You are in IMC, when *everything* fails! Now what?

Thomas Pappano wrote:

Ha! Excellent point! Now then, I wonder how many would buy a
modestly priced transient voltage protector for their expensive
GPSs, PDAs, laptops, CD/DVD players, XM radios, etc?
My little company could turn them out easy enough...

I was just thinking about posting a query re inexpensive
voltage protector.

If the price was modest, I'd just as soon buy it as cobble
it together.

Cheers,
Sydney

"Sydney Hoeltzli" wrote in message
...

My suspicion is that some GA aircraft, such as little Pipers and
Cessnas esp. fixed gear models of same, are sufficiently stable
that the plane will stay in control so long as the pilot doesn't
flagrently get in its way.

My suspicion is that other GA aircraft, such as Mooneys and
Bo's and perhaps little fixed-gear Grummans, Katanas, maybe
the RV series (basically anything with a reputation for being
'sporty' to fly, are sufficiently light and sensitive in pitch
that this has to be paid attention, it really won't take care
of itself.

Pretty much without exception GA aircraft are stable in pitch and unstable
in the spiral divergence mode. If displaced in pitch a Mooney will take
more phugoid cycles to get back to equilibrium when you release the
controls, but it *will* get back there. By contrast, if you stick almost
anything into a 45 degree bank, things are only going to get worse. The
difference between the C172 and the Bo is only to do with the speed at which
things happen, as more slippery aircraft will tend to reach red line speeds
more quickly.

So the key is always "get and keep the wings level". Anything else is
finesse. The only advantage that I can think of of doing this with rudder
is that it avoids inadvertent pitch inputs. If you're calm and experienced
in IF, I'd guess you'd have a more successful time with the ailerons.

Julian Scarfe

"Thomas Pappano" wrote in message
. ..
I've long figured that even with a 1 second position update rate, the
simplest GPS should give you enough turn data to stay in control
in addition to guiding you to an airport and making a useable approach.
I and iron-gut acro/safety pilot Doug found out yesterday.

I've often wondered if a pendulum, in lieu of a GPS or compass, would
provide sufficient yaw information to keep the wings. But I've never tried
the experiment.

--Gary

"Gary L. Drescher" wrote in message
. net...
provide sufficient yaw information to keep the wings.

Er, meant to say "to keep the wings level". Though I guess it sort of made
sense the way I typed it, too.

"Julian Scarfe" wrote:
So the key is always "get and keep the wings level". Anything else is
finesse. The only advantage that I can think of of doing this with rudder
is that it avoids inadvertent pitch inputs. If you're calm and experienced
in IF, I'd guess you'd have a more successful time with the ailerons.

The other advantage to using rudder is that the rudder is more effective
in a stall or spin. In a fully developed spin, the ailerons are
probably useless. When I teach stall recovery, I stress use of the
rudder to pick up a dropping wing.

On the other hand, the most likely unusual attitude you're going to get
into in IMC because of gyro failure is a steep spiral, in which case the
ailerons should be completely effective. But, do you trust yourself to
diagnose a steep spiral from a spin in IMC, with failed gyros, spatial
disorientation, and maybe a bit of panic setting in too?

"Gary L. Drescher"wrote
Er, meant to say "to keep the wings level". Though I guess it
sort of made sense the way I typed it, too.


Great idea Gary! You just may have saved me a lot of
money on that new gyro based Attitude Indicator that
I need.

Bob Moore

Julian Scarfe wrote:

Pretty much without exception GA aircraft are stable in pitch and unstable
in the spiral divergence mode. If displaced in pitch a Mooney will take
more phugoid cycles to get back to equilibrium when you release the
controls, but it *will* get back there.

*if* you keep the wings level, right?

But how about if you're struggling to figure out what "level" is?

Perhaps I'm mistaken, but I don't see the two as unrelated problems.
Yes, from an airplane design standpoint, little Cessnas and Pipers
are also "unstable in the spiral divergence mode", but anyone who
has flown same vs. Grumman/Mooney/Bo will say that the latter are
much lighter in both pitch and roll, and that they require more
attention to fly. I'm no aeronautical engineer type, but someone
told me once that Cessnas are designed to have something like 'positive
roll stability' (meaning if you take your hands off the yoke in a turn,
they want to return to level flight) whereas Grummans (dunno about
Mooney and Bo) are designed for 'neutral roll stability' (meaning if you
take your hands off the stick, they want to stay where you put them).
(even money I've got the terms wrong)

Add this factor to pitch light enough that someone shifting around in
the cockpit will alter the trim, and the chances of it getting "back
there" hands off are much less in any sort of unstable air. IME.

My point is that within your generalization about GA aircraft
design, I think there are details which differ, and those details
make a difference.

The difference between the C172 and the Bo is only to do with the
speed at
which things happen, as more slippery aircraft will tend to reach red
line
speeds more quickly.

That's definately a difference, and I don't have beans in Bo time so
I can't comment, but I don't think that's the only difference.

Otherwise, they'd fly the same, right, and people wouldn't be talking
about "sweet" "nimble" planes vs. "stable trucks".

I guess I'm not certain how being "experienced in instrument flight"
helps very much either, when the topic is "You are in IMC when
*everything* fails!" meaning "all gyros -- AH, DG, TB". This seems
to me to call for a different set of skills than holding 2,2 and 20
on a full panel or even conventional 'partial panel'

Best regards,
Sydney

Julian Scarfe wrote:
Pretty much without exception GA aircraft are stable in pitch and unstable
in the spiral divergence mode. If displaced in pitch a Mooney will take
more phugoid cycles to get back to equilibrium when you release the
controls, but it *will* get back there.

Sydney Hoeltzli wrote:
*if* you keep the wings level, right?

But how about if you're struggling to figure out what "level" is?

If the only thing you've got is a GPS, you have no way to directly know
what "level" is. All you know is what your course over the ground is,
and you can see which way it's changing. Here's the emergency control
strategy:

Use opposite rudder to keep the course from changing.

That's it.

There's a fun exercise I do with some more advanced students. Take your
hands off the yoke and fly with just rudder, power, and trim. It's
ugly, it's sloppy, and it's uncomfortable, but it works. Most can
actually get the plane over the runway and in a position to make a
survivable landing after a few trips around the pattern (I don't
actually let them land like that, just get close enough to demonstrate
that it's possible). The biggest key is to make very small power and
trim changes and then be patient and wait for the fugoids to damp out
before deciding if you got the descent rate you were looking for.
Go-arounds can be kind of exciting too!

I've done another exercise with people who insist on trying to use
aileron to pick up a wing drop in a stall. I take control of the yoke
and they get the rudders. The game is for them to keep the plane on a
constant heading while I try to turn us. The rudder wins every time!

My advise, Definately find out where VFR conditions exist in relationship
to your route PRIOR to taking off and highlighting the area on the LE chart.
At least you'll which way to turn. I put together a backup electrical
system.
Small 12 volt battery..16.00
Small padded bag.........3.00
Lighter jack parts, female, male, fuses etc...
I can power up a hand held GPS, handheld radio etc...
You still have to fly the plane first, but you can talk, ya know where you
are, and you can get the hell out of the situation. The battery will power
both for hours. I have a male to male that could backfeed power to the
xponder is some AC to at least squawk the 7600,7700 or what ever the case
may be.
Chris Grotewohl
--
http://irish5string.homestead.com/chrisG.html
http://home.kc.rr.com/grotewohl/CFI.html

"chris grotewohl" wrote in message
...
My advise, Definately find out where VFR conditions exist in relationship
to your route PRIOR to taking off and highlighting the area on the LE
chart.
At least you'll which way to turn. I put together a backup electrical
system.
Small 12 volt battery..16.00
Small padded bag.........3.00
Lighter jack parts, female, male, fuses etc...
I can power up a hand held GPS, handheld radio etc...
You still have to fly the plane first, but you can talk, ya know where you
are, and you can get the hell out of the situation. The battery will power
both for hours.



I have a male to male that could backfeed power to the
xponder is some AC to at least squawk the 7600,7700 or what ever the case
may be.
Chris Grotewohl
--
http://irish5string.homestead.com/chrisG.html
http://home.kc.rr.com/grotewohl/CFI.html



Hi Chris,
This is something I have planned, have not yet tested, but should work
great. Carry a small gel-cell equipped with a fuse and male lighter plug.
When electrical is lost, turn off master switch, turn off non-critical
equipment, lights, etc. Plug in the battery, which will then backfeed the
bus. This should power the electric TC, radios, and transponder long
enough to get down with a more or less "normal" instrument approach.
A pair of 7 amp/hr 12 volt gel-cells total about 10 lbs & $40.

Tom Pappano, PP-ASEL-IA