RV-14E
Well Known Member
Executive summary: At least 80 undocumented audio alerts are available on most GRT EFISs. This post explains what they are and how to enable most of them.
If you want the highly detailed, verbose version of this information, you may visit my blog post here. What follows is primarily the key points.
Greetings.
As many folks know, most GRT EFISs can provide audio alerts to your intercom by uploading wav files to the EFIS with specific filenames as has been explained GRT. For example, for an audio alert to sound when the fuel flow is excessive, you would copy "fuel_flow.wav" to your EFIS from a USB drive using the Set Menu (complete list of GRT's predefined audio alerts is below).
However, based on some information that GRT publicly provided several years ago, I have been able to identify nearly 60 additional available voice alerts (at least 20 more are probably available). They are listed at the bottom of this post.
To use the additional alerts, it's helpful to understand how the EFIS manages audio alerts. Briefly, alarms are assigned a number internally so that when one occurs (e.g., high RPM), the EFIS looks for a file with the associated alarm number in its filename (in the case of high RPM, it would look for alarm0010.wav) on the USB drive and/or the EFIS. If it finds the file, the file is played.
Thus, if you would like to make use of the alarms that I have identified below, follow these steps:
There are additional factors to consider which you can read on my blog post. Please, please, please read that absurdly long post. I also explain how I came to figure this out so you can help contribute to documenting additional alarms.
Key considerations:
If you want the highly detailed, verbose version of this information, you may visit my blog post here. What follows is primarily the key points.
Greetings.
As many folks know, most GRT EFISs can provide audio alerts to your intercom by uploading wav files to the EFIS with specific filenames as has been explained GRT. For example, for an audio alert to sound when the fuel flow is excessive, you would copy "fuel_flow.wav" to your EFIS from a USB drive using the Set Menu (complete list of GRT's predefined audio alerts is below).
However, based on some information that GRT publicly provided several years ago, I have been able to identify nearly 60 additional available voice alerts (at least 20 more are probably available). They are listed at the bottom of this post.
To use the additional alerts, it's helpful to understand how the EFIS manages audio alerts. Briefly, alarms are assigned a number internally so that when one occurs (e.g., high RPM), the EFIS looks for a file with the associated alarm number in its filename (in the case of high RPM, it would look for alarm0010.wav) on the USB drive and/or the EFIS. If it finds the file, the file is played.
Thus, if you would like to make use of the alarms that I have identified below, follow these steps:
- Decide what message you want your EFIS to voice for each alarm you're interested in having.
- Create the voices in wav file format using an online text-to-voice service.
- Save each message with the proper filename (alarm####.wav - must use four digits).
- Copy your new alarm####.wav files onto your USB drive into a folder named Alerts.
- Plug the USB drive into your EFIS.
- You're done. Verify it works on the ground with engine off, prior to flight.
There are additional factors to consider which you can read on my blog post. Please, please, please read that absurdly long post. I also explain how I came to figure this out so you can help contribute to documenting additional alarms.
Key considerations:
- If you decide to copy your alarm files to your EFIS, your collection of selected audio files should not exceed 100 MB in size.
- Keep in mind that the EFIS will play the entire file when the alarm triggers, so very terse messages are probably best.
- Alarm files on the USB drive are played first then the file on the EFIS is played next. Do not keep the same file on both the USB drive and EFIS if you don't want to hear both files.
- I have verified that wav files in Microsoft PCM, 16-bit format with either 44.1 kHz or 22.05 kHz sampling rates work. Other wav formats and sampling rates might also work. The free Open Source Audacity program can help you manipulate audio files.
- There are lots of text-to-speech providers available. I use Amazon Polly, which requires a (free) Amazon Web Services account.
- I have not identified all the alarms. You can help find others. I explain how to do so in my blog post here.
- My AUX inputs probably don't match yours. Be sure to use messages that match your configuration.
- I make mistakes.
GRT's Documented Predefined Audio Alerts
- Minimum oil pressure (oil_pressure.wav)
- Minimum fuel pressure (fuel_pressure.wav)
- Obstacle alarm (obstacle.wav)
- New traffic within alert criteria (traffic.wav)
- Autopilot disconnect (ap_disconnect_advisory.wav and ap_disconnect_warning.wav)
- Maximum oil temperature (oil_temperature.wav)
- Maximum CHT (cht.wav)
- Low/High Voltage (low_volts.wav and high_volts.wav)
- Maximum fuel flow (fuel_flow.wav)
- Vne exceeded (speed.wav)
- Trim alert (from GRT pitch servo), repeats every 30 seconds (trim.wav)
- SAP height above runway at 500, 200, and 100 feet (100.wav, 200.wav, 500.wav)
- Minimums if decision altitude is set (minimums.wav)
- Approaching minimums when 200 feet above decision altitude (approaching_minimums.wav)
- Waypoint sequence (waypoint.wav)
Additional Undocumented Alarms
Columns:- Alarm: Alarm number (remember, the alarm####.wav filenames need to be four digits).
- Message: My suggested voice message for the alarm. You can use something different if you prefer. Note: Your AUX inputs are probably different than mine so those associated messages will need to be changed to match your configuration.
- Description: What the alarm represents.
- Predefined: If it is also a predefined alarm, the associated special filename.
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