Travelled to Bali with the Mavic Air combo, so bird, batteries, charger, RC etc.
I did some checks with the airlines (BA, Qatar and Garuda) via their twitter feeds and all were really helpful and seemed pleased I’d taken the trouble to ask. None of them expressed any problems as the batteries are well below their interest thresholds. Nevertheless I did partially discharge all batteries, taped the terminals and put two spares in a flame proof bag - not really convinced the bag (ex-eBay) is really very effective other than the labelling! One battery stayed in the MA. All batteries and MA packed in hand luggage with RC. All cables, chargers, etc in main luggage.
End result, not a flicker of interest through any of the security scans.
I’m flying on Air Asia tomorrow to Yjogjakarta but I’m disinclined to take the MA as it’s a NFZ around Borobudur so I think I might just watch the sunrise and snap some stills.
Hope this info is helpful.