I'm wondering whether anyone has had an issues bringing their in-reach mini 2 on a commercial flight? I will be brining it carry on and don't plan to use it on the flight. Thanks!

If you don’t use it during the flight, it is no problem at all. If you want to use it: depends on government regulations and individual airline rules. in larger passenger planes, however, there is no or only poor gps reception.

volker answered the specific question. 

I have occasionally had problems getting handheld units through the TSA security check for carry-on. When they X-ray your stuff, handhelds do not look like laptops or tablets or phones or anything else TSA has seen. Be prepared to turn the unit on at the security checkpoint, just to prove it is working electronics not some type of contraband.

I've used my mini 2 in a 777. Picked up GPS when held near windows and I tracked our loops around Bangkok

Have not attempted to send inreach message though. Wouldn't think signal would make it out of aluminium tube plus Volkers point about possible interference with plane Comms and systems.

Customs seemed ok. More interested in my li-on battery pack.

I don't know about customs. From a safety perspective, TSA requires spare LiIon batteries (not installed in a device) to be in carry-on bags. I believe they recommend the same for batteries installed in a device - but might permit those in checked baggage. Never made any sense to me. Best to check w/TSA or the airline before packing your luggage.

maybe important: do not bringt the InReach Mini to India, its forbidden here. i had to leave it there :/ 

support.garmin.com/.../