Procedure turn required?

A procedure turn requires a course change of over 130 degrees (including
getting back onto the outbound course). And then of 180 degrees. You can
fly the transition at the same altitude allowed for the procedure turn.

How is the procedure turn better?

All the maneuvering is done prior to the FAF, and prior to descent.

Jose
--
The price of freedom is... well... freedom.
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On the other hand, there are "Some procedure turns are specified by
procedural track. These turns must be flown exactly as depicted."

This refers to things like charted teardrop reversals, where one goes
(for example) outbound on the 155 radial for five miles, turns right and
comes inbound on the 183 radial, all charted on the plate.

I would not infer from this that the outbound course of an ordinary PT
is not specified. What is in fact up to the pilot in a normal PT is the
method of reversing course once one is tracking the (given) outbound course.

One is required to fly the PT (exceptions discussed upthread). =Since=
this is true, one must turn to the outbound course in order to do so,
and cannot simply turn inbound. Since one is therefore flying outbound,
a course reversal is necessary at some point. Therefore, the type of
course reversal to be performed must be a procedure turn (of some sort).

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

"Jose" wrote in message
. com...
How is the procedure turn better?

All the maneuvering is done prior to the FAF, and prior to descent.

Offset by the significant increase in the amount and difficulty of
maneuvering required. I agree you've shown it to be different. I don't see
how it's better.

Pete

How is the procedure turn better?
All the maneuvering is done prior to the FAF, and prior to descent.
Offset by the significant increase in the amount and difficulty of
maneuvering required. I agree you've shown it to be different. I don't see
how it's better.

It's better because it's safer. There is no real increased difficulty -
one standard rate turn is like another, and making a longer turn is no
harder (unless you fall asleep during the turn, then the landing is much
harder!).

When you make the turns used for the full procedure, you end up right
where you are supposed to be. But if you make a turn to final that
takes fifty degrees, you will =not= be on the FAC. You'll have lagged,
and have to squirrel yourself back to be on course. You're also
approaching the MAP and descending.

This is harder.

Or you can anticipate the turn. How much? Well, (fudge fudge fudge)...
This is harder.

Maybe not harder enough to be =unsafe=, but harder enough that, combined
with proximity (to the ground and the airport) it is less safe.

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

"Jose" wrote in message
om...
It's better because it's safer.

You have not demonstrated that. To demonstrate an improvement in safety,
you need to compare a statistically significant number of samples using both
methods, and then look at the resulting accident rates for each method.

You certainly can't claim that it's "obviously safer". That is, it's not
true that "one standard rate turn is like another". Any maneuvering runs
the risk of causing an accident, and the more time spent maneuvering, the
greater the exposure to that risk (this is no different from saying "any
flight runs the risk of causing an accident, and the more time spent flying,
the greater the exposure to that risk").

As far as the difference in difficulty, one can debate that as well.
Inasmuch as a pilot ought to be maintaining a mental picture of his position
while flying by instruments, an extended turn away from one's destination
certainly could be more difficult than a prompt turn toward one's
destination. Furthermore, the right-310 turn is just one option of many,
and several of the other options involve multiple turns in multiple
directions. Increased complexity implies increased difficulty IMHO.

Whether this increase in complexity offsets the potential increase in
complexity of turning directly 50 degrees onto the final approach course,
has not been established. I suggest it does, you suggest it doesn't, and
neither of us has any justification for making such statements, other than
our own intuition.

[...]
When you make the turns used for the full procedure, you end up right
where you are supposed to be.

You might be, if you do it right. There's no guarantee though. Even if
done properly, you are still "allowed" a significant margin of error.

But if you make a turn to final that takes fifty degrees, you will =not=
be on the FAC.

If you simply intercept the approach course, how would you not wind up on
the approach course?

You'll have lagged, and have to squirrel yourself back to be on course.
You're also approaching the MAP and descending.

This is harder.

It is different. I see it as being FAR from a foregone conclusion that it
is harder.

Or you can anticipate the turn. How much? Well, (fudge fudge fudge)...
This is harder.

Maybe not harder enough to be =unsafe=, but harder enough that, combined
with proximity (to the ground and the airport) it is less safe.

Well, we're back to that. You haven't demonstrated "less safe". You simply
asserted it. There's a difference.

Pete

On Wed, 08 Jun 2005 22:57:11 GMT, Jose wrote:

What is in fact up to the pilot in a normal PT is the
method of reversing course once one is tracking the (given) outbound course.

Although I agree there is a requirement to turn outbound, I see no
requirement that one must, at any time, "track" the outbound course.

(By that I mean flying over the earth on the line indicated by the outbound
course).

For example, at the procedure which started this thread, one could overhead
the facility and execute a racetrack turn. In that case, one would never
be tracking the outbound course.


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

You have not demonstrated that [it's safer]. To demonstrate an improvement in safety,
you need to compare a statistically significant number of samples using both
methods, and then look at the resulting accident rates for each method.

I'm not going to do that. Neither are you going to do the same for your
contention that it's best to simply turn final, irrespective of what the
regulations (including the opinion of FAA legal council) state.

So we are back to using reasoning to infer safety from (personal and
shared) experience.

Any maneuvering runs
the risk of causing an accident, and the more time spent maneuvering, the
greater the exposure to that risk

True. However, turns happen all the time. I'm not convinced that a
standard rate turn is so risky that an extra hundred degrees or two
makes a significant difference, all other things being equal.

That said, all other things are =not= equal. "My" turns are done at
altitude, flying towards protected airspace, in an area that has been
certified for such turns. "Your" turns are done flying towards the
final approach fix, at the commencement of a descent, off from the final
approach course, and in an area that has been proscribed by the FAA for
such turns (which means in this case that the terrain and airspace has
not been checked and approved for these turns).

It is those conditions that I contend make "your" turns less safe.

an extended turn away from one's destination
certainly could be more difficult than a prompt turn toward one's
destination.

I'm not sure I follow this reasoning, and I don't agree with what I
think you mean. A pilot who's on top of things should have no problem
with either turn (in terms of situational awareness) and one that's a
little behind could use the extra time flying away and then back,
establishing themselves on the FAC long before the FAF.

I suggest it does, you suggest it doesn't, and
neither of us has any justification for making such statements, other than
our own intuition.

Well, we have our own flight experience, and I assume that much of it is
similar.

If you simply intercept the approach course, how would you not wind up on
the approach course?

This paraphrases as "if you succeed, how could you have failed"? A
course interception involves some S-turning or anticipation, iow some
slop. The shallower the intercept, the less slop. Intercepting the FAC
at low altitude is a critical enough maneuver that slop should be
minimized. You need to be dead on. (fsvo "dead" However, turning
away from the FAC and =not= descending would allow slop to be safer.
The FAA has chosen 30 degrees as the amount of turn which balances slop
one way with slop the other way. I don't know whether the number
"should" be 30 degrees, 50 degrees, or 10 degrees, but I suspect the
TERPS designers have some data to back themselves up, and I'll trust
their design.

You haven't demonstrated "less safe". You simply
asserted it. There's a difference.

I have asserted it and given my reasoning. Reasoning isn't proof, and
isn't intended to be.

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

I don't see how you came up with 1.4NM.
If you look at the example again, R1 distance for a standard 10 mile PT
starting at or below 6000 ft is 5 miles. Since the R1 pivot point is 1
mile offset from a point abeam the PT fix, that means there are 4 miles
of primary protection (5NM -1NM) on the non-PT side (not 1.4 miles) and
6 miles of primary protection on the turn side (5NM + 1NM) extending to
8 NM on the turn side (R3 6NM value plus 2 mile offset). There is an
additional 2 miles of secondary protection (R2 7NM value less 1 mile
offset = 6 NM)

JPH

Bob Gardner wrote:
Followed the instructions in TERPS 234 and plotted it out.

Bob Gardner

wrote in message ...


Bob Gardner wrote:


Gotta wonder why the protected airspace on the non-PT side is 1.4 miles
wide
all the way out to the maximum distance. If flying on the black line is a
regulatory requirement, why not just protect the turn area alone?


Where did you get that number?

wrote in message ...

A feeder route is part of an IAP, and issued under Part 97 along with the
other segments of the IAP.


Not according to the Pilot/Controller Glossary. That defines the four
segments of an instrument approach procedure as initial, intermediate,
final, and missed. I can't find "feeder route" anywhere in Part 97.

"Paul Lynch" wrote in message
news:cmFoe.34289$Fv.22813@lakeread01...

Wilma may be a feeder, but it is not an Intial Approach Point (IAP). That
means if you filed to Wilma as the final point on your route, your next
point is your destination. Thinking in terms of lost communication, which
is
a driver for many procedural practices... If you went from Wilma to one of
the 2 initials (SLI or ALBAS) you have some predictability. If you go from
Wilma to some place on the approach because you believe you can hack the
intercept (which some proposed), you have less predictability. If you were
shooting an approach at some airports that have several more feeders, then
what is ATC supposed to do? Clear the airspace for a 25 NM radius?


There is no predictability in these situations. ATC is going to do whatever
is necessary to ensure separation. If you still present a radar target they
can work with then they'll keep other IFR aircraft away from you and
continue with other operations as best they can. If it means clearing the
airspace for 25 miles then that's what they'll do.