At home, outside, the crystal-clear blue sky was silent. No airplane noise. No contrails. No nothing.
How unusual is that? Here’s how the airspace shakes out above Frederick, Maryland: At the lowest altitudes are the Robinson R22s from our local helicopter school. They’re almost always flying, and frequently get far enough west of the airport to overfly our house. Above them is the fixed-wing traffic going to and from Frederick Municipal Airport. Next are the airliners heading south to Dulles; and a couple of thousand feet higher, eastbounds for Baltimore-Washington International. Higher still are the contrails of flights making their way up and down the East Coast.
Of course, they all were grounded that night. The only airplane noise came when the fighters flying combat air patrols above Washington, D.C., occasionally strayed in our direction.
Today, 10 years later, all the normal traffic was present and accounted for–although we did hear fighter jets, just once or twice. I much prefer the airplane noise, thank you very much.