INAV 9.1 is primarily a **maintenance release** focused on reliability improvements, safety fixes, and GPS accuracy. Since 9.0.1: **46 fixes** and **76 new features/enhancements**, including 19 new hardware targets. It contains no incompatible settings changes — your 9.0.x `diff all` will load cleanly.
For full PR-by-PR detail, see the [wiki release notes](https://github.com/iNavFlight/inav/wiki/9.1.0-Release-Notes).
---
##### Upgrading from INAV 9.0.x
1. Download and install the new [INAV 9.1 Configurator](https://github.com/iNavFlight/inav-configurator/releases)
2. Backup your configuration: CLI → `diff all` → save to file
3. Flash INAV 9.1.0 — **Full Chip Erase is NOT required** when upgrading from 9.0.x
4. Restore settings from CLI or use the _Keep current settings_ option
---
##### Upgrading from INAV 8.x
1. Download and install the new [INAV 9.1 Configurator](https://github.com/iNavFlight/inav-configurator/releases)
2. Backup configuration: CLI → `diff all` → save to file
3. Flash INAV 9.1.0 **WITH** _Full Chip Erase_ enabled
4. Load your 8.x diff into the CLI; note any settings shown in RED
6. Use the [INAV CLI Update Tool](https://mrd-rc.com/iNav/INAV-CLI-Update.php) or manually update incompatible settings from the 9.0.0 release notes
7. See [Upgrading from an older version](https://github.com/iNavFlight/inav/wiki/Upgrading-from-an-older-version-of-INAV-to-the-current-version) for full instructions
> [!NOTE]
> The INAV 9.1 Configurator includes a settings migration tool in the CLI tab that can assist with upgrading from older versions.
---
##### ⚠️ Important Notes for 9.1
###### FLYINGRCF4WINGMINI alignment change
If you have the FLYINGRCF4WINGMINI, you will need to re-do the accelerometer alignment, as the gyro rotation has been corrected.
###### GPS Default Settings Changed
Two GPS defaults have changed. These only affect you if you never explicitly set them in your configuration (i.e., they are not in your `diff all`):
- **`gps_ublox_nav_hz`** default changed from **10 → 8 Hz**. Lower rate allows more satellite constellations to be tracked for better accuracy, especially on M8/M9 modules. If you want to keep 10 Hz, add `set gps_ublox_nav_hz = 10` to your diff.
- **`gps_ublox_use_galileo`** and **`gps_ublox_use_beidou`** now default to **ON**. More constellations generally improves position accuracy.
###### Position Estimator — Altitude Controller Gains
> [!WARNING]
> If you have increased `nav_mc_pos_z_p` or `nav_mc_vel_z_p` above their default values since INAV 7.1, it is advisable to **lower those gains or re-tune them** to avoid possible throttle oscillations in navigation modes that control altitude (WP, Cruise, RTH, and forward-flight Poshold).
>
> The improved position estimator relies more on accelerometer weighting, so ensure your multicopter or VTOL is free from propeller and motor vibrations. See [Multirotor filter setup](https://github.com/iNavFlight/inav/wiki/Multirotor-guide#5-selecting-filters) for tips.
---
##### Highlights
###### GNSS Constellation and Update Rate
INAV now provides an optimized GPS update rate based on your hardware type (M8, M9, M10) and the number of active constellations.
_[Truncated at 4000 characters — full notes: https://github.com/iNavFlight/inav/releases/tag/9.1.0]_
### 9.0.1 — INAV 9.0.1
- Date: 2026-02-14
- Version: 9.0.1
- Original notes: https://github.com/iNavFlight/inav/releases/tag/9.0.1
- Permalink: https://whatsnew.fyi/product/inav/releases/9.0.1
- **fixed** — Fix missing frame length verification when handling CRSF_FRAMETYPE_MSP_REQ/MSP_WRITE, preventing potential buffer issues
- **fixed** — Fix position and velocity corrections for improved GPS hold and navigation accuracy
- **fixed** — Relate correction sanity limit to loop rate for consistent behavior across different loop rates
- **fixed** — Fix CLI dfu command on H743/H750 targets which would reboot as VCP instead of entering DFU mode
- **fixed** — Fix feedback loop where DShot beeper confirmation prevents re-arming by resetting the guard timer on each attempt
- **fixed** — Fix mathematical inconsistency where AGL velocity update used squared acceleration weight factor while altitude update used linear weight factor
- **fixed** — Fix rangefinder driver for TeraRanger Evo sensors
- **added** — Add support for AIKONF4V3 flight controller
- **added** — Add support for CoreWing F405 Wing V2
- **added** — Add build-time Parameter Group struct size validation to catch EEPROM-breaking changes before release
#### Hello and welcome to INAV 9.0.1
Please carefully read all of this document for the best possible experience and safety.
Contact other pilots, share experiences, suggestions and ask for help on:
