From: rdd@rascal.ics.utexas.edu (Robert Dorsett)
Newsgroups: sci.aeronautics
Subject: Re: Coffee cups in the cockpit (Re: A320 yarns)
Date: 21 Jul 1992 21:30:59 -0500
Organization: UTexas Mail-to-News Gateway
Reply-To: rdd@rascal.ics.utexas.edu
NNTP-Posting-Host: cs.utexas.edu

richieb@bony1.bony.com (Richard Bielak) writes:

>>> There are at least five major ways to disengage FMS's or autopilots--2 pickle
>>> switches, control column force, glareshield off-switch, circuit breaker,
>>> and internal self-diagnostic disengage. ...
>
>Why are there *five* ways to disingage the autopilot? There should be
>only one switch, with a circuit breaker for backup. 

Well...

1.  Pickle switches: it's nice to be able to just twitch a thumb and turn
the thing off, if necessary.  Often, this is done on short final; it's
distracting to have to reach over and turn if off.

2.  Control column force: occasionally, one has to be highly reactive
to a situation, and doesn't have time to "think" about ways to turn it off.

3.  Glareshield switch.  When one has the leisure to reach over and turn
it off.  Come to think of it, I've never really seen a glareshield switch
used to turn one OFF, only to turn it ON...

4.  Internal self-diagnostics.  When a malfunctioning piece of hardware
is malfunctioning bad enough to know it's malfunctioning, it should have
the right to turn itself off.

5.  Circuit breaker.  Well, a lot of people want to move them well away from
those irksome pilots, maybe in the wheel wells or someplace inaccessible.
Damn pilots keep on power-cycling avionics to clear gitches, sending 
shudders down the spines of their creators, see. :-)  We might have to 
remove this one from the list, RSN. :-)


>Of course, the real answer is that the designers of the system are to
>blame. I think the guy who thought of not moving the throttles when
>the computer changes power in the A-320, should be fired, banned from
>aircraft design and travel everywhere by foot...

Speaking of which: I'm looking for this paper:

%A: Steve Last
%A: Martin Aider
%T: British Airways Airbus A320 pilots' autothrust survey
%B  Aerospace Technology Conference and Exposition, Long Beach, CA, USA,
Setpember 23-26, 1991.
%S	Advanced Aerospace Hydraulic Systems and Components, SAE Special
Publications n 885 
%P  51-63


>P.S. The title "Coffee Cups In The Cockpit", refers to the practice of
>  airline pilots to put styrofoam cups over certain important levers, as
>  a memory aid. You know, you don't want to forget to lower the flaps,
>  just because lowering flaps is squeezed between turning on the "no
>  smoking" sign rewinding the cockpit voice recorder on the take-off 
>  checklist.

Every time I see that title, it reminds me of a number of "environmental"
criticisms pilots have always had about cockpits--lighting, cooling, heating,
moisture, dryness, back support, etc.  The British ALPA's initial in-service 
critique of the A320 had an observation on the lack of decent coffee-cup 
holders:

"4.15.  Cup holders.  Cup holders are cunningly designed for maximum mess.
Those to the rear of the center predestal are located just under a projecting
lip, so that as the cup is raised out of the holder it strikes the lip and
spills.  The holders should be relocated 1 centimeter further away from the
rear face of the pedestal to avoid this happening.  The cup holders in the
side window sills are sure to catch you out if you try to open the window with
a drink in place.  Even without opening the window, some spills are inevitable,
so it's a bit daft to locate the cup-holders right over the document 
manual stowages.  Our manuals are rapidly becoming cofee-covered and with
pages stuck together."




--
Robert Dorsett
Internet: rdd@rascal.ics.utexas.edu
UUCP: ...cs.utexas.edu!rascal.ics.utexas.edu!rdd