Interesting consequence of improperly programming GPS route

On Thu, 16 Jun 2005 18:33:19 -0400, "Icebound"
wrote:

This is from 2003 so it may be old for some of you....

When ferrying from the West Coast to New Zealand, what happens when you
program some key waypoints as Longitude WEST, instead of Longitude EAST in
the vicinity of the dateline.

http://www.tsb.gc.ca/en/publications..._sec2.asp#over

An interesting read that show the value of MOVING map GPS vs. a
lat/long display and CDI course display.

-Nathan

Jose wrote:

PressÂ*oneÂ*wrongÂ*buttonÂ*andÂ*theÂ*calculatorÂ*w ill
tell you that you have 143,226.21079 gallons left in your 152.Â*Â*I'm
amazed at how many people would just put that down as the answer these
days, because the calculator said so.

Nice long-range tanks you've there.

- Andrew

All the DR data that might be needed for
reference...time, distance, course for each leg... is contained on the
computer generated flight plan

.... and if the computer's wrong, do you draw the wrong line on the
chart? We might be saying the same thing here, but I am advocating
drawing the line with =no= computer help whatsoever, and using a plastic
plotter to figure the course lines. This would be totally independent
of the computer, and then when the computer does its thing, you have a
reality check.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain."
(chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

he instructor however had supposedly bugged the calculators so that on
certain problems they gave impossible answers, off by orders of
magnitude; and in the grading gave lots of bonus points to those
students who noticed and said something about it.

Probably an urban legend

I hope not!

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain."
(chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

("Andrew Gideon" wrote)
Press one wrong button and the calculator will
tell you that you have 143,226.21079 gallons left in your 152. I'm
amazed at how many people would just put that down as the answer these
days, because the calculator said so.

Nice long-range tanks you've there.


I hope the calculator person noticed that big number and figured "something"
wasn't right.

143,226.21079 is probably pounds, not gallons. Divide by 6 for gallons
(23,871) ...which is almost 1 gallon per mile at the equator :-)

Next: Weight & balance.


Montblack

On Fri, 17 Jun 2005 22:42:36 GMT, Jose
wrote:

... and if the computer's wrong, do you draw the wrong line on the
chart? We might be saying the same thing here, but I am advocating
drawing the line with =no= computer help whatsoever, and using a plastic
plotter to figure the course lines. This would be totally independent
of the computer, and then when the computer does its thing, you have a
reality check.

Drawing the line on a plotting chart is done with =no= computer help,
which is precisely why the chart is a valid cross check, along with
the "raw data" contained within the Flight Plan.

Jose

-Jack Davis
B737

-J. David
B737

----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

"Jose" wrote in message news:wlIse.2580

... and if the computer's wrong, do you draw the wrong line on the chart?
We might be saying the same thing here, but I am advocating drawing the
line with =no= computer help whatsoever,

That's actually a little impractical where oceanic crossings are concerned.
Routes are assigned based on several factors, and you only get the
information when the flight plan is generated. The waypoints are merely
Lat/Long points. You could draw the whole thing by hand, but you'd be
starting with computer generated data, anyway.

What you're suggesting is actually covered by quickly pencilling the
assigned route onto the plotting chart, and applying the smell test.

AES wrote:
In article ,
Jose wrote:


It's like working a calculator without doing a rough calculation in your
head at the same time. Press one wrong button and the calculator will
tell you that you have 143,226.21079 gallons left in your 152. I'm
amazed at how many people would just put that down as the answer these
days, because the calculator said so.



Heard a tale once of a physics prof who allowed use of programmable
calculators during the final exam, but only ones supplied by him, "so
that no one could program in any unauthorized stuff in advance".

The instructor however had supposedly bugged the calculators so that on
certain problems they gave impossible answers, off by orders of
magnitude; and in the grading gave lots of bonus points to those
students who noticed and said something about it.

Probably an urban legend -- but an instructive idea nonetheless.

The college I went to (Colorado School of Mines) has a top-rate
geophysics program. One of the lab courses in the program supposedly
(I wasn't in the program) starts out by having you use sound
transducers and an oscilliscope to determine the length of a steel
bar. If you don't get the right answer, you have to redo the experiment.

The thing students aren't told is that the oscilliscope has had a 2-3%
error built into it. The purpose of the lab is not to learn any
geophysical facts, but to learn that you always need to calibrate
your instruments.