Here's what AA says:
Overweight/Oversize Baggage Charges
Additional charges apply to this type of baggage and are collected at the airport ticket counter.
FLIGHTS WITHIN THE UNITED STATES, THE U.S. VIRGIN ISLANDS, PUERTO RICO AND CANADA
Overweight Baggage Charges
Checked baggage weighing over 50 lbs./23 kgs but not more than 70 lbs./32 kgs will be charged at the rate of $100 per piece.
Checked baggage weighing over 70lbs./32 kgs but not more than 100 lbs./45 kgs will be charged at the rate of $200 per piece.
Oversize Baggage Charges
Checked baggage which is larger than 62 in/158 cm will be charged at the rate of $200 per piece.
The size limitation of your luggage is calculated by adding the total outside dimensions of each bag, that is, length + width + height.
Certain aircraft types cannot accept some oversized articles due to the dimensions of the cargo doors. If you are traveling with an oversized article, please contact an American Airlines representative to ensure your destination is typically served by an aircraft that can accommodate your article.
For information related to travel outside of United States, Puerto Rico and USVI, please contact Reservations to ensure your destination is typically served by an aircraft that can accommodate your article.
Maximum Size and Weight
Items that are larger than 126 inches and 100 lbs. will not be accepted as checked baggage. Contact a freight forwarder for assistance with these items.
Additional items not included in the item description below must not be packed inside the sports case and are subject to overweight and/or oversize charges.
All inches are dimensional inches (length + width + height)
AA/American Eagle/AmericanConnection® carrier are not liable for any damage to sports items not presented in a hard-sided case. If the outside of the hard-sided case does not have visible damage, AA/American Eagle/AmericanConnection carrier are not liable for any damage to the sports item inside the case.
Sports cases designed for specific items such as golf bags, boot bags and bike cases are intended to carry only that sports item.
Charges listed are in U.S. dollars
For information related to travel outside of United States, Puerto Rico and USVI, please contact Reservations to verify currency.
SKIS: WATER OR SNOW / SNOWBOARDS
One pair of skis/snowboard and one bag containing a pair of ski /board boots only
One pair of skis/snowboard and one boot bag containing only boots/bindings will be treated as a single item with the applicable checked bag charge.
Boot bag must not exceed 45 linear inches (length + width + height) and must contain only boots/bindings. Boot bags that contain other articles will be subject to the excess baggage charge for a single piece.
Maximum Weight and Size
One pair of skis/snowboard up to 126 inches and one boot bag containing boots/bindings only and not to exceed 45 dimensional inches (length + width + height)
Lighters or torches for applying ski wax are considered dangerous goods and are not allowed in checked or carry-on baggage