Two quick followups about the airplane in the Hudson
1) As mentioned yesterday, the captain of the airplane -- the one you can identify in the cockpit because he or she is in the lefthand seat, and the one you can identify in the terminal because (usually) he'll have four stripes on the epaulet or uniform sleeve rather than three for the first officer - is getting deserved credit for handling the situation with such coolheaded competence.
But, as mentioned in passing at the end of the previous note, he's not the only one who deserves praise. Another reason US airline travel is so safe is that flight crews -- typically, the two people in the cockpit plus the rest of the staff in the cabin, plus dispatchers and others on the ground -- are so systematically trained to support each other, work together, and check or offset each other's errors. Along with the cabin attendants and the New York rescue crews, the first officer, Jeff Skiles, undoubtedly played an important part in getting the airplane down safely and deserves celebration. The safe outcome involved good luck -- the time of day, the nearness of potential rescuers, the absence of congested river traffic at that moment -- but it was mainly attributable to an extremely high level of well-trained professional performance by all involved. That is why it is fine to consider it "heroic" rather than "miraculous." People did what they were trained to do, very very well.
2) I noted the silly error in an initial NYT report saying that "airliners are not meant to glide." Aerodynamically, every airplane is designed to glide - that is, descend gradually and under control even without engine power, rather than plummeting straight down if the engine stops. I mentioned that all pilots routinely practice gliding as part of "engine-out" drills. Several readers pointed out the more obvious illustration: virtually every airplane of any size glides down to the runway when it comes in to land.* Airline passengers can notice this by hearing the dramatic cutback in engine noise and power when the airplane is on its final approach. Yes, there is a difference between gliding toward a landing at "idle power," with the throttle pulled all the way back -- versus gliding with dead engines, with no power to call on for final adjustments or if conditions change. Still, gliding is normal, not an emergency in itself.
* Shorthand for the underlying explanation here. An aircraft's "total energy" is the combination of its airspeed and its altitude. When sitting on the ramp, a plane has total energy of zero. While in flight. it can trade one form of energy for another: with no adjustment in engine power, it will speed up if it descends, trading altitude for velocity. Or, again with no change in engine power, it can make the opposite trade off: climbing higher into the air, but at a lower speed. Because gravity is always trying to pull the airplane down, and because wind resistance (drag) is always trying to slow the airplane down, the engine must be running to keep the airplane in "straight and level" flight -- that is, with a constant speed and altitude.
The process of landing the airplane involves steadily reducing the plane's total energy - its airspeed plus altitude -- toward their lowest possible level by the instant of touchdown. As the airplane descends toward the airport, it will naturally speed up -- unless power is reduced at the same time. Mile by mile and then foot by foot, the pilot manages the plane's speed, altitude, and power -- toward the ideal of having it reach its lowest possible flying speed (stall speed) when its wheels are just above the runway's surface. There are variations for different kinds of aircraft, which land with different amounts of power and different margins of speed above their absolute minimum flying speed, but this is fundamentally why typical flights end in a glide.