GPS approach safety case

If you have contacts at FAA HQ, check out Mitchell Narins, AND-702, whose
2002 paper "FAA Evaluation of Loran-C I-CNS Conference Briefing" laid a
foundation for many of the arguments in favor of continued funding. He is
not, to my knowledge, in the pocket of the loran manufacturers.

Bob Gardner

wrote in message ...


Bob Gardner wrote:

OK, then, go to www.avionicsmagazine.com, June 2004 issue, and see the
future. My point is that within a few years, enhanced loran will be
available when GPS is not.

That must be some joke fostered by the LORAN equipment manufacturers.

The high-end stuff that goes oceanic all have triple IRS units, which with
position mix will do far better than any LF "enhanced ADF."

"Bob Gardner" wrote in message ...
If you have contacts at FAA HQ, check out Mitchell Narins, AND-702, whose
2002 paper "FAA Evaluation of Loran-C I-CNS Conference Briefing" laid a
foundation for many of the arguments in favor of continued funding. He is
not, to my knowledge, in the pocket of the loran manufacturers.

I've seen him give several talks at ION and attended the ICNS
conference. Mitch is good people with a sound technical understanding
and has no problem dancing

Bob Gardner

Regards,
Jon

Bob Gardner wrote:

I usually appreciate your input to these newsgroups because you obviously
have an insider's perspective. In this case, however, you have not done your
homework. Enhanced GPS meets the RNP 0.3 standard, which will make it good
for nonprecision approaches when the funding is solid and the whole system
is upgraded.


What's enhanced GPS in this context? GPS today meets RNP 0.3.

If you meant enhanced LORAN, no one I have dealt with is even talking about such
a requirement.

And, the airlines aren't about to spend any money on anything like that. Like I
said, "triple mixed" IRS does quite nicely in a pinch and they are already part
of the equation.

The GPS goes out and you use triple mix IRS postion until you get into a DME
environment, then DME/DME does the update until you get onto the ILS.

If you meant enhanced LORAN, no one I have dealt with is even talking about
such a requirement.

And, the airlines aren't about to spend any money on anything like that.
Like I said, "triple mixed" IRS does quite nicely in a pinch and they
are already part of the equation.

In June 2002 I attended a presentation on LORAN given by Mitch Narins. Here
are the key points I noted then:

- The goal would be to provide a backup to GPS, capable of RNP 0.3
non-precision approach.

- LORAN availability, accuracy, integrity, and continuity were all
insufficient, and were all considered medium technical risks. Integrity was
considered the biggest challenge.

- It was estimated that 5 to 7 years of development would be needed before
LORAN could serve as a backup to GPS.

- No market was seen for standalone LORAN receivers - the enhanced LORAN would
be used only as an integrated component in multimode receivers.

I don't know what progress, if any, has been made in the past two years.

Barry

Barry wrote:

In June 2002 I attended a presentation on LORAN given by Mitch Narins. Here
are the key points I noted then:

- The goal would be to provide a backup to GPS, capable of RNP 0.3
non-precision approach.

I have a goal to win the Lottery Jackpot, too. ;-)

I had an Azure portable Loran that I got in 1988, as I recall. Then, they filled
in the mid-continent gap a couple of years later. Nonetheless, here in Southern
California, where the goemetry goes tango-alpha, I often saw 1/2 nautical mile
errors.

Keep in mind that RNP is a total system commitment, from pilot, to avionics, to
accuracy and integrety of the sensor. The powers-that-be decreed that GPS could
deliver RNP 0.3 with RAIM and approach display scaling of 0.3 n.m. Thus, we got
GPS RNP 0.3 by fiat, rather than by the ICAO definition of RNP. The snake oil
salesmen have been working hard to get to .20 and even .11, but so far
(fortunately) the feds won't buy into it, except for local differential. Boeing
has a great demo system at Moses Lake that works at one airport with one very
advanced 737-900.

Fours years have passed and there is no RNP .20 or .11 except with Boeing's demo
at one airport with one very expensive airplane.

And, this is working with the best stuff, not with "computed ADF." ;-)

Four years have passed and there is no RNP .20 or .11 except with Boeing's
demo at one airport with one very expensive airplane.

Doesn't Alaska Airlines have a special procedure into Juneau with RNP less
than 0.3?

Barry wrote:

Four years have passed and there is no RNP .20 or .11 except with Boeing's
demo at one airport with one very expensive airplane.

Doesn't Alaska Airlines have a special procedure into Juneau with RNP less
than 0.3?

Yes, but that is bogus RNP, in that they use terrain mapping radar and some
other enhancements to keep off the canyon walls.

In article , wrote:

Doesn't Alaska Airlines have a special procedure into Juneau with RNP
less
than 0.3?

Yes, but that is bogus RNP, in that they use terrain mapping radar and
some
other enhancements to keep off the canyon walls.

anything that helps the nav system maintain containment and integrity
is perfectly ok.

--
Bob Noel

Bob Noel wrote:

In article , wrote:

Doesn't Alaska Airlines have a special procedure into Juneau with RNP
less
than 0.3?

Yes, but that is bogus RNP, in that they use terrain mapping radar and
some
other enhancements to keep off the canyon walls.

anything that helps the nav system maintain containment and integrity
is perfectly ok.

--
Bob Noel

By that definition, eyeballs work well when you can see.

No doubt that belts and suspenders work well, but using the terrain mapping
feature of airborne weather radar doesn't fit the ICAO definition of RNP. It
works at Juneau because of the topography. It wouldn't work at most places.