Why The Hell... (random rant)

"Ron Natalie" wrote in message
m...

Huh? What does the wind have to do with VOR's. If the needle is
centered, you're within the tolerance of the VOR. The tolerance
is primarily 4-6 degrees. This keeps you inside the airway at
moderate distances from the VORs.


What about at more than moderate distances from the VOR? At 40 miles from
the VOR 6 degrees is 4 miles.

On Wed, 04 Apr 2007 16:28:41 GMT, "Steven P. McNicoll"
wrote:


"Ron Natalie" wrote in message
om...

Huh? What does the wind have to do with VOR's. If the needle is
centered, you're within the tolerance of the VOR. The tolerance
is primarily 4-6 degrees. This keeps you inside the airway at
moderate distances from the VORs.


What about at more than moderate distances from the VOR? At 40 miles from
the VOR 6 degrees is 4 miles.

Under the heading of "Enquiring Minds Want to Know:

In defining an intersection, what's the maximum distance from a VOR
that's allowed?

Does an intersection in a GPS database represent the actual
intersection of VOR radials, or is it defined in LAT/LON terms?
(I.e., can there be two locations for an intersection, depending on
whether you're using VORs or GPS?

Apart from shifting declination, what is the mechanism by which VORs
drift out of calibration? Isn't the phase shift for each antenna in
the array set by the length of coax between it and the transmitter?
Does Velocity Factor change significantly as the coax ages? If it is a
matter of aging cable, does that mean the error is uniform and the
pattern is shifted consistently around the compass rose, or are the
longer cables affected more? And in the latter case, how would that
affect the error? (I would think that the higher the radial, the
greater the error, if this were the case.)

(Or do I not understand how a VOR array is phased?)

Don

"Don Tuite" wrote in message
...

Under the heading of "Enquiring Minds Want to Know:

In defining an intersection, what's the maximum distance from a VOR
that's allowed?


I guess the simple answer is 135 miles.

The limiting factor is the minimum divergence angle. The minimum divergence
angle (smaller angle of the two crossing radials) is one degree per NM up to
45 miles, beyond 45 miles it's 1/2 degree per NM. Since the mimimum
divergence can't exceed 90 degrees, the furthest you can get is 135 miles.



Does an intersection in a GPS database represent the actual
intersection of VOR radials, or is it defined in LAT/LON terms?
(I.e., can there be two locations for an intersection, depending on
whether you're using VORs or GPS?


There can be many locations for a given fix. For example, a fix identified
by intersecting radials as well as radial/DME from either navaid. The exact
position varies with altitude and which navaid you choose to determinr
position.

Steven P. McNicoll wrote:
"Ron Natalie" wrote in message
m...
Huh? What does the wind have to do with VOR's. If the needle is
centered, you're within the tolerance of the VOR. The tolerance
is primarily 4-6 degrees. This keeps you inside the airway at
moderate distances from the VORs.


What about at more than moderate distances from the VOR? At 40 miles from
the VOR 6 degrees is 4 miles.


At 51 miles, 4.5 degrees gives you 4 miles. 6 degrees gives you about
6. Theres' 2 miles of protected area outside the airway.
Statistically you're within it, but even in the worst case you're
safe.