Poor research on my part. At a glance, the presentation didn't look like
what I had seen in the past, and I dismissed it. But my original point is
valid...there is a ton of protected airspace on the non-maneuvering side.

Bob Gardner

wrote in message ...


Bob Gardner wrote:

I rely on the Summit Aviation CD-ROM...guess they don't provide
everything...


How current is your Summit CD? Mine shows Paragraph 234, the graphic, and
the
three tables for construction area, depending on altitude.

The three different sizes, depending on altitude, were added in the past
five,
or so, years.

Another thing to keep in mind, just like with holding pattern crtieria (a
different handbook, also in Summit) is that where the procedure turn is a
VHF
fix, the fix error could already chip away at the margins, so you might
not
quite be where you think you should be when starting a procedure turn
under
those circumstances.

Then, there is the ever-present issue of FAA policy directives that are
not
reflected in handbooks that are not "spot current." For instance, in the
holding pattern crtieria there is a selection table for GPS (RNAV)
holding, but
that was challenged at the Aeronatucal Charting Forum about three years
ago as
being an untested selection process that presumed positive course guidance
throughout an RNAV holding pattern. Only some high-end LNAV platforms can
do
that; others must fly outbound in the traditional manner using dead
reckoning.
As a result of that ACF issue paper the FAA made simulator tests, which
confirmed the industry objection. Thus, by policy letter, that GPS
selection
table can no longer be used for RNAV holding patterns.


Thanks.

Bob

"JPH" wrote in message
news:xC5qe.9693$mC.6960@okepread07...
Bob,
The TERPS manual that contains the PT instructions can be found at this
website;
http://av-info.faa.gov/terps/Directi...260.3_1-18.pdf

If you go to page 34 (of 268) you can find the graphic and on page 35
you
can find the table that gives the instructions on how to build the PT
manually.

JPH

Bob Gardner wrote:
It is apparently not possible to communicate with you directly, so let
me
explain how I got the 1.4 miles of protected airspace on the
non-maneuvering side of procedure turn airspace, and apologize for
being
wrong...the protected airspace is 4.0 miles wide, giving the pilot
even
less reason to work at tracking the outbound.

Back when TERPS was an actual publication with pages rather than an
online source, Para 234 included instructions for constructing
procedure
turn airspace based on max allowed distance. In the instructions for a
ten-mile PT, the procedures designer was told to select a point one
mile
inside of the airspace on the manuevering side, perpendular to the
outbound course at the fix. The next step was to select another point,
ten miles from the original point but two miles inside of the
maneuvering
airspace. The designer was then told to swing an arc with a 5 nm
radius
from the first point and a 6 nm radius from the second point. A line
drawn tangent to these two arcs, parallel to the outbound course,
defines
the edge of the primary protected area on the non-maneuvering side.
The
primary area gives 1000 ft of vertical clearance...beyond that, the
protected airspace vertical protection tapers down to zero over an
additional two miles.

Can't find the detailed instruction in the online TERPS, but the
illustration remains.

Bob Gardner