Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Use Of Metric System In Aviation  
User currently offlineDocLightning From United States of America, joined Nov 2005, 20186 posts, RR: 59
Posted (6 years 6 months 4 weeks 1 day ago) and read 15104 times:

So why are airspeeds given in kts? Why are altitudes given in hundreds of feet?

Wouldn't it make sense for the international aviation community to switch to Metric?

Wasn't the whole Gimli Glider incident an issue of Imperial vs. Metric?

167 replies: All unread, showing first 25:
 
User currently offlineAcey559 From United States of America, joined Jan 2007, 1542 posts, RR: 2
Reply 1, posted (6 years 6 months 4 weeks 1 day ago) and read 15110 times:

They do use metric in some parts of the world so most new airplanes are able to switch between feet and meters by the flick of a switch. Other planes have conversion charts. Otherwise, I don't know why some parts of the world use it and others don't.

User currently offlineF.pier From Italy, joined Aug 2000, 1524 posts, RR: 9
Reply 2, posted (6 years 6 months 4 weeks 23 hours ago) and read 15068 times:

All of us should use the metric international system, so we'd reduce mistakes.
Is it so hard to do?


User currently offlineMQTmxguy From United States of America, joined Nov 2007, 197 posts, RR: 0
Reply 3, posted (6 years 6 months 4 weeks 23 hours ago) and read 15062 times:

The way I understand it, back when the powers that be (ICAO?) were setting these global standards it was just a way of compromising between the various systems.


Well at least we can all take comfort in the fact that NW will never retire their DC-9s
User currently offlineLeskova From Germany, joined Oct 2003, 6075 posts, RR: 70
Reply 4, posted (6 years 6 months 4 weeks 23 hours ago) and read 15038 times:



Quoting F.pier (Reply 2):
All of us should use the metric international system, so we'd reduce mistakes.

We'd be able to reduce mistakes as well if everyone would use the imperial system... doesn't really matter whether the metric system is used or not - what does matter is that it's standardized.

Quoting F.pier (Reply 2):
Is it so hard to do?

Less a question of being hard or not - more a question of willingness...



Smile - it confuses people!
User currently offlineDavid L From United Kingdom, joined May 1999, 9533 posts, RR: 42
Reply 5, posted (6 years 6 months 4 weeks 23 hours ago) and read 15015 times:

Yes, the metric system is tidier but half the aviation world changing from one system to another could be a problem. Aviation had nautical influences in its origins, hence the knots, nautical miles and feet. I guess the USA being so influential in western aviation, and therefore the UK, indirectly, has to take some of the blame.

Quoting DocLightning (Thread starter):
Wasn't the whole Gimli Glider incident an issue of Imperial vs. Metric?

It was an issue of converting from one system to another - it was just as likely to happen converting in the opposite direction.


User currently offlineCubsrule From United States of America, joined May 2004, 23194 posts, RR: 20
Reply 6, posted (6 years 6 months 4 weeks 23 hours ago) and read 15001 times:



Quoting F.pier (Reply 2):
All of us should use the metric international system, so we'd reduce mistakes.

How many mistakes has imperial vs. metric caused? And couldn't the carelessness that causes that sort of mistakes just as easily cause a dozen others even if we had a standardised system?



I can't decide whether I miss the tulip or the bowling shoe more
User currently offlineDfwRevolution From United States of America, joined Jan 2010, 997 posts, RR: 51
Reply 7, posted (6 years 6 months 4 weeks 23 hours ago) and read 14977 times:

Quoting DocLightning (Thread starter):
Wasn't the whole Gimli Glider incident an issue of Imperial vs. Metric?

First, there were about two dozen mistakes that led to the incident. Not the least of which was confusion about the MEL for a 767-200.

Second, the mistake that led to the aircraft being loading with pounds of fuel versus kilograms of fuel took place while AC was in the process of switching their procedures over to metric. Certainly the switch to metric itself created the opportunity for an erroneous conversion factor to be used in the calculation.

Leskova is absolutely right IMO. The likelihood of unit errors is highest when working between different types of units. That's why standardization is important and aviation decided a long time ago to make imperial units the standard. I see no compelling reason to change, and history shows that making a switch would leave us more prone to incident.

[Edited 2008-04-27 11:48:10]

User currently offlineTGV From France, joined Dec 2004, 874 posts, RR: 20
Reply 8, posted (6 years 6 months 4 weeks 22 hours ago) and read 14935 times:



Quoting DfwRevolution (Reply 7):
and aviation decided a long time ago to make imperial units the standard

Is it the case all around the world :

Quoting Acey559 (Reply 1):
They do use metric in some parts of the world so most new airplanes are able to switch between feet and meters by the flick of a switch.

Like Acey559 I though some parts of the world (Russia for example) were using the metric system in aviation.



Avoid 777 with 3-4-3 config in Y ! They are real sardine cans. (AF/KL for example)
User currently offlineMQTmxguy From United States of America, joined Nov 2007, 197 posts, RR: 0
Reply 9, posted (6 years 6 months 4 weeks 22 hours ago) and read 14925 times:



Quoting DfwRevolution (Reply 7):
That's why standardization is important and aviation decided a long time ago to make imperial units the standard

Except that temperature is almost always in Celsius, weird how that one snuck through.



Well at least we can all take comfort in the fact that NW will never retire their DC-9s
User currently offlineDfwRevolution From United States of America, joined Jan 2010, 997 posts, RR: 51
Reply 10, posted (6 years 6 months 4 weeks 22 hours ago) and read 14893 times:



Quoting TGV (Reply 8):
Like Acey559 I though some parts of the world (Russia for example) were using the metric system in aviation.

They do, but that's why they are called non-standard.


User currently offlineL-188 From United States of America, joined Jul 1999, 29812 posts, RR: 58
Reply 11, posted (6 years 6 months 4 weeks 22 hours ago) and read 14901 times:

The answer is to go back to standard measures such as feet, inches and knots.

The metric system is a completely arbitrary system of measures and doesn't make sense. in fact the meter doesn't even equal up to what it is supposed to because they made a mistake in the distance between the poles when they figure it out. They just looked at the distance to the pole and split it up by a million. No science behind that at all.

The knot however is based on the circle and that makes sense since we live on a big sphere.

Just a bit of education about the knot. From my copy of "Navigation and Nautical Astronomy" but Dutton

The Nautical Mile(Sea mile) is a measure of distance, equalling 6080.27. Ths value was chosen because it is practically the length of one minute of arc of a meridian, or of one minute of arc of the equator.

That defintion made sense in 1942 when my copy was published and still does today.

There are 360 lines of latitute on the earth, which is oddly enough shaped as a 360 degree arc or circle if you prefer. Each of those lines is split up into 60 minutes of longiture which are 6080.27 feet long....on knot...how about that?



OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
User currently offlineTGV From France, joined Dec 2004, 874 posts, RR: 20
Reply 12, posted (6 years 6 months 4 weeks 21 hours ago) and read 14805 times:



Quoting L-188 (Reply 11):
The metric system is a completely arbitrary system of measures and doesn't make sense. in fact the meter doesn't even equal up to what it is supposed to because they made a mistake in the distance between the poles when they figure it out. They just looked at the distance to the pole and split it up by a million. No science behind that at all.

In reality the meter was based on the earth circumference divided by 40 000 000.

Quoting L-188 (Reply 11):
The knot however is based on the circle and that makes sense since we live on a big sphere.



Quoting L-188 (Reply 11):
There are 360 lines of latitute on the earth, which is oddly enough shaped as a 360 degree arc or circle if you prefer. Each of those lines is split up into 60 minutes of longiture which are 6080.27 feet long....on knot...how about that?

Well I don't see much difference in a system that has a unit (the meter) based on 1/40 000 000 of the earth circumference, and a system based on a unit (the nautical mile) which is 1/ 21 600 of the earth circumference.

As said above there is an arbitrary part here. But what I find far easier in the metric system is the relationship based on base 10 between the units, while having ratios of 12 between inch and foot, then 6080.27 between foot and nm does not make any sense to me.



Avoid 777 with 3-4-3 config in Y ! They are real sardine cans. (AF/KL for example)
User currently offlineKalvado From United States of America, joined Feb 2006, 492 posts, RR: 0
Reply 13, posted (6 years 6 months 4 weeks 21 hours ago) and read 14756 times:

I believe it's more about traditions, like flying, most of sea navigation is done in imperial, as far as I know.
As of right now, I believe there are 3 countries are still officially using Imperial, US, Burma, and I don't remember the third one.
Even without metric, there is enough mess in imperial system - just think nautical mile vs statue mile.

Moreover, there is no such thing as independent imperial system any more. All precision metrology is done in metric, and by now all imperial units are officially defined through metric: international foot is defined as 0.3048 meter, nautical mile is 1852 m, statue mile is 1609.344 and so on; it's not an approximation - it's the legal definition of imperial units.


User currently offlineFlyb From Canada, joined Aug 2006, 698 posts, RR: 0
Reply 14, posted (6 years 6 months 4 weeks 21 hours ago) and read 14751 times:



Quoting L-188 (Reply 11):
The answer is to go back to standard measures such as feet, inches and knots.

The metric system is a completely arbitrary system of measures and doesn't make sense. in fact the meter doesn't even equal up to what it is supposed to because they made a mistake in the distance between the poles when they figure it out. They just looked at the distance to the pole and split it up by a million. No science behind that at all.

And the English way makes sense? It is a hard arguement to say that Metric is not a good standard, especially when you compare it to the English standard. Yikes! Glad that I didn't learn ft and pounds, but rather metres and kilos since that makes 1000X more sense.


User currently offlineCubsrule From United States of America, joined May 2004, 23194 posts, RR: 20
Reply 15, posted (6 years 6 months 4 weeks 21 hours ago) and read 14717 times:



Quoting Flyb (Reply 14):
Yikes! Glad that I didn't learn ft and pounds, but rather metres and kilos since that makes 1000X more sense.

I can definitely get around both systems (I have a science degree and have lived in metric countries), and I've concluded that the ONLY factor that determines which system "makes more sense" is the system you grew up with.



I can't decide whether I miss the tulip or the bowling shoe more
User currently offlineSCCutler From United States of America, joined Jan 2000, 5579 posts, RR: 28
Reply 16, posted (6 years 6 months 4 weeks 21 hours ago) and read 14698 times:

There is no useful reason why the USofA has not changed to the metric system- when I was a kid in elementary school in 1965, we were taught the metric system, and were told that we'd be fully-converted by 1970. They got as far as putting up dual-unit signs on highways, etc., then for political reasons, the process faded.

And yet...

... most manufacturing in the US has, in fact, gone metric, for reasons of global competitiveness.

As for aviation, notwithstanding the foregoing, since nearly all aircraft are certified with performance tables, etc., in knots (and the nautical mile is not a ridiculous and dimensionless measure), there are compelling reasons of safety to retain them, and no compelling reason to change.



...three miles from BRONS, clear for the ILS one five approach...
User currently offlineFriendlySkies From United States of America, joined Aug 2004, 4120 posts, RR: 5
Reply 17, posted (6 years 6 months 4 weeks 20 hours ago) and read 14647 times:



Quoting SCCutler (Reply 16):
There is no useful reason why the USofA has not changed to the metric system- when I was a kid in elementary school in 1965, we were taught the metric system, and were told that we'd be fully-converted by 1970. They got as far as putting up dual-unit signs on highways, etc., then for political reasons, the process faded.

I thought a lot of it had to do simply with the cost of converting the entire US infrastructure to metric.


User currently onlineGrahamHill From France, joined Mar 2007, 2860 posts, RR: 2
Reply 18, posted (6 years 6 months 4 weeks 20 hours ago) and read 14602 times:



Quoting Cubsrule (Reply 15):
I can definitely get around both systems (I have a science degree and have lived in metric countries), and I've concluded that the ONLY factor that determines which system "makes more sense" is the system you grew up with.

Spot on!



"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 19, posted (6 years 6 months 4 weeks 20 hours ago) and read 14570 times:



Quoting DocLightning (Thread starter):
So why are airspeeds given in kts?

Nautical heritage of aviation.

Quoting DocLightning (Thread starter):
Why are altitudes given in hundreds of feet?

US & English dominance of early air travel.

Quoting DocLightning (Thread starter):

Wouldn't it make sense for the international aviation community to switch to Metric?

If you could convert everyone without any pain yes. But getting there from here is more trouble that it's worth.

Quoting F.pier (Reply 2):
All of us should use the metric international system, so we'd reduce mistakes.
Is it so hard to do?

Yes, it's that hard to do. There is an absolutely staggering amount of documentation, maps, plans, tooling, and design done in knots/feet/pounds.

Quoting L-188 (Reply 11):
The metric system is a completely arbitrary system of measures and doesn't make sense.

Arbitrary? Once cubic meter of water = 1 tonne. Almost everything else falls out of that. All conversions are 10 or 1. It's far less arbitrary than any other system of measurement.

Tom.


User currently offlineNed Kelly From United Kingdom, joined Feb 2001, 413 posts, RR: 0
Reply 20, posted (6 years 6 months 4 weeks 19 hours ago) and read 14539 times:

I always hate it when aviation TV programs like Air Crash Investigator quote altitudes in metric when most aircraft fly at altitudes in feet! Which prompts me to my question regarding Russia, do pilots in Russia for example fly at 10,000 metres instead of 30,000 feet, or do the fly at the metric equivalent of 30,000 feet which is 9144 metres? Can anyone answer this?

User currently offlineJayDub From , joined Dec 1969, posts, RR:
Reply 21, posted (6 years 6 months 4 weeks 19 hours ago) and read 14532 times:



Quoting Cubsrule (Reply 15):
I can definitely get around both systems (I have a science degree and have lived in metric countries), and I've concluded that the ONLY factor that determines which system "makes more sense" is the system you grew up with.

Ding, ding, ding...we have a winner.

They are both acceptable...and the same arguments for which system is "better" can be made on either side of the fence.


User currently offlineGooner From United Kingdom, joined Mar 2006, 137 posts, RR: 0
Reply 22, posted (6 years 6 months 4 weeks 19 hours ago) and read 14508 times:

I was bought up as a child with the imperial system but as i got older the metric system became nore prevelant.When i started my apprenticeship in engineering in 1975 it was unbelievable how many types of screw threads etc were used.I for one would use the metric system anytime.How many others on here remember £ s d before decimilisation.What a stupid way to have your money

User currently offlineMir From United States of America, joined Jan 2004, 21791 posts, RR: 55
Reply 23, posted (6 years 6 months 4 weeks 19 hours ago) and read 14461 times:



Quoting L-188 (Reply 11):
The metric system is a completely arbitrary system of measures and doesn't make sense.

The length of a meter may be arbitrary, but the way the system works (base 10) is certainly not. It makes far more sense than does the imperial system.

Quoting Ned Kelly (Reply 20):
Which prompts me to my question regarding Russia, do pilots in Russia for example fly at 10,000 metres instead of 30,000 feet, or do the fly at the metric equivalent of 30,000 feet which is 9144 metres? Can anyone answer this?

When airplanes fly at metric altitudes, they separate by 300 meters. I can't say whether they would fly at 10,000 meters or not, but it would be a round (to the hundreds place) altitude like 9,700 meters or soemthing like that. They don't just convert every altitude level to exact meters and fly it.

Which leads to another reason for the imperial system to be used in altitude - 1,000 feet is a pretty good separation distance. 300 meters is good too, but in this rare case it's much easier to use the imperial system.

-Mir



7 billion, one nation, imagination...it's a beautiful day
User currently offlineZkpilot From New Zealand, joined Mar 2006, 4841 posts, RR: 9
Reply 24, posted (6 years 6 months 4 weeks 18 hours ago) and read 14410 times:



Quoting DocLightning (Thread starter):
So why are airspeeds given in kts? Why are altitudes given in hundreds of feet?

Wouldn't it make sense for the international aviation community to switch to Metric?

Wasn't the whole Gimli Glider incident an issue of Imperial vs. Metric?

Kts are not imperial either... they are based upon nautical miles (which are completely different from imperial miles). Nautical miles are based on degrees of arc (of the earth).
The reason why aviation generally uses imperial measurements such as feet is that the USA and the UK were the 2 major powers that be in the initial development of aviation and in the USAs case it has continued this. Events like WWII where the USA produced huge numbers of aircraft for itself and allies of course entrenched that standard. If Germany had won the war then most certainly the world would all be using metric (one of the few things that they did right). As the USAs power and influence internationally is on the wane (China and India are on the rise), expect to see more pressure for the USA to change to metric... like Canada and almost the entire rest of the world.

Quoting Ned Kelly (Reply 20):
I always hate it when aviation TV programs like Air Crash Investigator quote altitudes in metric when most aircraft fly at altitudes in feet!

They do this because most people around the world use metric and don't really know how high 10,000 or 30,000ft really is (just that it is up there). They can comprehend metric distances however.

Quoting Mir (Reply 23):
The length of a meter may be arbitrary, but the way the system works (base 10) is certainly not. It makes far more sense than does the imperial system.

 checkmark 



56 types. 38 countries. 24 airlines.
25 DocLightning : 1m=100cm=1000mm=100,000µm 1g=1cc H2O=1/1000kg 1(Kg*m^2)/s^2=1n 1g=~10m/s^2 What doesn't make sense? I think that not being able to remember whether
26 MrBrightSide : Currently live in US, and it is funny to drive next to a traffic sign showing San Francisco 25 mi / 40 km. So, there are some signs of duality in US.
27 Rafabozzolla : I agree that the system that makes sense is the one you can relate to. But the base 10 is surely a logical advantage of the metric system and, tempera
28 AC183 : I was very amused when once as a kid when we were holidaying in the southern US, and stopped to pick something up at a grocery store when someone stop
29 Cubsrule : "Hard" scientists in the US are learning exclusively metric in college these days... I suspect the engineers won't be far behind.
30 Sphealey : Actually I would say both base 12 (even fractions of 1/2, 1/3, and 1/4) and base 16 (best for electronic calculation; might as well get used to our r
31 Mir : You might have a point if the whole imperial system was base 12, but it isn't. One foot is twelve inches, but one inch is divided into 16ths. And a m
32 FXRA : The former Soviet Union (at least some fo them) and China are pretty much the ony regions of the world that are all metric. And the altitudes they us
33 Tdscanuck : That's "ton" vs. "tonne". Different things. Tom.
34 Banjo76 : Since the metric system is as arbitrary as the the imperial systems I guess al of you guys, when designing parts of aircrafts still use the imperial s
35 MBJ2000 : Interesting thing is, that the "imperial" system is not completely dead in some parts of Europe. In Germany for example, AFAIK they still use "Zoll" (
36 Antonovman : I lived in Germany for 10 years and was astonished when i went to buy plumbing supplies and found them to be in 1/2 or 1/4 inch sizes, just like the
37 FlyingClrs727 : But a square mile is 640 acres which is also known as a section. It can be divided using base 10 or powers of base 2 without the use of fractions. Th
38 TheSonntag : There are quite a lot of applications for which the use of the metric system makes sense, for others it does not... I do not think that it would be us
39 MBJ2000 : Wow, put this way the imperial system suddenly makes sense! Thanks for this informative post and welcome to my RU list!
40 FlyingClrs727 : Thanks, I was beginning to feel like Rodney Dangerfield.
41 BrianDromey : Well in Ireland we changed from Miles/Hour to kilometers per hour one day and there were no serious problems. If the change is well publicised and pe
42 Ferroviarius : Good morning, as a matter of fact, it is ONLY the US and Lybia and Myanmar that have not officially adapted the metric system (source en.wikipedia.org
43 Schtaiws : as an engineer i can't see how anyone can function effectively using imperial, SI is so straightforward... as a pilot however i'd have a lot of troubl
44 Sphealey : I wasn't referring to the Imperial or ANSI measuring systems; I was speaking generically. The committee that designed what was then known as the metr
45 GrahamHill : In France, we use the inch for PC monitors (not for TV screens, though...) and wheel rims.
46 David L : I think it's just that not enough people think the change is worth the effort while in other other countries they did. It's what we're familiar with
47 YWG747 : The metric system makes way more sense once you have learned it. Everything fits equally. 1000 grams for one kilogram not like 16 ounces in a pound. N
48 ShannoninAMA : Exactly. Its not like someone decided to chose random numbers. There is order involved in it. Either way...I think it really boils down to this -
49 BeechNut : 1 nautical mile = the distance of 1 minute of arc at the Earth's equator. Therefore, a very useful unit for navigation calculations back in the days
50 Sebolino : ??? Incredible to hear that. Inches, feet, yards and gallons (different in US and UK) makes probably much more sense !! Using the international syste
51 ORDagent : Both are completely arbitrary. However the metric system is more "rational" in the aspect that all measures are based on mutltudes of ten which makes
52 Cubsrule : I think maybe there's a suggestion in here: use whatever measure makes more sense. For altitude, that's pretty clearly feet or hundreds of feet (beca
53 Joost : Adding to this, I heard the story that with slightly older aircraft, including the 744, pilots can only select predefined flight level in the autopil
54 Post contains images AF1624 : Not exactly. In the classics, you could select at least 100 of feet in the autopilot. So 29100, 29200,29300 and so on. But there was no conversion be
55 Levent : Surprisingly I didn't see this accident mentioned: the mid-air collision between an Il-76 and a 747 over India. Reports suggested that the accident w
56 Boston92 : Pilot error. Imperial vs metric cannot be the cause of an accident...it will always be pilot error.
57 YULWinterSkies : The HUGE advantage of metric system over imperial is the factor of 10 everywhere, not 3 (ft to yd), 16 (oz to lb), 12 (in to ft), and is there any st
58 MBJ2000 : Same in Germany, I forgot about that!
59 Jamesbaldwyn : Yeah - Really annoys me as well. They could at least give both values!
60 Gearup : Not always. I grew up with Imperial in Ireland. Ireland partially metricated in the 70's, got used to that. Emigrated to Canada in 1980 which at that
61 Pihero : Origin of the meter : Surprisingly enough for a lot of posters on this thread, it is equivalent to the nautical mile. The revolutioin scientists start
62 Post contains images NAV20 : I can help with the measurements, anyway. It comes from the days before there were any formal methods of measuring things and people needed simple wa
63 RFields5421 : Why - because in the early parts of the past century when standards were set much more of the world use knots and feet than metric. Also long distanc
64 David L : Ah yes, I'd forgotten about that. I've never heard "inches of mercury" used anywhere other than the USA. Don't get me wrong - if aviation was startin
65 Xtoler : I do remember as a little kid in the '70's there were people in the US still trying to talk us into switching to Metric. As late as the late '80's, an
66 LH423 : No. It pretty much had to do with a lack of political will. The US congress passed the 1975 Metric Conversion Act but set voluntary target dates that
67 RFields5421 : I can do that with my Chevy mini-van today - a six year old model. Since courtesy of Uncle Sam's Navy - is spent 12 years living and driving in count
68 WPIAeroGuy : I think its not just the system you grew up on, but how everything, at least in the USA has a certain unit system with it. Any runners know how long a
69 Post contains links Asturias : Alternatively this could be a silly fictional internet rumor http://www.truthorfiction.com/rumors/r/railwidth.htm asturias
70 Jetlagged : Interesting to see even the American posters refering to US units as "Imperial". You never left the British Empire after all it seems! The US gallon i
71 Vikkyvik : Eh, I'd have to disagree. I've spent my entire life in the US, and I'd MUCH rather do calculations in Metric rather than English units. Sometimes, wh
72 DALMD88 : So far it seems everyone here is just talking about how the travel of aviation, ie altitude, speed, distance; or the weight aspect of the metric syste
73 Starlionblue : As mentioned both systems are arbitrary. It's all in what you're used to. If you grow up with meters and liters they are completely intuitive. Howeve
74 Vikkyvik : Well....generally when you hear people in the US say "ton", they're referring to 2,000 lbs. I think if a person or a document of US origin was referr
75 474218 : Why should we all use the same measuring system when: We don't all use the same language. We don't all drive on the same side of the road. We don't al
76 Post contains links NAV20 : As a matter of interest, I've only seen airborne GPS working in nautical miles. Is there a facility for putting it into 'metric' mode? And, further to
77 Tdscanuck : Oh, it's worse that than. "Which one, the 17/64th, the 1/4, the A, or the 5?" Switching the displays is trivial. Switching the tooling, engineers', m
78 Sphealey : > As mentioned this is a myth. Having read fairly deeply in railroad history, I find it is neither a fact nor a myth. There is some evidence for the t
79 Vikkyvik : Hmmm, well this sort of seemed apropos to this thread...just saw this on tonight's Jeopardy: Alex Trebek: "This distance is 9.46 trillion kilometers,
80 Post contains links NAV20 : Hi Sphealey - Stephenson hailed from North-East England which was a coalmining area. He built a lot of colliery railways before he invented the locom
81 Pihero : Because we communicate with each other and we trade with each other. as for US products, they conform to the EU directives on packing and consumer in
82 Starlionblue : Potatoid, is it? While cute, I'm pretty sure the Earth is a spheroid. As in (and respect to anyone who gets the reference): "Hurl that spheroid down
83 GrahamHill : True! I never paid attention to that. I guess it's an old heritage of the English rules, isn't it? Anyway, 9 meters or 9.15 meters, it does not make
84 David L : All the receivers I've used allow the selection of all of the commonly used units. That will depend on the receivers, not the "system".
85 Post contains links Pihero : Hey ! Can't I have my ellipsoid-shaped potatoes, please ? ..."True geodetic datums were employed only after the late 1700s when measurements showed t
86 CosmicCruiser : All areas that use meters eg. Russia, China, use rounded meter levels, eg. 11,900m = 39,100' 10,700m = 35,100' 6,900m = 22,600' China now uses RVSM b
87 Bond007 : I completely disagree. I think if you really take an unbiased look at both systems, it's tough to say that metric doesn't make much more sense, purel
88 NAV20 : It would probably mean that the poor referee has to push them back three yards instead of two before you can take the kick...... That's rather worryi
89 CosmicCruiser : Well they're still separated by 300m or approx 970'. That's also why most of us SLOP in China RVSM.
90 NAV20 : Sure, CosmicCruiser - but the trouble with the metric system in general is that the primary dimensions are just too big. A metre is too long for most
91 DALMD88 : That's easy, which size does the paperwork call for? BTW the order from largest to smallest is 17/64th, A, 1/4, 5. 17/64 is the first over -8 hi-lok.
92 Starlionblue : Fair enough. I meant "the basis of both systems is arbitrary". I agree completely that the actual mechanics of metric are much simpler to understand
93 Bond007 : Well, the same argument can be made for imperial measurements, of course! If a metre is too long, then so is a yard! A litre too big for a bottle of
94 Asturias : Here is the alternative theory. Your story is really cute, but I find this explaination to be far more satisfactory. The anecdote you told was an int
95 Jetlagged : The cgs system does use the gram as it's unit of mass, but then you would have to accept the centimeter as the unit of distance. The SI unit of mass
96 NoWorries : With gasoline selling for $4/gallon, now would be a great time to switch to litres ...
97 Vikkyvik : My basic point was that it seems to me that the kilogram should have been called the gram - to bring it in line with the other SI units, where the ba
98 Post contains links Jetlagged : I understand, but that would be even more confusing, and you'd have to rewrite history. If you reclassified the kilogram as a gram, everything writte
99 Vikkyvik : Oh trust me, I'm not saying we should change it. I just wish it was done that way in the first place Since basic SI units are all inter-related, a gr
100 Kalvado : Not really. There are several arbitrary chosen units, and entire system is build on those. In general, you can use just one unit, but that wouldn't b
101 Starlionblue : Pints in the UK (and Ireland?). The rest of Europe is firmly on ml. That's because they are US. England used Imperial, which are almost but not quite
102 Jetlagged : But the gram, which predates SI, is the mass of one cc of water, so it makes some sense after all. We could always go back to graves (original symbol
103 Vikkyvik : Ah, OK, I missed that it predated SI. Well, I knew the metric system predated SI, but.... Eh, whatever, I shall choose to still be annoyed by kilogra
104 Bond007 : Right, all "a pint" means is a glass of beer roughly a pint (well exactly in the UK), or roughly half a litre. Little different than saying you want
105 Jetlagged : If the glass is styled like a traditional English pint mug then I suspect it is actually a pint. But, overall you are right, beer tastes the same whe
106 474218 : Vikkyvik is correct a "pint" in the UK is 20 oz and in the US its 16 oz. When I was living in the UK a messed up more than one meal, by not adding th
107 Jetlagged : It gets worse. A fluid ounce in the UK is not the same as a fluid ounce in the US!
108 Starlionblue : That's because large parts of Spain are basically the British beach. May I introduce you to another unit called the percentage. Of alcohol in this ca
109 Vikkyvik : Hah. Well I figured Guinness had the same percentage of alcohol whether it came from a tap in the UK or in the US. However, I have not confirmed that
110 NAV20 : Except that, with respect, Asturias, it isn't a theory. It just says that Stephenson "simply chose to make the rails for his project 4-foot, eight in
111 Starlionblue : It depends on the state. IIRC Utah and New Mexico have the lowest alcohol content at the tap.
112 Post contains links and images NAV20 : Tom Lehrer, "Fight Fiercely, Harvard"? Thanks for that. As it happens, I got just a little fed up with being accused of propagating myths, and idly g
113 Asturias : Perhaps those accusations aren't without merit? I don't know, I certainly only pointed out to you that your claim or hypothesis is worth as much your
114 Jetlagged : Nothing you posted debunked anything, both you and NAV20 appear to agree the existing tramways were the basis of the gauge. NAV20's idea is a theory,
115 David L : What a pity IK Brunel's broad gauge (7 ft) didn't catch on - no theories, no myths.
116 Jetlagged : Indeed. Broad gauge and Betamax: both beaten by technically inferior but more widely used competitive formats.
117 Viscount724 : Car manufacturers (among others) would probably disagree with that. Many cars are now built in a few countries but sold all over the world, often und
118 Starlionblue : Indeed. A great song.
119 474218 : The UK uses Celsius for temperatures, petrol is sold in liters, the distances and speed limits are posted in kilometers, however, weights were a mixt
120 Bond007 : Ah, you were the guy in the Rover going only 70 km/h in a 70mph zone!!! Perhaps those who don't live in the UK (myself included) should refrain from
121 NAV20 : Fair enough, Asturias, silly thing to say, apologies. Dead right, David L, brilliant man. I believe that he did actually build the Great Western Rail
122 DALMD88 : Just like the amount of "Injury time" that is added to the end of a a match. I'm sure that is one of the "what the hell" aspects of Futbol that that
123 David L : Correct about the temperature and petrol but distances and speed limits are in miles and MPH. A lot of people still use Fahrenheit informally because
124 Bond007 : But when you order it, you order a bottle ... not 12oz. Just like a "pint' could in theory be 1/2 liter, or 20oz, or 22oz .. doesn't matter that much
125 CosmicCruiser : Gee don't make it that big of a deal. My wife is European and we never get confused when one or the other mentions temp in C or F. If it's summer and
126 Starlionblue : The Mad Nitpicker strikes: The plural of stone is stone.
127 474218 : Thank You, If I would have caught that I would been all over it myself.
128 Jetlagged : Except in Rugby (either code). Maybe that's not a major sport for you. Also both Rugby codes embraced metrication so much that the rules were changed
129 David L : I'm saying I, personally find it confusing, not that it's a big deal. Since I hear Fahrenheit used about twice a year, it's hardly a big deal. It was
130 Vikkyvik : In Non-Av, I've seen many a non-American complain about baseball, and complain that the field isn't a standard size (meaning different ballparks have
131 David L : Yes, I eventually deduced that. Ever said something and very soon wished you hadn't?
132 Bond007 : The problem is when you say "it's -5 outside". Not an uncommon phrase, and could me -5C or -5F depending on the person/country. Jimbo
133 David L : Ah, it's not just me! Fine if you're near enough for the temperature to be similar where you are. Not so clear cut when someone in a completely diffe
134 Post contains links Jetlagged : Yes, the field is not a standard size, but must be between stated limits. The limits for international matches are much tighter than for other matche
135 Cubsrule : At least in the parts of the US that routinely get below 0 F, "x degrees below" always means below 0.
136 Jetlagged : Thanks for confirming that. The usage is different in the UK when using deg F, which isn't that often. Two countries divided by a common language and
137 BAe146QT : You are almost correct. In fact it's worse than you specify - the pitch can be between 90 and 120 metres in length. That level of variance is, it see
138 Post contains links and images Vc10 : Now that you lot have changed the aviation reporting system and the temperature scales, can you now turn your attention to Time----60secs to a minute
139 David L : Ah, one of the classic pub quiz questions. You might need to change the Earth's orbit around the sun and the moon's orbit around the Earth while you'
140 Vikkyvik : Indeed. In fact, I haven't understood a word you've said. Ah, interesting. So there can be about a 100-foot variance in the length of the field. That
141 Starlionblue : As mentioned this is true. And I don't understand that complaint about baseball. It's part of the game and I assume it adds to the inherent charm for
142 Viscount724 : As a sidenote, the 2010 Winter Olympics in YVR will be the first Olympics with ice hockey events played on the North American (National Hockey League
143 FlyingClrs727 : But mm of mercury are also sometimes used, and that unit is called the Torr.
144 FlyingClrs727 : Well, 5K is about 3.1 miles, 800 m is about 15 feet short of a half mile. All bottled and canned goods in the US are actually packaged in metric pack
145 Starlionblue : Interesting. In any case most teams in the Olympics have a lot of experience with the NHL standard rink, both through players in the NHL and tourname
146 FlyingClrs727 : No, that would be below 0°F. I think that is the freezing point of a saturated salt water solution at 1 atm. Fortunately if the temperature is -40°
147 NAV20 : Dead right as far as I know, FlyingClrs727. We'll never know the origin of the Fahrenheit scale for certain, but as far as I know Sir Isaac Newton wa
148 Vikkyvik : That is indeed what I remember learning as well. I was wracking my brain trying to remember what it was....then I saw that you had already posted it
149 NAV20 : Hi Vickyvik. Since I wrote that it occurred to me how often people here in Australia still say, "Better put it off for a while - the forecast is that
150 Starlionblue : Same thing as metric/US. Just a matter of habit. 37 degrees sounds plenty warm to me! As for "messy minuses", I've never really felt about it that wa
151 David L : Ah. I rest my case. It means different things to different people. In millibars (mb) or hectopascals (hPa) - they're the same thing. I.e. the pressur
152 CosmicCruiser : I've heard a few places around the world that give both or have in. of mercury readily available. I can't remember where but I'm off in just a few ho
153 David L : Fair enough, I'll have to backtrack slightly and say I've only heard inches of mercury given by ATC outside the USA if it was specifically requested
154 Post contains images NAV20 : You're dead right, Starlionblue. I'm basically literate rather than numerate - started off hating all that decimal and fractional stuff, and never lo
155 Bond007 : I agree completely. Sure does. My Father never had a problem with how big 5/32" was, and I have no issue with 2.75cm. BUT ... if you really sat down
156 BAe146QT : You may also want to point out that non-league football fields often have a slope to them - length or widthways - and very often have a camber. There
157 David L : And mine, too. The fact that we use Base 10 in simple arithmetic is what gives the metric system more advantages than disadvantages for anyone not al
158 DocLightning : So I find it interesting how I think, since I'm a trained scientist. If I walk outside, I will tell you the temperature in degrees F. If I stick my ha
159 Starlionblue : Yes but variety is the spice of life.
160 Viscount724 : Until Canada switched to metric sometime in the mid-1970s, many U.S. tourists probably wondered why their cars suddenly started getting about 20% bet
161 757767lover : Quite true as long as we all use the same one it should not matter There is a saying that is uysed mainly to do with computers GARBIDGE IN GARBIDGE O
162 Ajd1992 : On the continent, yes. Although if you ask for a pint you'll likely be laughed at, you ask for a half litre of beer. In the UK they're pints... and n
163 Post contains links BAe146QT : There's a scene in the book 1984 by George Orwell about this. One of the proles is complaining that since the (fictional) forced change to the Metric
164 Avioniker : Okay my two cents; Three nations have not adopted the Metric system as a standard in any government mandated form: Myanmar, Liberia, and The United St
165 Starlionblue : HAHA. Don't forget St. Lucia! I'm pretty sure it's "garbage". Yet another reason to use Firefox is the built-in spell checker.
166 SpeedyGonzales : A brilliant video on how easy it is to calculate fractions of i**** in your head:
167 Starlionblue :
Top Of Page
Forum Index

Reply To This Topic Use Of Metric System In Aviation
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Only 4600ft Of LGA Runway 4 In Use Tonight posted Sat Dec 14 2002 06:05:15 by AA 777
Types Of Error In Aviation posted Fri Jun 21 2002 18:50:38 by Saab340
The Use Of Scanners In Flight? posted Mon Apr 1 2002 14:21:12 by Vh-daq
The Most Thankless Job In Aviation! posted Sat Mar 29 2008 19:50:57 by Wirelock
Regarding The Use Of Blown-Flaps posted Mon Jun 11 2007 02:10:26 by Blackbird
Getting A Job In Aviation At 17 posted Mon Jun 4 2007 03:45:56 by C0ex
Careers In Aviation Management - Help! posted Tue May 15 2007 17:17:28 by Jimbo27L
Use Of Fans On North Atlantic posted Wed Mar 21 2007 10:27:47 by XXXX10
Cooling Of Cabin Air In Engine posted Wed Dec 13 2006 03:34:25 by Jawed
Subjects Needed To Work In Aviation posted Mon Oct 9 2006 10:41:10 by PureKiwi
Use Of Autoflight In Emergencies posted Thu Jun 18 2009 03:29:15 by Faro
Only 4600ft Of LGA Runway 4 In Use Tonight posted Sat Dec 14 2002 06:05:15 by AA 777
Types Of Error In Aviation posted Fri Jun 21 2002 18:50:38 by Saab340
The Use Of Scanners In Flight? posted Mon Apr 1 2002 14:21:12 by Vh-daq
SMS In Aviation Organisations. posted Wed Apr 4 2012 03:35:10 by HAWK21M

Sponsor Message:
Printer friendly format