IFR in A/C with Single Nav

I am a relatively new CFII looking for some advice. I am starting an instrument student in a 172 that is bare bones IFR. The plane has a single nav with glideslope, a VFR GPS installation, and no ADF or DME. I haven't flown the plane on an IFR flight yet, but it seems that the way to make it work is to just have fast fingers, and good SA. Any tips on how to navigate/teach in this airplane?

I've been looking over local approaches, flying them on paper. If, for instance, a VOR approach uses a cross radial from another facility to ID the FAF then what is the best way to proceed? My plan would be work hard to nail the approach course as early as possible, and have the cross-radial VOR in standby. Then I could flip the nav to the cross-radial, spin the OBS and see where I was, then flip back to the approach VOR/course.

Of course, knowing the distance to the cross-radial VOR could be helpful. Using the 60nm = 1nm per degree of deflection on the CDI could give ete to the fix.

Am I approaching this correctly? Any advice, tips, techniques would be greatly appreciated. Thanks!

First, let me tell you where I'm coming from. I got my instrument
rating and my CFII in an airplane equipped as you describe, and I
taught an instrument student from zero to the checkride in another such
airplane. Further, I know at least one other pilot who got an
instrument rating in an airplane equipped that way. So - the first
thing to know is that it is entirely doable.

Second, I think you're approaching the problem correctly. All your
ideas look good. Let me give you some other pointers.

When dealing with a cross-radial stepdown fix, try to give yourself as
much time as possible. A 172 with a notch of flaps flies just fine at
75 KIAS. That's a good speed to be flying when doing a full procedure
anyway - gives you time to think and maintain good SA. Anyplace where
you need to keep your speed up will have RADAR vectors to final. No
reason to go 1 minute outbound after crossing the IAF - you have 10
miles. Take 2-3 minutes before starting the procedure turn outbound.
It will give you a nice long final so you can nail the heading - and at
75 kts, you can't go far off course while you crosscheck. Of course
none of this works when you get into a faster airplane - but a faster
airplane will have better nav.

The VFR GPS makes flying IFR with such a setup practical - as long as
it works. That means you need to be sure your student knows how to use
it effectively, but also knows how to get by without it. For example,
most GPS units give a direct readout of track. That lets you know
right away that you've nailed your heading - or not. You can also set
it to that radial crossfix. Then, when you're 30 seconds from the fix,
hold your heading (and you can monitor the GPS to make sure you're
holding course and track as well) and take the crossfix. Amazing - you
checked at just the right time, and it is centered.

You will basically be training 3 approaches - VOR, LOC/LOC BC, and ILS.
You might find an SDF or LDA, but that's basically the same as a LOC
and everything I say about it will apply.

Remember that on the ILS, GS intercept at published altitude is the
FAF, nothing else. Don't wate time here flipping back and forth.

The only LOC you will be able to do is the kind that uses a
cross-radial for a FAF. Find one in your area, and practice flying it.
Doing this approach without GPS will be the biggest challenge your
student will face.

With a limited setup like this, good SA is worth its weight in gold.
At first the GPS will help, but wean your student off it quickly. He
should be able to point at the approach plate and tell you where he is
on it at any time - not at first, but before you're done with him.

A good ground briefing is worth its weight in gold here. Start out by
only doing one approach repeatedly, let the student know which exact
approach that will be, work with him to figure out exactly how it will
be flown and where the crosschecks (if any) will happen, and have HIM
brief YOU on the approach before you get in the plane. That will very
quickly develop good SA.

Find your examiner early. The PTS is very clear on this subject, but
some of them still insist that you need ADF, GPS, or DME. They are
wrong, but it's a lot easier to find a different DE than fight it out.

Remember, both GPS failure AND vacuum failure together is a very rare
event. Do teach your student to do a VOR and ILS approach partial
panel and without GPS. Don't waste your time teaching him how to do a
LOC or VOR with FAF defined by cross-radial that way - it's just not
worth it, unless the student is doing really well and you have the time
to do it. It's a great proficiency exercise, and will make a great
exercise for recurrent training, but the likelihood of needing to do it
is just about nil.

Michael

"Michael" wrote in message
ups.com...
Remember that on the ILS, GS intercept at published altitude is the
FAF, nothing else. Don't wate time here flipping back and forth.

But then you can't verify your altimeter's accuracy when crossing the FAF.
Alternatively, you can leave the OBS set to the cross radial, and check it
with just a push of the flip-flop button. Unless circumstances make the
workload unusually high, I'd think that'd be worthwhile.

--Gary

But then you can't verify your altimeter's accuracy when crossing the FAF.

Only if the GPS goes TU - otherwise the GPS will give you at least as
good a fix as a cross-radial. What are the odds you lose the GPS and
the altimeter goes wonky at the same time? In low IMC? In a minimally
equipped C172? Really think it's worth raising the workload at FAF
intercept for that? I sure don't. Then again, I don't time my ILS
approaches either.

Michael

On 7/20/2005 13:08, Michael wrote:

[ snip ... ]

Then again, I don't time my ILS
approaches either.

Michael


I realize that you are assuming the odds of losing the GS are low,
and I get that. But I'm wondering how you identify the MAP in the
event of GS failure? After all, you can't begin the missed approach
procedure until you've reached the MAP.

I guess if you're in a Radar environment, you could tell them that
you just lost the GS and would like to get vectors for another
approach. What if there is no Radar?

.... just a curious student ;-)


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

"Michael" wrote in message
ups.com...
Remember that on the ILS, GS intercept at published altitude is the
FAF, nothing else. Don't wate time here flipping back and forth.

But then you can't verify your altimeter's accuracy when crossing the
FAF.

Only if the GPS goes TU - otherwise the GPS will give you at least as
good a fix as a cross-radial.

Oh ok. Initially you said "GS intercept at published altitude... nothing
else" identifies the FAF. (Although I'd still be reluctant to rely on a VFR
GPS for identifying a fix.)

--Gary

Originally Posted by Michael

First, let me tell you where I'm coming from. I got my instrument
rating and my CFII in an airplane equipped as you describe, and I
taught an instrument student from zero to the checkride in another such
airplane. Further, I know at least one other pilot who got an
instrument rating in an airplane equipped that way. So - the first
thing to know is that it is entirely doable.

Second, I think you're ..........

Michael

Michael- Thanks for taking the time to type out a response! Much appreciated.

Oh ok. Initially you said "GS intercept at published altitude... nothing
else" identifies the FAF. (Although I'd still be reluctant to rely on a VFR
GPS for identifying a fix.)

Well, my experience with both VFR and IFR GPS leads me to believe that
the difference is basically the blessing of a federal bureaucrat.

Legally, the GS intercept at published altitude, nothing else,
identifies the FAF on an ILS. There is no requirement to check the
altimetry or anything else. Of course if it's not a big deal to do so,
the prudent pilot will. A VFR GPS makes a fine check without adding
workload. I would suggest that this is good enough, and there's no
reason to make things more difficult by flying the LOC inbound by dead
reckoning while checking the cross fix if you don't have to.

Michael

I guess if you're in a Radar environment, you could tell them that
you just lost the GS and would like to get vectors for another
approach. What if there is no Radar?

You have several options.

First off, you can climb immediately - it's only an early turn that is
verboten. If there is no turn, there is no issue.

Second, the GPS will show you when you are at the MAP. I suppose you
could have an ILS with no RADAR coverage and the GPS could fail and the
GS could fail. I think the odds of that are something like "Not in
this lifetime" but let's say it happens.

Even then, it's really not the end of the world. At some point, you're
going to pass over the antenna. When that happens, you are going to
peg the needle. Most pilots can keep from pegging the LOC needle down
to DH, and virtually all can keep from pegging it to about 500 ft. So
somewhere between a mile short of the middle marker and being over the
airport you're going to peg the needle - and then you can start
whatever turn the missed approach calls for, if it actually calls for
one. Unless your airspeed control and your estimate of winds is
spectacular, this is going to be as accurate as timing the approach
anyway.

There are enough important things to do at the FAF - power back, carb
heat, switch to tower/advisory (if not already there) - that I hate
adding one more thing to do for the novice instrument pilot. It makes
it just that more likely that he will forget or screw up something.
Nonessential activities at and inside the marker are bad news.

I am not a fan of increasing pilot workload on every approach just in
case something very unlikely happens. Most IFR accidents are the
result of pilot failure, not equipment failure. I also consider the IR
an introductory ticket. I think most pilots who fly IFR in IMC
regularly will develop beyond the minimum standards of the IR
relatively quickly. When they do, it makes sense to add to their
procedures, which will be no big deal because they will have the cycles
to handle additional tasks.

Pilots who fly IFR only infrequently have so little exposure to the low
probability equipment failures, and so much exposure to pilot overload,
that I really don't want to add anything not essential to their
workloads.

Michael

"Michael" wrote in message
oups.com...
Legally, the GS intercept at published altitude, nothing else,
identifies the FAF on an ILS.

Yes, you're right (I was conflating the ILS FAF with the LOC FAF that would
be used to check the altimeter on an ILS approach).

There is no requirement to check the
altimetry or anything else. Of course if it's not a big deal to do so,
the prudent pilot will. A VFR GPS makes a fine check without adding
workload. I would suggest that this is good enough, and there's no
reason to make things more difficult by flying the LOC inbound by dead
reckoning while checking the cross fix if you don't have to.

Ok, that sounds reasonable.

--Gary