We're Landing Where? Why Planes Are Diverted to Maine

May 24, 2005 — -- The headline on May 17 had that same ring to it: "Jet from Italy to Boston diverted to Maine; passenger questioned."

We've heard it before, although it doesn't happen all that often. Despite the fact that tens of thousands of international airline passengers board a small air force of airliners every day and make it all the way to their destination in the United States without delays or diversions, every now and then a "system" of international passenger screening -- a system that clearly needs improvement -- fails.

When that happens, someone who may be listed on the Transportation Security Administration's "no-fly" list of suspected terrorists or potential threats to aviation actually gets airborne on their way to the United States.

The response, when that occurs, is what you hear us reporting about, often as it happens: an airliner diverted and ordered to land, usually at Bangor International Airport in Maine, so the subject passenger can be removed, questioned, and either deported or arrested.

But why do airlines let such "undesirable" passengers on board in the first place?

The answer is a bit more complex than you might think, but it comes down to a balance in economics between the U.S. government and the airlines not wanting to inordinately delay inbound flights, versus the very legitimate security interests of a nation at war.

The problem is that the no-fly list -- a database of names compiled in the United States -- isn't checked against the final passenger manifest of an inbound flight until the doors of the aircraft have been closed and the list is, indeed, final.

That doesn't mean the no-fly list is a mystery before the flight departs. In fact, the international airlines authorized to fly into the United States constantly cooperate with the TSA in using that list to keep from selling tickets to or making reservations for people who may be listed.

For the airline, this is no casual process, because the penalty for failure is the huge cost of having a flight diverted to Bangor, Maine, an expense measured in lost time, lost fuel, missed connections at the destination, and an airliner not available for its next flight assignment, as well as flight crews whose crew duty time may be exceeded and who, therefore, may have to be replaced on the next flight.