Let's say that your flight is delayed or canceled. And let's say an airline official explains that the delay is due to "bad weather." You're out of luck on two counts. First, your flight won't depart on time—or perhaps at all. But worse, because the airline has invoked weather as the cause of the delay, it doesn't have to offer you vouchers for free or cheap lodging, meals, or transportation. Had the airline instead blamed the problem on something that was within its control, such as a mechanical problem, then it would probably offer vouchers.

Now let's say you look out the nearest window, and you see sunny skies.

Should you use the Internet—or call a friend who has Internet access—and check up on the claim that there is a weather delay at your destination?

Oh, heck. Why not! You check up on the airline's claim by consulting a website that offers images of live National Weather Service Doppler radar, such as http://radar.weather.gov/.

For argument's sake, let's say that you find out that the weather at your destination airport is now sunny.

Should you go to the airline counter (or wave over a flight attendant) and politely say, "Are you sure there aren't other problems besides weather delays?"

Assume that you do ask this question. Here are the two most likely things to happen:

The official may explain that the bad weather isn't at the destination airport but is at the place where your plane is arriving from. Delays elsewhere in the country can cause—through a ripple effect—traffic to back up at your airport, other airports, and in the skies.

Alternatively, the airline official might—assuming this situation to be the case—admit that there is some other problem besides the weather, such as a mechanical malfunction. "Besides the bad weather," the official might say, "there's also a mechanical problem."

If this happens, you could politely say that your airline's contract of carriage pledges that passengers receive a free voucher for a hotel room or a meal for delays caused by problems within its control. That's the main advice of consumer ombudsman Christopher Elliott.

Yet what if you speak with the airline official and he or she simply laughs at you? After all, it can sound kind of silly to advise the airline on when its plane should fly simply by looking at a weather map on your own. Professional pilot Patrick Smith strongly discourages passengers from attempting to second guess air traffic controllers in this Salon essay.

Fueling this debate—oddly enough—is an Apple iPhone commercial.

In this commercial (shown below), an actual pilot for a major airline claims that he once used the Web-browser on his iPhone to look up the weather at his plane's destination. He says he radioed air traffic control with a weather update. And he claims that the controller then cleared his plane for takeoff, cutting short a delay.

What do you think? Is it worthwhile to question airline officials about "weather delays"—to hope to receive a voucher for a hotel stay or free meal if your flight is canceled or delayed overnight?

Or should you trust that airlines will follow the honor system? After all, you might look ridiculous if you try to second guess the professionals by using a website to check the weather?

ELSEWHERE ON THE WEB If you've got money to burn, you can hire a forensic meteorologist to dispute an airline's weather claim in a legal suit, according to The Consumerist.