I’ve taken an internal frame as a carry on before, but it’s much smaller….about 45L I think. It’ll probably depend on the airline so you better check with them.

I haven’t tried taking a big internal frame backpack as a carry on. I’ve always checked mine. Check what your airline’s published carry-on dimensions are. Typically you can get away with a little more than that since they hardly check unless if the bag looks significantly bigger. If the bag ends up being a lot bigger than that, my guess is you’ll have to check it.

Probably not. That’s just too big. If you are very rsk averse, buy insurance.

Internal/external/no frame doesn’t matter, size does. The biggest pack you’d probably get on board would be approximately 40-45 liters.

Check with the airline to find out what the maximum carry-on dimensions are. If you are on an American airline, you’ll probably be able to carry it on your flight to Europe, but will likely have to check it for the trip home. European carriers are much stricter about carry-on baggage.