Phil wrote in news:1191732077.235895.295410
@w3g2000hsg.googlegroups.com:

On Oct 6, 1:51 pm, Bertie the Bunyip wrote:
Phil wrote in news:1191696116.820241.83540@
19g2000hsx.googlegroups.com:







On Oct 6, 10:21 am, Arno wrote:
Hello,

I am computer scientist and usually really like fancy technology. But
I just had my first flight with a "glass" PFD (Avidyne) and must say
I
am not impressed. In particular reading altitude and airpeed from
these scrolling bands requires a lot more attention than with regular
gauges, just like reading a digital clock takes longer than reading
an
analog one. Glancing at it and checking against a known picture, like
"speed at 3 o'clock is fine on final" or "altitude at 20 minutes past
midnight is minimum", just does not work anymore, instead I end up
reading the actual numbers every time I look. Does anyone feel the
same? Am I missing a particular technique?

Arno

I am a fellow computer geek, and a student pilot. I usually fly a
plane with steam gauges, but a couple of times now I have flown with
digital displays. Like you, I found it a little hard to adjust to the
digital displays. The digital displays I was using presented altitude
and tachometer values simply as numbers. The analog displays I am
used to present these values as positions on a dial, showing the
current value in its context of a spectrum of values. With the analog
displays, I am used to adjusting the position of the pointer. With
the digital display, I need to simply set the correct numerical
value. It's a little mental adjustment, and given that I am a newbie
to all this it is an extra distraction.

But, I do think that it is mostly a matter of what you are used to.

Flying is a right hand brain activity. At least the handling portion is.
The right hand side of the brain dosn't do abstractions like numbers, at
least not until the left hand side (which can't fly worth a ****) sends
it over to the right side in a readily digestable form which enables the
right brain to chew it into a picture.

An analogue display cuts the left hand side out of the loop and enables
the calcualtion rate to increase the right sides "frame rate" so that
corrections can be made more frequently thus enabling the pilot to fly
the airplane more smooothly and with more authority.
Caorse rule of thumb math can be laid over this for descent angles,
interceptin angles and wo on, but generally, the fewer numbers involved,
the better.
People who prefer the numbers usualy don't fly very well at all.

You don't do trig while you're shooting pool and expect to win the game.

Bertie- Hide quoted text -

- Show quoted text -

As I understand it, the whole right-brain left-brain thing has pretty
much been discredited. The more recent research shows that any
complex task engages both sides of the brain. I don't think there
were too many neuroscientists who ever embraced the idea that one side
does "art" and the other side does "math" anyway.



Well, it's a simplification, but I have had cause to chat with some
neurosurgeons in the recent past over a protracted period and they still
seem to think it's pretty much still the way it works.

anyone who has ever known a stroke victim know that if the left side gets
zapped they can lose the power of speech altogether, for instance.

(no, my own brain was not invovlved)


Found this anyway http://www.bbc.co.uk/dna/h2g2/alabaster/A659874

I think the biggest difference between steam gauges and digital
displays is that steam gauges give you a value in context of a
spectrum of values. When you look at a analog tachometer, you can see
the where the needle is compared to the minimum and maximum values.
If you are trying to set 75% power, it might be useful to have the
information presented that way, because you can see where 3/4 of the
range is. Same with airspeed. You can see how close you are to the
red arc, where you are in the green arc, etc.


Yes, I agree and is pretty much what I was trying to say. Your brain picks
this up in the same language it's doing the flying job in. You don't have
to convert a bunch of numbers to a mental picture of what's going on, The
rate the needles move, their angle, the way they quiver and dance as they
pick up what's going on, all give subtle information in a form that's easy
to digest

On the other hand, why would you want to see altitude displayed with
needles? If I want to fly at a specific altitude, I am looking for a
number, not a position in a range. I think the traditional altimeter
was made the way it was because it was the easiest way to get a
mechanical instrument to display the information that way, not because
it was the easiest way to digest the information.

Yeah, another god point. trad altimiters aren't great that way, but you do
get used to them.
Sill, if you have a tape only, you have to read the numbers...


Ideally, every instrument should be designed to convey the appropriate
information in a way that is conducive to how that information is
going to be used. If you just need a value, then a digital display of
a number make sense. If you need to have a sense of where you are
relative to minimum and maximum, then a display showing relative
position in a range should be used. The nice thing about a
computerized display is it can be set up to display the information
either way.


Well, not in the things I fly! They pretty much give you what has been
decided for you.

One thing I positivley loath on some modern EFIS displays is the "track
up" option on the nav screen. For those not fmailiar, basicallly the DG
function puts our actual ground track on the lubber line and has a bug to
indicate your heading. This is the reverse of the traditional display where
the heading is on the lubber line and if you have some sort of RNAV
comouter giving info your track is displayed by a bug. It's OK when you are
motoring along enroute, but if you arent used to it, shooting an approach
is a nightmare. Adherents of track up say that it is actually easier, but
it isn't if you are used to the old way. doing an NDB appraoch, for
instance, all you need to do is put the track on the lubber line and the
ADF needle should stay glued to the inbound track, but if you have to
constantly remind yourself to do the oppostie of what you are used to it
can be an absolute nightmare to do by hand. If we did NDB appraoches every
day of the week it wouldn't be a problem, but I've done one in anger in the
last five years and the rest are all in the sim.
Even weirder, the newer airbusses use a speed reference system that uses
groundspeed on the approach. so, you set your Vref and the airplane
automatically raises it to accomodate a headwind by flying a constant
ground speed. (or advising you to fly faster by pushing the speed bug up)
It's simple, but interferes with the pilot's direct communications with the
wing. I suppose I'm trying to say it's translating for you and somethng is
always lost in the translation..

But don't mind me, I wish the 75 had flying wires so I could hear them sing
to me..


Bertie