Airway intersections on Sectionals -- info incomplete / inaccurate?

[Tman[_2_]]

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 re:
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?

Tman...

[BT]

Looks like you have it right. It does appear to be miss plotted on the VFR
chart.
On the VFR Chart notice the two arrows at the MSLIN intersection, those
should be pointing to the two VORs that make up the intersection, one is
definitely HUO, but one cannot discern where the other arrow is pointing to
the SE (LGA??)

I was looking at to why MSLIN would be there and not on the intersection of
the two airways but I did not find a local instrument approach that
transition from MSLIN to the approach. Any local pilots have an idea on
that?

BT

"Tman" > wrote in message
...
> 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 re: 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?
>
> Tman...

[Mike]

"Tman" > wrote in message
...
> 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 re: 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?

There are numerous other examples of what you describe. As far as why it is
that way, I can only speculate that MSLIN and others like it are defined
inaccurately on the sectional because they are close enough to the
intersection to be used as a reporting point without having to label another
fix right by the existing IFR one. Since VOR radials are quite inaccurate
anyway, the difference is well within allowable tolerances, especially for
VFR use.

[Steven P. McNicoll[_2_]]

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 re: 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.

[Ross]

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 re: 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

[Steven P. McNicoll[_2_]]

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

They're not intersections, they're DME fixes. They shouldn't be on the
sectional at all. I tried to explain that to the folks in charge, no
success.