Why are some NDBs not displayed on Low Alt Enroute Charts?

"Dave Butler" wrote in message
news:1146665519.212250@sj-nntpcache-5...

PETIS NDB doesn't seem to have an enroute function, but PETIS reporting
point does. The two are very nearly, but not exactly colocated. Note that
PETIS reporting point is not defined from the NDB, but rather by 4
different methods using two VORs and 2 localizers.

Navaid identifier: SB
type: NDB
name: PETIS
city: SAN BERNADINO
state: CA
latitude: 34-03-23.285N
longitude: 117-21-58.014W
elevation: 0
magnetic variation: -14

Fix identifier: PETIS
state: CA
use: REPORTING POINT
latitude: 34-03-23.290N
longitude: 117-21-58.010W
VOR HDF, radial 317.77
VORTAC PDZ, radial 029.62, DME 11.63
ILS/DME I-ONT, radial E CRS, DME 12.86
ILS I-SBD, radial SW CRS


Very nearly, but not exactly collocated? Let's see, running those
coordinates through an online distance calculator shows the distance between
them to be 0.0000887267 NM. That's less than 6 1/2 inches. That's smaller
than any NDB antenna I've ever seen, I'd say they ARE exactly collocated.

Steven P. McNicoll wrote:
"Dave Butler" wrote in message
news:1146665519.212250@sj-nntpcache-5...

PETIS NDB doesn't seem to have an enroute function, but PETIS reporting
point does. The two are very nearly, but not exactly colocated. Note that
PETIS reporting point is not defined from the NDB, but rather by 4
different methods using two VORs and 2 localizers.

Navaid identifier: SB
type: NDB
name: PETIS
city: SAN BERNADINO
state: CA
latitude: 34-03-23.285N
longitude: 117-21-58.014W
elevation: 0
magnetic variation: -14

Fix identifier: PETIS
state: CA
use: REPORTING POINT
latitude: 34-03-23.290N
longitude: 117-21-58.010W
VOR HDF, radial 317.77
VORTAC PDZ, radial 029.62, DME 11.63
ILS/DME I-ONT, radial E CRS, DME 12.86
ILS I-SBD, radial SW CRS



Very nearly, but not exactly collocated? Let's see, running those
coordinates through an online distance calculator shows the distance between
them to be 0.0000887267 NM. That's less than 6 1/2 inches. That's smaller
than any NDB antenna I've ever seen, I'd say they ARE exactly collocated.

0.0000998688619566808 nm, or a little over 7 inches, by my calculation. Point
taken. They are collocated. Thanks for correcting my spelling, too.

Dave

--
Dave Butler, software engineer 919-392-4367

Did you use the link to the charts I provided for you?

Jim Macklin wrote:

Don't know, don't have that chart.


"Sam Spade" wrote in message
news:VoK5g.175045$bm6.45600@fed1read04...
| Jim Macklin wrote:
| A NAVAID is shown on a chart if it has a function on
that
| chart. Enroute charts don't show NAVAIDS that only
serve an
| IAP, and IAP charts don't show all the enroute NAVAIDS
in an
| area.
| The NDB in question has some enroute function, perhaps a
| bearing or even a route segment.
|
|
| Could you be more specific about the case in point? What
en route
| function does PETIS have?

Jim Macklin wrote:
Don't know, don't have that chart.

My web site reference now has the official FAA form for Petis NDB/INT in
addition to the Jeppesen Charts.

It is charted on the area chart, but not the enroute chart, because it
serves several STARs.

If you've never seen the source document for a fix, you might find it of
some interest. It also documents the holding patterns authorized for
ATC's use and whether a pattern is to be charted.