Thursday, March 22, 2007

Tomorrow we have a pop-up charter - heading 3 hours northwest then 2 hours southeast back home.

Yeah, that's right; what will take us 2 hours and 57 minutes to get to will only take us 1 hour and 47 minutes to return home from.

What causes this crazy difference in time? Let's blame it on the jetstream! Tomorrow, the jetstream is predicted to be directly along most of our route at around 140 miles per hour.

What's the jetstream anyway? Well, first of all it's a mass of air around thirty thousand feet up. It's a relatively skinny airmass, like a ribbon, that usually moves from west to east at a hundred and fifty miles an hour in summer, and two hundred and fifty miles an hour in winter.

That's great if you are going east, but not so good if you are going west. If we are going 400 mph heading west through the air but the air is doing 150 mph heading east, then we are only flying over the ground at 250mph, which means it takes us longer to cover the distance of a trip. This map shows the jetstream and is scheduled to come into effect at 8am Toronto time tomorrow morning.

The jetstreams are the thick blue lines on this chart.

If a jetstream is unusually strong it might have CAT, or clear air turbulence associated with it, which can make for a really bumpy ride. If you refer back to the weather chart, you'll see that around Toronto, there is a warning on the map to expect moderate Clear Air Turbulence (CAT) below 36,000', expressed exquisitely in aviation talk as MDT CAT BLO 360. You'll also see that just north of the Toronto area, 2 jetstreams merge into one. You know that ain't good when it comes to turbulence.

So this is where I can earn my Captain's bars - I look at that and decide maybe we should climb up to 38,000' on our flight so as to be above the predicted turbulence. By eliminating one source of possible discomfort for my passengers, I have potentially saved hot coffee from being spilled in a lap, or perhaps fresh catered lunches from being barfed on our expensive interior.

But unfortunately even though we'll be above the core of the jetstream, we'll still have to suffer through 3 hours of headwind and maybe 2 hours of tailwind. Good thing we have an MP3 player on board :)

I have a fresh battery pack for the camera and I'll be sure to get some good photos.


Anonymous said...

make sure to snap some pics of the mach indicator

Anonymous said...

Sulako, if all the aircraft in Canada had to land at the same time, would that be physically possible? This question is unrelated to your post but I had to put it somewhere. km