Metric Soaring

Nyal Williams wrote:

At 03:30 15 September 2007, Marc Ramsey wrote:
snip
That does explain the change in airspeed units, the
change to knots on
the vario still seems a bit 'radical' for glider pilots
to pull it off
that quickly...
Does this have something to do with US pilots' copying
the panels of the Europeans, who were winning big time?

Europeans were using knots, not m/s? Now that's weird! There was a
transition period, when you could order a Ball vario (and probably other
US varios) in fpm or knots. The only difference was the label - the
vario, including markings, was otherwise identical.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
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U¿ytkownik "Paul Hanson"
napisa³ w wiadomo¶ci

Why do metric variometers read in m/s, instead of kph
when the metric airspeed is in kph? Would it not make
more sense to use kph on the vario too so quick mental
L/D calculations could be done (for those who do not
use a flight computer etc to think for them)?

And why do english vaariometers read in ft/min, when the english airspeed is
in knots?

multiply the m/s by 4, and then reduce the result by 1/10 and you will get
the exact value in km/h if you need to.

Eric Greenwell wrote:
The only difference was the label - the
vario, including markings, was otherwise identical.

Yes, my understanding is that (e.g. from Winter) the vario is the same
with alternative label plates, 1,000 fpm = 10 kt = 5 m/s (within 1%).

At 11:42 15 September 2007, MacIek wrote:
They are in knots. Although I would guess that most
people think of the climb rate as hundreds of feet
per minute. 1kt is 100' per min.

And why do english vaariometers read in ft/min, when
the english airspeed is
in knots?

multiply the m/s by 4, and then reduce the result by
1/10 and you will get
the exact value in km/h if you need to.

On Sep 14, 9:27?pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Actually, I think it's one minute of latitude equals a nautical mile - works
great at a chart table with dividers but not much use in a glider cockpit.



Bill, It's one minute of LONGATUDE that equals a nautical mile.
minutes of latitude vary in spacing depending how far north or south
they go. Just got my Navigator wings, so I guess I can correct
you. :-)

-EX

Yikes! What are you going to be navigating?

Go north or south one nautical mile, and you have moved a minute of
latitude.

Move a minute of longitude, and you have moved east or west, and the
distance varies how far north or south you are.




Mitch wrote:
On Sep 14, 9:27?pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Actually, I think it's one minute of latitude equals a nautical mile - works
great at a chart table with dividers but not much use in a glider cockpit.



Bill, It's one minute of LONGATUDE that equals a nautical mile.
minutes of latitude vary in spacing depending how far north or south
they go. Just got my Navigator wings, so I guess I can correct
you. :-)

-EX

Mitch wrote:
On Sep 14, 9:27?pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Actually, I think it's one minute of latitude equals a nautical mile - works
great at a chart table with dividers but not much use in a glider cockpit.



Bill, It's one minute of LONGATUDE .....
Just got my Navigator wings, so I guess I can correct you. :-)

Then why don't ya know how to spell "Longitude"? :-)

Tony V.

On Sep 15, 11:51?am, Tony Verhulst wrote:
Mitch wrote:
On Sep 14, 9:27?pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Actually, I think it's one minute of latitude equals a nautical mile - works
great at a chart table with dividers but not much use in a glider cockpit.

Bill, It's one minute of LONGATUDE .....
Just got my Navigator wings, so I guess I can correct you. :-)

Then why don't ya know how to spell "Longitude"? :-)

Tony V.

Both points above, absolutely correct by Tony and Greg. LOL It was a
LONG night last night, so I'm gonna have to eat crow in public on this
one. It has been a while since I have actually gotten a set of
dividers out. We always measured mileage by spanning our dividers
north and south along a line of longitude which would be measuring
latitude. The misspelling...I blaim on the fact that my spell checker
does not correct words in all caps. :-P I'm gonna go crawl in a hole
now, and continue recovery from my hangover and prevent future idiotic
postings! :-) see ya!

At 17:06 15 September 2007, Mitch wrote:
On Sep 15, 11:51?am, Tony Verhulst wrote:
Mitch wrote:
On Sep 14, 9:27?pm, 'Bill Daniels' wrote:
Actually, I think it's one minute of latitude equals
a nautical mile - works
great at a chart table with dividers but not much
use in a glider cockpit.

Bill, It's one minute of LONGATUDE .....
Just got my Navigator wings, so I guess I can correct
you. :-)

Then why don't ya know how to spell 'Longitude'? :-)

Tony V.

Both points above, absolutely correct by Tony and Greg.
LOL It was a
LONG night last night, so I'm gonna have to eat crow
in public on this
one. It has been a while since I have actually gotten
a set of
dividers out. We always measured mileage by spanning
our dividers
north and south along a line of longitude which would
be measuring
latitude. The misspelling...I blaim on the fact that
my spell checker
does not correct words in all caps. :-P I'm gonna
go crawl in a hole
now, and continue recovery from my hangover and prevent
future idiotic
postings! :-) see ya!

Don't BLAME you, Mitch! grin

Nyal

On Sat, 15 Sep 2007 10:03:24 -0700, Mitch wrote:

On Sep 15, 11:51?am, Tony Verhulst wrote:
Mitch wrote:
On Sep 14, 9:27?pm, "Bill Daniels" bildan@comcast-dot-net wrote:
Actually, I think it's one minute of latitude equals a nautical mile - works
great at a chart table with dividers but not much use in a glider cockpit.

Bill, It's one minute of LONGATUDE .....
Just got my Navigator wings, so I guess I can correct you. :-)

Then why don't ya know how to spell "Longitude"? :-)

Tony V.

Both points above, absolutely correct by Tony and Greg. LOL It was a
LONG night last night, so I'm gonna have to eat crow in public on this
one. It has been a while since I have actually gotten a set of
dividers out. We always measured mileage by spanning our dividers
north and south along a line of longitude which would be measuring
latitude. The misspelling...I blaim on the fact that my spell checker
does not correct words in all caps. :-P I'm gonna go crawl in a hole
now, and continue recovery from my hangover and prevent future idiotic
postings! :-) see ya!

Well, to get all pedantic, there have been several definitions of the
nautical mile, one of which was one minute of longitude at the
equator -- which has the advantage of being unambiguous since the
equator is a circle to very high precision. If you define it as a
minute of latitude you still have to specify the latitude where you
make the measurement, because the earth is not exactly spherical;
England defined it for a time as one minute of latitude measured at
the latitude of London.

Today it's simply defined as exactly 1852 meters, but "the arc length
subtended by one minute of latitude" is just peachy for navigational
purposes.

rj