Procedure turn required?

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?

Bob Gardner


"Peter Duniho" wrote in message
...
"Bob Gardner" wrote in message
...
Since it's such a nice day, I'm going to quibble. Where is it written
that you have to track the inbound course when outbound?

IMHO, that's in the definition of "procedure turn" (97.3(p)). "The
outbound course, direction of turn, distance within which the turn must be
completed, and minimum altitude are specified in the procedure". Note
that they say "outbound course", not "outbound heading". To me, this
means you are required to fly exactly that course (inasmuch as you are
required to fly the procedure turn at all).

I don't disagree that there are situations in which it's perfectly safe to
parallel the outbound course. Your example at KPAE is a fine one.

But if someone believes that the regulations require the full procedure to
be flown even when no course reversal is actually necessary for the
approach, they darn well better believe that the regulations require
flying the outbound *course* as depicted, rather than just the outbound
heading. That seems much more explicitly stated than the presumed
requirement to fly the full procedure.

Pete

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?

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?

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?

On Sun, 5 Jun 2005 10:53:40 -0700, "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?

Maybe to take into account and give some protection for VOR, onboard
equipment, and operator error? At the far end of the maximum 10NM
circle for a standard procedure turn distance, if the VOR itself was
drifted say 4 degrees and then your aircraft was off 4 degrees and
then you didn't have the exact number dialed in and so were off 1
degree to begin with... So say there is a combined error of 9 degrees
off, you're already 1.1NM off the 'desired' track at about 7nm, right,
but still would have a centered needle. Even with a perfect needle
(say glass cockpit for the VOR OBS setting and autopilot handling
accuracy) the VOR approach to 6B6 puts you at/over (I forget the exact
number right now) around 1NM to the right of the airport at the MAP.
It was quite interesting doing it under the hood, having the needle
centered the whole time, and then playing 'find the airport' when I
pulled up the hood.

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?

Probably because neither pilots, their nav radios more the ground VOR
stations are that accurate. :-)


Matt

Matt Whiting wrote:

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?

Probably because neither pilots, their nav radios more the ground VOR
stations are that accurate. :-)

Matt

Especially at a VOR intersection.