Re: A ride on an A320

From: (Kevin Driscoll)
Organization: Honeywell Systems & Research Center
Date:         17 Jun 93 13:02:09 PDT
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>and I realized we were mains down, but nose in the air.  The announcement
>must have self-deactivated when the squat switch compressed, because we 
>lowered the nose in silence and stopped fairly rapidly.

So, you didn't get to the part where the announcement gets insulting to
the crew ("Retard ... Retard").  8^)  I was on a A320 flight where the
right seater was going to make her very first A320 landing.  She was
nervous and her gain was way up.  She came in shallow and at the first
syllable of "Retard" she had the throttle snapped back.  The captain
calmly said, "We are still 10 feet high."  At that point, all we could do
was hang on for the landing gear test.

>The return flight was also on an A320, but some other lucky fellow got
>to the jump seat.

Mexicana has only one jump seat?  All A320s I have been in have had two.
One of the pluses for the A320 is that the jump seat which slides out
into the aisle is the best for seeing the controls and displays of any
jump seat I have been in (DC9, DC10, 727, 737, 747, 757).

>One thing I found interesting:  In this world of spring loaded sidesticks
>and non-moving throttles, the pitch trim wheel was constantly moving back
>and forth.  An interesting piece of mechanical works in the otherwise digital

And one of the few remaining controls available after the FBW goes belly up.

>essentially a sequence of four numeric displays across the glareshield.  The

The Flight Control Unit (FCU) in Airbus speak.

>four displays were speed, heading, altitude, and vertical speed.  Below
>each display was a knob.  You could turn each knob to adjust the setting of
>the display, or you could (pull, push, not sure) it to say "don't care".

The knob operations are:  push to "give" control to the Flight Management
and Guidance System (FMGS) and pull to "take" control.  The latter
meaning is that the FCU/"autopilot" is in control versus the FMGS.
There really isn't a "don't care"; the control stays with whatever the
last push/pull was.

>the heading mode to track a localizer), "exped" to command greater rates of
                                          ^^^^^ = Expedite Mode

>altitude change, and "appr" which somehow modified the rate of descent (I
                       ^^^^ = Final Approach Guidance Mode (ILS or RNAV)

>the flight with one hand on these knobs and the head looking out the window.

That impressed me too.  The much talked about side-sticks are never used
in cruise.  It looked tiring to keep one's hand up on the FCU for
extended periods of time while using the FCU to dodge storm cells.  I
have been thinking that once you have a electric stick, why not have a
switch which couples the stick longitudinal and lateral motion into the
altitude and heading FCU inputs respectively?

On the other hand, a nice thing about "flying" the plane via the FCU and
the placement of the aisle jump seat is that a tall person like myself
(6' 4") could easily "fly" the plane from the aisle jump seat.

>Is this autopilot configuration unique to the A320 or is it standard?

It is a matter of degree; there are similarities and there are differences.

>Well that's enough rambling for now.  It was really a great experience - I
>recommend it highly....

I second that.

Kevin R. Driscoll, Staff Research Scientist   PHONE: (612) 951-7263  FAX: -7438
INTERNET:     UUCP: {any smart host}!srcsip!driscoll
POST: Honeywell M/S MN65-2500; 3660 Technology Drive; Mpls, MN  55418-1006; USA