Absolute lowest altitude you can fly (legally)

Mxsmanic wrote:
Walt writes:

But, this is not a big deal, since you'll be using waypoints along the
way, and the heading between waypoints won't change enough to be a
worry. But, you'll probably notice that your true heading changes by a
degree or so from one waypoint to another.

This is an interesting point. I do see the heading towards a waypoint
change slowly over time, and I've naturally assumed that it was just
the wind. However, if the distance between waypoints is quite long, I
can see that the actual track to follow could change over time due to
the great-circle character of the track between the waypoints.
Unfortunately, I don't remember offhand how long the distance would
have to be before it would change by a degree or more at intermediate
latitudes.

That's the whole reason for waypoints. We live on a sphere but
dead-reckon on a flat surface.

So, for dead reckoning today it's not incidental at all.

Yes, _if_ someone is navigating by dead reckoning. My point was that
hardly anyone uses dead reckoning by hand these days. And as one
increases in latitude, the 1 degree = 1 minute relationship gets more
and more iffy, too.

Your original statement was about dead reckoning. That was what I was
responding to.

35 years ago I could whip up a comp for a celestial shot in less than a
minute. Today it would probably take me a week. Of course, we used an
Air Almanac and an H.O. 249 to take care of the pesky trig stuff, so it
was mainly adding and subtracting stuff involving the GHA of Aries.
:)

I'm sure most other pilots have the same problem--if they ever knew
how to do this in the first place, that is.

Just a teary-eyed remembrance from an old fart. I didn't expect much of
a response.


ANYWAY, if you're serious about plotting your course on a chart, know
what map projection you're using and the distance between waypoints.
Using a conical projection chart and a standard plotter will be plenty
accurate for any kind of dead-reckoning, no matter which direction
you're going.

Not very practical for me these days.

That wasn't my point. I thought you were interested in navigation. Try
reading Dava Sobel's _Longitude_. Fascinating read if you're really
interested in navigation, whether 300 years ago or present time.

--Walt (who is probably showing his age)

When you flew, the B-52 was an important part of the military's
aircraft inventory. Whereas today, the B-52 is an important part of
the military's aircraft inventory.


Nice putdown.

I gave you some tantalizing clues about navigation. Pursue them or
ignore them. Up to you.

--Walt

Walt writes:

That wasn't my point. I thought you were interested in navigation. Try
reading Dava Sobel's _Longitude_. Fascinating read if you're really
interested in navigation, whether 300 years ago or present time.

I did read it, but it talked too much about politics and other
matters, and not enough about technical stuff.

Nice putdown.

How so? I was alluding to the fact that some things in aviation have
not changed.

I gave you some tantalizing clues about navigation. Pursue them or
ignore them. Up to you.

At the moment I don't have time to investigate them, but I'll keep
them under consideration.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote:
Walt writes:

That wasn't my point. I thought you were interested in navigation. Try
reading Dava Sobel's _Longitude_. Fascinating read if you're really
interested in navigation, whether 300 years ago or present time.

I did read it, but it talked too much about politics and other
matters, and not enough about technical stuff.

Ignore the political aspects of the book, although they're pretty
interesting in their own right. Just take the way they tried to figure
out a longitude fix 300 years ago and look at how it's done now.

Nice putdown.

How so? I was alluding to the fact that some things in aviation have
not changed.

The current B-52 is what, the H model? It's changed. The current Walt
model is still the A model, although there have been a number of dot
releases over the years.


I gave you some tantalizing clues about navigation. Pursue them or
ignore them. Up to you.

At the moment I don't have time to investigate them, but I'll keep
them under consideration.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Do it when you have the time.

--Walt

Walt wrote:
Mxsmanic wrote:
When you flew, the B-52 was an important part of the military's
aircraft inventory. Whereas today, the B-52 is an important part of
the military's aircraft inventory.

Nice putdown.

What putdown? I read that statement as a compliment. You were
commenting about growing old, and he was inferring that the things you
were involved with years ago, haven't grown old and useless.

Regards,
Kev

Walt writes:

Ignore the political aspects of the book, although they're pretty
interesting in their own right. Just take the way they tried to figure
out a longitude fix 300 years ago and look at how it's done now.

In those days, mariners had to be very brave, or slightly stupid.

The current B-52 is what, the H model? It's changed.

Yeah, but it was supposed to be gone, replaced by fancier stuff. Now
the AF is talking about keeping it for another 40 years. It's a good
aircraft.

Who would have thought, more than four decades ago, that he could tell
his grandson "Someday you'll fly this plane, too"?

--
Transpose mxsmanic and gmail to reach me by e-mail.

Kev writes:

What putdown? I read that statement as a compliment. You were
commenting about growing old, and he was inferring that the things you
were involved with years ago, haven't grown old and useless.

Exactly. Other aircraft have come and gone, but some aircraft, such
as the B-52, have outlived them all, and still serve just as they did
when they were "young."

--
Transpose mxsmanic and gmail to reach me by e-mail.

Kev wrote:
Walt wrote:
Mxsmanic wrote:
When you flew, the B-52 was an important part of the military's
aircraft inventory. Whereas today, the B-52 is an important part of
the military's aircraft inventory.

Nice putdown.

What putdown? I read that statement as a compliment. You were
commenting about growing old, and he was inferring that the things you
were involved with years ago, haven't grown old and useless.

Regards,
Kev

Good point. I read it as saying, "The B-52 is an important part of the
inventory and you're not."

Which is, of course, true.

But it still hurt.

sob

--Walt

Walt writes:

Good point. I read it as saying, "The B-52 is an important part of the
inventory and you're not."

Nope, that's almost the opposite of what I intended.

But it still hurt.

The least complimentary interpretation is not neccesarily the right
interpretation.

--
Transpose mxsmanic and gmail to reach me by e-mail.

Mxsmanic wrote:
Walt writes:

Good point. I read it as saying, "The B-52 is an important part of the
inventory and you're not."

Nope, that's almost the opposite of what I intended.

But it still hurt.

The least complimentary interpretation is not neccesarily the right
interpretation.

--

And from you, I will take that as a compliment. Thanks.

--Walt

Gentlemen and Ladies:

Sorry, but if I read these correctly . .

Knots are not dimensionless in aviation. A knot is one nautical
mile per hour, and that nautical mile is the distance corresponding to
one minute of latitude at the equator.

Yes, _if_ someone is navigating by dead reckoning. My point was that
hardly anyone uses dead reckoning by hand these days. And as one
increases in latitude, the 1 degree = 1 minute relationship gets more
and more iffy, too.

It appears to me (unless I misunderstand the posts cited above) that there
may be a misunderstanding of latitude and longitude's relationship to
Nautical Miles.

If I recall correctly, 1 min of latitude = 1 NM everywhere (not just the
equator), aren't lines of latitude also called parallels and thus maintain
there equidistant relationship all the way to the poles? And don't lines of
longitude meet at the poles and therefore their angles maintian the same
angular relationship yet the distances decrease the further one travels from
the equator?

Regards,

Watson