ON WEDNESDAY, MARCH 5, 2003, AROUND 5:30 P.M., a single-engine Cessna 172 passes over the Santa Monica Mountains, just west of the 405 freeway, heading southeast at 3,500 feet. Over the next 10 minutes it will fly over Brentwood, LAX, Hawthorne, Torrance and Long Beach. Because it will stay carefully in the prescribed north-south transit corridor through the Los Angeles Special Flight Rules Area and squawk code 1201 on the transponder; air traffic control will pay no attention to the plane, and the pilot won't be required to file a flight plan or identify himself in any way.Although the pilot...