That fact the you "state it" doesn't make it so. The crosswind/crosscurrent
calculation may be the same, but there are lots of "qualitative" differences
between air navigation and nautical navigation. DR may have similar meanings
and similar problems in both, but navigation in general involves many
techniques, used in various combinations, as appropriate.

For example, how do you take soundings in a plane? Can you hear foghorns? Can
you read the windspeed from a lobster pot? DR by itself is just one technique,
and one that admittedly has certain limitations. But combined with other
techniques it can be quite useful.


"JAXAshby" wrote in message
...
jeffies, I stated from the get-go that there is no qualitative difference
between air and sea navigation.

It's a physics thing. get your wife to explain it to you.

So tell us please, jaxie, what is the difference? So far, you have only
demonstrated your ignorance in both air and nautical navigation. Why don't
you
try for space navigation?


"JAXAshby" wrote in message
...
jeffies, don't comment on how aircraft fly. you don't have a clew.

you should know **if** you did have that degree in physics you claim you
have,
but you don't.

Its very simple, jaxie: a 20 knot crosswind affects a 100 knot airplane
about
the same way that a 1 knot cross current affects a 5 knot sailboat.
There
is a
major difference, however: the wind can change dramatically with little
notice
and no way to detect it, resulting in huge potential errors for the plane,
while
the current is usually well behaved, especially if you understand the
local
conditions.

You never have done either, have you jaxie?



"JAXAshby" wrote in message
...
jeffies, pahleeeeeeeeeeeeeeeeeeeeeze ask your wife to read every last
thing
you
write **before** you hit the post key. that way we won't see the trash
you
wrote below.

PLEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEAAAAAAAAAAAAAAAAA AAAAASSSSSSSSSSSSSSSSSSSS
SSEEEEEEEEEEEEEEEEEEE. okay?

There are no aircraft flights under discussion here. However, if we're
talking
about planes where electronics might not be used, then the speed is
probably
rather low, and the wind speed could easily be 20% of the plane speed.
Worse,
you could have a significant wind shift and have no idea it happened.
In
a
boat, the currents are usually under a knot, and rarely is the
deviation
from
the prediction more than knot. You seem to be basing your entire claim
on
the
possibility of unexpected 10 knot current in totally random directions.
This
show your complete lack of experience.

Further, your completely ignoring that fact that for piloting, a major
part
of
navigation, there are many techniques that have no analogue in flying.
But
you
wouldn't know anything about this, would you?




"JAXAshby" wrote in message
...
But to claim that there is "no qualitative difference between
navigating"
a
plane and boat just shows you have no practical experience doing
either.

quite the contrary. it shows I have done both.

actually, in air nav you don't have to make as much allowance for
winds,
for
the speed of the an airplane is many times the speed of the winds,
for
the
aircraft flights under discussion here.