Flight rights: What you're due when bad things happen

It was the first Saturday in August -- peak travel season -- and the Newark airport was in chaos. A string of delays had thousands of passengers with missed connections scrambling to find replacement flights, which were so overbooked that hundreds had to be shuttled to airport hotels to wait for flights going out the next day. Bumped from a US Airways flight to a departure that would cause him to miss the Irish wedding he was flying for, one frustrated international passenger exclaimed, "Don't airline passengers have rights?"

Indeed, they do. In fact, if you can prove economic harm, some airline regulations provide thousands of dollars in compensation. However, you generally can't rely on airline employees to tell you about your rights or provide the appropriate payment without a nudge. Precisely what you are entitled to also is likely to hinge on whether you're traveling within the U.S. or internationally, and, to some degree, which airline you're flying.

That's because passenger rights are dictated by three things: U.S. Department of Transportation rules; international agreements under the Warsaw and Montreal conventions; and your airline's "contract of carriage." What are your rights if your flights are cancelled, delayed or overbooked, or your bags are lost (or stalled) in transit? Read on.

Delays. There's no compensation for unavoidable flight delays that are caused by weather, war, terrorism and "acts of God," like a natural disaster. But if a delay was caused by an airline's error, what you're due depends on whether you're traveling domestically or internationally.

International delays. The Montreal and Warsaw conventions govern international travel and require substantial compensation for costly delays that are caused by an airline's mistake or negligence. Under the Montreal Convention, a 1999 treaty, the maximum liability for economic damage caused by a flight delay is equivalent to 4,694 "special drawing rights." Special drawing rights are an international unit of measure that has a floating exchange rate, just like a government currency. As of August 5, each SDR was worth $1.53 in U.S. dollars, according to the International Monetary Fund. That means the maximum compensation for this kind of delay would work out to $7,182. What you have to do to establish the value of your loss can vary by carrier.

Domestic delays. The U.S. government doesn't require airlines to compensate their passengers for domestic travel delays. Yet most airlines have provisions in their so-called Contracts of Carriage -- a legal stipulation that you (and they) automatically agree to when you book the carrier's flights -- that provide at least some measure of passenger relief.

For example, United Airline's contract stipulates that if your original flight is cancelled or significantly delayed, the airline will put you on another United flight to the same destination. If there are no seats on United flights that will get you to your destination city within a reasonable time of your scheduled arrival, the airline will pay to fly you on a competing carrier, in the same class of travel, without any additional economic obligation from you.

When there are no available flights and you end up stranded overnight, United's rules say the airline will provide a hotel voucher and transportation to get you there. The airline also offers vouchers for meals, where appropriate.

While many other airline contracts also say they'll put up passengers who have been delayed overnight, few are willing to book passengers on competing carriers to reduce their wait, said George Hobica, founder of AirfareWatchdog.com.

To find your airlines rules and regulations, go to the company's website or Google the name of the airline with "contract of carriage."

Cancellations. If your flight is cancelled, most airlines will find you another flight within a reasonable arrival time of the original flight or provide you with a refund of the full cost of your fare - even if that fare was otherwise non-refundable.

Involuntary "bumps." Airlines frequently overbook flights, assuming that some passengers will be no-shows. Normally, when more confirmed passengers show up for a flight than there are available seats, the airline will ask for "volunteers" to give up their seats. Volunteers are typically offered an alternative flight plus some level of compensation, such as vouchers for future travel. But when there aren't enough volunteers, airlines can involuntarily "bump" confirmed passengers off the flight.

If you are bumped in this manner, Department of Transportation rules require that you be compensated, and the compensation is generous. Indeed, in 2011 the agency doubled the eligible compensation that involuntarily bumped passengers are entitled to receive. If the airline is able to get you to your domestic destination within two hours of the original arrival time, you are entitled to a cash refund of twice the cost of the one-way ticket to a maximum of $650.

If the involuntary bump lands you in your destination more than two hours late, you are due an amount equivalent to four times the cost of your ticket to a maximum of $1,300. The rule is the same for international flights, except that the DOT defines "short" international delays (which net up to $650) as those that get you to your destination within four hours of the original arrival time. Those that get you to an international destination more than four hours late entitle you to $1,300.

It's worth noting that most airlines will try to pay this fee in travel vouchers, but you can demand a check. The DOT regulation requires the airline to give you cash compensation if that's what you prefer, Hobica said.

Lost and delayed luggage

The Transportation Department also requires airlines to compensate you if they've lost your luggage or sent it on a slow boat to your destination, forcing you to replace packed items. The amount of compensation is aimed at replacing what you've lost, so it would vary based on what you packed and how long you were without an item.

If, for instance, the airline delivered your luggage a day late, you could file a claim for the cost of replacing necessary toiletries and, perhaps, one clean outfit. On the other hand, if it was permanently lost or went missing long enough that you lost the use of your packed items for the entire trip, the airline may be on the hook for the replacement cost of everything in your bag. This would apply, for instance, to people who are going on a cruise and must depart before the bag catches up to them, Hobica said.

The maximum replacement value for luggage lost on a domestic flight is $3,300. The maximum claim for luggage lost on an international flight amounts to 1,131 in special drawing rights, which is worth roughly $1,730 in U.S. dollars.