GPS clearance puzzle

Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

Roy Smith wrote:

Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX).

Interesting. I flew from BVY to CDW this past Monday. My clearance ended

... CMK V? SAX Direct

As I was approaching the CMK VOR, I was told to depart on the 275 radial.
When I acknowledged that, I was told: "Oh, let's make this easy" and was
told to follow the airway to SAX (I forget which V that was at the moment).

The difference between the airway and the 275R is pretty slight. Extra room
for EWR or TEB departures (the wind was from the northeast)? Something
else?

Either way, I appreciated sticking with the airway. It saved me from having
to find the CDI button on the 430 grin.

- Andrew

"Roy Smith" wrote in message
...

Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.


Determine the point of intersection of the radials and fly direct to that
point from CMK then direct to SAX.

On Tue, 30 Nov 2004 22:39:38 -0500, Roy Smith wrote:

Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

If you get it a lot, set up a user waypoint.

If you know the distance off one of the VOR's, it should be easy.

If you fly it repeatedly, push the MARK button (or equivalent) the
next time you fly over it.

On Tue, 30 Nov 2004 22:39:38 -0500, Roy Smith wrote:

Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

The only way I know of to due it "purely" with the GPS mode would be to set
up a user waypoint at the intersection of those two radials.

But what I would do with my CNX80, assuming that was not worthwhile, would
be to also use it's VOR mode. I would set up an OBS track to SAX on the
039R. That should give a display on the screen. I would then use the VOR
mode to fly direct CMK and outbound on the CMK 275 until I intercepted the
course to SAX. Then I would switch back to GPS mode.


--ron

Roy Smith wrote in message ...
Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

Use the GPS's OBS mode to fly outbound on the radial from the first
VOR. Then call up the second VOR on the GPS (for example through the
Nearest function or the VOR page or on any other information page).
There you will see the actual radial/bearing from or to the second VOR
depending on how you have set it up. Once you reach the required
radial from the second VOR you go direct to or continue using the OBS
mode with the second VOR as a new waypoint.

Gerd, ATP
T182 C-FDOW

On a 430/530 you can create a user waypoint based on radials from waypoints
in the database. I created someof these user waypoints when I was given the
same clearance often. Most of the time I use the method you described with
OBS and a VOR reciever to locate the crossing radial.

Mike
MU-2


"Roy Smith" wrote in message
...
Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

gwengler wrote:
Use the GPS's OBS mode to fly outbound on the radial from the first
VOR. Then call up the second VOR on the GPS (for example through the
Nearest function or the VOR page or on any other information page).
There you will see the actual radial/bearing from or to the second VOR
depending on how you have set it up. Once you reach the required
radial from the second VOR you go direct to or continue using the OBS
mode with the second VOR as a new waypoint.

Sounds like a good plan, thanks!

Roy, just curious, does the CNX-80 use the facility magnetic variation when
setting up a VOR radial in OBS mode? I believe the Apollo GX-60 does not.
I think the 430/530 does use the facility variation, and I wonder if Garmin
changed what the Apollo units do, either in the CNX-80 or going to the
GNS-480.

There is a four degree difference between facility variation and actual
variation at our local VOR. It would make two miles of crosstrack error at
30 miles from the VOR, usually not a big deal, but worth knowing about.

Stan


"Roy Smith" wrote in message
...
Apparently, if you file IFR HPN - MMU, you get a clearance which starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good old
days of 2 VOR receivers, this is trivial to fly; the radios don't know
or care that the cross-radial fix you're going to doesn't have a name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm using
a CNX-80, but it might be interesting to see how other units would do it
too.

From page 37 of the GNS 480 Pilot's Guide;
"NOTE: When using the OBS mode with a VOR station, the GNS 480
will use the station declination of the VOR.
For other waypoints, the GNS 480 will use magnetic variation based on
your present position."

In my opinion, it should use VOR station declination *only* in OBS
mode, but in Salem they chose to use it in all modes involving VORs.
That wasn't their original choice, but the UPS pilots wanted it that =
way.
---JRC---

"Stan Prevost" wrote in message =
...
Roy, just curious, does the CNX-80 use the facility magnetic variation =
when=20
setting up a VOR radial in OBS mode? I believe the Apollo GX-60 does =
not.=20
I think the 430/530 does use the facility variation, and I wonder if =
Garmin=20
changed what the Apollo units do, either in the CNX-80 or going to the =

GNS-480.
=20
There is a four degree difference between facility variation and =
actual=20
variation at our local VOR. It would make two miles of crosstrack =
error at=20
30 miles from the VOR, usually not a big deal, but worth knowing =
about.
=20
Stan
=20
"Roy Smith" wrote in message=20
...
Apparently, if you file IFR HPN - MMU, you get a clearance which =
starts
"CMK CMK275R SAX039R SAX" (i.e. fly outbound on the CMK 275 until you
intercept the SAX 039, then fly that inbound to SAX). In the good =
old
days of 2 VOR receivers, this is trivial to fly; the radios don't =
know
or care that the cross-radial fix you're going to doesn't have a =
name.
But, how would you fly that with a GPS?

I've been puzzling over that one for a week or so now, and the best I
can come up with is to use the GPS's OBS mode to track outbound on =
the
CMK 275, and set up a VOR receiver to indicate the crossing radial.

Can anybody figure out a way to set it up purely on the GPS? I'm =
using
a CNX-80, but it might be interesting to see how other units would do =
it
too.=20