IFR with a VFR GPS

In article et,
"Steven P. McNicoll" wrote:

Do you see any hazard in the use of a handheld GPS during enroute IFR
flight?

Increased risk of hazardously misleading information.

I'll leave it to the safety experts to determine or estimate the
increased risk.

--
Bob Noel
no one likes an educated mule

"Bob Noel" wrote in message
...

Increased risk of hazardously misleading information.


What hazardously misleading information?



I'll leave it to the safety experts to determine or estimate the
increased risk.


I posed a similar question to the safety experts some years ago, none could
identify any risk.

"Steven P. McNicoll" wrote:

Increased risk of hazardously misleading information.


What hazardously misleading information?


I posed a similar question to the safety experts some years ago, none could
identify any risk.

Steven, if you have other sources that will alert you to GPS HMI then
you can make the assertion that from an overall system view you are
protected. If not, then you are at risk. FACT!

Of course the risk may be smaller than running out of gas and dying
but it is quantifiable at the rate of about 10E-4 per hour.

Ron Lee

In article et,
"Steven P. McNicoll" wrote:

Increased risk of hazardously misleading information.

What hazardously misleading information?

A navigation solution that is incorrect.





I'll leave it to the safety experts to determine or estimate the
increased risk.


I posed a similar question to the safety experts some years ago, none could
identify any risk.

If those safety experts were unable to identify any risk, then they didn't knew
the subject area. I suggest that you find some real safety experts with actual
knowledge of aviation.

--
Bob Noel
no one likes an educated mule

"Ron Lee" wrote in message
...

Steven, if you have other sources that will alert you to GPS HMI then
you can make the assertion that from an overall system view you are
protected. If not, then you are at risk. FACT!


Well, then, since there are other sources that will alert to GPS "HMI", we
are protected.

"Bob Noel" wrote in message
...

A navigation solution that is incorrect.


What is the hazard?



If those safety experts were unable to identify any risk, then they didn't
knew
the subject area. I suggest that you find some real safety experts with
actual
knowledge of aviation.


There is no risk. Anyone that says there is a risk in the use of a handheld
GPS for IFR enroute navigation in US controlled airspace is not a real
safety expert with actual knowledge of aviation.

Jonathan Goodish wrote in message ...
In article ,
(Ron Lee) wrote:

Jonathan Goodish wrote:

In my opinion, there is no practical difference for enroute navigation
between a panel-mount certified GPS and a hand held which is not
certified.

Yes there is. RAIM provided integrity. As long as no signal error
exists (vast majority of the time) then your assertion is basically
correct.


But what if signal error exists? How is risk increased because of it
for enroute navigation? For practical purposes, it isn't.

My understanding is that RAIM calculates your location using all available
GPS signals and then goes back and "evaluates" each individual signal
against the collective result to determine the amount of error that exists.
If excessive error is present then that signal is disqualified from the
position calculation. Its only when not enough signals are left after the
disqualification process that the pilot will see a RAIM alert.

A navigation solution that is incorrect.



What is the hazard?


Cumulo Granite.

Jose
--
He who laughs, lasts.
for Email, make the obvious change in the address.

Steven P. McNicoll wrote:
"Tauno Voipio" wrote in message
...

There is one fundamental difference to other means
of IFR navigation: It is impossible to test and
approve the GPS signal. For the other NAVAIDs the
station can be measured on ground and fly the measuring
flights and compare the results with the specs in
ICAO Annex 10, and that's it.

Been there - done that.



Why is it impossible to test the GPS signal?

It is possible to measure the signal, but it does
not tell anything of the signals of the rest of the
constellation.

We can be pretty sure that an on-ground navaid
station will preform quite like how it did when
measuring it. There is no similar guarantee of
a satellite system controlled by a foreign
authority.

Also, there are no internationally accepted
standards of the GPS signal. For the other
navaids, there are technical performance
requirements in ICAO Annex 10 which is agreed
to be legally binding to all member states.

--

Tauno Voipio
tauno voipio (at) iki fi

"Jose" wrote in message
.. .

Cumulo Granite.


Explain.