Edwards air show B-1 speed record attempt

On Fri, 24 Oct 2003 23:57:02 GMT, Gene Nygaard wrote:

On Fri, 24 Oct 2003 09:12:12 -0700, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
. ..
On Fri, 24 Oct 2003 08:15:17 -0700, "Tarver Engineering"
wrote:


"Gene Nygaard" wrote in message
.. .
On Thu, 23 Oct 2003 12:46:36 -0700, "Tarver Engineering"
wrote:

snip
Why not "pounds", like an aircraft?

Because there are too many engineers too stupid to understand the
simple fact that those pounds are, by definition, units of mass
exactly equal to 0.45359237 kg.

I find it unlikely that there are many engineers that can not operate a
calculator.

Show me a calculator that will figure out *which* pounds are being
used, so that they get converted correctly.

Aircraft already have units of measure. Why use different units? Why is
anyone working in NASA Operations that does not know aircraft units?

What you write is a non-sequitur.

You also underestimate the effects of systematic miseducation. The
mere existence of a conversion factor from pounds to kilograms on a
calculator isn't going to undo the fact that some favorite teacher has
drummed into someone's head the notion that pounds are always units of
force and not units of mass, so you can't really convert between
pounds and kilograms. In fact, in today's screwed up world, there are
a number of textbooks which tell you just exactly that.

Why change from the units of aerospace to some other arbitrary set of units
in the first palce?

Because it is the interdisciplinary and International System of Units.
There is no reason to have to learn different units of measure for
each activity we engage in.

Such changes have taken place in the past, of course. But when the
air speed indicators of many aircraft were changed in the second half
of the twentieth century, they weren' t changed to metric. Instead,
they were just changed from one Fred Flintstone unit to another.

That's about as silly as if the United States were to change now from
inches of mercury to millimeters of mercury for altimeter settings.

In my 20 20 hindsight I can say for a fact that
attempting to apply si units to aerospace has come at the cost of confusion
and we are very fortunate to have avoided toumbstones.

In fact, the calculator is the end of any need to change to si
units, as si is a slide rule reality.

Any time you make a conversion, at least other than by factors that
are exact powers of 10, you lose something.

Perhaps, but not enough to matter from an engineering, of operational
standpoint.

Certainly enough to matter.

Often the "something" which you lose is the sense of how precise a
measurement is.

Any time there is a need to make conversions, it is an opportunity for
all sorts of other errors, including misentry of the numbers into the
calculator, transposition of digits in copying the result, or
whatever.

In that case, why stray from what already works and play silly SI games?

Because there is only one way to get rid of the need to do
conversions:

You are right, when do you intend to start the conversion to the inch??

Al Minyard

"Tarver Engineering" wrote...

And you start with pounds as the basis and convert to have the fuel
vended, no matter what units of volume are used. Then the weight of the
airplane is checked to see if the fuel got onboard.

So, the FE begins with a takeoff weight, calculates the fuel to be ordered
and leaves the weight on the dash for the pilot to cross check.

Nope! It is apparent you don't know at all what you are talking about.

In "a high reliability sysetm" such as that in a 777 or 747-400, the fuel
vendor is simply told the "final fuel" figure in kilograms

My goodness Weiss, you mean what I wrote in the first place is completely
correct.

No, your fantasy "explanation" of what you think might happen isn't anywhere
near "completely correct."

First, many airlines don't use pounds as the basis for fuel or aircraft weight
at all.

Second, there is no conversion done "to have the fuel vended." The weight of
the fuel is entirely transparent to the vendor. Even the volume of fuel vended
is unknown until AFTER the fueling is complete -- there is no predicted/expected
number.

Third, the "weight of the airplane" is not checked in the fueling process. The
fuel indicating system in the airplane, which displays the weight of the fuel in
the airplane, is crosschecked with the volume shown as delivered by the vendor.

Fourth, there is no FE in the loop in most modern commercial aircraft.

Fifth, the Captain determines the final fuel figure, not the FE or FO. That
fuel figure is not normally predicated on the takeoff weight of the airplane,
but on the desired landing fuel weight and expected fuel burn as calculated by
the Dispatcher. Only if a Maximum Takeoff Gross Weight is a limiting factor for
a specific flight might the fuel be adjusted to meet a specific takeoff weight
of the airplane.

Pat Norton wrote:

Over a long period, the problem is being resolved. The trend is
towards metric, not away from it. North American aviation converted
from F to C in 1996. US military airports now give Terminal Area
Forecast visibility in metres. All without a fuss.

In some cases they might, but the last time I got ATIS here at
Davis Monthan AFB, visibility was in nautical miles, with no
mention of meters. The weather briefing sheet didn't include
metric visibility data either. Temperatures are typically given
in both centigrade and farenheit, but sometimes just one (or,
somwhat confusingly, the other, depending on where you are).

Mike

On or about Sat, 25 Oct 2003 08:51:44 -0500, Alan Minyard
allegedly uttered:

On Fri, 24 Oct 2003 20:51:10 +0200, Andreas Parsch wrote:

Alan Minyard wrote:

Actually, the unit of mass is the gram.

Of course the gram is a unit of mass, but it's not _the_ unit (depends
on the definition of "_the_" ;-) ). All I said is that the kilogram is
used in SI to derive units, and not the gram (as in 1 N = 1 kg m / s^2).

Andreas

I look at it as "a kilogram is 1,000 grams, therefore the underlying "unit"
of mass is the gram". Simply a matter of semantics, and I suppose
that the two definitions are interchangeable. :-)

True. However the standard SI unit is the kg (makes no sense to me
either, but that's life), and indeed there is a standard kg (of
palladium IIRC) somewhere in Paris that is the grandaddy of them all.

---
Peter Kemp

Life is short - Drink Faster

"Alan Minyard" wrote in message
...
On Fri, 24 Oct 2003 17:34:08 GMT, lid (Goran Larsson)
wrote:


Well, the US has, unquestionably, the most advanced scientific
system in the world, the US economy (GDP) is much larger than
any other, etc, etc. It does not appear that the unit of measure is
"broken".

Al Minyard

The trouble is the US is incurring a cost by using a
standard of units nobody else does and this made
worse by the simple fact that SI units ARE used
in most scientific and reseach estblishments so
even in domestic use its necessary to do these
conversions with the costs and risks that it involves.

Keith

I almost don't want to go here, but... a 2 x 4 piece of lumber is really
only 1.75 x 3.75, and I've seen some that are only 1.5 x 3.5

LOL!

On Fri, 24 Oct 2003 10:01:14 -0700, (Harry
Andreas) wrote:

In article ,
wrote:

In other words, was Harry Andreas telling you that this standard size
isn't really 1.75 mm = 44.45 mm, but rather 45 mm = 1 98/127 in or
about 1.77 in? That's what it sounds like to me, but I don't know if
that is the case or not.

I almost don't want to go here, but... a 2 x 4 piece of lumber is really
only 1.75 x 3.75, and I've seen some that are only 1.5 x 3.5

If you want a 2x4 that's really 2"x4", you have to buy a 8/4x16/4.
There are two size systems that I'm familiar with for buying wood.

One, in inches, uses the unfinished size as nominal, but finishing
uses 1/8" for each size, so the actual size is a quarter-inch
undersized in each direction. This system is used mostly for lumber
like Douglas fir, pine, etc. You frame houses with such wood.

The other, in quarters, uses the finished size as nominal. However,
it's only used for hardwood of fairly high grade, that's bought by
cabinet makers, etc. You make fine furniture with such wood.

Then there's metric, about which I know very little except that there
are common sizes that correspond to the old standards like 2x4, 2x6,
and so on. Whether they use the finished or unfinished size is not
something I know.

Mary

--
Mary Shafer Retired aerospace research engineer

"Tarver Engineering" wrote...

Nygaard, if they had bought the fuel by weight, there could have been
confusion about liters.

Now there's a perfectly nonsensical statement!

OTOH, if you meant to say "...been _no_ confusion...", it makes a bit more
sense, but is still a non-sequitur. As you stated just yesterday:

When we engage in industry, we must use the language
of that industry, as well as the existing infrastructure.

Existing infrastructure for refueling of commercial airplanes dictates
volumetric measurement -- gallons or liters -- when dispensing fuel. Therefore,
a commercial flight crew is unable to "[buy] the fuel by weight.

Further, there is NO NEED to change the fuel dispensing infrastructure, because
the aircraft systems and airline procedures work just fine as they are.
Regardless of procedures used, there will ALWAYS be the exceptional case where
someone violates those procedures, with "bad" results.

"Tarver Engineering" wrote...

All fuel is bought as weight, that is how an aircraft works.

Speaking of nonsensical statements...

(B2431) wrote:

From: "Tarver Engineering" j

snip

All fuel is bought as weight, that is how an aircraft works. The fact that
you pay for volume is a book keeper's issue.


I have never seen anyone buy avgas by weight for small GA aircraft like the
Cessna 172.

Dan, U. S. Air Force, retired

And I'll back Dan up for the Military (Canadian Mil at least)
It's never bought fuel by the pound either (and I bought a lot
too, pretty well all over the world, it was always ordered and
billed in either Imperial Gallons or US Gallons)
--

-Gord.