using GPS derived altitude/heading and "attitude" displays for aircraft control

[Todd W. Deckard]

I have seen the high end GPS units present a psuedo panel display (I am
specifically refering to the Garmin 296).

It provides a DG/HSI presentation, GPS derived altitude, turn-and-bank and
vertical speed.

Has anyone experimented with this to maintain level flight in lieu of actual
gyroscopic instruments. I am *very*
skeptical of this, but have heard it suggested. Has anyone experimented
with recovering from an upset using it?
I would be eager for first hand experiences.

In my '170, which only had a needle and ball, if you were trapped on top and
the gyro failed, that all things being equal it was bravely suggested you
turn to a southerly heading, and use only the rudders and wet compass to
maintain wings level during the descent.

In these same heroic hanger flying sessions (when the weather was cloudy and
you weren't going to fly the airplane anyway) we speculated that setting up
an upright spin was the safest course of action. Spin thru the clouds and
then recover when you are visual, just like the old DH-4 air mail pilots.

I am curious if anyone has played with a hood and one of these gyro
displays. Let me know.


--
"Instrument flying, I had concluded, is an unnatural act, probably
punishable by God."
--Gordon Baxter

[Dave Butler]

Todd W. Deckard wrote:
> I have seen the high end GPS units present a psuedo panel display (I am
> specifically refering to the Garmin 296).
>
> It provides a DG/HSI presentation, GPS derived altitude, turn-and-bank and
> vertical speed.
>
> Has anyone experimented with this to maintain level flight in lieu of actual
> gyroscopic instruments. I am *very*
> skeptical of this, but have heard it suggested. Has anyone experimented
> with recovering from an upset using it?
> I would be eager for first hand experiences.

<snip>

> I am curious if anyone has played with a hood and one of these gyro
> displays. Let me know.

I think you are late to the party. Please search the archives of this
and other aviation newsgroups and you'll find lots of people have
experimented with this under the hood. I think you'll find the consensus
is that in an emergency it can help you, if you're in a relatively
stable, slow airplane.

[karl mcgruber]

Hey, another worthless post from a newsgroup cop!!!!

"Dave Butler" > wrote in message
...
> Todd W. Deckard wrote:
>> I have seen the high end GPS units present a psuedo panel display (I am
>> specifically refering to the Garmin 296).
>>
>> It provides a DG/HSI presentation, GPS derived altitude, turn-and-bank
>> and vertical speed.
>>
>> Has anyone experimented with this to maintain level flight in lieu of
>> actual gyroscopic instruments. I am *very*
>> skeptical of this, but have heard it suggested. Has anyone experimented
>> with recovering from an upset using it?
>> I would be eager for first hand experiences.
>
> <snip>
>
>> I am curious if anyone has played with a hood and one of these gyro
>> displays. Let me know.
>
> I think you are late to the party. Please search the archives of this and
> other aviation newsgroups and you'll find lots of people have experimented
> with this under the hood. I think you'll find the consensus is that in an
> emergency it can help you, if you're in a relatively stable, slow
> airplane.

[Bob Gardner]

Note the caution against such use in the AIM:

AIM 1-1-19:

4. The GPS receiver verifies the integrity (usability) of the signals
received from the GPS constellation through receiver autonomous integrity
monitoring (RAIM) to determine if a satellite is providing corrupted
information. At least one satellite, in addition to those required for
navigation, must be in view for the receiver to perform the RAIM function;
thus, RAIM needs a minimum of 5 satellites in view, or 4 satellites and a
barometric altimeter (baro-aiding) to detect an integrity anomaly. For
receivers capable of doing so, RAIM needs 6 satellites in view (or 5
satellites with baro-aiding) to isolate the corrupt satellite signal and
remove it from the navigation solution. Baro-aiding is a method of
augmenting the GPS integrity solution by using a nonsatellite input source.
GPS derived altitude should not be relied upon to determine aircraft
altitude since the vertical error can be quite large and no integrity is
provided. To ensure that baro-aiding is available, the current altimeter
setting must be entered into the receiver as described in the operating
manual.

Bob Gardner

"Todd W. Deckard" > wrote in message
...
>I have seen the high end GPS units present a psuedo panel display (I am
>specifically refering to the Garmin 296).
>
> It provides a DG/HSI presentation, GPS derived altitude, turn-and-bank and
> vertical speed.
>
> Has anyone experimented with this to maintain level flight in lieu of
> actual gyroscopic instruments. I am *very*
> skeptical of this, but have heard it suggested. Has anyone experimented
> with recovering from an upset using it?
> I would be eager for first hand experiences.
>
> In my '170, which only had a needle and ball, if you were trapped on top
> and the gyro failed, that all things being equal it was bravely suggested
> you turn to a southerly heading, and use only the rudders and wet compass
> to maintain wings level during the descent.
>
> In these same heroic hanger flying sessions (when the weather was cloudy
> and you weren't going to fly the airplane anyway) we speculated that
> setting up an upright spin was the safest course of action. Spin thru the
> clouds and
> then recover when you are visual, just like the old DH-4 air mail pilots.
>
> I am curious if anyone has played with a hood and one of these gyro
> displays. Let me know.
>
>
> --
> "Instrument flying, I had concluded, is an unnatural act, probably
> punishable by God."
> --Gordon Baxter
>

[Dave Butler]

My posting provided useful information... and your posing provided what?

Cop

karl mcgruber wrote:
> Hey, another worthless post from a newsgroup cop!!!!
>
> "Dave Butler" > wrote in message
> ...
>> Todd W. Deckard wrote:
>>> I have seen the high end GPS units present a psuedo panel display (I
>>> am specifically refering to the Garmin 296).
>>>
>>> It provides a DG/HSI presentation, GPS derived altitude,
>>> turn-and-bank and vertical speed.
>>>
>>> Has anyone experimented with this to maintain level flight in lieu of
>>> actual gyroscopic instruments. I am *very*
>>> skeptical of this, but have heard it suggested. Has anyone
>>> experimented with recovering from an upset using it?
>>> I would be eager for first hand experiences.
>>
>> <snip>
>>
>>> I am curious if anyone has played with a hood and one of these gyro
>>> displays. Let me know.
>>
>> I think you are late to the party. Please search the archives of this
>> and other aviation newsgroups and you'll find lots of people have
>> experimented with this under the hood. I think you'll find the
>> consensus is that in an emergency it can help you, if you're in a
>> relatively stable, slow airplane.
>

[Ray Andraka]

Todd W. Deckard wrote:


> I am curious if anyone has played with a hood and one of these gyro
> displays. Let me know.
>
>


I have used both the compass on a southerly heading and the HSI page on
a Garmin III-pilot while under the hood while flying a Cherokee Six.
You can keep the shiny side up with either one if you have a reasonably
stable airplane AND you aren't getting tossed around by lots of
turbulence. It takes a little bit of practice, as you need to keep your
banks shallow and make only small changes. nevertheless, it is doable
given the right conditions (airplane and turbulence). I haven't tried
it with the panel page on a 496, but I imagine that makes it easier as
the update rate is faster and the information is presented in a more
easily digested format.

[Dave J]

I've tried it under the hood as well, with my Garmin 196. As I
commented in another thread, it's no more difficult than partial-panel
without gyros, and in fact is probably easier as you still have the
heading "gyro" (actually, track, even better).

Like any other partial panel situation, with practice one can fly the
airplane pretty "normally", except for maybe the added fatigue factor.
However, also like any other no-gyro situation, if you're starting
from an unusual attitude or spin, your odds of recovery are probably
slim.

-- dave j

On Dec 6, 5:53 pm, Ray Andraka > wrote:
> Todd W. Deckard wrote:
> > I am curious if anyone has played with a hood and one of these gyro
> > displays. Let me know.
>
> I have used both the compass on a southerly heading and the HSI page on
> a Garmin III-pilot while under the hood while flying a Cherokee Six.
> You can keep the shiny side up with either one if you have a reasonably
> stable airplane AND you aren't getting tossed around by lots of
> turbulence. It takes a little bit of practice, as you need to keep your
> banks shallow and make only small changes. nevertheless, it is doable
> given the right conditions (airplane and turbulence). I haven't tried
> it with the panel page on a 496, but I imagine that makes it easier as
> the update rate is faster and the information is presented in a more
> easily digested format.