WAAS Airport Costs?

Bob Gardner wrote:
http://www.avweb.com/newswire/10_18a.../187168-1.html

This will link you to an article that describe LAAS as being delayed for
quite a while. Don't hold your breath.

Bob Gardner

The principle problem with LAAS is that the government has a schedule to replace
ALL of the GPS sats with higher precision versions. I.e., the precision of GPS
is going up, without any particular new infrastructure going into place on
the ground or in the air. Which means that by the time any LAAS program got
on its feet, standard GPS, and presumably WAAS, might well offer the same
capability.

--
Samiam is Scott A. Moore

Personal web site: http:/www.moorecad.com/scott
My electronics engineering consulting site: http://www.moorecad.com
ISO 7185 Standard Pascal web site: http://www.moorecad.com/standardpascal
Classic Basic Games web site: http://www.moorecad.com/classicbasic
The IP Pascal web site, a high performance, highly portable ISO 7185 Pascal
compiler system: http://www.moorecad.com/ippas

Good does not always win. But good is more patient.

wrote:

I have the ear of some local government development people, who are
contemplating upgrading some airports. Money is tight, so an ILS is
probably not under consideration. So, I want to recommend to them
checking into a WAAS installation. Does anyone know what the prices of
such equipment for an airport are, which companies are selling them,
and how much it costs to get the FAA to then create a WAAS IFR
approach?

Sincerely,

/iaw


As the AOPA has stated, WAAS will first be used to offer controlled
descent on standard approaches, an alternative to "dive and drive"
stepdowns, which makes it completely legal. There is no requirement
for HOW you get down to the runway, just as log as you observe minimums,
which means a likely mention in the AIM that you are supposed to keep
an eye on your standard altimeter.

I don't think the outlook for WAAS aproaches is rosy. What will happen
is WAAS approaches that have minimums just as bad as the normal GPS
approaches. To get more would require new lighting, runway marking,
and FAA surveys. And recall that the FAA does not just survey the
runway once, they have to do it regularly, with an expensive monitoring
aircraft. Runway markings are not a trivial subject. A lot of fields
have runways so bad they would have to get resurfaced just to be
properly painted.

I think it will happen, but the AOPA seems to be spreading this idea
that we will get 250 minimums overnight. This is going to be a long
process.

--
Samiam is Scott A. Moore

Personal web site: http:/www.moorecad.com/scott
My electronics engineering consulting site: http://www.moorecad.com
ISO 7185 Standard Pascal web site: http://www.moorecad.com/standardpascal
Classic Basic Games web site: http://www.moorecad.com/classicbasic
The IP Pascal web site, a high performance, highly portable ISO 7185 Pascal
compiler system: http://www.moorecad.com/ippas

Good does not always win. But good is more patient.

On 16 Feb 2005 17:02:23 -0800, wrote:

this does not look like great news for WAAS or LAAS. where is WAAS
actually functioning right now? (is there a map of applicable areas?)
or is it "so much for the heavily advertised WAAS features of the
GNS480"?

WAAS usually covers most of CONUS, southern CANADA, northern Mexico and
Caribbean islands with accuracy sufficient to provide LPV approaches.

See http://www.nstb.tc.faa.gov/vpl.html for a map that is updated every six
minutes.


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

"Ron Rosenfeld" wrote in message
news
On 16 Feb 2005 17:02:23 -0800, wrote:

this does not look like great news for WAAS or LAAS. where is WAAS
actually functioning right now? (is there a map of applicable areas?)
or is it "so much for the heavily advertised WAAS features of the
GNS480"?

WAAS usually covers most of CONUS, southern CANADA, northern Mexico and
Caribbean islands with accuracy sufficient to provide LPV approaches.

See http://www.nstb.tc.faa.gov/vpl.html for a map that is updated every
six
minutes.


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

What is the 'vertical protection level' on the map? Is this the altitude (in
meters!) that waas is guaranteed? If so, it looks like over 120 meters
coverage is everywhere. This can't be, can it? What am I missing?

Harvey

See http://www.nstb.tc.faa.gov/vpl.html for a map that is updated every

six

minutes.

What is the 'vertical protection level' on the map? Is this the altitude (in
meters!) that waas is guaranteed? If so, it looks like over 120 meters
coverage is everywhere. This can't be, can it? What am I missing?

From the WAAS Terms & Definitions link at the bottom of the page:

Vertical Protection Level (VPL). The Vertical Protection Level is half the
length of a segment on the vertical axis (perpendicular to the horizontal plane
of WGS-84 ellipsoid), with its center being at the true position, which
describes the region that is assured to contain the indicated vertical position.
It is based upon the error estimates provided by WAAS.

Eclipsme wrote:
"Ron Rosenfeld" wrote in message
news
On 16 Feb 2005 17:02:23 -0800, wrote:

this does not look like great news for WAAS or LAAS. where is
WAAS
actually functioning right now? (is there a map of applicable
areas?)
or is it "so much for the heavily advertised WAAS features of the
GNS480"?

WAAS usually covers most of CONUS, southern CANADA, northern Mexico
and
Caribbean islands with accuracy sufficient to provide LPV
approaches.

See http://www.nstb.tc.faa.gov/vpl.html for a map that is updated
every
six
minutes.


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

What is the 'vertical protection level' on the map? Is this the
altitude (in
meters!) that waas is guaranteed? If so, it looks like over 120
meters
coverage is everywhere. This can't be, can it? What am I missing?

Harvey


VPL is what the receiver compares against a VAL (alert limit) to
determine whether or not to raise the Integrity flag. The VAL for
LNAV/VNAV and LPV is 50 meters.

Regards,
Jon

wrote:

Now this I find interesting.

I understand obstacle clearance, but had no idea that runway markings
and taxiway spacing affects DA.

I can understand runway markings (although I thought they were
standard for precision approaches) but taxiway spacing?


Yes. It's an Airports standard, not a TERPs criteria. It's contained in the
airport design advisory circular.

The rationale is spacing for wingtips in low visibility for spacing. And, there
is the issue of avoiding back-taxi at Class E or G airports.

wrote:

I still don't get it.

What does descending to 250 ft vs 200 ft on an approach have to do
with wingtip spacing or back-taxi operations?


I believe wingtip spacing has to do with the lowest visibility that can be
authorized. One location I am familiar with is KCRQ where the ILS vis was increased
from 2400 to 4000 because the taxiway was too close for Dash 8 aircraft to use at RVR
2400.

I do not have experience with how the airport design folks think. If you want to
know more, I recommend you look at the airport ACs.

As to back-taxi, I guess it becomes an issue of having sufficient visibility to see
and avoid the aircraft on the runway coming at you.

wrote:

Well, I can understand where the visibility requirement would be
affected, but I don't see why DA would change because of taxiway
spacing.

I am not sure it would affect DA. It didn't at KCRQ.

On Fri, 18 Feb 2005 07:50:48 -0500, "Eclipsme" wrote:

If so, it looks like over 120 meters
coverage is everywhere. This can't be, can it? What am I missing?

I'm not sure what you are missing. A map reading lesson? Bad color
rendition on your monitor? Perhaps some other issue when you downloaded?

At the present time (1:13 PM EST) it looks like the LPV contour includes
virtually all of CONUS, Alaska, southern Canada, Northern Mexico, Caribbean
and inside that contour the VPL is 50M or less. For about 99% of the US it
looks as if the VPL is around 20M.


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