Reasoning behind course reversal

Well, as an example, the BJC ILS 29R. In this case ALIKE is both the IAF and
the FF. Clearly if you are coming in from the west or southeast quadrants,
the course reversal is needed to lose altitude, as John pointed out. Also,
as Andrew pointed out, even if the approach was in Kansas, you migt be
approaching on a 090 heading to a final approach course of 293, and hence
the course reversal makes sense. I guess my question is why not have a
conditional, say if approaching with heading 270 - 330 at altitude of 7300,
no PT required.

I'm not trying to be arugmentative - I just think the procedure turn, in
IMC, may cause more danger than it allieves. On the other hand the
conditional may complicate the instruction - conditionals always provide
more opportunity for error.

Michael


"Ron Rosenfeld" wrote in message
...
On Wed, 18 Feb 2004 20:32:22 GMT, "Michael 182"
wrote:

What is the reasoning behind the required course reversal in many
approaches? It's hard to believe that I will be safer flying the
racetrack
and then the approach to the runway than simply flying to the IAF and
proceeding inbound - especially with GPS guidance. I have no problem
flying
the full published course, done it many times, I'm just curious why they
are
designed that way.

Michael


Michael,

Others have given you some good answers. However, the reasoning often
depends on the particular approach. So it would be useful if you could
post a reference to a procedure about which you have a question.




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

Why would a maneuver in protected airspace, sterilized against other IFR
(and VFR talking to ATC) airplanes be dangerous?

Bob Gardner

"Michael 182" wrote in message
news:4E5Zb.78441$uV3.535345@attbi_s51...
Well, as an example, the BJC ILS 29R. In this case ALIKE is both the IAF
and
the FF. Clearly if you are coming in from the west or southeast quadrants,
the course reversal is needed to lose altitude, as John pointed out.
Also,
as Andrew pointed out, even if the approach was in Kansas, you migt be
approaching on a 090 heading to a final approach course of 293, and hence
the course reversal makes sense. I guess my question is why not have a
conditional, say if approaching with heading 270 - 330 at altitude of
7300,
no PT required.

I'm not trying to be arugmentative - I just think the procedure turn, in
IMC, may cause more danger than it allieves. On the other hand the
conditional may complicate the instruction - conditionals always provide
more opportunity for error.

Michael


"Ron Rosenfeld" wrote in message
...
On Wed, 18 Feb 2004 20:32:22 GMT, "Michael 182"
wrote:

What is the reasoning behind the required course reversal in many
approaches? It's hard to believe that I will be safer flying the
racetrack
and then the approach to the runway than simply flying to the IAF and
proceeding inbound - especially with GPS guidance. I have no problem
flying
the full published course, done it many times, I'm just curious why
they
are
designed that way.

Michael


Michael,

Others have given you some good answers. However, the reasoning often
depends on the particular approach. So it would be useful if you could
post a reference to a procedure about which you have a question.




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

I think I said " I just think the procedure turn, in IMC, may cause more
danger than it allieves". I don't think the turn is dangerous per se, but an
approach directly to the FF and inbound, with no dramatic changes in
altitude and direction, seems less dangerous than the same approach with the
addition of a run around the racetrack.

Michael



"Bob Gardner" wrote in message
news:jK6Zb.359414$na.536935@attbi_s04...
Why would a maneuver in protected airspace, sterilized against other IFR
(and VFR talking to ATC) airplanes be dangerous?

Bob Gardner

On Thu, 19 Feb 2004 16:38:24 GMT, "Michael 182"
wrote:

Well, as an example, the BJC ILS 29R. In this case ALIKE is both the IAF and
the FF. Clearly if you are coming in from the west or southeast quadrants,
the course reversal is needed to lose altitude, as John pointed out. Also,
as Andrew pointed out, even if the approach was in Kansas, you migt be
approaching on a 090 heading to a final approach course of 293, and hence
the course reversal makes sense. I guess my question is why not have a
conditional, say if approaching with heading 270 - 330 at altitude of 7300,
no PT required.

Now you have to ask yourself how you would navigate to an area South or
East of ALIKE at an altitude of 7300'? I'm having to look at a NACO chart,
and I'm used to Jepps. But it seems that there is no airway leading to
ALIKE. And the MSA for that area is 10500'.

If ATC can give you "vectors to final" in that area, then you would not
have to do the course reversal (and can't do it without permission). But
absent radar vectors, I don't see a charted way to get to ALIKE at an
altitude low enough to avoid the course reversal.



I'm not trying to be arugmentative - I just think the procedure turn, in
IMC, may cause more danger than it allieves. On the other hand the
conditional may complicate the instruction - conditionals always provide
more opportunity for error.


If you feel that procedure turns cause danger, you probably need to
practice them. They should be second nature.


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

"Ron Rosenfeld" wrote in message
...
On Thu, 19 Feb 2004 16:38:24 GMT, "Michael 182"
wrote:


Now you have to ask yourself how you would navigate to an area South or
East of ALIKE at an altitude of 7300'? I'm having to look at a NACO
chart,
and I'm used to Jepps. But it seems that there is no airway leading to
ALIKE. And the MSA for that area is 10500'.

MSA to the NE is 7300. Navigation by GPS.


If ATC can give you "vectors to final" in that area, then you would not
have to do the course reversal (and can't do it without permission). But
absent radar vectors, I don't see a charted way to get to ALIKE at an
altitude low enough to avoid the course reversal.


If you feel that procedure turns cause danger, you probably need to
practice them. They should be second nature.

Hard to argue I need more practice since I live in Colorado where we get
very little actual and I only fly 100-150 hours or so a year. In fact, I
just hired a CFII for some practice (and an IPC) the other day. No argument
that more practice and currency would make me a better pilot. Regardless, my
point was not that the PT was dangerous, but relative to an almost straight
in approach just added some incremental danger, since there is more time
spent maneuvering in IMC at a reasonable low altitude.



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

On Fri, 20 Feb 2004 03:04:53 GMT, "Michael 182"
wrote:

MSA to the NE is 7300. Navigation by GPS.


Hmmm. According to the NACO chart I downloaded from AOPA, it looks as if
the MSA is centered on BJC (VORTAC). So if you are NE of ALIKE, and south
of the BJC 090° radial, you would be in the 10500 segment.

If you have a Jepp chart that shows the MSA centered on ALIKE, we need to
report the discrepancy.


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

You're right. My mistake.

Michael

"Ron Rosenfeld" wrote in message
...
On Fri, 20 Feb 2004 03:04:53 GMT, "Michael 182"
wrote:

MSA to the NE is 7300. Navigation by GPS.


Hmmm. According to the NACO chart I downloaded from AOPA, it looks as if
the MSA is centered on BJC (VORTAC). So if you are NE of ALIKE, and south
of the BJC 090° radial, you would be in the 10500 segment.

If you have a Jepp chart that shows the MSA centered on ALIKE, we need to
report the discrepancy.


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

MSA is not an operational altitude...it is for emergency use only. Read
5-4-5 AIM.

Bob Gardner

"Michael 182" wrote in message
newsPeZb.82854$uV3.542041@attbi_s51...

"Ron Rosenfeld" wrote in message
...
On Thu, 19 Feb 2004 16:38:24 GMT, "Michael 182"
wrote:


Now you have to ask yourself how you would navigate to an area South or
East of ALIKE at an altitude of 7300'? I'm having to look at a NACO
chart,
and I'm used to Jepps. But it seems that there is no airway leading to
ALIKE. And the MSA for that area is 10500'.

MSA to the NE is 7300. Navigation by GPS.


If ATC can give you "vectors to final" in that area, then you would not
have to do the course reversal (and can't do it without permission).
But
absent radar vectors, I don't see a charted way to get to ALIKE at an
altitude low enough to avoid the course reversal.


If you feel that procedure turns cause danger, you probably need to
practice them. They should be second nature.

Hard to argue I need more practice since I live in Colorado where we get
very little actual and I only fly 100-150 hours or so a year. In fact, I
just hired a CFII for some practice (and an IPC) the other day. No
argument
that more practice and currency would make me a better pilot. Regardless,
my
point was not that the PT was dangerous, but relative to an almost
straight
in approach just added some incremental danger, since there is more time
spent maneuvering in IMC at a reasonable low altitude.



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

On Sat, 21 Feb 2004 22:40:09 GMT, "Bob Gardner" wrote:

MSA is not an operational altitude...it is for emergency use only. Read
5-4-5 AIM.

Agreed.

However, the context of this discussion seems to be pilot-nav random
routing and the reason for a procedure turn at this particular approach.
It is not a vectors-to-final routing where ATC may assign an altitude.

Are you of the opinion that the IFR charts suggest that when on a random
route and NE of ALIKE (but south of the BJC 090 radial) that 7300 is a
perfectly OK altitude to use?

My teaching has been that when not on a "solid black line" or receiving
radar vectors from ATC, to not go below the MSA, OROCA, etc., for that
area.


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

Ron Rosenfeld wrote
Are you of the opinion that the IFR charts suggest that when on a random
route and NE of ALIKE (but south of the BJC 090 radial) that 7300 is a
perfectly OK altitude to use?

My teaching has been that when not on a "solid black line" or receiving
radar vectors from ATC, to not go below the MSA, OROCA, etc., for that
area.

The relevant regulation is 91.177 - other than when on approach, 1000
ft above any obstacles within 4 nm of course, or 2000 in designated
mountainous areas. If you meet that, you're complying with 91.177.
The question is how to best comply with this?

On a solid black line, the altitude is published. On vectors, it's
ATC's responsibility. On a random route, it's your responsibility -
sort of. It is relatively common (at least in my neck of the woods)
to have approaches where the FAC is not depicted on the controller's
scope. In this situation, RADAR services are available, but vectors
to final are not. It's fairly common (in my experience) to get a
clearance direct to the IAF (NOT a vector) at an altitude lower than
anything published - OROCA, MSA, or even the published minimum
altitude for crossing the FAF. Clearly the controller is using his
MVA for this. Are you suggesting that accepting such a clearance is
improper?

Even without RADAR services, it's not all that clearcut. Certainly if
you maintain OROCA or MSA, you're complying, and in many cases this is
the way to go. However, this is often not practical. For example, in
my next of the woods there are tethered balloons going to 15000 ft,
and that makes OROCA just over 16000 for the sector. This would make
direct routings impossible for anyone without turbos. In reality, the
minimum altitudes for direct routings in most of that sector are in
the 2000-4000 range.

I've seen a similar situation apply to the MSA, where an entire sector
had an MSA about 1500 ft higher than it would have been had it not
been for ONE tower, about 23 nm away from the fix. I have to believe
that in mountainous terrain, this is even more common, since airports
tend to be in valleys.

Under Part 91, there is really no defined requirement for where the
data you use to comply with 91.177 should come from. However, I have
to believe that any FAA-recognized chart is fair game. I have no idea
if 7300 is OK in the area you describe, because I have not seen the
relevant VFR chart. It might be. If the obstructions that make the
MSA in the sector 10,500 are 20 miles away, and the local terrain is
much lower, then maybe it is. However, with only the infomation on
the approach plate, I sure wouldn't try it.

Michael