Us and them, measuring up

I was looking at a weather forecast from another country which shall remain nameless *cough* Canada *cough* and it was interesting to see that they use imperial measurements for pretty much everything.

NZ uses a curious mixture of imperial and metric.  I have no idea how or why the powers that be decided it was a good idea but it seems to me that some of the measurements are arbitrary anyway.  So lets look at the breakdown:

Altitude and Elevation:  feet - at least we are the same as the rest of the planet.
Altimeter:  hectopascals/millibars, aka QNH
Airspeed:  knots - American aircraft, although some (Cherokee 140) are in mph and planes from eastern Europe (Yak-52) are in km/h.
Runway length:  meters
Visibility distance:  kilometers
VFR ATC reporting distance:  X nautical miles from visual reporting point Y (I figured this makes things easy to work out when you are map reading so it actually makes sense from a navigation point of view)
Fuel capacity/mass:  liters and kilograms.  Makes for a hard time converting liters to Kg to pounds to fuel/pounds.  Fun fun fun!

So you have to think in both measurements.  This is easy enough to do on the ground but in the air things can get a little tense and mathematics tend to suffer when stress builds.  That is why decent flight planning is a must because when the excrement hits the air distributor you have some numbers you've jotted down previously to fall back on. 


Hmm, I wonder where you’ve been picking up the Canadian weather ? 
The problem is, it isn’t as simple as it appears. Canada is a predominantly metric country except when it isn’t!
In everyday life distances are measured in kilometres, temperatures in degrees Celsius, mass in kilograms and so on. But in aviation, as you’ve seen we use feet, miles, pounds and gallons (US not imperial ones!)
But because of the proximity of our US neighbours who are still rigidly imperial, stuff kinda creeps over the border. Construction materials are a great example of this, they are either sold in a strange conversion of the imperial measurement to metric (often to 3 decimal places) or an even weirder bastardization of the two units.
It is genuinely possible to buy 3 metres of 2” by 4” wood in a hardware store here.
As for the conversion factor, well our greatest aviation claim to not fame is indeed the Gimli glider where not one but two people failed to convert things the right way!
Flyinkiwi said…
LFE: It was your post on A4 that inspired me. I work in IT and its annoying that printers come with US Letter as the default paper size and I need to change it every time we unbox one.