulation by setting the 2nd GPS DIRECT TO the NDB, reading the bearing TO and projecting this on the HSI imagining the arrow superimposed…"

That book is a good idea. Better than pasting messages together from the board…

Han (N144CD)

Stop me if you’ve heard this one before…

For situational awareness and a rough idea of runway centerline extension, set your GPS direct to the airport (which it probably is already), set OBS mode, and twist the course pointer to runway heading. The needle will show more or less where the runway centerline is (actually a bearing to the ARP, but close enough for most purposes). Handy for getting set up for approach when arriving from an oblique angle and you’re having trouble picking out the airport.

Meanwhile, your GPS will be reading out the bearing and distance to the airport (set the heading bug) so you know where to keep looking.

This seems obvious, but I never thought of it until yesterday (arriving at an oblique angle and having difficulty picking out the airport.)

OBS mode is one of those things that made me ask “why?” but for which the answers are slowly emerging.

Somebody ought to write a “getting the most out of your GPS” book if it hasn’t already been done…

6

Why not just use the heading bug?

The heading bug won’t directly tell you when you’re going to intercept the runway centerline. You could just watch the BRG reading until it matches the runway heading (which is what OBS mode does) or use Walt’s trick instead.

7

We call it the Mexican ILS.

8

Holy thread resurrection, Batman… :slight_smile:

9

I used this on smoggy days in LA to KWHP.

10

17.5 years! New record?