International, don't know.
(Well, not since our Chamonix & Paris honeymoon in 2001...)
Domestic, on all the major airlines, especially to PDX & SEA, lots of experience!
1. A ski bag counts as a single normal piece of luggage, even though its dimensions are of course far different from a normal piece of luggage. Definitely do go crazy trying to stuff as much other gear in there, up to the 50-lb limit. This has been unchanged now for many many years.
2. The nightmare stories you hear almost always come from people really trying to bend the rule that ski gear of skis + poles + boots = one "piece" of luggage, even if bagged separately. This is supposed to apply though to a bag carrying only a pair of skis and poles, and another bag carrying boots. It doesn't mean that you can count a 49.99-lb ski bag plus a 49.99-lb boot bag as a single piece of luggage.
3. Although all the major airlines are fine with a 49.99-lb "ski" bag counting against the normal first bag allowance, they're all fairly pricey now for that first bag, and even more so for the second bag. SW is the sole holdout: both bags are still free! Otherwise, remember to pay for your bag on-line when you check-in for a significant discount over paying at the airport. Frequent flyer credit cards also often have savings, sometimes even a free first bag.
