Since I have only read about it and have not really had an
opportunity to check it out, consider the Bellamy drift is
based on the average crosswind, I do believe you can also
derive the average tail/headwind and apply that to the
expected trip distance.

The USAF Navigtation manual has a section on these
techniques.

If you look at the
http://www.e-publishing.af.mil/pubfi...-130v3cl-5.pdf
you will see steps for rules of thumb.


Note the original links below are broken and are repaired.

http://www.planeandpilotmag.com/cont...evisiting.html

http://www.flyingmag.com/article.asp...age_numbe r=2


"xerj" wrote in message
...
| Thanks for those Jim. I'd seen a couple of them before.
The thing is that
| unless I'm missing something, there isn't an explanation
of WHEN you'll
| arrive. There's an explanation of HOW and WHERE, but I'm
wondering how you
| work out time and fuel planning when using the pressure
pattern method.
|
| "Jim Macklin" wrote
in message
| news:aewog.49771$ZW3.4494@dukeread04...
| Plane & Pilot Magazine | Feature Articles | Revisiting
| Pressure ... Initiated in 1943, pressure-pattern
navigation
| is attributed to Dr. John Bellamy. His so-called
"Bellamy
| Drift" was used widely during the late 1940s, ...
| www.planeandpilotmag.com/content/
| pastissues/2001/mar/revisiting.html - 37k - Cached -
Similar
| pages
|
|
| Flying Magazine - You want to put them where? The
| relationship between barometric pressure and wind drift
is
| enshrined in the so-called Bellamy Drift, named for John
| Bellamy, a civil engineer and ...
| www.flyingmag.com/article.asp?section_
| id=12&article_id=602&page_number=2 - 24k - Cached -
Similar
| pages
|
|
| [PDF] AFI 11-2C-130 Volume 3, Checklist 5 File Format:
| PDF/Adobe Acrobat - View as HTML
| Whiz Wheel Formula for finding Bellamy Drift:. ZN.
=.
| DCA. Grnd Dist. 57.3. PRESSURE PATTERN ALTITUDE CHANGE.
| FORMULA METHOD ...
| www.e-publishing.af.mil/pubfiles/
| af/11/afi11-2c-130v3cl-5/afi11-2c-130v3cl-5.pdf -
Similar
| pages
|
|
|
|
| "xerj" wrote in message
| ...
| | ... when using pressure pattern nav techniques, what's
a
| standard way for
| | working out groundspeed for flight planning purposes?
Do
| you take the
| | forecast curved route and divide it up into segments
and
| average it out?
| |
| | TIA
| |
| |
|
|
|
|