I was never able to get a straight answer from AA re: ski baggage when we flew to Europe this past winter. Domestic, it's pretty simple - their website even has the answer (most airlines have very similar policies for domestic flights), but international flights are a whole 'nother story - I got the feeling that it would probably depend on the gate agent at the airport whether they would apply the domestic limitations, the "straight up" international reg's, or some hy-brid of the two.
What we ended up doing was just abiding by the weight and number of bags limitations for international flights (two people = 4 checked bags at <50lbs each, so a three week trip: 2 suitcases, one big boot bag (both pairs of boots), and one ski bag (both sets of skis)), and assumed that they would treat the ski bag like any other piece of luggage (in other words, that the airline would not charge for the "bulky" or odd size of the ski bag, but that they would still count both it and the boot bag as two bags (not one like domestic) and weigh the two separately bags as well) - this is exactly what ended up happening - our ski bag (with 2 sets of skis, 2 sets of poles, ski jackets & ski pants came in at 49 lbs) and our boot bag (with 2 pairs boots, socks, long johns, helmets, basically the rest of the ski necessities came in at 47 lbs) were treated just like any other bag that we could have checked.
Get a double or triple ski bag. Get a very large boot bag. If it's just you, plan on them being your only bags (plus your carry-on); if there's two of you, plan on putting all of your ski equipment in the two bags, and then you get one regular suitcase each. Pack both of them (the ski and boot bags that is) full (i.e. don't just put your skis/poles in the ski bag by themselves, but pack other stuff in them). Pay attention to the weight limits - it's tempting to think that airlines are just being bastards by enforcing strict bag weight limits, but on long-haul flights (and Dallas or Miami to Santiago (or really anywhere in SA) certainly counts as a long haul flight
), the amount of weight that they are flying around is critical, both in terms of fuel costs and, perhaps more importantly, safety (they want that plane to be able to take off, fly a circuitious route to avoid really nasty weather against a 150 mph head wind the whole way and still have enough fuel to divert to an alternate airfield with a runway large enough to handle the plane if the destination airport is closed due to weather (or other incident) just as much as you do