Flying IFR with Garmins

There's nothing to stop you using the VOR for course guidance but using
the
GPS track readout to ensure that your track matches the VOR radial.
Forgive
me if that's very obvious, but I'm always surprised at how many pilots
don't
use that aspect of the GPS to take the hard work out of tracking
conventional navaids (particularly on the ILS).

"Robert M. Gary" wrote in message
om...
How do you do that with the 296? How do you program in a radial to fly
to? I don't even see radials on the VORs when I look at it. I haven't
been able to find anything on this in the manual.

That's not what I mean. I'm talking about something much more trivial. The
only number on the GPS you need is the TRK readout. Use the NAV's CDI for
course guidance. Best illustrated with an example.

You're on the 250 radial and want to track a 070 course to the ABC VOR. Set
the CDI to 070 and turn the aircraft until the track readout shows 070. The
aircraft will (barring VOR errors) stay on the radial. If it does move,
turn the aircraft to adjust the track.

The GPS doesn't need to know about the existence of VORs or LOCs.

It doesn't help you with programming the GPS for course guidance along a
winding airway, but it's an aspect of GPS utility that many pilots seem to
ignore.

Julian Scarfe

"John Harper" wrote in message
news:1087790958.150362@sj-nntpcache-5...
I agree that this is a great technique. In fact I never use NAV mode on
my autopilot, I just tweak the heading until the track matches what it
should
be (and keep an eye on it obviously). Much better than the autopilot
zigzagging its way down the airways.

"Michael 182" wrote in message
newsDtBc.126215$3x.55034@attbi_s54...
Sounds like you have a Cessna 300A.

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement. Then it makes largish corrections and ends up snaking its way
along the centerline, albeit with decreasing amplitude oscillations. And if
*all* you have is a CDI, that's probably the best you can do. But it's
hooked up to the GPS and so I would expect it to be able to turn directly to
a waypoint without the major heading excursions that scare the hell out of
ATC in a busy environment.

Julian Scarfe

On Mon, 21 Jun 2004 08:11:04 +0100, "Julian Scarfe"
wrote:

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement.

I have an STEC50 and a CNX80.

The CNX80 has airways, so regardless of how I am cleared, I track enroute
using GPS mode.

As recommended by STEC, I use the APR mode for tracking a GPS course.

My off-track distance does vary, but by usually less than 1000'. In
heading mode, I will eventually drift off that much, or more. The turns
are rarely more than five degrees, once centered.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Robert M. Gary wrote:
How do you do that with the 296? How do you program in a radial to fly
to? I don't even see radials on the VORs when I look at it. I haven't
been able to find anything on this in the manual.

If it's like the 196, go to the page displaying the pseudo-HSI and press Menu,
one of the options is "OBS".



There's nothing to stop you using the VOR for course guidance but using the
GPS track readout to ensure that your track matches the VOR radial. Forgive
me if that's very obvious, but I'm always surprised at how many pilots don't
use that aspect of the GPS to take the hard work out of tracking
conventional navaids (particularly on the ILS).

Julian Scarfe

Michael 182 wrote:

You enter the one behind you and activate the leg you are intercepting.

This is about intercepting an airway at some point that's not a fix, right?
In that case, you could "build" the airway segment with the fixes before
and after your intercept point or you could get "after" fix into the GPS
and then use OBS mode.

I have to admit, though, when given an airway intercept I find it easier to
use a VOR receiver. The "user interface" seems to involve less work to me
(although the end result of the GPS process yields more benefit).

- Andrew

Newps wrote:


"Andrew Sarangan" wrote in message


Why not use a VOR receiver for airway navigation? Using a GPS for
airway navigation kind of seems backwards.

Have you tried it? Putting a flightplan in the GPS and then flying the
line on the moving map eliminates having to worry about crosswind
correction. None of this flying a heading for awhile and seeing how that
works. Then
adjusting that heading constantly for constantly changing conditions.
With a GPS you don't need a DG to fly an airway.

Unless you're happy with S turning your way along, this is only true if
you've the GPS providing track information. A 172S I used to fly had an
MFD plugged into the GPS. It provided not just the flight plan on the map,
but also a line indicating the path the flight would take if no changes
were made. Put that line over the course line, and details like heading,
deviation, and such become pretty trivial.

Alternatively, just match desired track with actual track (starting from a
zero OBS deflection, of course {8^).

That damned MFD really spoiled me, in fact. I was S turning for a while
when I stopped flying that airplane laugh.

On the 430s I fly now, there are only four fields in which information can
be displayed. I use "next waypoint", distance to next waypoint", "desired
track", and "ground speed". I had to give up "actual track", sadly.

- Andrew

We have an STEC 60-2 in our Bonanza 36 with a Trimble Approach 2000 GPS and
a King HSI. After we had the autopilot tweaked for tracking a GPS course,
it's been very good tracking in NAV mode.

"Julian Scarfe" wrote in message
news:OKwBc.8$AX2.5@newsfe6-win...

I do the same and I have an STEC 60-2.

The problem seems to be the tracking algorithm. If you're slightly off
track a/p turns the aircraft through, say, 20 degrees, and waits for a CDI
movement. Then it makes largish corrections and ends up snaking its way
along the centerline, albeit with decreasing amplitude oscillations. And
if
*all* you have is a CDI, that's probably the best you can do. But it's
hooked up to the GPS and so I would expect it to be able to turn directly
to
a waypoint without the major heading excursions that scare the hell out of
ATC in a busy environment.

Julian Scarfe

Sounds more like the old days of trying to fly an NDB intercept.
Correcting cross winds in your example sounds harder than actually
usnig a VOR. The reason I like airways on the GPS is because while the
clouds are wacking the crap out of you and you're jumping through busy
airspace, you can quickly turn the plane to maintain the center of the
airway. You also don't need to figure out what intersection the airway
turns at next. It sounds like Garmin IFR pilots keep an enroute very
close at hand so they can figure out where all the turns are in the
airway.

-Robert


"Julian Scarfe" wrote in message news:vzwBc.5$AX2.0@newsfe6-win...
You're on the 250 radial and want to track a 070 course to the ABC VOR. Set
the CDI to 070 and turn the aircraft until the track readout shows 070. The
aircraft will (barring VOR errors) stay on the radial. If it does move,
turn the aircraft to adjust the track.

The GPS doesn't need to know about the existence of VORs or LOCs.

It doesn't help you with programming the GPS for course guidance along a
winding airway, but it's an aspect of GPS utility that many pilots seem to
ignore.

Julian Scarfe

"Robert M. Gary" wrote in message
om...
Sounds more like the old days of trying to fly an NDB intercept.
Correcting cross winds in your example sounds harder than actually
usnig a VOR.

I think that's only because I laid it out so painfully. How about this
method?

1) At VOR, turn aircraft to track towards next VOR
2) Goto 1.

The reason I like airways on the GPS is because while the
clouds are wacking the crap out of you and you're jumping through busy
airspace, you can quickly turn the plane to maintain the center of the
airway. You also don't need to figure out what intersection the airway
turns at next. It sounds like Garmin IFR pilots keep an enroute very
close at hand so they can figure out where all the turns are in the
airway.

Some of the differing perspective in this thread are due to flying in
environments with different demands. I fly in an environment in which the
requirement is almost always to fly direct towards a waypoint rather than
track a centerline, and which is sufficiently busy that making significant
turns to make aggressive radial intercepts is going to raise some eyebrows
at ATC. You fly in an environment in which the choice is to follow the
airway centerlines or hit rock.

All that said, airways on Garmins would be a nice feature.

Julian Scarfe

"Julian Scarfe" wrote in message news:nKRBc.1345$I43.1315@newsfe6-win...
"Robert M. Gary" wrote in message
om...
Some of the differing perspective in this thread are due to flying in
environments with different demands. I fly in an environment in which the
requirement is almost always to fly direct towards a waypoint rather than
track a centerline, and which is sufficiently busy that making significant
turns to make aggressive radial intercepts is going to raise some eyebrows
at ATC. You fly in an environment in which the choice is to follow the
airway centerlines or hit rock.

All that said, airways on Garmins would be a nice feature.


Well, I ordered the unit and am pretty excited about getting it.
Sportys said they should have some in this week to ship. I'm really
excited about putting on the hood and seeing if I can maintain the
blue side up using their turn-coordinator display. I think that could
be a HUGE IFR backup. It will also be cool to take the unit out when
you get to your destination and use it to find your hotel.

-Robert