Why are non precision approaches not lined up?

The title just about says it - I've always wondered WHY many
non-precision approaches (not talking about LOC only here, but VOR,
VOR/DME, NDB etc) are not lined up with the runway heading. Sometimes it
looks as though the approach desginers have gone out of their way to
make sure the non-precision approach is just a few degrees off - as if
to say - "look stupid - this is not a precision approach . . ." But if
this were so, then we would have to wonder why SOME of these approaches
ARE lined up and straight-in. I'm surev there's a simple explanation
that will be pointed out here.

thanks,
G Faris

Many VORs are used for approaches to multiple airports (CGT for
example) - it would be a bit much to expect that every one will line up
perfectly. I'm surprised at how close they usually are.

In article .com,
says...


Many VORs are used for approaches to multiple airports (CGT for
example) - it would be a bit much to expect that every one will line up
perfectly. I'm surprised at how close they usually are.


Nah - happens just as often with the VOR or NDB right on the field!

GF

"Greg Farris" wrote in message
...

The title just about says it - I've always wondered WHY many
non-precision approaches (not talking about LOC only here, but VOR,
VOR/DME, NDB etc) are not lined up with the runway heading. Sometimes it
looks as though the approach desginers have gone out of their way to
make sure the non-precision approach is just a few degrees off - as if
to say - "look stupid - this is not a precision approach . . ." But if
this were so, then we would have to wonder why SOME of these approaches
ARE lined up and straight-in. I'm surev there's a simple explanation
that will be pointed out here.


Because the navaid is not on the extended runway centerline.

In article . net,
says...


Because the navaid is not on the extended runway centerline.



Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just
grabbed the book and picked that one by chance). The VOR is on the
centerline, the runwya heading is 144.6° and the VOR approach is 133°. When
you break out, you have to turn 11.6° right to land. I don't see why they
couldn't have published it right on the 145° radial.

GF

"Greg Farris" wrote in message
...
In article . net,
says...


Because the navaid is not on the extended runway centerline.



Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just
grabbed the book and picked that one by chance). The VOR is on the
centerline, the runwya heading is 144.6° and the VOR approach is 133°.
When
you break out, you have to turn 11.6° right to land. I don't see why they
couldn't have published it right on the 145° radial.

GF

Because if they had you flying the 145 radial, you'd be flying parallel to
the extended centerline of runway 14 and would still have to sidestep to be
aligned.

"Greg Farris" wrote in message =
...
In article . net,=20
says...
=20

Because the navaid is not on the extended runway centerline.=20


=20
Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just=20
grabbed the book and picked that one by chance). The VOR is on the=20
centerline, the runwya heading is 144.6=B0 and the VOR approach is =
133=B0. When=20
you break out, you have to turn 11.6=B0 right to land. I don't see why =
they=20
couldn't have published it right on the 145=B0 radial.
=20
GF


Don't just say "no", Greg.
Examine the airport surface chart, and see where the VOR 14 course must =
lie
in order to cross the approach end of Runway 14.
Looks like about 133=B0 to me.
Then check the VOR 32 approach to see the corresponding offset the =
opposite way.

Greg Farris wrote:

Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just
grabbed the book and picked that one by chance). The VOR is on the
centerline, the runwya heading is 144.6° and the VOR approach is 133°. When
you break out, you have to turn 11.6° right to land. I don't see why they
couldn't have published it right on the 145° radial.

The VOR is on the centerline? I gotta get my eyes examined.

In a previous article, Greg Farris said:
Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just
grabbed the book and picked that one by chance). The VOR is on the
centerline, the runwya heading is 144.6° and the VOR approach is 133°. When

The VOR most definitely is NOT on the centerline. Look at the airport
diagram on that approach - it's a hundred feet or more from the
centerline.

you break out, you have to turn 11.6° right to land. I don't see why they
couldn't have published it right on the 145° radial.

Because then you would never cross the extended centerline, but would be
that same distance (a hundred feet or more) to one side. I'm guessing
that in a case like this they want the course to cross the runway
centerline some specific distance from the runway. Even ROC's VOR/DME 4
(an approach which I've never heard used in 10 years of being based at
ROC) is offset a tiny bit.


--
Paul Tomblin http://xcski.com/blogs/pt/
I read [.doc files] with "rm". All you lose is the microsoft-specific
font selections, the macro viruses and the luser babblings.
-- Gary "Wolf" Barnes

Greg Farris wrote:

In article . net,
says...


Because the navaid is not on the extended runway centerline.




Nope - Look at the VOR 14 approach to ITH (Ithaca New York - Just
grabbed the book and picked that one by chance). The VOR is on the
centerline, the runwya heading is 144.6° and the VOR approach is 133°. When
you break out, you have to turn 11.6° right to land. I don't see why they
couldn't have published it right on the 145° radial.

No, the VOR is not on the runway centerline. It is several hundred feet
off to the side of the runway. Why they didn't use the runway heading
for this approach I don't know, but it could be for noise abatement,
obstruction clearance, or other reasons.


Matt