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

Hello All,

There has been much discussion here about the obvious benefits of
redundant systems, engines, vacuum, electrical etc., when flying in IMC.
We've also read NTSB reports of crashes of very well equipped planes
where the pilot did not make use of redundant instruments.
As for myself and perhaps others, I will most likely never have access
to any aircraft with system redundancy beyond the simple electric
TC/vacuum gyro combo. I fly singles such as the 172 and 182, all
usually at least 25 years old. I did however, obtain my ratings for the
purpose of going places and doing things, and I seem to be flying about
5% of my hours in actual IMC. Being a person that places a high value
on my own ass, and the asses of the people who fly with me, like others
here I carry some backup equipment. A Magellan 315 I have flown 24,000
miles with so far, a JHP-520 portable com, Palm VII/CBAV for weather, and
spare batteries for all. For now I fly well maintained rentals.

So far in my meager 400 hours I have experienced a total electrical failure,
an AI failure, and a few VOR and ILS problems. All these were easy to
work around. I'm satisfied that with a vacuum failure I can fly just fine
on the TC, and vice versa. How about when you lose your vacuum
instruments *and* your electrical system? No nav, no com, no gyros
at all, just your engine and pito-static instruments. The essence of
maintaining control in IMC is being able to determine if you are turning.
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.

Conditions:
Clear, 92 degrees, fairly rough thermal TB about 2000 agl. For warmup,
we did 2 full hours of currency approaches and holds, building a
"pyramid" of stress and fatigue.

The task:
"Fail" all gyros, AI, TC, DG, and all nav equipment. Trying this for the
first
time ever, now navigate 25nm to an airport and make a successful
non-precision approach using only the handheld GPS, the "ball", and
pito-static instruments.

My strategy is to make good use of the inherent stability of the 172,
keeping my hands off the yoke as much as possible and turning with
the rudders. To keep things simple, I plan only 2 turns. The GPS is
simply set for a "go-to" to our airport. Our destination was to
the northwest, so fly due west a while, then 45 to the right to
intercept a long final approach course. The GPS display mode was
a simple numbers-only bearing/heading/distance/speed. Right off the
bat it was very strange and we thought our test might be over in about
1 minute. The GPS, though updating every second, is still giving you "old"
information. Now using the rudder to turn, the airplane takes a while
to respond. With the constant upsetting influence of the thermals, the
plane is always wanting to turn. You see it on the GPS, and by the time
you get some rudder pressure on, you are maybe 10 to the right. Now
you hold the rudder and wait for the plane to respond, and slowly you
come back on course, but overshoot. I try to adjust my inputs to smooth
things out but the TB makes it pointless. I resign myself to the fact that
at best we will make constant small s-turns all the way. Every now and
then a good thermal jolts us into a significant bank. My instinct was to
get the ball centered, check our pitch with the airspeed etc, then check
the GPS to see which way we were now going and slowly urge us back.
Seems to work. Soon I realize we've gone several miles already, and all
this actually seems to be working! Patience seems to be the rule- put a
small amount of pressure on the rudder, hold and wait for results.
Soon we are intercepting our 8 mile final approach course, using a
published NDB approach as a template, and doing our altitude
stepdowns based on GPS distance to the field. Closer to the ground
thermal induced turns made it difficult to get down to MDA as soon
as I would have liked, but we did arrive at MDA right over the field and
a circle to land could have been easily done. In spite of the constant
s-turning, we maintained our final approach course within +- 3 degrees,
better than I could have done with the ADF and the full panel!

We finish up with a partial panel ILS into our home field, and hot and
tired, I manage an embarrasing multi-bounce landing. The conclusion
of course, is that a battery powered GPS is an absolutely essential
piece of backup equipment that can save you even with major system
failures. We did a worse case scenario, but for example, you could use
the GPS to simply hold a course to VFR conditions. At higher altitude
you would have a smoother ride needing only occasional control input.
We must, in an emergency, actually remember to use the backup info
available whether from a portable device or a panel instrument.

Anyone else tried this type of emergency procedure?
Thoughts? Tips?

Tom Pappano, PP-ASEL-IA

ps: Howard Stark's 1-2-3 Method of Blind Flying was Needle-Ball-Airspeed.
This could be the 4-5-6 method: GPS-Ball-Airspeed

Thomas Pappano wrote:
Anyone else tried this type of emergency procedure?
Thoughts? Tips?


My only suggestion would be to try this at night under the
hood. I am not convinced that you can adequately simulate
IMC in daytime VMC conditions. I find it *much* easier to
keep wings level under a hood (or foggles) in daytime VMC
than in actual. So if you can pull this off at night under
a hood, I'd believe this would work for you.

Also, if this is to work, you would need to have the GPS
powered up and running at the moment of the failure. It's
not like you'd be able to hold wings level while taking three
minutes for the GPS to power up and acquire satellites....

--
David Rind

David Rind writes:

Also, if this is to work, you would need to have the GPS
powered up and running at the moment of the failure. It's
not like you'd be able to hold wings level while taking three
minutes for the GPS to power up and acquire satellites....

Another option would be the old whiskey compass, as long as you can
get to an east or west heading.


All the best,


David

--
David Megginson, , http://www.megginson.com/

If you've lost everything, one thing that semms to work is to:

1. go to East or West heading
2. set power to idle
3. set trim to full up
4. use ruddar only to keep mag compass set to East (or West, which
ever was chosen).

I have taught this to my instrument students, and introduce it when I
act as check pilot. One of our instructors was caught on top when she
lost both vaccum and electrical. She used this technique, and was
able to drop below the clouds where she could land safely VFR.

Maurice Givens


Sydney Hoeltzli wrote in message ...
Thomas Pappano wrote:

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've long been skeptical of this. Experience reinforced my
skepticism.

I have to admit, when I tried it, I did NOT use your "rudder only"
technique. My plane also lacks the "inherent stability" of the
C172. So it's a bit of a different situation.

But....I do think one receives significant clues under the hood
in daylight, even if one is actively trying to NOT cheat.

I'd be curious as to the results if you repeated some portion
of this exercise at night; I don't think it's necessary to
exhaust yourself first, simply try it on a dark night over an
unpopulated area with barely enough visual cues for your safety
pilot.

An interesting exercise, though, thanks for sharing it.

Cheers,
Sydney

IFR Magazine reported, that in several tests, pilots were able to
control the aircraft and fly to VFR conditions using only the Garmin
196. Check there web site. The article may have been placed there.

Maurice Givens


Sydney Hoeltzli wrote in message ...
Thomas Pappano wrote:

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've long been skeptical of this. Experience reinforced my
skepticism.

I have to admit, when I tried it, I did NOT use your "rudder only"
technique. My plane also lacks the "inherent stability" of the
C172. So it's a bit of a different situation.

But....I do think one receives significant clues under the hood
in daylight, even if one is actively trying to NOT cheat.

I'd be curious as to the results if you repeated some portion
of this exercise at night; I don't think it's necessary to
exhaust yourself first, simply try it on a dark night over an
unpopulated area with barely enough visual cues for your safety
pilot.

An interesting exercise, though, thanks for sharing it.

Cheers,
Sydney

Roy Smith wrote:
(Maurice Givens) wrote:
IFR Magazine reported, that in several tests, pilots were able to
control the aircraft and fly to VFR conditions using only the Garmin
196. Check there web site. The article may have been placed there.

I've tried stuff like this a couple of times with students. So far, we
seem to do pretty well using the GPS as a heading reference only, and
maintaining heading with rudder only.

Roy,

Can you be a bit more specific?

Did you use the GPS as a substitute for DG, otherwise "partial
panel" of TC and pitot-static?

Or did you try Thomas' experiment of "fail all gyro instruments,
only pitot-static"?

What were your wx conditions ie day/night overcast/clear etc?

What GPS?

When you say "most light planes are so stable in pitch" would you
mind sharing which light planes you've tried this in?

I have not tried the "rudder only" trick. But I have to say neither
my Garmin 90 nor our (older) panel-mount GPS update rapidly enough
to serve as an adequate substitute for a DG IMO.

Thanks,
Sydney

"Thomas Pappano" wrote:
A work-around for this might be to always power the unit from
the plane as SOP, so that max battery life would be available in an
emergency.

One problem with plugging into ship's power is a catastrophic surge or
spike as the alternator self-destructs might take out your handheld at
the same time it takes out the panel.

"Roy Smith" wrote in message
...
(Maurice Givens) wrote:
IFR Magazine reported, that in several tests, pilots were able to
control the aircraft and fly to VFR conditions using only the Garmin
196. Check there web site. The article may have been placed there.

I've tried stuff like this a couple of times with students. So far, we
seem to do pretty well using the GPS as a heading reference only, and
maintaining heading with rudder only.

We once tried to do unusual attitude recoveries with the nifty new
Garmin that gives you a simulated instrument panel. We came to the
conclusion that the pitch information you get from the synthsized
AI/ASI/Alt/VSI is so bad that you should ignore it completely in a UI
recovery. It might be of some value in stable cruise, or setting up for
a controlled 500 fpm descent.

Fortunately, most light planes are so stable in pitch that if you just
keep the power and elevator trim set to reasonable levels, and keep it
heading in one direction with rudder inputs, the pitch will take care of
itself.

Thanks for everyone's comments!

In our experiment, in spite of the rough ride and constant heading
correction,
our altitude remained pretty stable, requiring adjustment only when we
would be tossed into a pretty good bank. Just a little finger back-pressure
on the yoke hub would put things back on track. I just finished skimming
the 196 manual on Garmin's site and gleaned a couple tidbits:

The 196 update rate is still only once per second, (same as inexpensive
units)
but when in "battery saver" mode it drops to once every *three* seconds.
The "up to" 16 hour battery life is only when in battery saver mode.
They gave no hint of battery life when in "normal" mode.
A 196 user would surely want to check the battery mode if needing to
control his plane solely by the GPS. Another thing, they say you only get
about 10 more minutes of operation once you get the "low battery"
warning. A work-around for this might be to always power the unit from
the plane as SOP, so that max battery life would be available in an
emergency.

I will also try a repeat of all or part of this excercise at night for a
closer
to IMC experience. My experience has been that "actual" is easier to
fly because the sun, shadows, and glimpses seem to distract more
than help. 8-)

Tom Pappano, PP-ASEL-IA

Thomas Pappano wrote:

The 196 update rate is still only once per second, (same as inexpensive
units)

Interesting!

Well, when able, I will try the "rudder only" bit and report on
my experience. In theory, if the heading info is all that matters
and the update rate is 1 per sec, any GPS should do...

I'll confess my suspicion.

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.

I think there's some evidence to this regard. I don't think it's
coincidence that in the vacuum failure study, the C172 and Archer
pilots all kept control of the plane and a good portion of the Bo
pilots "lost it".

It's possible that there's a work-around -- power back and dirty
it up perhaps.

Please note I'm not trying to say these planes can't be flown
partial panel or with limited instruments. They can. But I don't
think a GPS for heading info suffices, no how no way.

I will also try a repeat of all or part of this excercise at night for a
closer
to IMC experience. My experience has been that "actual" is easier to
fly because the sun, shadows, and glimpses seem to distract more
than help. 8-)

They may distract your conscious mind, but what research I'm aware
of suggests that they are keeping your primitive vestibular system
calibrated and happy (whether you know it or not), so that you don't
have to deal with your reptile brain screaming at you "WE'RE TURNING!
WE'RE STILL TURNING YOU DAMNED FOOL TURN THE OTHER WAY! RIGHT NOW!".

Thanks again for posting,
Sydney

"Roy Smith" wrote in message
...
"Thomas Pappano" wrote:
A work-around for this might be to always power the unit from
the plane as SOP, so that max battery life would be available in an
emergency.

One problem with plugging into ship's power is a catastrophic surge or
spike as the alternator self-destructs might take out your handheld at
the same time it takes out the panel.


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...

Tom Pappano, PP-ASEL-IA