stupid GPS question

OK I am just getting into the VFR GPS navigation thing. Here is my question:
what is the origin of all of these intersections? I see some as airway
intersections on sectionals, but many seem random.
And why is it when I file an airway flight plan with AOPA flight planner, it
always throws a couple of these in the route? Why not just go from the last
VOR direct to your destination airport? Does it assume that I have a GPS
with a current database? Or is it assuming that if I am creating an airway
route that I am IFR?

--
Hello, my name is Mike, and I am an airplane addict....

"Mike W." wrote in message
...
OK I am just getting into the VFR GPS navigation thing. Here is my
question:
what is the origin of all of these intersections? I see some as airway
intersections on sectionals, but many seem random.

Depends on what intersections you're talking about.

However, many "intersections" on an airway are not actually places where
another airway crosses. They are, instead, the intersection of that airway
and some reference from a navaid somewhere else. Usually for the purpose of
defining a distance, a transition route to an instrument approach, that sort
of thing.

Without knowing exactly what intersection you're referring to, it's hard to
answer the question more specifically than that.

And why is it when I file an airway flight plan with AOPA flight planner,
it
always throws a couple of these in the route?

I guess you'd have to ask the folks who wrote the routing algorithm for the
AOPA flight planner. However, your guesses could be correct, or it could be
related to some maximum distance from a point to the destination allowed by
the routing algorithm. It's possible (I don't know, not having used the
AOPA flight planner) that there's an option that tells it to only use VORs;
that would be an appropriate restriction on the routing algorithm for VFR
flight, and would eliminate those intersections from your route.

Pete

For example, just northwest of my home base airport, KOSU, there is an
intersection named DIPNE. It is on the V12 airway between the DQN and APE
vor's, but it doesn't appear on the sectional. So I guess not all
intersections appear on sectionals?

"Peter Duniho" wrote in message
...
"Mike W." wrote in message
...
OK I am just getting into the VFR GPS navigation thing. Here is my
question:
what is the origin of all of these intersections? I see some as airway
intersections on sectionals, but many seem random.

Depends on what intersections you're talking about.

However, many "intersections" on an airway are not actually places where
another airway crosses. They are, instead, the intersection of that
airway
and some reference from a navaid somewhere else. Usually for the purpose
of
defining a distance, a transition route to an instrument approach, that
sort
of thing.

Without knowing exactly what intersection you're referring to, it's hard
to
answer the question more specifically than that.

And why is it when I file an airway flight plan with AOPA flight
planner,
it
always throws a couple of these in the route?

I guess you'd have to ask the folks who wrote the routing algorithm for
the
AOPA flight planner. However, your guesses could be correct, or it could
be
related to some maximum distance from a point to the destination allowed
by
the routing algorithm. It's possible (I don't know, not having used the
AOPA flight planner) that there's an option that tells it to only use
VORs;
that would be an appropriate restriction on the routing algorithm for VFR
flight, and would eliminate those intersections from your route.

Pete

"Mike W." wrote in message
...
[...] So I guess not all intersections appear on sectionals?

That is correct. Especially those intersections created for the purpose of
IFR flight, one may find them only on instrument charts.

[...] So I guess not all intersections appear on sectionals?

That is correct. Especially those intersections created for the purpose of
IFR flight, one may find them only on instrument charts.

An example would be an intersection on an instrument approach that
defines an altitude step down point on the approach.

Mike W. wrote:
For example, just northwest of my home base airport, KOSU, there is an
intersection named DIPNE. It is on the V12 airway between the DQN and APE
vor's, but it doesn't appear on the sectional. So I guess not all
intersections appear on sectionals?

A small percentage of the intersections appear on the sectional.

"Newps" wrote in message
news
A small percentage of the intersections appear on the sectional.


Looking through http://www.airnav.com/airspace/fix/ shows quite a list of
intersections. Most aren't on the sectionals. Are they all on IFR charts?

-Greg B.
(kinda near MONTZ)

N93332 wrote:

"Newps" wrote in message
news
A small percentage of the intersections appear on the sectional.



Looking through http://www.airnav.com/airspace/fix/ shows quite a list of
intersections. Most aren't on the sectionals. Are they all on IFR charts?

Yes, and even a few more on STARS and SIDS

Newps wrote:

A small percentage of the intersections appear on the sectional.

So here's something I've wondered since I first began IFRing: What makes an
intersection worthy of appearance on a VFR chart?

- Andrew

So here's something I've wondered since I first began IFRing: What makes
an
intersection worthy of appearance on a VFR chart?

Here's the rule, straight from the FAR-AIM:

"IFR intersections are depicted on sectional charts only if by doing so
there will be a greater than 50% chance of covering up, obscuring, or
confusing something more important on that chart."

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"