Using feet not meters for altitude?
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IIRC, NASA lost an unmanned mission owing to a mix-up between metric and imperial units. In September 1999, its $125 million Mars Climate Orbiter probe was destroyed because its attitude-control system used Imperial units, but its navigation software used Metric units. As a result, it was 100 kilometres too close to Mars when it tried to enter orbit around the planet.
The interesting thing is that Uncle Sam has decreed (in a 1988 Act of Legislation), that all U.S. Govt Depts, including NASA, go all-metric.
The Inspector General has been hassling and pressuring all Depts to implement this change, under the enacted legislation.
Unfortunately, NASA, like so many other Depts, Entities, & Divisions... can't swap over to metrics overnight. Virtually everything they currently have, and operate with, is rooted in Imperial measure design. The 30 year old Space Shuttle design, is all-imperial measurements.
NASA have estinated the cost to convert fully to SI measurements is around $370M - almost half the cost of a Shuttle launch. Then, there's still the hangover of all the items that were built in Imperial sizes, that will still be around for a while yet. The unspoken thing is, that conversion to a full SI system, still isn't going to eliminate another possible disaster due to measurement system confusion.
The interesting thing is that Uncle Sam has decreed (in a 1988 Act of Legislation), that all U.S. Govt Depts, including NASA, go all-metric.
The Inspector General has been hassling and pressuring all Depts to implement this change, under the enacted legislation.
Unfortunately, NASA, like so many other Depts, Entities, & Divisions... can't swap over to metrics overnight. Virtually everything they currently have, and operate with, is rooted in Imperial measure design. The 30 year old Space Shuttle design, is all-imperial measurements.
NASA have estinated the cost to convert fully to SI measurements is around $370M - almost half the cost of a Shuttle launch. Then, there's still the hangover of all the items that were built in Imperial sizes, that will still be around for a while yet. The unspoken thing is, that conversion to a full SI system, still isn't going to eliminate another possible disaster due to measurement system confusion.
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The unspoken thing is, that conversion to a full SI system, still isn't going to eliminate another possible disaster due to measurement system confusion
Simples.
America is big enough, that actually, we don't care what the rest do.
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Just wondering, if an airline is flying to Russia or China, is there any provision for the altitude in the FMC or FMGC to be converted ? I know there is MTR button in the 777, not sure of Airbus though.
-Feet for altitude/vertical separation, and in some countries, RWY length.
-Metres for RWY length in other countries, and horizontal visibility.
-Km for horizontal visibility when the viz is greater than 5 or 8 KM, depending on the application (Metar/Atis)
-Nautical miles for horizontal separation.
-Operating systems (in my tower) based on both Windows and Unix. Configured to both work differently.
-For pilots, US fuel gauges in US gallons, dipstick in litres or gallons (IMP or US), consumption figures can be in US or IMP gallons, pounds, kilograms or litres. Typically when I was flying quite a bit in the 80's, the bowser was in litres, the dipstick in IMP gallons, the gauges in US gallons, weights were in either pounds or kilograms....I became pretty proficient at quick mental conversions, and an ace on the E6B.
Not confusing at all. No problem.
-Metres for RWY length in other countries, and horizontal visibility.
-Km for horizontal visibility when the viz is greater than 5 or 8 KM, depending on the application (Metar/Atis)
-Nautical miles for horizontal separation.
-Operating systems (in my tower) based on both Windows and Unix. Configured to both work differently.
-For pilots, US fuel gauges in US gallons, dipstick in litres or gallons (IMP or US), consumption figures can be in US or IMP gallons, pounds, kilograms or litres. Typically when I was flying quite a bit in the 80's, the bowser was in litres, the dipstick in IMP gallons, the gauges in US gallons, weights were in either pounds or kilograms....I became pretty proficient at quick mental conversions, and an ace on the E6B.
Not confusing at all. No problem.
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Flight Detent wrote:
Wasn't feet used because it's a part of a statute mile, and the earth's circumference is approximately 24,000 statute miles, (at the equator) and, I've heard, rotates once each 24 hour period, which conveniently aligns with my watch!
That's it then...
Cheers...FD...
Wasn't feet used because it's a part of a statute mile, and the earth's circumference is approximately 24,000 statute miles, (at the equator) and, I've heard, rotates once each 24 hour period, which conveniently aligns with my watch!
That's it then...
Cheers...FD...
Please keep an extra battery handy.
Avoid imitations
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I use feet because that's what is written on my altifeeter.
So what is stopping me flying in meters? What about the ATC side of things is there something that says they must operate in feet?
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Funny thing is, i learned flying in meters, speed in km/h. In an airspace that follows the european standard (altitude in feed, speed in knots, visibility in km, runway length in meters etc). And i know there are over 30.000 pilots in this country alone doing that. Glider pilots in germany...
It makes good sense using different units for different functions (altitide in feet, speed in knots, visibility in metres, etc) to avoid confusion. Similarly why do you climb and descend? Because you are less likely to confuse climb rather than ascend with descend.
On a separate issue, its just as well that tons aren't used (long, or short, a 12% difference).
Incidently do US airlines still use US gallons? They can be confused with imperial gals. Luckily I am not aware of imperial gallons being used anywhere.
On a separate issue, its just as well that tons aren't used (long, or short, a 12% difference).
Incidently do US airlines still use US gallons? They can be confused with imperial gals. Luckily I am not aware of imperial gallons being used anywhere.
Last edited by Peter47; 23rd Feb 2019 at 15:08.
When I started my apprenticeship in 1969, I was told by a college lecturer that we were going metric in 1971, but unfortunately we had to learn Imperial measure for the first two years, after that we would never use it again.
Last night I distinctly remember using a 7/16 inch socket on a 1/4 inch ratchet !!!!
Last night I distinctly remember using a 7/16 inch socket on a 1/4 inch ratchet !!!!
You could have used an 11mm one if you prefer to stay half metric wise.
Thank god the drive side hasn't changed.
One of the few small ones that are close enough for most purposes. I seem to recall that it works either way round.
= 11.125mm or if you prefer 11 1/8 mm
I have not checked but I seem to recall that 5/16 is v close to 8mm
Then you don't get a decent hit until 19mm and 3/4 which are also interchangeable.
I don't recommend this for work on Aircraft but it's OK for plumbing.
Thank god the drive side hasn't changed.
One of the few small ones that are close enough for most purposes. I seem to recall that it works either way round.
= 11.125mm or if you prefer 11 1/8 mm
I have not checked but I seem to recall that 5/16 is v close to 8mm
Then you don't get a decent hit until 19mm and 3/4 which are also interchangeable.
I don't recommend this for work on Aircraft but it's OK for plumbing.
Alternate is
"another term for alternative.
"a novel set in an alternate universe"" (thanks google)
in North America.
That one is going to spread in the aviation trade!
Out of interest are Boeing (others?) Manuals localised to UK English or are they available only in American English?
I'm 55, metrication arrived in Australia in my mid Primary school years, so I'm pretty much bilingual. I did my engineering degree ten years after leaving school, with a cohort who are now 45. They were notably less comfortable with imperial units, and the university went to enormous lengths to avoid anything non-metric, leading to some interesting odd numbers when doing practical classes on old steam equipment.