Rogue IFR

Seriously though, I'm sure the accuracy of the GPS and the cute little
moving map makes this much more tempting, and thus, common.

I'm sure you are correct -- especially for pilots with some IFR training.

Myself, for example. I don't have the IR, due to a myriad of time
constraints -- yet I've got all the flying requirements under my belt. I'm
sure I can keep my wings level in the soup as well as any newly minted
instrument pilot.

That said, could I fly an unauthorized instrument approach into Iowa City
using my giant color AvMap? Sure! In fact, I'd wager that I could fly a
BETTER instrument approach using just the AvMap, as opposed to (for example)
flying the full VOR 36 approach into Iowa City.

Would it be legal? Nope. Would it be safe? Except for the
not-talking-to-ATC part, yup. Would I do it? Nope. My ticket -- and my
family's lives -- are too valuable to me to risk on something so stupid.

But I'm sure there are those who would...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

We're talking here about a 150-200 hour pilot with no instrument training
other than that required for the PP
intentionally launching into weather that some new IFR ticket holders would
have the sense to avoid.

Being at about that level of experience myself, I can't imagine anyone being
tempted to try this without the very accurate position information provided
by the GPS. I'm sure people did it with Loran, and some even with just
gauges but I bet there were a lot less of them and they didn't get away with
it as long. There is something very seductive about seeing that little
airplane symbol on a full color map.

I'm also pretty sure that, if he weren't flying something as stable as a
Skyhawk, I'd have already read the account of his last flight.
--
Roger Long

Recently, Roger Long om
posted:

We're talking here about a 150-200 hour pilot with no instrument
training other than that required for the PP
intentionally launching into weather that some new IFR ticket holders
would have the sense to avoid.

Being at about that level of experience myself, I can't imagine
anyone being tempted to try this without the very accurate position
information provided by the GPS.

I'm not so sure that the biggest problem is one's location. Take a look at
the numbers of accidents which involve pilots losing their orientation
references. GPS isn't fast enough to be a good substitute for the gauges.
Also, take a look at the numbers involving impact with obstacles while in
IMC, which most GPS units don't give information about. Then, take a look
at the flying time those involved in such accidents have. Playing around
in the soup is just not safe flying, regardless of how many hours a pilot
has.

Regards,

Neil

No, but being able to just follow the little airplane symbol on the GPS to
your destination reduces the work load significantly. This lets you
concentrate more on the gauges and minimizes the head movement and
distraction that lead to spatial disorientation.

Think of flying rogue and NORDO before GPS (or Loran), even with the VOR's
you'd be juggling charts, plotters, looking up new frequencies, retuning the
VOR. One dropped pencil and you'd be dead.

I'm not saying it's safe, just that technology has made it significantly
easier and therefore enough safer to be more tempting.

--
Roger Long

I'm not so sure that the biggest problem is one's location. Take a look at
the numbers of accidents which involve pilots losing their orientation
references. GPS isn't fast enough to be a good substitute for the gauges.

Jay Honeck wrote:
Would it be legal? Nope. Would it be safe? Except for the
not-talking-to-ATC part, yup.

It might not be safe, either. IFR GPS's have an extra quality/geometry
"monitoring" algorithm called RAIM that VFR units don't have. It's
possible that you'd be OK, but it's also possible that you won't and
wouldn't know about it.

That said, I've had RAIM alarms on my IFR GPS, where my handheld GPSMAP
195 thought everything was OK, and I could see by looking out the window
that we were exactly where both GPSs thought we were.

-- Jay

__!__
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http://www2.ari.net/jmasino/ ! ! !

Checkout http://www.oc-adolfos.com/
for the best Italian food in Ocean City, MD and...
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It might not be safe, either. IFR GPS's have an extra quality/geometry
"monitoring" algorithm called RAIM that VFR units don't have. It's
possible that you'd be OK, but it's also possible that you won't and
wouldn't know about it.

True enough, but I'm comparing my AvMap to my King VOR -- not to an
IFR-certified GPS.

With my AvMap I am able to taxi to my hangar without looking out the
windows. I wouldn't want to try *that* using my VORs... :-)

Thus, comparing apples to apples, I'm positive I could fly a much safer and
more accurate non-precision instrument approach (which is all we have here)
into Iowa City using my AvMap, even though it's technically illegal. Still,
it's nice to have the capability on board, in case of an emergency.

But I sure wouldn't do it routinely, as was the case of the pilot in Roger's
example.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay Masino writes:

That said, I've had RAIM alarms on my IFR GPS, where my handheld GPSMAP
195 thought everything was OK, and I could see by looking out the window
that we were exactly where both GPSs thought we were.

Even a handheld GPS is more than sufficient for en route navigation.
Only takeoffs and landings require greater accuracy. Remember, typical
accuracies for GPS under an open sky without nearby obstacles (e.g., in
an aircraft) are in the range of a few metres, even with cheap,
handheld, uncertified units. Unless the sky is so crowded that aircraft
are only ten metres apart, this is more accuracy than anyone ever needs
en route. In fact, your commercial airline flights could navigate using
the GPS you're holding next to your window if they needed to, and things
would be just fine (at least outside of takeoff and landing).

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

In article ,
Mxsmanic wrote:
Even a handheld GPS is more than sufficient for en route navigation.

RAIM isn't about additional accuracy, that's WAAS. A receiver with
RAIM can't give you a better position fix, but it can tell you when the
the possible error in the position fix has gotten unacceptably large.

--
Ben Jackson

http://www.ben.com/

Ben Jackson writes:

RAIM isn't about additional accuracy, that's WAAS. A receiver with
RAIM can't give you a better position fix, but it can tell you when the
the possible error in the position fix has gotten unacceptably large.

How large is unacceptable? For en route navigation you don't have to be
that accurate. Older forms of navigation are considerably less
accurate, and people still use those.

--
Transpose hotmail and mxsmanic in my e-mail address to reach me directly.

Mxsmanic writes:

RAIM isn't about additional accuracy, that's WAAS. A receiver with
RAIM can't give you a better position fix, but it can tell you when the
the possible error in the position fix has gotten unacceptably large.

How large is unacceptable?

Most of the time my handheld GPS receiver is fine, but sometimes
(extremely rarely) it loses signal or has an inadequate coverage.
RAIM is essentially a requirement for the GPS to let you know when
something has gone wrong. If you're in VMC, presumably, you can tell
just by looking out the window, but in IMC, if the GPS is your sole
means (rather than just a cross-check on VOR and ADF), you have to
know. You could be talking about an error of dozens or even hundreds
of miles.

It's a lot like electricity. For your home, the electricity works
99.[multiple 9's] percent of the time, and on the very rare occasions
when it goes out, you just pull out the flashlights and battery
radio. In a hospital, the electricity *cannot* stop working, so there
are monitoring systems and backup generators.

The VOR and LOC/GS also have an error-monitoring system in the form of
the flags on the NAV head, for precisely the same reason -- if the
flags drop, you cannot trust the instrument. Ditto for some newer
AI's and TC's. The ADF is grandparented without any such error
indicator, which makes it a bit more dangerous: some snap to 90 deg
when they lose signal (which is hard to miss), and many people just
leave the ident volume on low. I have to admit that I occasionally
change course 10 degrees for 10 or 20 seconds to make sure that the
ADF is still working, since I frequently fly Romeo (LF/MF) airways
between Ottawa and Kingston.

For en route navigation you don't have to be that accurate. Older
forms of navigation are considerably less accurate, and people still
use those.

I don't think people are usually worried about being a mile or two off
course enroute.


All the best,


David