Edwards air show B-1 speed record attempt

In message , "Gord
writes
(B2431) wrote:
From: "Tarver Engineering" j
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)

Civilian light aviation in the UK buys fuel by volume, not weight. You
pay for the volume pumped, not the weight change: it's up to you to keep
track of the weight. (Our aircraft could go over MGTOW with a full tank
and two burly occupants: luckily I and my instructor were both wiry
types)

--
When you have to kill a man, it costs nothing to be polite.
W S Churchill

Paul J. Adam MainBoxatjrwlynch[dot]demon{dot}co(.)uk

On Sun, 26 Oct 2003 18:20:16 +0000, "Paul J. Adam"
wrote:

Civilian light aviation in the UK buys fuel by volume, not weight. You
pay for the volume pumped, not the weight change: it's up to you to keep
track of the weight. (Our aircraft could go over MGTOW with a full tank
and two burly occupants: luckily I and my instructor were both wiry
types)

And if you're doing flight research or test, you have to call over and
get the fuel temperature so you can do the conversion to pounds and
compute cg position.

So far as I know, all jets and turboprops fill in gallons and work in
pounds. Of course, the weight is just a straight calibration thing
and approximate, unless the fuel temperature is used to determine
density (which it isn't, that I know of).

The SR-71 was filled on the ground in gallons, but flown in pounds,
mostly for flight limits. The boundaries of the various regions are a
little peculiar because of how the fuel tanks sequenced, mostly to
minimize cg extremes, but this is pretty common for any airplane with
multiple fuel tanks.

Needless to say (but I'll say it anyway), the reason this works this
way is because volume is easy to measure, particularly for
free-flowing liquids. Weight is harder. Naturally, the world prefers
the easy way.

Mary

--
Mary Shafer Retired aerospace research engineer

Mary Shafer wrote:

snip

Needless to say (but I'll say it anyway), the reason this works this
way is because volume is easy to measure, particularly for
free-flowing liquids. Weight is harder. Naturally, the world prefers
the easy way.

Shafer's Corollary to Ockham's Razor? ;^)
--
Andrew Chaplin
SIT MIHI GLADIUS SICUT SANCTO MARTINO
(If you're going to e-mail me, you'll have to get "yourfinger." out.)

Mary Shafer writes:


Civilian light aviation in the UK buys fuel by volume, not weight. You
pay for the volume pumped, not the weight change: it's up to you to keep
track of the weight. (Our aircraft could go over MGTOW with a full tank
and two burly occupants: luckily I and my instructor were both wiry
types)

And if you're doing flight research or test, you have to call over and
get the fuel temperature so you can do the conversion to pounds and
compute cg position.

So far as I know, all jets and turboprops fill in gallons and work in
pounds. Of course, the weight is just a straight calibration thing
and approximate, unless the fuel temperature is used to determine
density (which it isn't, that I know of).


When I worked on a pipeline that send 500k gallons a day of JetA to
the airport, and then pumped it to the ramp, it worked thus:

We pumped/sold it by the barrel -- a barrel being 42 gallons.
(That's an API standard for "custody transfer"...)

The hydrant trucks, with a "in" hose, meter, filter, "out" hose
and a platform to reach the wings, metered it in gallons. The
ticket printer on it read in gallons. That went to the crew.

I'll assume the cockpit all read in pounds, but don't know that from
personal knowledge. But didja know some 737's have fuel gages under
the wing, by the fuel point? There are also switches to control
cross-feeding of the incoming fuel.





--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

In article ,
says...
From: Jim Campbell rchaic

snip

I say we should start measuring velocity in furlongs per fortnight.

Dan, U. S. Air Force, retired

The metric system is the tool of the devil! My car gets forty rods to
the hogshead and that's the way I likes it.
-- Grandpa Simpson

Which works out to about approximately 10.4 feet per gallon!
(US or Imperial is left as an exercise for the reader)


--
Jim Campbell

How long does it take for your car to accelerate from zero to 60 furlongs per
fortnight?


In English or Metric units of time ?


--
When dealing with propaganda terminology one sometimes always speaks in
variable absolutes. This is not to be mistaken for an unbiased slant.

David Lesher wrote:

I'll assume the cockpit all read in pounds, but don't know that from
personal knowledge.

Any that I flew did except Lancasters which read in gallons.

But didja know some 737's have fuel gages under
the wing, by the fuel point? There are also switches to control
cross-feeding of the incoming fuel.

Almost (if not all) larger passenger a/c have this 'pressure
refueling panel' (usually in a wheel-well) with electrical
switches to control the direction and amount of fuel being
uploaded.

Fuel is almost always loaded using gallons and the internal fuel
quantity indicators almost always indicate in pounds. Fuel weight
is a much more useful parameter than volume where a/c are
concerned.
--

-Gord.

On C-130s we had the SPR (single point refuling panel) where they hooked up the
nozzel. It had indicators reading pounds for each of the integral tanks. Just
an observation.

Dan, U.S. Air Force, retired

http://news.bbc.co.uk/1/hi/england/s...es/3081612.stm

"The court heard he had miscalculated the conversion from US gallons
to litres when requesting fuel before taking off and asked for 90
litres instead of 113.5 litres."


Official accident report at:
http://www.dft.gov.uk/stellent/group...ty_502314.hcsp

(Pat Norton) wrote:

http://news.bbc.co.uk/1/hi/england/s...es/3081612.stm

"The court heard he had miscalculated the conversion from US gallons
to litres when requesting fuel before taking off and asked for 90
litres instead of 113.5 litres."


Official accident report at:
http://www.dft.gov.uk/stellent/group...ty_502314.hcsp

Very interesting Pat, thanks.
--

-Gord.

"av8r" wrote in message
...
Hi

You all might want to read the story below about the Gimli Glider.

http://www.flightsafety.org.au/articles/t0357.php

Here's an extract from the above.

Cheers...Chris

The flight from Montreal to Edmonton, including a brief stop in Ottawa,
required 22,300kg of fuel, an amount expressed as mass because of the
importance of knowing an aircraft's weight.

The mechanics needed to work out how many litres made up 22,300kg. They
could then subtract the 7,682 litres already in the tanks, and use the
fuel gauge on the refueling truck to tell when they had reached the
right number of litres to make up 22,300kg.

But the 767 was the first aircraft in Air Canada's fleet to use metric
units (kilograms) rather than imperial (pounds). Metric units were being
phased in across Canada, and the conversions were still causing confusion.

And so, making a PC change, caused another near disaster.