"You live in a flight path," my friend Paul, a carpenter, told me as I was leaving for a lunch date around noon. "How do you stand it?"
His comment seemed odd, because I do not, in fact, live in a flight path. But I was in a hurry, and a little preoccupied, so all I said was, "You should hear the freight trains" before Paul resumed drilling the bookshelves he's putting up in my son's room. Only when I met up with my lunch date downtown did I learn that the loud droning in the sky was the sound of two F-16s and a Black Hawk helicopter intercepting a Cessna 152 that had wandered into the capital's Flight Restricted Zone.
News coverage of the incident is focused on the paperback-thriller what-if question. What if the plane had hit the White House? It was within 3 miles before it turned away! Or what if it had hit the Capitol, or the Supreme Court? But I find this entirely secondary to the question, What if the plane, or a piece of it, had killed me while I was walking to the Metro? This might conceivably have happened had the Air Force done what it says it will do when an unauthorized plane crosses into the 16-mile area surrounding the Washington Monument. This area just happens to include my house.
I use the example of myself here simply to illustrate a broader point. The risk that falling debris from a downed plane would kill me, Timothy Noah, is vanishingly small. But multiply one highly self-absorbed dot on the ground by a few million in greater Washington and you identify the paradox of Washington's homeland air defense. The risk that any given plane that's wandered into the Flight Restricted Zone will commit a deliberate act of terror is unacceptably high. But the risk that the Air Force, in shooting down said plane above the densely built greater Washington area, would kill one or more bystanders is infinitely greater, and therefore infinitely less acceptable.
This logic explains why the Air Force did not shoot down the Cessna today (instead, the intercepting planes got the Cessna to land 50 miles away in Frederick, Md.) and why it never has shot down any unauthorized plane that's approached any important government buildings.
Last June, a twin-engine Beechcraft carrying Kentucky Gov. Ernie Fletcher inadvertently buzzed the Capitol, and a general at the North American Aerospace Defense Command was supposedly prepared to shoot it down. But he didn't shoot it down. Back in February 1974 a flipped-out Army private named Robert K. Preston stole an Army helicopter, hovered over the White House for six minutes, landed on the south grounds, flew off, then returned. The Army helicopter did get shot at over the Mall by a Maryland state police helicopter, and, later, while it was hovering a mere 30 feet above the unoccupied White House lawn, the Secret Service shot at it and forced it down. But neither the Maryland State Police nor the Secret Service fired on the helicopter at any time when its downing threatened the lives of bystanders. (That same month, a mentally ill businessman named Samuel Byck who'd threatened President Nixon tried and failed to hijack a plane from Baltimore-Washington International Airport to fly it into the White House. But in this instance, the plane never left the ground. After shooting the pilot and co-pilot, killing the latter, Byck shot and killed himself.)
I can't tell you what the official procedure is, but judging from past history the de facto procedure is that an airborne threat to the White House or the Capitol will not be shot down if doing so poses a meaningful risk that one or more bystanders will be killed. I applaud the policy. But if I'm able to figure this out, I have little doubt that al-Qaida figured it out long ago.