Are sectional paths correct across "long" distances?

"Kyler Laird" wrote in message
...
No, but it does affect planning. I like to plan for "straight"-line paths
that keep me out of restricted airspace. Makes my life a lot easier.

That doesn't make any sense to me. Either a straight line between your
origin and destination will keep you out of restricted airspace, or it
won't. The origin, destination, and restricted airspace aren't moving.
It's not like there are multiple "straight line" paths. In reality there's
only one.

However, that's all irrelevant. If you are close enough to restricted
airspace that a Lambert "straight line" versus a great-circle makes the
difference between in or out, you need more than just a plotted route to
ensure you remain clear of the restricted airspace.

I don't know when the last time you flew a perfect straight line is. Maybe
it was yesterday. But I've never managed to do so.

It's something that matters to me. Am I going to have to think about
where I'm going around some airspace/mountain/...? Do I have to explain
my plans to Center?

That still doesn't explain why you are worried about the difference between
great-circle and a sectional straight line. You never have to explain your
planning to Center, and you always have to think about where you're going
around some airspace or mountain. How you plot the route is irrelevant. If
you have to go around, you have to go around.

If you fly the route plotted, then the route plotted is the one you fly.
Simple, no?

Simple except that it doesn't match the plot on the GPS I use to double-
check my progress.

In other words, you wouldn't be flying the route plotted. My statement is
still true.

I don't recall you ever stipulating that you needed a plotted route that
matched your GPS's great-circle calculations. I would agree that if what
you want to fly is a great-circle route, then you need to plot a
great-circle route.

Personally, I'd use the GPS to show restricted airspace and to ensure I'm
WELL clear. If I wanted to navigate using the GPS, and I had found that a
straight line plotted on a sectional kept me clear of the restricted
airspace, I'd simply add a waypoint to the GPS-direct route near the
airspace, on the line I plotted on the sectional. Likewise other obstacles.
If you're that close to stuff like that, you need something more reliable
(such as looking out the window) to ensure you avoid what you're trying to
avoid anyway.

I'm a horrible person for wanting to simplify flying...blah, blah, blah...
I'll never earn my "aviator balls"...blah, blah, blah...Yeah, I know.

I have no idea what that's all about. IMHO, you are making things more
complicated, not simplifying things. You are falling into the usual trap of
allowing your technology to provide you with false precision, overanalyzing
the flight to the point of distraction.

Maybe you're the best pilot around, and you can actually stay on centerline
when your GPS has a great-circle route for you to fly. Me, I know for a
fact that I'm doing good to keep headings that keep me within a half mile to
a mile of course, even with GPS or Loran.

Using a VOR, my precision goes down even more. I know better than to cut
things close to obstacles and restricted airspace using only my radio
navigation, simply because I can't fly that precisely by radio navigation.
I need outside references to cut things that close, and if I have those,
then I don't need to worry about the difference between a sectional
straight-line course and a true great-circle route.

More power to you if you always remain within a hundred feet or so of your
intended centerline throughout an entire cross-country. I guess if that's
the case, then you shouldn't feel worried at all about trusting your GPS to
guide you just past an obstacle or restricted airspace, and nothing I've
written is relevant to your operations.

Pete

"Peter Duniho" writes:

Either a straight line between your
origin and destination will keep you out of restricted airspace, or it
won't.

Yes. (If we're calling the Great Circle path a "straight line.)
That's why I want it to be exact.

I don't know if this would realistically affect me or not. I've never
planned long trips without GC paths. I don't want to deal with the
inconsistency though.

It's something that matters to me. Am I going to have to think about
where I'm going around some airspace/mountain/...? Do I have to explain
my plans to Center?

That still doesn't explain why you are worried about the difference between
great-circle and a sectional straight line. You never have to explain your
planning to Center,

And yet I've been asked on more than one occasion. Is this one of those
Wubba-logic things where "never" means "5% of the time" and I'm just
supposed to forget my experiences, or by "never have to" are you just
meaning that you can not divulge the information and remain in compliance
with FAA regs (even though they'll probably drop you and call you names)?

--kyler

"Kyler Laird" wrote in message
...
[...]
And yet I've been asked on more than one occasion. Is this one of those
Wubba-logic things where "never" means "5% of the time" and I'm just
supposed to forget my experiences, or by "never have to" are you just
meaning that you can not divulge the information and remain in compliance
with FAA regs (even though they'll probably drop you and call you names)?

There is absolutely no basis for Center ever asking you to justify your
choice in flight planning. Their job is to control airspace -- to keep you
from hitting other airplanes.

I have never had any controller ask me to justify my route of flight. I
won't go so far as to say you never have either, but it boggles my mind that
you would have, and that you'd think there's any reason you'd be required
to.

But frankly, that's just a red herring anyway. There's no way in hell that
any controller would want to know why you flew a sectional straight line
instead of a great-circle route or vice a versa. The difference is just
noise to them.

If it makes you feel better, feel free to detail the instances in which ATC
has asked you to justify your route. It's such a bizarre concept, I'm sure
we'd all learn something new from that. But it still has nothing to do with
this thread.

Pete

Peter, you saved me the effort of replying further; your replies
stated essentially what I would have said.

One comment: The reason I asked for the greatest distance between a
GC line and a straight line was that it looked to me, on Kyler's
chart, as though it was never more than a few miles. That would
indirectly indicate the difference between the distance to destination
of the two routes could not be more than a few miles.

I can't remember ever planning a flight of more than a couple hundred
miles that did not involve dodging around one or more restricted areas
or MOAs, so the question about the difference between a straight line
and a GC over a long distance is only of academic interest.

vince norris

"Peter Duniho" writes:

There is absolutely no basis for Center ever asking you to justify your
choice in flight planning.

My use of "explain" was apparently ambiguous. I've not been asked to
justify my route (that I recall), but I have been asked to elaborate on how
I'm going to deal with airspace barriers. I got the feeling that they
wanted more than "I'm going to avoid them."

But frankly, that's just a red herring anyway. There's no way in hell that
any controller would want to know why you flew a sectional straight line
instead of a great-circle route or vice a versa. The difference is just
noise to them.

Again, that's off the subject. I don't know that I'm capable of providing
further clarification on my preference to have all of my maps (and paths)
be aligned.

That's my own laziness though. I'm perfectly happy justifying the use of
Great Circle paths for the tools I build solely because it's The Right
Thing to do.

--kyler

"Kyler Laird" wrote in message
...
"Peter Duniho" writes:

There is absolutely no basis for Center ever asking you to justify your
choice in flight planning.

My use of "explain" was apparently ambiguous. I've not been asked to
justify my route (that I recall), but I have been asked to elaborate on
how
I'm going to deal with airspace barriers. I got the feeling that they
wanted more than "I'm going to avoid them."

But frankly, that's just a red herring anyway. There's no way in hell
that
any controller would want to know why you flew a sectional straight line
instead of a great-circle route or vice a versa. The difference is just
noise to them.

Again, that's off the subject. I don't know that I'm capable of providing
further clarification on my preference to have all of my maps (and paths)
be aligned.

That's my own laziness though. I'm perfectly happy justifying the use of
Great Circle paths for the tools I build solely because it's The Right
Thing to do.

--kyler

When flying VFR, I've been asking about my planned route of flight before.
The controller is just doing his/her job and wants to get the heads up.

"F1" wrote in message
...
When flying VFR, I've been asking about my planned route of flight before.
The controller is just doing his/her job and wants to get the heads up.

Did the controller ask you to explain why you chose one route versus
another? I doubt they did. That is the issue here, not a controller's
general interest in which way you're going.

In article ,
"Peter Duniho" wrote:

"F1" wrote in message
...
When flying VFR, I've been asking about my planned route of flight before.
The controller is just doing his/her job and wants to get the heads up.

Did the controller ask you to explain why you chose one route versus
another? I doubt they did. That is the issue here, not a controller's
general interest in which way you're going.



I've had controllers ask me "how I'm navigating" while VFR. But I
believe the intent of the question has generally been, "Can you give me
a heads-up where you're heading so I can anticipate your flight path
better?" Sometimes I think it's been, "Based on where you said you were
going, I'm wondering if you're lost; do you need some help?"

In all cases, if I've come back with something like, "We're going to be
maneuvering in the area of X for a while", or "We're going to be
following X, Y, and Z", (no matter how absurd or circuitous that path
might have been), that's seem to satisfy the controller.