Meters or feet???

[spacer]

Heh.
Working on Diamond DA-20 and 40 airplanes, I realized I needed both standard and metric tools.
Once I got used to it, it wasn't bad. Every nut 'n bolt had a part number, and we had to replace 'em by part number rather than size/thread count/pitch(yada yada yada).
Surreal in a way, but it worked.
It helps to have a well stocked parts department with parts database access (though a lot of our stuff still required flipping through parts catalogs).
The difference with my homebuilt is that I can be flexible with the hardware, so long as I use the proper grade stuff, and don't go too far off the plans.

[Stef]

Sorry for the late reply, but I wanted to add something here...

The British do not use, at all, any metric system. They simply refuse.

Well, the British law defines each Imperial unit entirely in terms of the metric equivalent. That's what I meant. Of course the imerial units are still in use, but I wouldn't be so sure that the metric system won't slowly replace the old one...

Prefer? What and for what? If somebody wants to nail me down I would prefer the imperial system. It is far easier to handle.

Okay, I admit that it might come down to a personal preference. But please explain to me what is easier about the imperial system? You might be more aquainted to it, or something, but easier? What confuses me most about it is that they not only use different units, but more than one unit for every dimension.
E.g. in the metric system you have only meter to measure length. Every other unit is derived by the power of ten (kilometer, milimeter...). In the imperial system, you have inches, feet, yards, miles, not even counting the funnier things such as links, poles, chains, furlongs and leagues... Same goes for weight: gram vs. mites, grains, drachms, ounces, pounds, stones, quarters, hundretweights, tons.

Also you can easily turn kilograms to grams or metric tons by just shifting the comma. In the imerial system you need a calculator or to be an ace at mental arithmetic.

[END PROPAGANDA SPEECH FOR METRIC SYSTEM] 

[Mike]

The only problem I have is that sometimes I don't know where imperial ends on an aircraft and where metric starts.
On the french helicopters almost everything is metric, but then there are some Canadian or US STC's on there and here we are back in imperial again.
The metric system makes more sense (although I have gotten so used to imperial that I can guess the wrench sizes better in inches than mm).

My argument is:
if the 9mm wrench is to small, what's the next bigger one?
if the 9/32 wrench is too big, which one is the next smaller one?
and:

how many kilometers is 746352 meters?
pretty easy, huh?

try figuring out how many miles 746352 feet is?

I really like Gulfstreams argument though:

I think that as long as the French are using the metric system, the US will use the imperial.

HA HA HA!!! you go Gulf!!    sooo true!!

[happylanding]

The only problem I have is that sometimes I don't know where imperial ends on an aircraft and where metric starts.
On the french helicopters almost everything is metric, but then there are some Canadian or US STC's on there and here we are back in imperial again.
The metric system makes more sense (although I have gotten so used to imperial that I can guess the wrench sizes better in inches than mm).

My argument is:
if the 9mm wrench is to small, what's the next bigger one?
if the 9/32 wrench is too big, which one is the next smaller one?
and:

how many kilometers is 746352 meters?
pretty easy, huh?

try figuring out how many miles 746352 feet is?

I really like Gulfstreams argument though:

I think that as long as the French are using the metric system, the US will use the imperial.

HA HA HA!!! you go Gulf!!    sooo true!!

Til it doesn't change kg to lbs, I will feel confortable either with one or with other.
I would get mad, anyhow, seeing the scale giving a measure that's more or less the double.................   
The point about France is interesting and true....

[Frank N. O.]

Well that the funny thing, in Denmark it takes exactly 2 pounds (pund) to make a kg, but in USA and UK it takes 2.205 lbs.
An imperial mile is around 1.60934 km, or 1 km, 609 m and 34 cm, but a swedish mile is 10 km.

Happy's comments makes me, again, remember a funny joke that a comic said happend to him while flying on a small prop-plane in USA, the pilot asked how heavy each person was, we all here know why, but the lady in front of the comic said 120 (lbs) and he thought: "yeah, your butt is 120! Now I gotta say I'm like 350 over here! Lying to your date is ok but don't lie to the pilot! I was just thinking we'd be crashing and the pilot turn around and yell, who lied about the weight? Miss 120 over here."
LOL I don't understand what women have problems with the weight-number since even if I was going straight for looks alone, and not the mind, then I'd look more on proportions in relation to her build and height and her physical condition (i.e. not weak and bony but not overly fat so she'd have a bad health either) than what weight-number she could say. A woman weighing 70kg can easily be a babe if she's tall and somewhat athletically trained, and a 50kg lady can easily be too overweight if she's short so that single number is a load of bull, totally oversimplified to the level it's useless and damageing.

I must say though that it'd be more cool to say you're 6ft tall than 1 meter and 83, but that's probably from the many cool american action movies and heroes like John Wayne etc. (for the record I'm just 1.75 but my leg-length is probably closer to one that's 183cm).

Is there at all any place where altitude is called out in m/km instead of ft? And any place one uses kph/mph instead of kts? And what kind of knot is aviation using? To my knowledge there are some differences there too, how many meters is a sea-mile (which is what a knot is defined by right? sea-miles per hour).

Nice topic for discussion btw, very interesting
Frank

[Gulfstream Driver]

Our 1974 C-172 has mph on the aispeed indicator.  Many older models use mph instead of kts.

A nautical mile is 6080 ft, or 1 degree of latitude, so knots are based on that scale.  I'm not sure what the conversion between nautical miles and meters is, though.  Aviation uses nm now because of the ease of calculating them into degrees (I think).

[Frank N. O.]

That converts to exactly 1853.184 meters and that's right what I know a sea-mile as used in Denmark is so that's universal it seems
Thanks for the information

Frank

[Stef]

Happy's comments makes me, again, remember a funny joke that a comic said happend to him while flying on a small prop-plane in USA, the pilot asked how heavy each person was, we all here know why, but the lady in front of the comic said 120 (lbs) and he thought: "yeah, your butt is 120! Now I gotta say I'm like 350 over here! Lying to your date is ok but don't lie to the pilot! I was just thinking we'd be crashing and the pilot turn around and yell, who lied about the weight? Miss 120 over here."

Haha! We could turn this into a comic strip maybe!  That reminds me of an episode Mike once told me: He had two couples for a helicopter flight and the guys told him their weight. Their own and the ones of their wives. But because Mike explained that this was to calculate the fuel, shortly after that the wives took him aside and said: "To be honest, I am rather 150 than 135, but don't tell my husband!!"  Hahaha...

LOL I don't understand what women have problems with the weight-number since even if I was going straight for looks alone, and not the mind, then I'd look more on proportions in relation to her build and height and her physical condition (i.e. not weak and bony but not overly fat so she'd have a bad health either) than what weight-number she could say. A woman weighing 70kg can easily be a babe if she's tall and somewhat athletically trained, and a 50kg lady can easily be too overweight if she's short so that single number is a load of bull, totally oversimplified to the level it's useless and damageing.

I am so with you there Frank!! Normal weight and slightly athletic is the best shape! For women AND men. Unfortunately there's many women who lose weight by just eating less. If you don't do sports, then you will probably lose more muscle than fat... Oh well, we drift off to a completely different topic now though...

[happylanding]

Haha! We could turn this into a comic strip maybe!  That reminds me of an episode Mike once told me: He had two couples for a helicopter flight and the guys told him their weight. Their own and the ones of their wives. But because Mike explained that this was to calculate the fuel, shortly after that the wives took him aside and said: "To be honest, I am rather 150 than 135, but don't tell my husband!!"  Hahaha...

I am so with you there Frank!! Normal weight and slightly athletic is the best shape! For women AND men. Unfortunately there's many women who lose weight by just eating less. If you don't do sports, then you will probably lose more muscle than fat... Oh well, we drift off to a completely different topic now though...

HAHAHA that's strange, definitely  a forum mainly run by men where you can read about planes, chicks, guns, PCgames and now....gosh....diets!!    BTW, I agree with you boys. athletic shape is the best, even if that unfortunatelz doesn't mean that there is no need to fight with scales, from time to time... concerning my vacation (and do not get jealous!) weather was gorgeous today, sunny and I was on the beach like a lizard, going for wonderful swims from time to time, walking and listening to some music and getting some tan. but, due to the wind, the water was not too much clean and I just hit, like Titanic, the rocks just below the surface...ops, got a lot cuts on the legs!  IFR swimming is not the best, I will get a mask! see ya my dear!

[spacer]

My sister is in the 'don't eat, thin is in' camp.

She'd fit right in the strip with her chicken/twig legs. Just don't tell her I said that.
My wife is a cyclist (I got her hooked) and she has great legs.
oh-yeahhhhh.

[fireflyr]

My sister is in the 'don't eat, thin is in' camp.

She'd fit right in the strip with her chicken/twig legs. Just don't tell her I said that.
My wife is a cyclist (I got her hooked) and she has great legs.
oh-yeahhhhh.

"GREAT' legs and cycling don't always go hand in hand----I cycle too but when I met Mike last year (I was wearing shorts), he asked me if "those" were my legs or was I riding a chicken?   

[Franz]

*dig* *revive*

I hope you do not mind that post in this topic after nearly a year.
But maybe someone is still interessed in an answer to the question why glider pilots use the metric system while most other people in aviaton use imperial units.

I think the reason for that is simply that gliders are a German invention and became quite popular in Germany, also because powered flight was banned in Germany after WW I & II. Additionally, the metric system was introduced in Germany in 1870.
On the other side of the Atlantic Ocean, where quite some of the developments of powererd flight took place, the imperial units were used.
So the, mostly German,  glider pilots stayed with the metric system they were used to (although until very recently maps gave heights only in ft, so that glider pilots had to use both).
And the US / British had absolutly no reason to use meteres in their powered aircraft, so things became the way they are now.
But that does not necessarily mean they are using kts, the Piper SuperCub our Club owned until 2 years ago had an airspeed indicator showing mph and that wasn't the reason we replaced it with a DV 20 Katana.

I personally use both, even as a glider pilot. It is easier to measure distances in Nautical miles when working with a map, because of that mile-degree thingy. Also, I'll get wind speeds in kts, as soon as I'm in controlled airspace I'll get clearances in ft and so on.
And besides it sounds much cooler (at least in Europe, except maybe UK) talking about knots, feet and miles when pedestrians are listening  (and btw, its cheaper than huge watches)

I hope my writing is not too confused, CU and good Night
Franz

P.S. If you think I should not have posted in such an old topic, please feel free to (re)move this post.

[Mic]

Just my few cents ...

Not only European (except UK) glider pilots use the metric system ... ex CCCP's countries use it for powered and gliders...

Second point is that the imperial system is ... temporarely allowed in aviation until metric system replace it !!!

I mean in the ICAO annex 5, (units to be used in aviation), it's clearly precise that the metric system MUST be used in aviation. due to the fact a lot of aircrafts are equipped in imperial system, and most of the pilots have been trained in the imperial system (quick calculation in flight), the imperial system may be still in use, restricted to few units (feet, feet/min, Kts and Nm only !!!) until the metric system will take in force. There is also an article recising that the imperail system will no longer be in use 10 years after the date ... (they just forgot to write the date !!)

Of course, due to the huge number of aircraft/pilots/ATC in operation, it's quite impossible to stop the imperial system. But in maintenance, more and more effort are done by manufacturers : the two values (metric and imperial) are often written in the maintenance manuals.

And each time an ATC ask me with an unfair message he wants to hear me speaking in imperial, I answer I'm conform to the ICAO annex 5 (which is in force in France) and he's not. In addition it's easer for him to convert it (seated in his tower). Of course, usually, the ATC is fair and we speak in imperial as often as possible ... but with a very low precision.

Finally as a mechanic, I had a lot of trouble in the begining to find which wrench is bigger than a 9/16 !!

[G-man]

in the ICAO annex 5, (units to be used in aviation), it's clearly precise that the metric system MUST be used in aviation.

This document was written in an attempt to standardise aviation. It merely "suggests" a standard---individual countries are NOT bound to use the standard laid out. There is the excemption pages to ICAO, which specifies which units each country uses.

[Mic]

Well, you're right G-man !

To be precise, ICAO produces two levels of standardization materials in the 18 annex of the Chicago Conference : Standard and Recommanded Practices (SARPS). The Standards are norms ICAO would like to see applied in each affiliated country while Recommanded Practices are only suggestions. If a country doesn't apply a Recommanded Practices, there is no problem for the ICAO but when a Standard is not applied, the country is obliged to declare it to the ICAO in order to precise it in the excemption pages.

the difference between Stds and Recommanded pratices is in the mode use for the verbs :
...... a country shall produce .... means Standards
...... a country should produce .... means Recommanded Practices.

The metric system is a standard practices