WAAS Airport Costs?

Scott Moore wrote:
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.

Actually, a principle problem with LAAS is that the funding was
seriously scaled back.

The CAT I portion of the program was still in the R&D phase, as they
were working the issues (problems with interference/iono, i believe,
were still not resolved).

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

I'd be sufficiently impressed if WAAS could provide CAT III, even with
dual-frequency, denser network of ground reference stations, algorithm
tweakage etc.

Regards,
Jon

An important part of the precision approach environment is the airport
surface itself: an adequate runway clear zone and adequate approach
lighting. Just because you can get a WAAS signal does not mean a
particular runway is going to be appropriate for a 200 ft minimum.

Dave

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

Dave S wrote:

An important part of the precision approach environment is the airport
surface itself: an adequate runway clear zone and adequate approach
lighting. Just because you can get a WAAS signal does not mean a
particular runway is going to be appropriate for a 200 ft minimum.

For whatever it's worth, the runway markings, taxiway spacing, and obstacle
clearance areas are what make for a 200-foot Decision Altitude (DA).
Approach lights (ALS) are for visibility credit. With everything else
satisfied but no ALS the DA will still be 200 feet, with a visibility of
3/4. Add ALS to that environment and it becomes 200 and 1/2.

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?

Porque?




On Wed, 16 Feb 2005 05:06:50 -0800, wrote:



Dave S wrote:

An important part of the precision approach environment is the airport
surface itself: an adequate runway clear zone and adequate approach
lighting. Just because you can get a WAAS signal does not mean a
particular runway is going to be appropriate for a 200 ft minimum.

For whatever it's worth, the runway markings, taxiway spacing, and obstacle
clearance areas are what make for a 200-foot Decision Altitude (DA).
Approach lights (ALS) are for visibility credit. With everything else
satisfied but no ALS the DA will still be 200 feet, with a visibility of
3/4. Add ALS to that environment and it becomes 200 and 1/2.

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.

An important part of the precision approach environment is the airport
surface itself: an adequate runway clear zone and adequate approach
lighting. Just because you can get a WAAS signal does not mean a
particular runway is going to be appropriate for a 200 ft minimum.

For whatever it's worth, the runway markings, taxiway spacing, and obstacle
clearance areas are what make for a 200-foot Decision Altitude (DA).
Approach lights (ALS) are for visibility credit. With everything else
satisfied but no ALS the DA will still be 200 feet, with a visibility of
3/4. Add ALS to that environment and it becomes 200 and 1/2.

For now, the lowest possible DA for WAAS approaches (LPV minima) is 250 feet.
Getting down to 200 feet (GLS minima) will require major system changes,
probably including a second civil GPS frequency, and will not happen before
2013 at the earliest.

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
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