http://www.usairways.com/en-US/traveltools/baggage/baggagepolicies.html
Esto es lo importante:
Carry-on baggage
Size requirements
You’re allowed one carry-on bag and one personal item. Personal items include a purse, briefcase or laptop bag.
- Up to 45 in/115 cm (14 x 9 x 22 in or 36 x 23 x 56 cm)
- Up to 40 lbs/18 kg