In article , Tim
wrote:


Second, a lot of the regs were written before the advent of moving-map
GPS. Many procedures that make sense if you're navigating on a VOR make
less sense if you always know at a glance exactly where you are.

I don't see how with a gps you know where you are and with 2 VORs (for
example) you don't know where you are.


I didn't say that either. I said with moving map GPS you know EXACTLY
where you are AT A GLANCE. With VORs it takes time to twiddle knobs and
cross-reference the results against a chart, and the margin of error is
much larger.


Why is that relevant?

Because the standard procedures involve compromises to compensate for
the delays and errors inherent in VOR navigation. When those delays and
errors do not exist the compromises can make the flight less safe than
it would have been under different procedures.

Third, going by the book makes you do some overtly stupid things. The
classic example is going NORDO while flying from AVX to FUL. Going by
the book requires you to fly to SLI, reverse course, return to the exact
spot you just came from (which is over water BTW), and reverse course
again. This procedure is manifestly more dangerous than just flying the
approach straight in (because it involves more maneuvering, more time in
the air, more time over water). Moreover, under normal conditions the
approach is ALWAYS flown straight in (via vectors) and under NORDO
conditions the controllers expect you to fly the approach straight in (I
know because I asked them) notwithstanding that this technically
violates the regs.

If you already know the answer and were given instructions by
controllers to do this in the past, why pose it here?


That was for a completely different set of circumstances.

Again, I misunderstood then. I only quoted you and responded based on
what you wrote.

You must not be reading very carefully. I say right there in the part
you quoted that I was talking about a different trip (AVX-FUL).


How does going to FUL require what you state? Cannot you pick which
approach and IAF?


It's a tangent, so if you really want to get into that you should start
a new thread. Or look up the old one. Or look at the charts.

How is that a tangent?

Because it's a different route. The circumstances are different. What
one does when flying to FUL may or may not apply when flying to VNY. I
only brought up FUL because it's a data point where I've had occasion to
ask controllers for their input, and they unequivocally told me NOT to
follow the regs. (Yes, I know that what controllers say doesn't matter.
Nonetheless, it's a data point.)

You can choose any IAF and any approach that
you are able to do when the clearance ends in "direct" - and the airport
is the clearance limit.

Yes, but by the book you have to fly to the clearance limit first.
91.181(b) is quite clear about this.

Why do you choose the VOR procedure at FUL rather than the LOC/DME? In
that case it is easy to pick the approach with nopt.


Not as easy as you might think. The preferred routing (which is the one
you will invariably be assigned) from AVX to FUL is V21 SLI Direct.

Again, "direct" does not mean direct to the airport.

That's news to me. Where in the regs does it say that?

Direct means you
go to an IAF then get to the airport. How are you supposed to land?

My reading of 91.185(c)(3)(ii) seems to imply that you have to fly to
the airport first, then to an IAF.

You can;t just go to the airport and circle down to land - that is the
whole reason for having defined instrument approaches.

If you're saying that it's stupid to fly to the airport first, I agree
with you. Hence my question.

Right. See above regarding what that last "direct" means. It does not
mean go froom the penultimate fix to the airport. It means go to an
IAF then fly the approach.

I'm pretty sure you're wrong about that.

My initial (and I guess overzealous) reaction to your post was that it
seemed like you just didn;t care what "the book" said or what you are
supposed to do based on part 91 regs for ifr flight. That is scary to me.

Of course I care. But that doesn't mean that I blindly follow the rules
without thinking.

rg