We get a lot of questions, but the most often asked is about luggage restrictions. if you have a travel questions, send it along.

Q: How large of a bag can I carry on an airplane?

Simple question? Not really. As of Feb., 2001 the International Air Transport Association "guidelines" (There are no uniform requirements or regulations.) recommend that the length plus height plus depth of a case should not exceed 45ins (115cm) the size most airline will allow.

Requirements on Go, Qantas, Ryanair, Easyjet and Aer Lingus are more stringent. British Airways will not allow a carry bag that exceeds 55 x 40 x 20cm.

Airline weight limits for carry-on bags are between 5 or 6kg (11 or 13lbs) for coach or standard class, and 9kg (20 lbs) for business or first class passengers. These weight limits apply even if your bag is within the size requirements.

Size requirements, however, are by no means standard. They vary from aircraft to aircraft and depend on the size of the overhead compartments, number of seats, etc. Some airlines line Northwest, limit carry on to one bag for coach, which must fit in the overhead bin or under the seat as determined by the "sizing" container located at their ticket counter and gate locations. Customers in First or World Business Class are allowed two pieces of carry-on luggage with the same size requirements. Everyone is permitted one additional carry-on item such as a briefcase or laptop computer, a coat, umbrella, computer case, purse, etc.

Weelchairs, other "assist devices" and strollers are considered as luggage restriction exceptions. Then there's the all bets are off clause that they throw in for good measure. It usually says that "Carry-on luggage may be restricted due to space availability".