Understanding G1000 Tones (Cesna 172)

I have been trying to understand how to use the G1000 autopilot. I’ve learned how to set a flight plan and load the approach I want. I’ve also set the Nav1 radio correctly. I’ve successfully captured the GS on a few different approaches.

One tone I notice occurs extremely close to the runway. If I’m not mistaken, this one is a series of beeps (maybe four or five). I’m not exactly sure what this tone means, but I’m thinking it is an alert that if you don’t see the runway now, you should go around.

My real question relates to a flight I did yesterday. Flying into KBNA runway 31. I had 111.95 on Nav1, was flying at 2600ft when I crossed HOLER. The glideslope indicator crossed my current altitude, but the plane didn’t follow it and a constant tone started blaring. Any idea what that tone would mean and/or what I might have done wrong? Maybe it has something to do with the RADAR note I see on the chart…?

I recommend you download the G1000 NXi from the Marketplace if you haven’t already. This is the improved version that will eventually be integrated into base simulator code. The stock G1000 has some flaws and really should be considered deprecated.

What you’re hearing are the Marker Tones, Outer, Middle, Inner. Pre-GPS, the OMIs would be a back-up to the directional instruments, confirming to the pilot their relative position following the ILS “feather.”


You can use them for that purpose.Generally, the Glideslope on an ILS would be picked up, meaning the plane should start following final vertical guidance to the runway, right around the time you hear the Outer Marker beacon.

My recommendation is to view some instructional videos on the G1000 NXi on YouTube by author “Kip on the Ground.” He’s very dialed into the NXi and how to use it.

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To hear the marker beacons, you have to turn on the Nav radio audio, right? I didn’t have mine on.

Also, the new tone I heard was a constant on blaring. It only stopped once I turned off autopilot. Seemed like an alarm.

I’ve seen Kip on the Ground’s videos. Thank you! They are very helpful.

I will note, I had been approaching for runway 12 when ATC sent me to 31… So I got a little confused. Was cleared to land, but it took me a while to get on the approach line (as I had to fly back away from the airport to it)… I’m thinking maybe I wasn’t cleared anymore or something. After turning off autopilot and flying to almost touchdown, ATC told me to go around… I’m wondering if maybe I wasn’t on RADAR and that’s why I got the alarm…?

Could be a stall horn.

I am familiar with that one. Wasn’t the stall horn. Thanks though!

The Nav radio volume doesn’t affect the marker beacon sounds. The marker beacons are on set frequencies not tied to the nav frequencies/audio. The G1000 has a built-in audio system with a marker beacon receiver. The “mkr/mute” button on the audio panel is used to turn off the audio for the beacons (outer, middle, inner). Or you can just ignore them for the little bit of time that the beacon receiver is active. You’ll still get the panel lights for “O”, “M”, or “I” even if the sound is muted.
The “radar” on the chart is a little more complex. Radar is not required for this approach, but it’s shown due to some older requirements. Since most (almost all) instrument approach procedures are designed to allow a non-radar transition from the enroute phase of flight to the approach phase, any instrument approach that does not have published transitions should show “Radar” on the chart. It’s confusing, and the rationale doesn’t really hold very well anymore. But it still exists and still shows on the charts.
P.S. I don’t think the mute button is actually implemented in the sim, but I’ll check later when I’m in the sim.

It could be the tone you hear when you’re within 1000ft of your selected altitude, it’s a long continuous beep that is played to warn the pilot that altitude capture is imminent afaik.

That seems possible.
Maybe I didn’t have barometric set properly.

Planning to try it again.

All replies are much appreciated!

I was referring to the selected altitude for the autopilot, not the barometric pressure. You can test it on the ground by turning the ALT dial, you should hear the tone when the selected altitude is within 1000ft of your current altitude.
Good luck! :slight_smile:

The “within 1000” feet is a single tone. So what causes beeps close to the runway? I still think it’s the OMI beacons.

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Its the Outer, middle and inner beacon. They are being removed at a lot of airports in real life.

Thats the sound you are hearing…. Just go fly around the end of the runway and just cross the end horizontally you will even just hear it, doing circles around the end of the runways…