Cool attitude indicator

[Jay Honeck]

Everyone has seen those "Laser Levels" advertised on TV. I own one,
and (although it's relatively useless) it's very cool.

Wouldn't it be slick to have a gyro-stabilized thin red line projected
onto your panel, graphically displaying the actual horizon? Talk about
situational awareness in the 21st century! You would have to be blind
not to see which way was up...

This sounds like science fiction (or, at least, it did to me) -- so
imagine my surprise when I found that this very system was used in the
SR-71 Blackbird -- a plane that was designed and built over 40 years
ago.

Who'd a thunk it?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Kev]

The AI is an instrument that's overdue for better human engineering.

Almost everyone's had a moment of confusion figuring out which way the
plane was banking, because of the way the horizon moves but the
airplane "wings" stay level.

I believe NASA's done studies showing that if you simply had the
current AI's "wings" tilt towards the side you were turning, pilots had
no problem instantly understanding their situation.

I seem to recall ads in old magazines pushing a visual horizon line on
the windshield such as you described. I think this was pre-laser.

I also saw a neat AI from the '60s on eBay that actually had a little
dome protuding towards you, with a tiny model airplane inside. If you
were banking / diving the little plane was too. Very cool.

Cheers, Kev

[Paul Tomblin]

In a previous article, "Kev" > said:
>The AI is an instrument that's overdue for better human engineering.
>
>Almost everyone's had a moment of confusion figuring out which way the
>plane was banking, because of the way the horizon moves but the
>airplane "wings" stay level.

Russian/Soviet AIs do the opposite - the horizon line is fixed and the
little airplane moves. It must be very confusing for people who had to
switch between "our" sort and "those" sort or back the other way.


--
Paul Tomblin > http://xcski.com/blogs/pt/
....would you work for a company that couldn't tell the difference in
quality of its employees' normal work product and the work product of
someone on drugs without performing a test? -- socks

[Stefan]

Kev wrote:

> I believe NASA's done studies showing that if you simply had the
> current AI's "wings" tilt towards the side you were turning, pilots had
> no problem instantly understanding their situation.

The very first AIs, then developed in Germany, worked that way, and
studies seem to imply that it's more intuitive. This design is still in
use in the countries of the former soviet union and their region of
influence. The AI as it is known in our part of the world was designed
by Sperry, IIRC, and I think it was at least partly a matter of
copyright to do it the way they have.

Pilots who were trained in eastern Europe and then are hired by western
companies have to be retrained, which is extremely difficult. In a
stress situation, you allways tend to fall back to the procedures
learned in primary training. There was at least one airliner crash which
was the direct result of this: Easterly trained pilots flying a westerly
equipped plane with inadequate training, consequently misinterpreting
the AI in a situation of high workload. The report is well worth a
reading: http://www.bfu.admin.ch/common/pdf/1781_e

Stefan

[Don Tuite]

On Sun, 10 Apr 2005 20:26:14 +0200, Stefan >
wrote:

>Kev wrote:
>
>> I believe NASA's done studies showing that if you simply had the
>> current AI's "wings" tilt towards the side you were turning, pilots had
>> no problem instantly understanding their situation.
>
>The very first AIs, then developed in Germany, worked that way, and
>studies seem to imply that it's more intuitive. This design is still in
>use in the countries of the former soviet union and their region of
>influence. The AI as it is known in our part of the world was designed
>by Sperry, IIRC, and I think it was at least partly a matter of
>copyright to do it the way they have.
>
>Pilots who were trained in eastern Europe and then are hired by western
>companies have to be retrained, which is extremely difficult. In a
>stress situation, you allways tend to fall back to the procedures
>learned in primary training. There was at least one airliner crash which
>was the direct result of this: Easterly trained pilots flying a westerly
>equipped plane with inadequate training, consequently misinterpreting
>the AI in a situation of high workload. The report is well worth a
>reading: http://www.bfu.admin.ch/common/pdf/1781_e

I have a buddy with a PhD in human-factors engineering (Purdue). I
gather from him that the phenomenon of figure-ground reversal as it
relates to flight instruments has been studied to death through the
years, There must be a couple of standard texts. I'll ask him the
next time I talk to him if I don't have a brain-fart.

I also imagine there's a lot of documentation at the Air Force Flight
Test Center at Edwards, but it's probably hard to search for.

Don

[Dale]

In article . com>,
"Jay Honeck" > wrote:


> This sounds like science fiction (or, at least, it did to me) -- so
> imagine my surprise when I found that this very system was used in the
> SR-71 Blackbird -- a plane that was designed and built over 40 years
> ago.
>
> Who'd a thunk it?

From looking at this picture I wouldn't have:

http://www.sr-71.org/photogallery/blackbird/17976/cockpit/

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

[Don Tuite]

On Sun, 10 Apr 2005 11:17:44 -0800, Dale > wrote:

Following up my own post, here's the first google hit on the terms:
'figure ground reversal 'artificial horizon'." It's a six page report
on a study at the USAF Academy.

http://atlas.usafa.af.mil/dfem/research_info/biomech/Paper-30-Self.doc

Don

[Icebound]

"Kev" > wrote in message
oups.com...
> The AI is an instrument that's overdue for better human engineering.
>
> Almost everyone's had a moment of confusion figuring out which way the
> plane was banking, because of the way the horizon moves but the
> airplane "wings" stay level.
>

Regardless of the form of the instrument, there will always be a "momentary
confusion".

There are two mismatched lines... one "moving" and one "fixed". No matter
which form of AI is used, there is ALWAYS "momentary confusion" until we
understand WHICH ONE is it that our control input will affect correctly (to
bring into alignment with the other).

> I believe NASA's done studies showing that if you simply had the
> current AI's "wings" tilt towards the side you were turning, pilots had
> no problem instantly understanding their situation.
>

I suppose that depends on how you teach pilots their relationship to their
environment.

If pilots feel themselves "fixed inside" the AIRPLANE, oriented in space the
same as is the airplane, then it makes more sense that they will feel at
ease "controlling" the FIXED line and matching it to the movable one.

If they feel themselves to be fixed relative to the earth, and therefore
controlling the aircraft from "outside", like a video game or an RC model,
they will feel at ease controlling the MOVABLE line to match it to the fixed
one.

I have flown an aircraft, and I have flown a model. In both cases I have had
no trouble understanding which "line" I had to control, but also in both
cases I have experienced that momentary "confusion".

I could be wrong but....
....I would think that from an unusual attitude in VMC, a pilot's first
reaction would be to try align his dashboard (fixed relative to pilots
vision) with the horizon (movable relative to pilot's vision). Why this
should be different in IMC, requiring the opposite form of AI, you can
explain to me.


By the way, I am assuming that Jay really meant to have his laser line
projected onto the windshield as a HUD, not onto the panel.... on the panel
its just an wider version of the current AI, isn't it???

[Matt Barrow]

"Kev" > wrote in message
oups.com...
> The AI is an instrument that's overdue for better human engineering.
>
Which is why ADAHRS is coming on so fast.

[Icebound]

"Don Tuite" > wrote in message
...
> On Sun, 10 Apr 2005 11:17:44 -0800, Dale > wrote:
>
> Following up my own post, here's the first google hit on the terms:
> 'figure ground reversal 'artificial horizon'." It's a six page report
> on a study at the USAF Academy.
>
> http://atlas.usafa.af.mil/dfem/research_info/biomech/Paper-30-Self.doc
>
> Don

From your google list, is this interesting research by the Canadians:

http://www.ainonline.com/Departments/AIN_hangar04.htm#jan04

....and it was purposefully done in a real airplane instead of a desk
simulation...

I wish he had supplied pictures...

[Icebound]

"Icebound" > wrote in message
...
>
>
> I wish he had supplied pictures...
>
>

I found one!

This looks like an early prototype picture of what he was talking about:
http://www.nrc-cnrc.gc.ca/aboutUs/corporatereports/annual_report2003/page2e_e.html#a4

[G. Sylvester]

> The very first AIs, then developed in Germany, worked that way, and
> studies seem to imply that it's more intuitive.

that's a funny statement. I worked for a Germany company for 5 years
and lived in MUC for a couple. German engineering is great if it has
been refined for many years like their automotive companies. Newer
German designed equipment makes no sense at all. My company had
some equipment with left-handed screws (worse yet it would jam if
you "opened" the screw by turning it to the left when locked).
I just did my German taxes using a German program. To go forward,
you would hit the Zuruck button which means "back." Even my German
friend who was helping me told me to "Shut up. I know it's crazy.
It's German."

nevertheless, having the plane tilt is probably a better concept.
After all, on the TC, the plane moves and not the backing. Now
that I am programmed for the non-USSR-designed AI, I'll stick with it
as I can't imagine how long it would take for me to change.

Gerald Sylvester

[tom418]

You should have seen me, the first time behind an FD-109
On the A/I, the bank scale is fixed with the airplane, and the pointer is
level with the horizon- the opposite of what I was used to. Made for some
interesting moments.

"Kev" > wrote in message
oups.com...
> The AI is an instrument that's overdue for better human engineering.
>
> Almost everyone's had a moment of confusion figuring out which way the
> plane was banking, because of the way the horizon moves but the
> airplane "wings" stay level.
>
> I believe NASA's done studies showing that if you simply had the
> current AI's "wings" tilt towards the side you were turning, pilots had
> no problem instantly understanding their situation.
>
> I seem to recall ads in old magazines pushing a visual horizon line on
> the windshield such as you described. I think this was pre-laser.
>
> I also saw a neat AI from the '60s on eBay that actually had a little
> dome protuding towards you, with a tiny model airplane inside. If you
> were banking / diving the little plane was too. Very cool.
>
> Cheers, Kev
>

[Icebound]

"Matt Barrow" > wrote in message
...
>
> "Kev" > wrote in message
> oups.com...
>> The AI is an instrument that's overdue for better human engineering.
>>
> Which is why ADAHRS is coming on so fast.
>

ADAHRS might address the old vacuum-driven gyro technology of the
conventional AI, but that still does not address what display should be
presented to the pilot. The ADAHRS systems that I see advertised on the
internet present essentially the same sort of view as a conventional AI.

[Jose]

> To go forward,
> you would hit the Zuruck button which means "back."

I'm contemplating the bottom left of my computer screen, and thinking of
Abbot and Costello.

Jose
--
Get high on gasoline: fly an airplane.
for Email, make the obvious change in the address.

[Stefan]

G. Sylvester wrote:

> I just did my German taxes using a German program. To go forward,
> you would hit the Zuruck button which means "back."

I know a cetain operating system which requires you to click on "start"
to turn it off... Incidentally, it's not a German design.
:-P

Stefan

[Peter Duniho]

"Stefan" > wrote in message
...
> I know a cetain operating system which requires you to click on "start" to
> turn it off

It also requires you to click "start" to run programs. To change settings.
To view files. To search for files.

In other words, in that context, it ought to be pretty obvious to all but
the most dim-witted that you might find a whole host of interesting
functions, like turning off the computer, there.

Why people continue to insist bring this up as if it's some failure of user
interface design, I have no idea.

I have heard there's another OS that puts the "turn off" function under a
menu named "Special". What's so special about turning off the computer?
And why aren't activities that are truly special not found there?

Pete

[Robert B.]

"Peter Duniho" > wrote in message
...
> "Stefan" > wrote in message
> ...
> > I know a cetain operating system which requires you to click on "start"
to
> > turn it off
>
> It also requires you to click "start" to run programs. To change
settings.
> To view files. To search for files.
>
> In other words, in that context, it ought to be pretty obvious to all but
> the most dim-witted that you might find a whole host of interesting
> functions, like turning off the computer, there.
>
> Why people continue to insist bring this up as if it's some failure of
user
> interface design, I have no idea.
>
> I have heard there's another OS that puts the "turn off" function under a
> menu named "Special". What's so special about turning off the computer?
> And why aren't activities that are truly special not found there?
>
> Pete

How about having to drag an icon of a diskette to the Trashcan to eject the
thing? Talk about intuitive!

[Matt Whiting]

Peter Duniho wrote:

> "Stefan" > wrote in message
> ...
>
>>I know a cetain operating system which requires you to click on "start" to
>>turn it off
>
>
> It also requires you to click "start" to run programs. To change settings.
> To view files. To search for files.
>
> In other words, in that context, it ought to be pretty obvious to all but
> the most dim-witted that you might find a whole host of interesting
> functions, like turning off the computer, there.
>
> Why people continue to insist bring this up as if it's some failure of user
> interface design, I have no idea.

Because it IS a failure of UI design. Then again, to say that Windows
was designed, is to misuse the word in the first place.


Matt

[Peter Duniho]

"Matt Whiting" > wrote in message
...
> Because it IS a failure of UI design. Then again, to say that Windows was
> designed, is to misuse the word in the first place.

And here I was thinking that, of the two Matt's posting these days, you
actually had a clue.

Sorry I have been proved wrong.

[Morgans]

"Matt Whiting" > wrote

> Because it IS a failure of UI design. Then again, to say that Windows
> was designed, is to misuse the word in the first place.

There are things all over the place that are counter intuitive. Like the
Western AI, and windoz, when you get used to something, it is not a problem.
--
Jim in NC

[Thomas Borchert]

Robert,

> How about having to drag an icon of a diskette to the Trashcan to eject the
> thing? Talk about intuitive!
>

Well, until this day I have this vague notion in the back of my head that it
will delete the contents rather than ejecting it whenever I do it. Very
disturbing.

--
Thomas Borchert (EDDH)

[Stefan]

Peter Duniho wrote:

> I have heard there's another OS that puts the "turn off" function
> under a menu named "Special". What's so special about turning off the
> computer?

Nothing, that's why the've moved it to an other place a couple of years ago.
(And you talk to Matt about having a clue... Let's hope your clue is
better when you talk about aviation.)

Stefan

[Stefan]

Thomas Borchert wrote:

>> How about having to drag an icon of a diskette to the Trashcan to eject the
>> thing? Talk about intuitive!

> Well, until this day I have this vague notion in the back of my head that it
> will delete the contents rather than ejecting it whenever I do it.

You still do? Interesting, since they've changed this a couple of years ago.

Stefan

[Thomas Borchert]

Stefan,

> You still do? Interesting, since they've changed this a couple of years ago.
>

Not in a company where we still use OS 9.2. Yes, there's a world out there
which is called "reality".

--
Thomas Borchert (EDDH)

[Stefan]

Thomas Borchert wrote:

> Not in a company where we still use OS 9.2. Yes, there's a world out there
> which is called "reality".

I know this world pretty well, believe me. But then, to be fair, we
should compare it to Windows 3... or even better, stop this discussion,
because it is a) off topic and b) boring.

Stefan

[Darrell S]

If you are VFR and enter a bank the airplane actual wings stay in the same
position in relation to your head/body and the external earth/sky is what
moves in your vision. That's why the AI does the same thing. The aircraft
symbol remains fixed and the earth/sky portion is what moves when you roll.
The aircraft symbol is FIXED and is basically strapped to your butt. Think
that way and you'll have no "moment of confusion". On some aircraft
displays the aircraft symbol/wings is actually painted on the display.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

"Kev" > wrote in message
oups.com...
> The AI is an instrument that's overdue for better human engineering.
>
> Almost everyone's had a moment of confusion figuring out which way the
> plane was banking, because of the way the horizon moves but the
> airplane "wings" stay level.
>
> I believe NASA's done studies showing that if you simply had the
> current AI's "wings" tilt towards the side you were turning, pilots had
> no problem instantly understanding their situation.
>
> I seem to recall ads in old magazines pushing a visual horizon line on
> the windshield such as you described. I think this was pre-laser.
>
> I also saw a neat AI from the '60s on eBay that actually had a little
> dome protuding towards you, with a tiny model airplane inside. If you
> were banking / diving the little plane was too. Very cool.
>
> Cheers, Kev
>

[George Patterson]

Kev wrote:
>
> Almost everyone's had a moment of confusion figuring out which way the
> plane was banking, because of the way the horizon moves but the
> airplane "wings" stay level.

It was never confusing to me. When I'm in visual conditions and bank the
aircraft, the real horizon moves but the aircraft's wings stay level from my
point of view. The AI behaves just like the real world.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

[Peter Duniho]

"Stefan" > wrote in message
...
> Nothing, that's why the've moved it to an other place a couple of years
> ago.

What's that got to do with it, other than an admission that the original
design (used almost two decades) was wrong?

> (And you talk to Matt about having a clue... Let's hope your clue is
> better when you talk about aviation.)

Since you haven't contradicted a single thing I said, you have no point.

Pete

[Stefan]

Peter Duniho wrote:

> Since you haven't contradicted a single thing I said, you have no point.

Better no point than no clue ... or, even worse, no sense of humour.

Stefan

[Morgans]

"Stefan" > wrote in message
...
> Thomas Borchert wrote:
>
> >> How about having to drag an icon of a diskette to the Trashcan to eject
the
> >> thing? Talk about intuitive!
>
> > Well, until this day I have this vague notion in the back of my head
that it
> > will delete the contents rather than ejecting it whenever I do it.
>
> You still do? Interesting, since they've changed this a couple of years
ago.
>
> Stefan

Really, it doesn't even do that. All it does is tell the OS that the
stuff's (deleted files) addresses, are now available to have "new" stuff
written in that location. That is why there are programs that can go back
and retrieve files that have supposedly been deleted.
--
Jim in NC

[Thomas Borchert]

George,

> The AI behaves just like the real world.
>

Feels the same to me. The one time this is confusing is with a sim like
MS FS, where nothing is really moving.

--
Thomas Borchert (EDDH)

[Bob Moore]

(Paul Tomblin) wrote
> Russian/Soviet AIs do the opposite - the horizon line is fixed and the
> little airplane moves. It must be very confusing for people who had to
> switch between "our" sort and "those" sort or back the other way.

Maybe some of them did, but the AI in the YAK-52s that I have
instructed in, had the horizon moving and the airplane fixed.
They were different from the "average" AI however, in that the
horizon ball was gimbled in an almost free fashion and had no
stops that would cause a "flip" during loops and rolls. The
downside of this arrangement was that the "blue" side was on
the bottom when "staight and level" and when pitching-up, the
horizon line on the ball moved up showing more of the Blue-On-
The-Bottom.

Bob Moore