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10-01-2009, 06:10 PM
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Join Date: Jun 2006
Location: Ottawa, Ontario, Canada
Posts: 2,116
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Quote:
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Almost every metric unit makes SOOO much more sense than the old imperial style.
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That's why we Canadians, like scientists, use metric units!
Although, building the RV has devolved me, and now I think in fractions of an inch. At least the fractions all have power-of-2 denominators (i.e. 1/8, 1/16, 1/32, etc)... for a computer scientist that actually makes more sense than metric fractions with powers-of-10 in the denominator.
__________________
Phil
RV9A (SB)
Flying since July 2010!
Ottawa, Canada
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10-01-2009, 06:26 PM
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Join Date: Jan 2005
Posts: 195
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Back to the original question, yes, it was all decreed to be the new standard a few years back by the International Civil Aviation Organization. I'm forever grateful that they also decided that English was the official language of ATC, though they seem to want us to say "tree" now when we mean the number "three" (roger, switching one tree tree decimal six).
I've often wondered why we in the US went along with the METAR/TAF system, all in the spirit of compromise, I guess.
Doug
Seattle area
-4, wings
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10-01-2009, 06:38 PM
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Join Date: Sep 2005
Location: Maple Grove, MN
Posts: 2,334
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I'm with Brent on this one
Both systems are based upon arbitrary relationships, and being fluent in both, I can assure you that neither system is fundamentally easier or better than the other.
Ever wonder where the meter comes from? How about the Celsius scale? How about seconds? Both systems rely on arbitrarily assigned fundamentals.
As an engineer, I have lots of options in both systems. I use what makes sense for the situation, which usually only has to do with the "customer" of my work, and not the calculations involved. Machinists? Inches and 1/1000's of an inch. Medical device design? Millimeters typically. Carpenters? Feet, inches and fractions (btw, a very convenient thing about the typical fractions we use is that one's eye can really split things into two equal lengths well - 1/2, then 1/2 of 1/2 or 1/4, etc.).
If converting to metric is so important, why does Europe or most of it still use English units in their pipe threads (or at least did when I lived there)? Rip out the plumbing! Lug nut threads on foreign cars? Lots of entertainment can be had in this topic.
__________________
Alex Peterson
RV6A N66AP 1700+ hours
KADC, Wadena, MN
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10-01-2009, 07:27 PM
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Join Date: Feb 2005
Location: Chesterfield, Missouri
Posts: 4,514
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Quote:
Originally Posted by seward747
Back to the original question, yes, it was all decreed to be the new standard a few years back by the International Civil Aviation Organization. I'm forever grateful that they also decided that English was the official language of ATC, though they seem to want us to say "tree" now when we mean the number "three" (roger, switching one tree tree decimal six).
I've often wondered why we in the US went along with the METAR/TAF system, all in the spirit of compromise, I guess.
Doug
Seattle area
-4, wings
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English is the official language but most reluctantly. French controllers speak French to Air France crews in their air space (at least they did years ago). A most common reply by Americans was "...standby, I will call you back" when a heavily accented clearance was something like ..."cleared to !@#$%^&*()". Usually, someone on the crew had heard it before and it was acknowledged when agreed upon what it meant.
Once, coming out of Libya (when Pan Am and TWA were the only means of transport for American oil workers before they were kicked out by Kadafi), a VOR along the coast simple stopped transmitting. I advised the controller the VOR had failed. He replied in fairly clear English, "Roger, I just shut it down". We had a distinct impression he did not like us, good English or not, he probably was educated in the US. With that we proceeded VFR along the coast to the point where we thought it was time to cross the water to Spain. All flights into Libya were turn-arounds in those days, they would not permit the crew to get off the airplane. Strange situation, we were buying their oil for big bucks and they did not like us. The world was as crazy then as it is now.
Celsius vrs Fahrenheit? It's really not important as long as a crew knows the difference. Sometimes such anomalies can lead to trouble, like the time a 767 was fueled in liters and the crew thought it was gallons or pounds or some such mix up. That was the one where the 76 became a glider.
ICAO standards are intended to smooth out such misunderstandings when traveling around the planet. For the most part they do. That's why we use celsius. At least we did not have learn kilometers in place of knots or feet. German airplanes in WWII flew in a world of meters and kilometers. But of course they lost the war so that's why they agreed to English, knots and feet. But they won with celsius. 
__________________
RV-12 Build Helper
RV-7A...Sold #70374
The RV-8...Sold #83261
I'm in, dues paid 2019 This place is worth it!
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10-01-2009, 08:00 PM
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Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
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After thinking about this a bit, I've decided I don't want to have such arbitrary units forced upon me. Therefore...
1. My altimeter shall be marked in fathoms.
2. My airspeed shall be calibrated in furlongs per fortnight.
3. I shall expect pressure settings to be read to me in atmospheres.
Who's with me?
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
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10-01-2009, 09:16 PM
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Join Date: Feb 2007
Location: San Diego, CA
Posts: 1,670
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Hmmmm....
This thread asks: Why degrees Celsius?
I say: Why Knot?

(Pun Intended)
__________________
Pete Hunt, [San Diego] VAF #1069
RV-6, RV-6A, T-6G
ATP, CFII, A&P
2020 Donation+, Gladly Sent
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10-01-2009, 09:55 PM
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Join Date: Dec 2005
Location: Oliver, B.C. Canada (Okanagan valley)
Posts: 786
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Quote:
Originally Posted by ChiefPilot
After thinking about this a bit, I've decided I don't want to have such arbitrary units forced upon me. Therefore...
1. My altimeter shall be marked in fathoms.
2. My airspeed shall be calibrated in furlongs per fortnight.
3. I shall expect pressure settings to be read to me in atmospheres.
Who's with me?
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I think I wish I were in Hawaii, scuba diving!
About 90 feet below the surface should do!! Just under 3 atmospheres I think.
__________________
Lorne
RV 7a tip-up
Pre-cover MD-RA Inspected.
Canopy completed. Bonded with Sika-Flex.
Up on her mains, Firewall Fwd and wiring on going.
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10-01-2009, 10:23 PM
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Join Date: Nov 2007
Location: Reno, NV
Posts: 2,125
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Celsius made easy...
Or in my case, Celsius for Dummies.
Funny thread (meant in a good way). I was told once (and I don't necessarily concur) that the US has the best money system (due to the decimal system, not for any other intrinsic value  ) and the worst measuring system in the world (due to the absence of the decimal system). I agree there are pros and cons to all (I can split things in two more easily, as the earlier poster mentioned! Cutting them in two, well, that's another story!  )
At work, we convert C (from a METAR or ATIS) to F twice per leg, so we can make departure and arrival PAs to the pax that they will understand (get a lot of funny looks if I announce that it's 37 in Las Vegas in the summer...ooops, meant 100!)
There are some memory aids in the scale itself, so thought I'd pass them on to the bubbas here (and perhaps they are already well known, but what the hey. They are not exact, but close enough!):
We all know 15 = 59 (standard day stuff)
There are a couple flip-flops that are easy to recall:
16 = 61
28 = 82
And a couple easy gouges:
0 = 32
10 = 50
24 = 75
37 = 100
From any of those six gouge points above, if you're close, just add/subtract 2F for each 1C (12C = 50+4, etc).
If you go into the minus, all bets are off...do the Navy thing (cheat  ) and pull out the conversion card!
Good rules of thumb for C:
In the 10s, and its cool to cold
In the 20's, and its mild...pretty nice
In the 30's, and its hot
In the low 40's, and its Phoenix
In the high 40's, and you're fighting a war far away (and thanks for your service!)
For those unafraid of math in public or math under pressure, the quickie formula is:
(C x 2) - 10% + 32
25 x 2 = 50 - 5 = 45 + 32 = 77
So easy, even a cave-man can do it! (Or a Navy guy!  )
Cheers,
Bob
PS: I was told in high school that we'd be converted to metric by the time I graduated (1975). Hmmm...I think it got shelved by consumer advocacy groups, concerned with rip-offs during the conversion...especially in gas ($0.39 per gallon = what per liter?!...if we only could be dealing with cents per gallon now, I'd happily make the switch!) 
Last edited by rvmills : 10-01-2009 at 10:28 PM.
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10-01-2009, 10:39 PM
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Join Date: Jul 2007
Location: Delta, CO/Atlin, BC
Posts: 2,391
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Of course most of us have heard of the multi-hundred-million dollar space failures because someone put something on the plans in inches and the builder built it in centimeters... The real need is a COMMON measuring system so such things don't happen. Sure, there will be things like the oil refinery that require old hardware etc. but if everyone started using the same system now, we would probably eliminate a lot of these issues in 25 years or so. Certainly makes sense to me. The Canadians changed over in 1967, and one doesn't (often) hear complaints from them about the issues with the metric system (the US tried this at the same time - remember all those highway signs with 161 km/100 miles etc. - and a bunch of stick-in-the-muds squelched it pretty quickly).
By the way, my local AWOS reports temperatures in F.
And there is a rationale for the meter:
The French Academy of Science decided to figure out the distance of an imaginary line that began at the North Pole, ended at the equator (AKA a quadrant) and ran through Paris. They would then divide this line into exactly ten million identical pieces. The length of one of these pieces would be the base unit for the new system of measurement.
Nowadays, it's defined in terms of wavelengths of light.
So much for my rant for the other side....
greg
__________________
Greg Arehart
RV-9B (Big tires) Tipup @AJZ or CYSQ
N 7965A
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10-01-2009, 11:07 PM
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Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
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Quote:
Originally Posted by Greg Arehart
The real need is a COMMON measuring system so such things don't happen.
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I completely agree - we need to completely abandon metric for the good of mankind. 
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
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