Re: The actual quote from the Post AAS article

[mfeldman@seas.gwu.edu (Michael Feldman)]

In article <RIGOTTI.93Mar15105925@ad4su1> rigotti@hermes.mod.uk (Kevin Rigotti) writes:
>In article <1993Mar11.213532.12259@seas.gwu.edu> mfeldman@seas.gwu.edu (Michael Feldman) writes:
>
>   Europe is rebuilding all its ATC systems in Ada; Ada is now the de facto
>   standard language for new ATC systems world-wide. People I know who are
>   close to the FAA project tell me that Europe's ATC problems are on a
>   much smaller scale than ours - many fewer flights. 
>
>Yes, Ada is what we're using and I'm glad that we are. I'm not too
>sure about our ATC problems being easier though ... ;-)
>
Hmmm. My sources around FAA tell me that the main reason for Europe's having
_fielded_ new ATC systems - In Ada - is that European air traffic is
simply less dense than that of the US; there are fewer planes flying fewer
corridors into fewer big airports. I know little about the internals of
ATC systems, but general intuition and experience tell me that problems
in this kind of system scale up perhaps linearly: 4 times the traffic 
results in a system 4 times as complex. Maybe the "big O" is even worse.
It would be nice if it were sublinear, but somehow I doubt it. 

The point is - once more for good measure - that Ada can hardly make an
ATC system worse to build and run, and may well make it better. The
"lessons learned" reports that will, I'm sure, eventually come out of the
European efforts, will be very interesting to read.

Mike Feldman