The crash of Flight 1549 was many things: a “Miracle on the Hudson,” with no fatalities among the 155 people on board; a rare ditching in American aviation history; a celebrity-making event complete with heroic airline pilots and fast-moving ferryboat saviors.

What has been less talked about is how the events tested emergency response communications and coordination. A commercial jetliner, after all, one having taken off from La Guardia Airport, had crashed into the heart of the city in the middle of the afternoon.