procedure turns revisited

"Roy Smith" wrote in message
...
I had almost exactly this same situation happen the other day with NY
Approach. We were coming into White Plains (HPN) from the north, IFR.
Controller gave us something like, "direct FARAN, cleared ILS-16".
FARAN's
not an IAF, the route from FARAN inbound is not marked NoPT, we hasn't
giving us vectors. By strict interpretation of the rules, he gave us a
bum
clearance. On the other hand, not only did I know that he wanted us to
fly
the approach straight-in, but there was no practical reason why anything
else would make any sense, so we did it.

The bottom line is that the AIM just hasn't caught up with real life.

If you regard the direct clearance as an implicit vector, then it was all
kosher. And I think the vector interpretation is reasonable: ATC was telling
you to fly the (off-airway) heading that takes you to FARAN (even though it
was left to you, or your equipment, to compute the numerical value of that
heading).

--Gary

Roy Smith wrote:
In article .com,
wrote:


Now let me ask a question. What if ATC clears you direct to the VOR
and then clears you for the "straight-in" approach? Isn't the
controller's instruction in conflict with the AIM? Who wins,
hypothetically speaking (say you can't contact him for clarification)?


I had almost exactly this same situation happen the other day with NY
Approach. We were coming into White Plains (HPN) from the north, IFR.
Controller gave us something like, "direct FARAN, cleared ILS-16". FARAN's
not an IAF, the route from FARAN inbound is not marked NoPT, we hasn't
giving us vectors. By strict interpretation of the rules, he gave us a bum
clearance. On the other hand, not only did I know that he wanted us to fly
the approach straight-in, but there was no practical reason why anything
else would make any sense, so we did it.

The bottom line is that the AIM just hasn't caught up with real life.

Not exactly. The following was added to the AIM recently. Note that it
is limited to RNAV IAPs. There were lenghty discussions within FAA and
with industry. It was at first proposed to permit the practice for all
instrument approach procedures with an intermediate fix, and limit it to
GPS or advanced RNAV aircraft. FAA's ATC management nixed the idea
for conventional, ground-based IAPs.

So, it isn't really the AIM not staying up with the "real world," it's
the real world inventing its own rules.


5-4-7 i. ATC may clear aircraft that have filed an Advanced RNAV
equipment suffix to the intermediate fix when clearing aircraft for an
instrument approach procedure. ATC will take the following actions when
clearing Advanced RNAV aircraft to the intermediate fix:
1. Provide radar monitoring to the intermediate fix.
2. Advise the pilot to expect clearance direct to the intermediate fix
at least 5 miles from the fix.
NOTE-
This is to allow the pilot to program the RNAV equipment to allow the
aircraft to fly to the intermediate fix when cleared by ATC.
3. Assign an altitude to maintain until the intermediate fix.
4. Insure the aircraft is on a course that will intercept the
intermediate segment at an angle not greater than 90 degrees and is at
an altitude that will permit normal descent from the intermediate fix to
the final approach fix.

In article .net,
"Steven P. McNicoll" wrote:

"Ron Garret" wrote in message
...

Unless you lose comm. That's the only circumstance where this issue
really rears its ugly head.

Case in point: suppose I'm flying from Catalina to Fullerton.
(http://204.108.4.16/d-tpp/0606/05136VA.PDF) The clearance is V21 SLI
direct. In practice they always vector you straight in. But if you
lose comm, technically you're required to fly to SLI, turn 178 degrees
(or 182), fly outbound for the PT, turn 180 degrees again to go back to
SLI (where you just came from) and then fly the approach.

I once flew this route and asked a controller what I should actually do
in this situation. His response was that it had never happened, they
had never thought about it, and that they'd probably expect me to just
fly the approach straight in.

Welcome to the real world.


I'd consider real world radio failure in IMC to be an emergency and use my
emergency authority to ignore any technical requirement to fly to SLI, turn
178 degrees (or 182), fly outbound for the PT, turn 180 degrees again to go
back to SLI (where I just came from) and then fly the approach.

Yeah, I suppose that works too :-)

rg

ATC was telling
you to fly the (off-airway) heading that takes you to FARAN (even though it
was left to you, or your equipment, to compute the numerical value of that
heading).

Then it's not a vector. A vector is "go in this direction". What you
got was "go to this point".

Jose
--
The price of freedom is... well... freedom.
for Email, make the obvious change in the address.

Controller gave us something like, "direct FARAN, cleared ILS-16". FARAN's
not an IAF, the route from FARAN inbound is not marked NoPT, we hasn't
giving us vectors. By strict interpretation of the rules, he gave us a bum
clearance. On the other hand, not only did I know that he wanted us to fly
the approach straight-in, but there was no practical reason why anything
else would make any sense, so we did it.

I'd reply "understand cleared direct FARAN, direct FOOBAR, cleared
straight in ILS-16, please confirm." (where FOOBAR is the FAF).

Jose
--
The price of freedom is... well... freedom.
for Email, make the obvious change in the address.

Jose wrote:
ATC was telling you to fly the (off-airway) heading that takes you
to FARAN (even though it was left to you, or your equipment, to
compute the numerical value of that heading).

Then it's not a vector.

Correct. A vector is defined in the PCG as, "a heading issued to an
aircraft to provide navigational guidance by radar". Unfortunately,
there is no PCG defintion of "heading", so we need to fall back on the
conventional definition of "put this number at the top of your DG and
keep it there".

The problem is, it's obvious to everybody (i.e. to both ATC and to
pilots) that "direct FARAN, cleared approach" is a completely
reasonable, flyable, safe, and convenient clearance to issue to a /G
aircraft under radar surveillance. The fact that it's also against
the rules just points out how silly the rules are.

Michael wrote:

Sam Spade wrote:



I don't know what you mean by recently, but I suspect it's less than 4
years. The practice that has now been made official has been used in
the Houston area for at least that long, on at least two approaches I
know of (both GPS RNAV). Both of these approaches serve small airports
where nothing bigger than a King Air 90 is ever seen (and nothing
bigger than a Baron is ever based) so it works fine.

As to recently, I believe it became effective this past February. And,
these things have to work for everyone, from Approach Category A to D.


So, it isn't really the AIM not staying up with the "real world," it's
the real world inventing its own rules.


That's right, the real world invents its own rules, and eventually the
FAA rules catch up to practice, as has happened here.

Sometimes that works, sometimes it results in airplanes flying into
mountains.

Sam Spade wrote:
wrote:
Sam Spade wrote:

wrote:


Sam Spade wrote:



The August 4, 2005, Aeronautical Information Manual (AIM) revision to
paragraph 5-4-9a, Procedure Turn, has generated pilot comments that
indicate the text may be misleading and could possibly cause deviation

from the requirements of 14 CFR Part 91.175(j).


I'm still missing something here. 91.175 doesn't say when you have to
do a procedure turn, just when you can't. The erroneous AIM doesn't
conflict with 91.175 as far as I can tell.


Read it as you choose.


But why do you choose it one way and not the other? Is there another
regulation out there, or just 91.175?

I choose ro read it the same way the industry and FAA charting folks
read it over and over at the semi-annual Aeronautical Charting Forum
held in Washington, DC.

The other regulation is the fact that the IAP is issued under Part 97,
and when a course reversal is specificed on that regultory form, and the
arrival is to that course reversal segment rather than a terminal route
designated "NoPT," the course reversal is a mandatory part of the
procedure set forth by the Part 97 regulation for that IAP. 91.175(j)
is the only regulation that trumps the course reversal component of the
Part 97 regulation for any given IAP, and 91.175(j) makes its three
exceptions clear. One of those three exceptions, an NoPT intitial
approach segment, is also set forth on the Part 97 regulation for the
IAP. Your copy of the Part 97 regulation is either a NACO or Jeppesen
approach chart. The official regulation is on either an FAA Form 8260-3
or 8260-5, and inacted by reference in the Federal Register, just like
any amendment to an FAR.

Thanks for the explanation. That makes sense.

Steven P. McNicoll wrote:

Why doesn't ATC like it?

Because it conflicts with San Jose's LOUPE ONE departure. The extra
three to four minutes hanging over the airport really ****es them off.
Especially since they're not expecting it.

Why wouldn't the controller provide vectors?

I don't know. Some of them are good about it and do provide vectors.
I suspect that the others aren't as familiar with the procedure turn
requirements as you are, so they don't see the need to do it.

You make it sound like it's a burden on them.

That's the impression I get. Its probably easier to give a one-time
instruction and then concentrate on talking to the airliners that are
getting vectors, than to make sure that the little single-engine
airplane doesn't get pushed around by the wind and correct the vectors,
then issue the turn to intercept at just the right time.

The way for them to avoid the procedure turn is to provide vectors to the
approach. The way for them to avoid providing vectors to the approach is to
accommodate the procedure turn. Those are the only options available, they
must choose one of them.

I agree with you, but in practice it doesn't always go that way.

Sam Spade wrote:

5-4-7 i. ATC may clear aircraft that have filed an Advanced RNAV
equipment suffix to the intermediate fix when clearing aircraft for an
instrument approach procedure.

Wouldn't a cleaner and more permanent change be to mark those
intermediate fixes as IAF or IF/IAF on the GPS/RNAV approach plates?
Or is there a reason that isn't practical? I guess that means the
initial segment would have a length of zero. (perhaps that's not
allowed in the TERPS?)