When I hover my Mavic Air (hands off all controls), it slowly drifts backwards rather than holding in one place.  I know there's a fix for this, but I've forgotten how to do it.

Calibrate joy sticks. Might help
Fly safe.

Aloha wgray,

     Besides the joysticks as suggested by 62+, you should also do an IMU calibration.  Both of these calibrations improve on the problem you are reporting.  

     Hope this helps!

     Take care and be safe!

Aloha and Drone On!

Hello there wgray105. I am sorry for the trouble this has caused and thank you for reaching out. Can you please try to calibrate your DJI Mavic Air's remote controller to see if the issue will still persist. I will post an official DJI tutorial video on how to calibrate the DJI remote controller. Please keep us posted for further assistance. Thank you.