Backup gyros - which do you trust?

Julian Scarfe wrote:

I think you're barking up the wrong tree here. Classic teaching of
partial/limited panel involves covering an instrument and then continuing to
fly without it. In the case of the Bandeirante accident, that wasn't the
issue. There was still a perfectly serviceable AI in the panel, and a pilot
sitting in front of it. The issue was identifying the failed instrument in a
complex cockpit environment.

I'm not sure I'm barking up the wrong tree.

Possibly practicing flying partial panel makes little sense. OTOH,
practicing partial panel *does* teach which combinations of instruments
can be used to provide the same information as the missing AI.

Surely this is relevant to obtaining and maintaining a good
crosscheck -- and wouldn't good crosscheck be the key to identifying
the failed instrument in a "complex cockpit environment"?

BTW, my reading of the accident report is that they weren't
certain but what both AIs had failed -- something that was certainly
within statistical likelihood given the low MTBUR

Cheers,
Sydney

Big John wrote:

NDB approach is a non precision approach. Takes less Partial Panel
proficiency.

I'm quite aware of what is and isn't a precision approach.

You ask and I gave a straight forward answer. Why did you parse my
answer and get snippy???? If you didn't want to know, why ask?

I edit what I see as extra text routinely. I'm sorry you see
my response as "snippy". To me, defining precision approaches
didn't explain why you feel an NDB approach in particular is
easiest to fly partial panel. That's what I wanted to know.

Perhaps I should clarify that I was assuming comparing "apples
to apples", ie an ILS vs a GPS vs an NDB approach flown down
to about the same height AGL, maybe 700-800 ft ceiling.

If we're talking 200 ft ceiling then I assume we agree it's
a moot point, the ILS or maybe an ASR or a PAR is the only
thing which will get you in.

Are you trying to tell me it's not easier to fly a PP NDB approach
than a PP ILS?

Well, that seems to be the general opinion of more experienced
pilots around here, including some folks I generally think pretty
highly of.

It's certainly my opinion from flying both partial panel in
simulated IMC at night.

We've been lucky enough that so far all our failures have occured
day VFR, so I can't speak from experience. And I won't in our
plane, because when we bought it, the ADF came in a cardboard
box having been pulled to install an ifr-certifiable GPS. So
it made the most sense to sell it and use the money to certify
the GPS, and that's what we did.

If you don't want to take advice from someone who has been
there and done that then use your own procedure.

Well, when one person who has "been there and done that"
offers advice which runs counter to that of a number of others
who have "been there and done that", I'd like to know the
reason for the discrepency.

It *is* a moot point to us, as explained above. Though I did
have a CFI who insisted I learn to fake NDB approaches on a
handheld GPS as an emergency procedure. Which sort of put me
in mind of modifying an auto to make it into a good horse-drawn
buggy.

I'd like to see you PP trying to use GPS to make an approach. It's
hard enough to keep the airplane flying PP without using the benefits
of GPS.

I don't follow this at all. There have been several articles
commenting on the heading assistance provided by some modes of
common handheld GPS. Unless you are thinking that the GPS is
tucked off to the side and must be scanned by turning one's
head constantly, instead of being readily in view?

In an IFR install, there ought to be a CDI for the thing, right
in one's primary scan and it shouldn't be necessary to turn one's
head much to fly it.

We have a moving map coupled to our GPS in the primary scan
area, between the AI and the CDIs. I find it so useful partial-
panel that our CFI fails it.

Where are you located?

Another post pointed out an individual practicing using his back up AI
across the panel and got vertigo. He probably was moving his head back
and forth which gives you vertigo when on instruments, Your scan is
only with your eye balls or you will probably get vertigo.

Yeah, that's probably part of the issue. Where my compass is located,
I can't read it accurately eyeballs only. I have to move my head.

So flying an approach like an NDB where I have to constantly scan
the compass is he**. It's much simpler to fly an approach where
I can pretty much drop the compass out of the scan and just center
the needle.

I'm going to back out of most of these threads and let yu'all have at
it. I'll just read and enjoy. Might even look at a sport bird since I
can't get a third class anymore. At least with out several years and a
lot of time and money to fight the system. Have you heard of any one
getting by OK City with a pacemaker? I pass a monthly check ok.

Have enjoyed many of your posts. Keep it up. You are not afraid to ask
questions which is good.

Thanks. Appreciate your info about the 17 hrs a month, too. Afraid
I can't quite pull that right now. A young child has a sad effect upon
free time 'fraid I don't have good news about a pacemaker. I know
someone who was a glider CFI/DE, and works for the local FSDO, and he
didn't even fight it. Of course, he's still flying the gliders and
enjoying every minute I assume.

Cheers,
Sydney

I have a Garmin 196. It has a simulated instrument
panel page on it that is pretty accurate. It would be
the tie breaker in the event of confusion over what
the gyro instruments were saying.


"Sydney Hoeltzli" wrote in message
...
Julian Scarfe wrote:

I think you're barking up the wrong tree here. Classic teaching of
partial/limited panel involves covering an instrument and then
continuing to
fly without it. In the case of the Bandeirante accident, that wasn't
the
issue. There was still a perfectly serviceable AI in the panel, and a
pilot
sitting in front of it. The issue was identifying the failed instrument
in a
complex cockpit environment.

I'm not sure I'm barking up the wrong tree.

Possibly practicing flying partial panel makes little sense. OTOH,
practicing partial panel *does* teach which combinations of instruments
can be used to provide the same information as the missing AI.

Surely this is relevant to obtaining and maintaining a good
crosscheck -- and wouldn't good crosscheck be the key to identifying
the failed instrument in a "complex cockpit environment"?

BTW, my reading of the accident report is that they weren't
certain but what both AIs had failed -- something that was certainly
within statistical likelihood given the low MTBUR

Cheers,
Sydney

I played with that page on the 196 yesterday in moderately gusty
conditions... You have to be smooth on the controls, make your correction
and then wait for the unit to update... Flown that way it is useable and I
suspect that I could fly an approach with it in real conditions (an ILS to
minimums would be hairy).. The work load is significantly higher than with
the gyros..

But, if you do not wait for the screen to update you get into a world of
hurt... Since it was nice and bumpy I put the hood on and then flew it like
I was panicky - rapid, big,. inputs - It only took about 30 seconds to get
out of sync, with the ship laid over on it's side, whereupon I had the fun
of recovering from an unusual attitude... Other than the speed having
gotten further into the yellow arc than I like it was good exercise... About
this time the controller came on and asked me to say intentions - uh, oh,
busted!

Denny

"Roger Tracy" wrote in message
...
I have a Garmin 196. It has a simulated instrument
panel page on it that is pretty accurate. It would be
the tie breaker in the event of confusion over what
the gyro instruments were saying.