Copyright © 2015  Grand Rapids Technologies, Inc.

Electronic Flight Instrumentation for Experimental Aircraft Since 1991

Data Recording

Data recording goes along with last week’s feature. In addition to saving display unit settings on your USB thumb drive, you can record flight data for later analysis and even for playback on your display unit. (On the ground, of course.) See the bottom of this page for information on how to use the free online engine analysis provided by SavvyAnalysis.com (partial screenshot shown here).



What data can I record?

There are two basic types of files that you can record off the EFIS.

  1. A simple “snapshot” still shot of the screen. This is saved as a PNG file on your USB drive. (HX, HXr and SX only using the most current software as of May 30th, 2013).
  2. A “demo file” recording of the EFIS and EIS parameters for later playback on the display unit itself. This includes all of the serial data as well as a recording of flight instrumentation data, GPS position, synthetic vision features, map data and EIS engine monitor data.

How to Take a Snapshot (HX/HXr/SX)

  1. If you haven’t done so already, load the newest display unit software (16-20 May 2013).
  2. Go to SET MENU page > General Setup.
  3. Scroll to the bottom of the screen and find “SNAP Button.” Highlight it and select YES.
  4. “SNAP Button Saves Menu”- Select YES to always display the softkey labels and NO to never display softkey labels in the screenshots.
  5. To imprint the PNG filename on the snapshot image, select YES for “Show DEMO Filename.”
  6. Save all settings. Your display unit will now have a “SNAP” button on many screens where there is an empty softkey. Notice that it will also display a SNAP button on menu screens. This can be very useful for recording settings in picture form to share with your friends (ie. Autopilot gain settings, etc) or sending them to us for troubleshooting.
  7. To take the picture, simply press SNAP to save the screen image to the installed USB stick.

How to Record Flight Information

Demo recordings can be recorded on a one-by-one manual basis or you can set up your EFIS to automatically record every flight. Files are not overwritten, so eventually you will need to either erase the USB stick or install a new one. Most flights average less than 1 MB/minute. This means that if you have a 2GB USB stick, you can record over 30 hours of flight time. If you use an 8 GB memory stick, you can record over 100 hours without thinking about it. Add “change or erase USB stick” to your oil-change checklist to make it really easy.

Go to SET MENU > General Setup. Highlight DEMO Settings (right above the SNAP settings) and press the right knob to activate the menu. Here you’ll find several choices.

To imprint date and time in the upper left corner of the recording: Choose YES next to “Use Date/Time in Filename.”  

Specify the maximum file size of the recordings (MB): Choose from 1 to 15 MB under “Max File Size.” You can specify how big you want the files to be for easier handling or emailing. A typical recording is less than 1 MB per minute. Yours may be more or less depending on how much data is being recorded. Upon reaching the max file size, the display unit will stop recording momentarily to write the data to the USB stick. SO, the bigger the file, the more continuous data you will get. The smaller the file, the more often it will save the data.

Specify maximum recording time in minutes: Choose from 1 to 120 minutes under “Max File Time.”

Start and save recordings automatically: Under the Automatic Start/Stop heading, choose to record nothing automatically (OFF), start automatically, stop automatically, or start and stop automatically. When automatic data recording is enabled, the EFIS will start and stop/save automatically when the Auto Start and Auto Stop menu settings are reached, whether it’s a specified RPM, Airspeed, Ground Speed, or N1 for turbines. Do not turn off the EFIS before or immediately after these limits are reached; it will take the display unit a few seconds to write the data from the last file recorded to the USB stick.   

Start and save recordings manually: In flight or on the ground, press NEXT repeatedly or MORE (HXr) until you see the DEMO softkey. START starts recording the demo. STOP ends and saves the demo. When manually recording, do not forget to STOP the demo, as this is the action that saves the flight from temporary internal memory to the USB stick.

What can I do with the recordings?

Snapshots are nice for times when you want to record things like really high ground speed or unusual performance, unusual terrain views on the synthetic vision, or neat weather picked up by ADS-B. We use customer-supplied snapshots almost exclusively for the graphics in our new manuals.

You can play back the demo file recordings directly on your EFIS to debrief a flight or review flight testing performance information. From the PFD screen, press NEXT or MORE until you see the DEMO softkey. Press it to PLAY the demo. If multiple demo files are on the USB stick, you will be taken to a menu page where you can select the file to play. Keep in mind that data on the USB stick can be recovered and analyzed by NTSB authorities after a wreck, similar to a “black box.” Because demo files record all the data from the AHRS, magnetometer, and other sensors during flight, they are useful for our techs to help customers solve problems.  

EIS engine monitor data can be used in a couple of ways. You can download the EIS LOG program to open the raw demo files and read the EIS data in textual columns. You can also upload the raw demo files to SavvyAnalysis.com for a very easy and quick way to graphically analyze your engine performance data. This is a free service– you just need to set up your log-in and aircraft information with Savvy Analysis first, then upload your GRT demo file. It’s a cool feature that can help isolate engine problems before they develop into major issues. See the Savvy Analysis screenshot below from a GRT demo recording. This one compares EGT to fuel flow, but you can select dozens of combinations to view and compare. Note that all EIS data must be recorded through a GRT EFIS unit because the EIS does not have the capability to save data independently.

If you have some unique or interesting demo files or snap shots you would like to share for our website, we want to see them! Please send them to us. (5 MB limit!)