[[US Airways]] will slightly reduce its carry-on size limits, bringing its carry-on policy in line with most other carriers. The maximum allowable carry-on size will shrink from 51 linear inches (length plus width plus height) to 45 linear inches. Carry-ons must also weigh less than 40 pounds or less. The airline hasn't exactly been militaristic in its enforcement of this rule, but carry-ons that don't fit within these limits could be checked, which means you'll have to pay a $15 fee.
Continental made a similar move this past fall, and as US Airways spokesman Morgan Durrant tells Matt Phillips at the Middle Seat Terminal, most other carriers have similar restrictions. "We were virtually the last airline to accept 51 linear inches," Durrant says. "Forty-four inches is by and large the global industry standard."