On Fri, 15 Dec 2006 15:24:52 -0500, Matt O'Toole
wrote:

If I were cruising long distance, I'd be relying on electronic charts
rather than buying paper ones all the time. Some may worry about
relying on electronic equipment. But if an F16 needs reliable software to
stay in the air, then surely we can figure out a reliable system for our
silly little boats.

Matt O.

Oh man, what a bad example. You wouldn't believe how many guys they
have working on that stuff, yet things like this happen (copied from
another group)
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A friend of mine who works for General Dynamics here in Ft. Worth
wrote some
of the code for the F-16, and he is always telling me about some
neato-whiz-bang bug/feature they keep finding in the F-16:

o Since the F-16 is a fly-by-wire aircraft, the computer keeps the
pilot from
doing dumb things to himself. So if the pilot jerks hard over on the
joystick, the computer will instruct the flight surfaces to make a
nice and
easy 4 or 5 G flip. But the plane can withstand a much higher flip
than that.
So when they were 'flying' the F-16 in simulation over the equator,
the
computer got confused and instantly flipped the plane over, killing
the
pilot [in simulation]. And since it can fly forever upside down, it
would
do so until it ran out of fuel.

(The remaining bugs were actually found while flying, rather than in
simulation):

o One of the first things the Air Force test pilots tried on an early
F-16
was to tell the computer to raise the landing gear while standing
still on
the runway. Guess what happened? Scratch one F-16. (my friend says
there
is a new subroutine in the code called 'wait_on_wheels' now...)
[weight?]

o The computer system onboard has a weapons management system that
will
attempt to keep the plane flying level by dispersing weapons and
empty
fuel tanks in a balanced fashion. So if you ask to drop a bomb, the
computer will figure out whether to drop a port or starboard bomb in
order
to keep the load even. One of the early problems with that was the
fact
that you could flip the plane over and the computer would gladly let
you
drop a bomb or fuel tank. It would drop, dent the wing, and then
roll off.

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My boss at one of the software companies I worked at always said that
software is like sausage. If you think you like it, you should never
see it being made. Old joke but accurate.

Don't want to rehash old arguments, but even if you trust your
software and the hardware totally, there's the matter of power.

Regarding cruising without charts, I've never seen a chartplotter that
gives me the same situational awareness boost that I get from looking
at the proper chart. When I'm in home waters, the only time I get out
a chart is for guests to look at. I know the area and the
chartplotter is sufficient. When I'm coming into a new inlet, I want
every source of information I can get. But in a pinch I'd rather do
without the gps than the chart unless visibilty is an issue.



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