Wednesday, August 03, 2005

A small cautionary note...

Air France lost an Airbus A340 yesterday in Toronto. A quick thumbnail analysis of what happened...

The weather absolutely sucked...


YYZ 022004 SPECI 022004Z CCA 34024G33KT 1 1/4SM PTSRA SCT015 OVC045TCU 23/ RMK RA2SF2TCU5 CB ASOCTD

YYZ 022020 SPECI 022020Z 34024G33KT 3SM PTSRA FEW015 OVC040TCU 23/ RMK SF2TCU6 CB ASOCTD

To help those who need the important parts translated from Aviation Meteorology-talk into English... There are three reports here. The first two are basically the same; YYZ (Toronto) on the second (the date) at 2004 (GMT-which is 4:04pm local and 1 minute after the accident). But here's where it gets interesting--winds 340˚ (from a direction just a bit west of due North) at 24 knots gusting to 33 knots. Visibility 1¼ miles and heavy(P) thundershowers(TS) and rain(R). The third report comes 16 minutes later, and has the visibility lifting to 3 miles, but otherwise is basically the same.

So for their landing on runway 24, they had to assume a crosswind at 33 knots--which, although I don't know what the limits of the A340 are, it has to be quite near the plane's crosswind limit.

Most runways in America are grooved. They diamond cut grooves into the concrete about 2 inches apart, and maybe ½ an inch deep. These grooves act to channel water off the runway and improve traction. For some reason (climate perhaps), most runways in Canada are not grooved, and none of the runways in Toronto are. What I'm getting to here is that, with the heavy rain they were getting at the moment of the accident, it is likely that the runway surface was very slick. [I'm here to tell you it doesn't take much water on a runway to make it feel like you're landing a locomotive on a skating rink.] Given these crosswind conditions, IMO it is admirable that they were able to keep it on the runway at all. [Of course, their best choice would have been to go around and wait for the thunderstorm to clear before attempting to land. However, there's lots more yet to investigate (reports of lightning, possibility of microburst, etc), so I won't Monday-morning Quarterback things quite yet.]

So, although they kept it on the runway despite the rain and crosswind, they were unable to brake sufficiently before they ran off the end of the runway by some 200 yards. Their evacuation went just about as perfectly as you can make it. For those who don't know, most airline captains (or maybe it's just me) assume that an evacuation--for any reason--will result in minor injuries to about 10% of your passengers. This is just about what we see here.

However, related to this, and the real reason why I'm writing this comes from this sentence from this report...

"We were all trying to go up a hill; it was all mud, and we lost our shoes. We were just scrambling, people with children." [emphasis mine]

I cannot tell you how many times I cringe inside, especially this time of year, when I see someone board my plane while wearing sandals. Men, kids, but especially women. I understand that everyone wants to be comfortable, and that on flights of more than an hour or so, feet tend to swell. But I sense that much of the trend towards sandals--again, especially for women--seems to be more out of a sense of fashion than of comfort. Ladies will often go out and get a cute pair of sandals or thongs, a nice pedicure, maybe a toe-ring, and you just want to show it all off. Now I like a well-turned ankle as much as the next guy, but I'm here to tell you that, at the moment you jump down that evacuation slide, lose your shoes, and then attempt to get away from the twisted and burning wreckage of an aircraft accident while in your bare feet, you'll wish more than anything that you'd put on that pair of Nikes.

Moral of my story: Despite how incredibly rare it is to be a passenger in an aircraft accident--Wear sensible shoes.

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