When is a plane a boat?
Well, most of us saw that first-hand last week. I, for one, sat mesmerized in front of my computer watching the live TV coverage -- intent on that large jet bobbing aimlessly in the Hudson River.
I almost couldn't believe my eyes, as I strained to hear the story of US Airways Flight 1549 -- and one thought kept going through my brain: How in the heck was that plane staying afloat?
Of course, much of the credit has to go to Capt. Chesley B. Sullenberger for his remarkable skills -- as well as his inspiring grace under pressure. I mean, he landed his crippled aircraft almost gently on the Hudson. And it stayed afloat. Well, it floated long enough so that all of the 150-plus people on board were able to get to safety -- most of them with only wet feet to show for it.
And of course, let's not forget that his US Airways plane -- an Airbus A320 -- was equipped with a "ditch switch." This is an innocuous little device that is literally an on/off switch located on the aircraft's overhead panel (above the plane's windshield). A pilot can manually activate it to close the outflow valve and avionic ventilation ports -- in other words, the openings below the aircraft's float line that could let water in.
So that explains those incredible photos of passengers standing on the wings -- and how everyone was able to get out in plenty of time, right? Except, according to an Associated Press report based on interviews with federal aviation officials, neither Sullenberger nor his co-pilot had time to flip the ditch switch.
Of course, a couple of other factors were in play, in regards to the plane's floatability: Fuel is lighter than water, which helped the aircraft stay buoyant. Plus, today's planes are well made, so that if a pilot can land one without breaking it up or causing other structural damage, it can float for a while -- as we have seen.
And a rare sight it is: Some have said this is the first successful water landing of a jet in modern aviation.
OK, so why don't other planes have a "ditch switch"?
After all, I saw one report that said this was unique to Airbus planes -- but it turns out, it's not exactly unique. Or at least, other airliners have procedures in place, a checklist to go through, to accomplish the same thing by shutting a variety of vents.
And that is what the FAA requires: that all U.S. planes have a plan to make an aircraft as buoyant as possible in the event of a water ditching in order to keep it afloat long enough to "allow the occupants to leave the airplane and enter the life rafts."
Of course, the really tricky part is -- landing the plane -- in one piece. Again, kudos to Capt. Sully, as his friends call him.
So, what else did I notice about this extraordinary event?
Well, I saw that some of those Flight 1549 passengers had life vests on -- or so it appeared -- but not all of them. The meaning of this? I'm not sure -- just as I'm not sure why some of the passengers thought to grab their laptops before they left the plane -- or so it looked from some of the photos.
Actually, I do understand why they did that ("that's my life on my laptop!"). But I would have thought everyone would have had a vest on.
Poor flight attendants -- they are driven to despair by our lack of attentiveness during their life vest demonstrations. And remember that story from last summer -- about the decision by Canada's Jazz Air to remove the life vests from its plane (while retaining those floatable seat cushions) in order to save weight and get better gas mileage? That didn't help the flight attendants, trying to hammer home the message of safety and why you should put on those funny-looking vests.
I recall some bloggers saying back in August, who cares about life vests? This was a typical comment: "Let's be honest. For the most part, if a plane goes into the [water], there's not much left of it or anyone onboard."
Beware of generalities. Besides, when I look at those pictures of the people in the Hudson, I have to wonder about life vests vs. seat cushions: Don't you think it would be tough to hang onto a seat cushion in freezing temperatures?
By the way, this was overheard during a flight attendant safety demo: "In the highly unlikely event of a water landing between Omaha and Denver, clutch the seat cushion tightly to your chest and stand up. The water won't be that deep."
We can laugh now -- especially since all survived the US Airways crash.
But let me go back to Jazz and its decision to save gas by ditching its life vests: Did you know one airline actually added life vests -- you heard me right, they added them -- to save weight and gas? Yes, that's what Southwest did a couple of years ago -- so it could fly far out over the water -- which actually made for more direct routes on some of its flights. More direct means fewer miles and less gas.
And I'll bet, after last Thursday's "crash-that-killed-no-one," having the extra security of knowing life vests are aboard might be a comfort to some.
Which brings me to my final thought: we've just gone through a year of saving weight and saving money by doing everything from tossing olives off of salads to removing those in-flight magazines and getting rid of almost everything else that wasn't bolted down. And yet, now the airlines are planning to outfit their planes with Internet service.
The equipment required for the luxury of surfing the net can weigh as much as 150 pounds, which is about the same weight as life vests for 136 passengers. I don't know that any airline is contemplating an either-or situation, but -- if push did come to shove, which is more important to you -- a life vest or your Facebook page?
This work is the opinion of the columnist and in no way reflects the opinion of ABC News.
Rick Seaney is one of the country's leading experts on airfare, giving interviews and analysis to news organizations, including ABC News, The New York Times, The Wall Street Journal, Reuters, The Associated Press and Bloomberg. His Web site FareCompare.com offers consumers free, new-generation software, combined with expert insider tips to find the best airline ticket deal.