Steven P. McNicoll wrote:
Tman wrote:
I've been paying attention to intersections a lot lately since I'm
looking at the IFR charts more.

Check this example out; Dial up the MSLIN intersection on your New
York section or skyvector.com.

Looking at that; I've always interpreted that picture as the MSLIN
intersection is at the intersection of V205 and V374, and I could use
the associated radials defining those airways from the closest
relevant VORs to know when I'm at that intersection. Upon closer
examination, it appears to suggest that the intersection is actually
defined off of the LGA VOR, but it doesn't give a clue as to which
radial or DME off that VOR might define it.

All of which appears to be wrong; look at it on the Enroute
low-altitude chart, say L33. First of all, MSLIN is NOT at the
intersection of V205 and V374. It is at the 5DME fix off the HUO 030
radial (off the V205 airway quite a bit -- quite different than the
location implied by the VFR sectional).

That other arrow on the IFR chart at MSLIN suggests I can locate the
MSLIN intersection using the DME fix off of the CFB VORTAC (81 DME fix
along V374 / R129). Now, CFB is an "L" VORTAC and normally would
have a service volume of 40 miles, but I guess one has to pay
attention to the rather high 10000 MEA on this airway in order to
affix their MSLIN position using CFB. It prompted me to go back to
the AIM Ch 1 service volumes -- it says that the L VORTAC does
indeed have a service volume of only 40 miles, but that service
volumes don't apply to charted IFR routes -- the MEA and route
instruction on the chart supersede. So it appears that one would
need to be above 10000 to use this airway in general and affix MSLIN
in particular using CFB.
I guess I learned a couple things today

It does blow my mind though that the VFR sectional has a.) very
misleading and incomplete information on how to locate the MSLIN
intersection, and b.) oh yeah, didn't tell you that you needed to be
10000 or higher in order to fly V374 reliably using the VORTAC
system.... I know I wouldn't pick up any quality signal from an 80nm
distant VOR at 4,000 in that vicinity.

Any other thoughts on what I'm interpreting?


MSLIN intersection is drawn incorrectly on the sectional. It's actually the
intersection of the HUO 030R and the CFB 129R. The arrow pointing toward
HUO is correct, the other one should be pointing to the northwest toward
CFB.

If you think that's bad, go to SkyVector and take a look at WARWF and GAYLE.



Those are absurd. They should closer to 90* if possible. I would think
it would be impossible to determine my position that way.

--

Regards, Ross
C-172F 180HP
KSWI