Rogue IFR

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).

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G.R. Patterson III writes:

The obvious solution is for him to stay on the ground.

If he's already in the air when the bad weather develops, what does he
do then?

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"Dave" wrote in message
...
Answers the question really!

What "answers the question really"? My reply to the question answers it?
Then please, tell me...am I the type of guy that wonders every day if the
sun will rise?

For extra credit, explain how ANY answer to that question has anything to do
with the reliability of a PIREP.

Pete

In article ,
Roger Long om wrote:
While the GPS may give them more accuracy, this was being done long
before the GPS became available.

But now they live long enough to amaze the rest of us

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

Yep, not like the old days when people knew better right The real
problem is maps of any kind, and autopilots...

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/

Mxsmanic wrote:

If he's already in the air when the bad weather develops, what does he
do then?

Several people have suggested a popup IFR flight plan.

George Patterson
You can dress a hog in a tuxedo, but he still wants to roll in the mud.

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.

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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

I'm approaching the completion of basic private pilot certificate but I
already know I want to go ahead and pursue an instrument rating. I've
found this discussion quite enlightening.

I do have a question: What would happen if this rogue pilot who is
flying VFR in solid IMC were to land at a towered airport such as we
have in Santa Fe? SAF has no radar but the controller is in front of the
windows and knows for certain what the weather is like around the airport.

If this pilot were to call in to request a landing would the controller
be obligated to report this? I know where to find the regs governing
pilots but don't think my AIM/FAR manual has the controller's regs.

Thanks,
david
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to me personally.

Roger Long wrote:
I ran into an old client today and we stumbled on to the flying topic.
Turns out he got his PP a couple years ago and bought a plane.

He said with a completely straight face that he's thinking of getting an
instrument rating because he "flies in IMC a lot." He does OK but would
like to be able to ask ATC where the other planes are and fly into towered
airports.

Yikes! What are they teaching student pilots these days? I've asked here
before and seem to find myself asking myself that question a lot. You can'
t teach common sense but the legality of what he's doing didn't even seem to
be on his radar screen.

What does ATC do when they see a 1200 target boring through what they know
is solid IMC?

--
Roger Long

David Gunter writes:

If this pilot were to call in to request a landing would the
controller be obligated to report this? I know where to find the
regs governing pilots but don't think my AIM/FAR manual has the
controller's regs.

I think that they'd simply deny the VFR aircraft clearance to enter
the control zone.


All the best,


David