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Garmin G5 Software Update: What Certified Owners Should Check
A G5 software update is not just a download on a certified aircraft. The current software version, applicable STC documentation, aircraft configuration and return-to-service paperwork all matter.
What Is the Current Garmin G5 Software Version?
Garmin Service Bulletin 26099 Rev A identifies G5 Software Version 8.70 for installations using the Part 23 AML STC SA01818WI. The bulletin says the update is optional for the affected installations and that it is authorized by STC SA01818WI Master Drawing List Revision 34.
Version 8.70
SA01818WI MDL Revision 34
Garmin Service Bulletin 26099 Rev A
Garmin says software updates require avionics-shop work and a logbook entry.
What Changed in G5 Software 8.70?
Garmin’s 2026 Service Bulletin identifies several changes in version 8.70:
- Corrected the backlight dimming setting.
- Added combined use of NAV radio RS-232 and ARINC 429 data.
- Added a barometric-scale blink feature.
- Improved microSD card reader robustness.
These changes may look small, but certified avionics software is part of the approved system configuration. That is why an owner should not treat a G5 update like updating a consumer tablet.
Does a Certified G5 Need an Avionics Shop for Software Updates?
Yes, according to Garmin’s current support guidance. Garmin states that certified G5 software should be updated at an avionics shop because software changes functionality and, for certificated aircraft, require a logbook entry.
Garmin’s support instructions also say that the update is loaded to a FAT32-formatted microSD card and installed through the G5. The procedure warns not to remove power during the update.
Why the Software Version Matters for a Certified G5
| Why check it? | Reason |
|---|---|
| Approved configuration | Certified avionics software versions are tied to the applicable approved documentation. |
| System compatibility | A G5 can interact with navigators, autopilots and other avionics, so software compatibility matters. |
| Maintenance documentation | Garmin specifies applicable maintenance and flight-manual documentation for certain approved updates. |
| Aircraft records | Garmin states that certified G5 software updates require a logbook entry. |
G5 Software 8.70: Documentation You Should Check
For the 2026 version 8.70 update, Garmin Service Bulletin 26099 Rev A identifies the documentation that must be available to the aircraft operator/owner before return to service following the update.
| Document | Revision identified by Garmin |
|---|---|
| G5 Part 23 AML STC Maintenance Manual / ICA | 190-01112-11, Revision 10 or later |
| Airplane Flight Manual Supplement or Supplemental Airplane Flight Manual for G5 | 190-01112-13, Revision 9 or later |
Always verify the current revision before maintenance because Garmin documentation can change independently of the hardware model.
How the G5 Software Update Process Works
- Identify the aircraft configuration. Confirm whether the aircraft uses the certified G5 under STC SA01818WI.
- Check the installed software. Record the existing G5 software version and configuration.
- Review current Garmin documentation. Confirm the update is applicable and identify any associated service bulletin or document revisions.
- Prepare the microSD card. Garmin’s support procedure specifies a FAT32-formatted microSD card with adequate free space.
- Load the software. Transfer the authorized update to the card using Garmin’s current instructions.
- Install the update. Insert the card into the G5 and follow the on-screen process.
- Do not interrupt power. Garmin specifically warns against removing power while the update is loading.
- Complete required checks. Verify the unit operates correctly and perform the applicable maintenance/configuration checks.
- Update aircraft records. Complete the required logbook entry and documentation before return to service.
Can You Update a Certified G5 Yourself?
Garmin distinguishes certified-aircraft support from ordinary consumer-style software updating. Its current support guidance says certified G5 software updates should be performed at an avionics shop and that the update requires a logbook entry.
That does not mean an owner cannot physically prepare a microSD card. It means the certified-aircraft maintenance process should be treated as an avionics maintenance task rather than an informal software download.
G5 Software Compatibility With Other Avionics
A G5 rarely exists in isolation on a modern panel. It can be connected to other equipment, and software changes can affect system behavior.
Check the applicable navigator interface and current approved documentation.
Review the approved interface when the G5 is connected to compatible navigation or autopilot equipment.
Verify the complete approved configuration rather than assuming software compatibility.
Pay particular attention to Garmin’s compatibility notes when a G5 is used as a standby instrument.
Important 2026 Compatibility Warning
Garmin’s 2026 Service Bulletin 26099 Rev A states that G5 Software Version 8.70 is not compatible with G5 standby instruments interfaced to G3X Touch Flight Display Systems running software version 9.18 or earlier.
G5 Software Update vs G5 Installation Manual
| Document / topic | Primary purpose |
|---|---|
| G5 Installation Manual | Defines installation, wiring, configuration and approved interfaces for the applicable system. |
| G5 Maintenance Manual / ICA | Covers maintenance and continued-airworthiness procedures. |
| Flight Manual Supplement | Provides aircraft operating information associated with the approved G5 installation. |
| Service Bulletin | Communicates a specific approved software or hardware change and its associated requirements. |
What Owners Should Check Before Booking the Update
- Current G5 software version.
- Whether the aircraft is using the certified G5 under STC SA01818WI.
- G5 quantity and role: AI, DG/HSI or standby configuration.
- Connected Garmin navigators and autopilot equipment.
- G3X Touch software version if the G5 is used as a standby instrument.
- Current G5 Maintenance Manual / ICA revision.
- Current AFMS or flight manual supplement revision.
- Required logbook and return-to-service documentation.
Should You Update a G5 Just Because a New Version Exists?
Not necessarily. Garmin’s 2026 Service Bulletin 26099 Rev A describes version 8.70 as optional for the affected G5 installations. Owners should weigh the benefits of the update against the aircraft’s current configuration and any compatibility considerations.
If your G5 is integrated with other avionics, the decision should be based on the complete approved system—not simply the fact that a newer software version is available.
G5 Hardware and Installation Resources
Jet Aviation Spare Parts offers G5 configurations for certified-aircraft applications. The exact package depends on the installation and may include different interfaces or accessories.
View G5 Flight Instrument Kit View G5 HSI / GPS Interface Kit
See the Garmin Aviation Systems category for related avionics.
Related Jet Aviation Guides
- Garmin G5 Installation Guide: What Pilots Need to Know Before Upgrading
- Garmin G5 STC SA01818WI: What the Approval Covers
- Garmin GAD 29B: What It Actually Does in a G5 Installation
- Garmin Aviation GPS: Which Features Actually Matter?
FAQ: Garmin G5 Software Updates
What is the latest Garmin G5 software version?
Garmin Service Bulletin 26099 Rev A identifies version 8.70 for certified G5 installations under STC SA01818WI.
Is G5 software 8.70 mandatory?
Garmin’s 2026 Service Bulletin states that the update is optional for the affected installations. Specific aircraft or system circumstances can have separate requirements, so check the applicable documentation.
Does a certified G5 software update require a logbook entry?
Yes. Garmin’s current support guidance states that software updates change functionality and require a logbook entry for certificated aircraft.
Can G5 software 8.70 work with every G3X Touch system?
No. Garmin specifically states that version 8.70 is not compatible with G5 standby instruments interfaced to G3X Touch systems running software version 9.18 or earlier.
Can I use experimental G5 update instructions on a certified G5?
You should not assume they are interchangeable. Use the documentation applicable to the certified G5 and its approved aircraft installation.
Before Your Next G5 Software Update
Check the installed version, connected avionics, current Garmin documentation and aircraft records requirements first. For certified aircraft, treat the update as part of the approved avionics maintenance process—not just a software download.