I took my Mavic Air out for the first time since January.
Six batteries and controller all fully charged, calibration and basic service done after previous flights. I fired up the controller and Litchi on my Android tablet, fired up the aircraft which went through its self check and such at red. So I tried compass calibration. Solid red.
Litchi gave no clue so I tried switching to GO4. Even after several rebooys of the tablet whenever I connected the controller it went straight to Litchi. Tried my phone, same Litchi grabbing control problem. Tried my other phone and got GO4 up. It demanded a firmware update. I updated the firmware.
Red LED
After a reboot GO4 then suggested that I recalibrate the vision sensors using Assistant 2 on a PC or Mac. That wasn’t going to happen, seeing as I was on top of a hill in the Hampshire countryside. Then there was another item on the phone screen )not easy for me to see, hence using a tablet for flying),
Battery not secure
Bearing in mind that the aircraft had been powered up, powered down rotated in two planes for compass calibration and generally moved around it seemed odd that the battery was insecure. I checked and both latches were in place, no red showing.
TL;DR
Red LED, removed and reseated battery, powered up, good to go!
So - if you get that problem try reseating the battery - FIRST!
Yes, all my devices are Android and all my PCs are Linux - except the iPad Pro I have just bought on eBay for an iOS-only app (thanks DJI) and a Windows PC I have built for a Windows-only program (thanks again DJI ! )
And I have never set phones or tablet to use Litchi as the default app.
Thanks Grant - I solved the problem in the field and posted the story as a cautionary tale for others. The solution is at the end but the post is a little TL;DR
The Mavic Air battery is held by latches either side that click on insertion and show red if the latch is not fully home. All appeared ok with the batery which stayed firm during compass calibration but, after wading through various notifivations there was one saying battery not seated. Re-installing the battery did the trick.
Ironically I had done a successful IMU recalibration after its previous flight. Due to weather and lockdown that was on January 21st - four months layoff. I was 30 miles away ftom home so did a compass calibration as a matter of course but feared that the INU recalibration hadn’t gone as planned and there was no way I could do it on a windy and sloping hillside.
Moral - reseat the battery as the FIRST thing if you get a solid red LED!
