Don't know about standards, but I wouldn't expect any - they each want
to protect their turf.
More seriously, I was browsing a boating magazine in my doctor's rooms
recently, & hit an article in which a yachtsman nearly ran smack into
Diego Ramirez Is. (near Cape Horn), because it simply wasn't shown on
the electronic chart he was using.
Don't trust your life to one of those electronic charts, would be my
conclusion. (I doubt the land maps are much better).
This seems an apples to oranges comparison as I imagine the data used in
personal GPS receivers is less accurate, less often updated, and no where
near as trustable as that used in the GPS receivers used in aviation.
Michael Kesti | "And like, one and one don't make
I'm afraid you misunderstood Michael.
As I read him, he stated that aviation GPS units
base on much more reliable data than "personal" GPS's
(though I'm not sure what this latter amounts to).
So "apples" = personal GPS units' data,
"oranges" = aviation GPS units' data.
Confirming your idea that pilots want and
generally get quite correct info from their GPS units.
As for uncharted shoals and their aviation equivalents:
what about danger, restricted, and forbidden areas?
In certain countries these are in almost permanent change,
requiring an alert database manager and frequent updates.
For myself, I should much welcome the advent of a
community driven database of pilot's navigation info,
a bit like DAFIF but more up to date,
that could be used by public domain GPS software.
And am much willing to contribute to any such initiative
within the limits of my poor abilities.
Best rgds & season's wishes,
KA (student pilot)
Hummm...are you talking about pilots trusting their lives to personal GPS?
Handheld aviation GPS units are remarkably accurate, and are great at
facilitating navigation. But that is as far as the 'hand held' variety
goes, I know of no pilots who actually trust their lives to the hand held
units. think of it as a way to verify and cross check other nav aids.
My own flying, I use it to supplement the regular aviaonics...and the hand
held is much more accurate than the standard VOR type units. <Panel mounted
LORAN is pretty slick as well, almost as good as GPS>
Is he (and/or she)? Each one? Really?
Sure and guaranteed? How can you know?
On my side I HAVE seen pilots fly with "consumer-oriented"
GPS-units, though not as a primary means of navigation, luckily.
And don't come and tell me about "certified" units:
unless I'm much mistaken not any single GPS unit has been certified
by any single European civil aviation authority.
On Sat, 24 Dec 2005 21:58:41 -0500, Gene S. Berkowitz
Yes. I use a handheld to double check position. I do not navigate
with it [see below].
Aviation units compute location much faster. AFAIK there aren't any
consumer oriented units that can reliably locate themselves while
moving at 150 knots ... many turbocharged and/or multi engine aircraft
can cruise faster than that.
Also aviation units with navigation plot great circle courses rather
than straight lines.
I think it's more because GPS is controlled by the U.S.
for email reply remove "/" from address
Would you do an approach without much assurance of the GPS satellite
signal quality ? Assuming that the SA would be suddenly switched on
during the approach (or a satellite would experience some sudden
problem), this could have quite serious consequences. For any critical
navigation, you really need some assurance about the signal quality.
A differential-GPS station can constantly verify the signal quality
from all satellites and broadcast this signal quality information to
nearby users (in addition to the differential correction). Without a
DGPS transmitter at every airport, I don't see how you could make a
safe approach with only a GPS receiver.
On Sat, 24 Dec 2005 16:52:22 -0500, Gene S. Berkowitz
I think the relevent term is "should" be using an aviation GPS.
Unfortunately as more comsumer oriented devices comes on the market,
the chances of pilots using inapropriate quality GPS systems
increases. This is very much equivalent in the embedded market where
general prupose PC based systems are employed where they have no
business of being empoyed.
I was flying my Twin Cessna 310 out of Pheonix at night going east.
North east of Tuscon, while Flight Following, VOR, and GPS had me in a
valley, I was sure I saw rocks in the sky ahead. Cross check of
altimeter and GPS also showed us higher than local terain, but we could
definitely see mountian peeks on each side of us, towering maybe
thousands of feet higher than we were. It just didn't look like we were
going to clear the next ridge ahead. No stars to the horizon there, as
there were many other places around us, only blackness. So dispite
assurances of all instruments and data, we advised Flight Following we
were going to error on the side of caution, and climbed. They
understood. Did we avoid anything? We'll never know. We lived through
it, though. That was enough.
Ultimately the aircraft pilot or ships captain is responsible for the
craft's and passenger's saftey. Pilots often die when they get fixated
on one source of information, and ignore any data to the contrary.
Nature often corrects their impression on how it "has to be" by instead
being "what it actually is".
I think what has been confused in this conversation is 1) the position
data from the GPS, which should be remembered is just data, one point of
reference in a suite of navigation instruments, and 2) the information
in the data base. Any functional GPS gives pretty good position data
within the limitations of spec'd accuracy. The map is another issue
entirely. Generally people don't put up new mountains to run into, but
they sure do build new TV towers, etc. A pilot should have a current
sectional, and be checking it for highest projections from the ground,
that's makered specifically by area. The idea that your GPS database map
is a substitute for a recent sectional is pretty dangerous thinking.
While there is nothing to prevent a pilot from taking any "NAV AID" he wants
on a plane including a toy compass and a 30 year old map, there are
regulations regarding NAV AIDs designed to be mounted/installed in aircraft.
Any device to be used for navigation must be designed against certain
standards such as RTCA DO-178B for software and then "type certified" by the
FAA (US, other countries/other agencies) for use in that type of plane.
In addition, data to be used in the NAV AID is covered by RTCA standard
DO-200A - Standards for Processing Aeronautical Data. All data to
be used in aviation must be handled in accordance with this standard.
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